1 /* 2 * Copyright (C) 2006 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.widget; 18 19 import com.google.android.collect.Lists; 20 21 import com.android.internal.R; 22 import com.android.internal.util.Predicate; 23 24 import android.annotation.IdRes; 25 import android.annotation.NonNull; 26 import android.annotation.Nullable; 27 import android.content.Context; 28 import android.content.Intent; 29 import android.content.res.TypedArray; 30 import android.graphics.Canvas; 31 import android.graphics.Paint; 32 import android.graphics.PixelFormat; 33 import android.graphics.Rect; 34 import android.graphics.drawable.Drawable; 35 import android.os.Bundle; 36 import android.os.Trace; 37 import android.util.AttributeSet; 38 import android.util.MathUtils; 39 import android.util.SparseBooleanArray; 40 import android.view.FocusFinder; 41 import android.view.KeyEvent; 42 import android.view.SoundEffectConstants; 43 import android.view.View; 44 import android.view.ViewDebug; 45 import android.view.ViewGroup; 46 import android.view.ViewHierarchyEncoder; 47 import android.view.ViewParent; 48 import android.view.ViewRootImpl; 49 import android.view.accessibility.AccessibilityNodeInfo; 50 import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction; 51 import android.view.accessibility.AccessibilityNodeInfo.CollectionInfo; 52 import android.view.accessibility.AccessibilityNodeInfo.CollectionItemInfo; 53 import android.view.accessibility.AccessibilityNodeProvider; 54 import android.widget.RemoteViews.RemoteView; 55 56 import java.util.ArrayList; 57 import java.util.List; 58 59 /* 60 * Implementation Notes: 61 * 62 * Some terminology: 63 * 64 * index - index of the items that are currently visible 65 * position - index of the items in the cursor 66 */ 67 68 69 /** 70 * A view that shows items in a vertically scrolling list. The items 71 * come from the {@link ListAdapter} associated with this view. 72 * 73 * <p>See the <a href="{@docRoot}guide/topics/ui/layout/listview.html">List View</a> 74 * guide.</p> 75 * 76 * @attr ref android.R.styleable#ListView_entries 77 * @attr ref android.R.styleable#ListView_divider 78 * @attr ref android.R.styleable#ListView_dividerHeight 79 * @attr ref android.R.styleable#ListView_headerDividersEnabled 80 * @attr ref android.R.styleable#ListView_footerDividersEnabled 81 */ 82 @RemoteView 83 public class ListView extends AbsListView { 84 /** 85 * Used to indicate a no preference for a position type. 86 */ 87 static final int NO_POSITION = -1; 88 89 /** 90 * When arrow scrolling, ListView will never scroll more than this factor 91 * times the height of the list. 92 */ 93 private static final float MAX_SCROLL_FACTOR = 0.33f; 94 95 /** 96 * When arrow scrolling, need a certain amount of pixels to preview next 97 * items. This is usually the fading edge, but if that is small enough, 98 * we want to make sure we preview at least this many pixels. 99 */ 100 private static final int MIN_SCROLL_PREVIEW_PIXELS = 2; 101 102 /** 103 * A class that represents a fixed view in a list, for example a header at the top 104 * or a footer at the bottom. 105 */ 106 public class FixedViewInfo { 107 /** The view to add to the list */ 108 public View view; 109 /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */ 110 public Object data; 111 /** <code>true</code> if the fixed view should be selectable in the list */ 112 public boolean isSelectable; 113 } 114 115 ArrayList<FixedViewInfo> mHeaderViewInfos = Lists.newArrayList(); 116 ArrayList<FixedViewInfo> mFooterViewInfos = Lists.newArrayList(); 117 118 Drawable mDivider; 119 int mDividerHeight; 120 121 Drawable mOverScrollHeader; 122 Drawable mOverScrollFooter; 123 124 private boolean mIsCacheColorOpaque; 125 private boolean mDividerIsOpaque; 126 127 private boolean mHeaderDividersEnabled; 128 private boolean mFooterDividersEnabled; 129 130 private boolean mAreAllItemsSelectable = true; 131 132 private boolean mItemsCanFocus = false; 133 134 // used for temporary calculations. 135 private final Rect mTempRect = new Rect(); 136 private Paint mDividerPaint; 137 138 // the single allocated result per list view; kinda cheesey but avoids 139 // allocating these thingies too often. 140 private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult(); 141 142 // Keeps focused children visible through resizes 143 private FocusSelector mFocusSelector; 144 145 public ListView(Context context) { 146 this(context, null); 147 } 148 149 public ListView(Context context, AttributeSet attrs) { 150 this(context, attrs, R.attr.listViewStyle); 151 } 152 153 public ListView(Context context, AttributeSet attrs, int defStyleAttr) { 154 this(context, attrs, defStyleAttr, 0); 155 } 156 157 public ListView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { 158 super(context, attrs, defStyleAttr, defStyleRes); 159 160 final TypedArray a = context.obtainStyledAttributes( 161 attrs, R.styleable.ListView, defStyleAttr, defStyleRes); 162 163 final CharSequence[] entries = a.getTextArray(R.styleable.ListView_entries); 164 if (entries != null) { 165 setAdapter(new ArrayAdapter<>(context, R.layout.simple_list_item_1, entries)); 166 } 167 168 final Drawable d = a.getDrawable(R.styleable.ListView_divider); 169 if (d != null) { 170 // Use an implicit divider height which may be explicitly 171 // overridden by android:dividerHeight further down. 172 setDivider(d); 173 } 174 175 final Drawable osHeader = a.getDrawable(R.styleable.ListView_overScrollHeader); 176 if (osHeader != null) { 177 setOverscrollHeader(osHeader); 178 } 179 180 final Drawable osFooter = a.getDrawable(R.styleable.ListView_overScrollFooter); 181 if (osFooter != null) { 182 setOverscrollFooter(osFooter); 183 } 184 185 // Use an explicit divider height, if specified. 186 if (a.hasValueOrEmpty(R.styleable.ListView_dividerHeight)) { 187 final int dividerHeight = a.getDimensionPixelSize( 188 R.styleable.ListView_dividerHeight, 0); 189 if (dividerHeight != 0) { 190 setDividerHeight(dividerHeight); 191 } 192 } 193 194 mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true); 195 mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true); 196 197 a.recycle(); 198 } 199 200 /** 201 * @return The maximum amount a list view will scroll in response to 202 * an arrow event. 203 */ 204 public int getMaxScrollAmount() { 205 return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); 206 } 207 208 /** 209 * Make sure views are touching the top or bottom edge, as appropriate for 210 * our gravity 211 */ 212 private void adjustViewsUpOrDown() { 213 final int childCount = getChildCount(); 214 int delta; 215 216 if (childCount > 0) { 217 View child; 218 219 if (!mStackFromBottom) { 220 // Uh-oh -- we came up short. Slide all views up to make them 221 // align with the top 222 child = getChildAt(0); 223 delta = child.getTop() - mListPadding.top; 224 if (mFirstPosition != 0) { 225 // It's OK to have some space above the first item if it is 226 // part of the vertical spacing 227 delta -= mDividerHeight; 228 } 229 if (delta < 0) { 230 // We only are looking to see if we are too low, not too high 231 delta = 0; 232 } 233 } else { 234 // we are too high, slide all views down to align with bottom 235 child = getChildAt(childCount - 1); 236 delta = child.getBottom() - (getHeight() - mListPadding.bottom); 237 238 if (mFirstPosition + childCount < mItemCount) { 239 // It's OK to have some space below the last item if it is 240 // part of the vertical spacing 241 delta += mDividerHeight; 242 } 243 244 if (delta > 0) { 245 delta = 0; 246 } 247 } 248 249 if (delta != 0) { 250 offsetChildrenTopAndBottom(-delta); 251 } 252 } 253 } 254 255 /** 256 * Add a fixed view to appear at the top of the list. If this method is 257 * called more than once, the views will appear in the order they were 258 * added. Views added using this call can take focus if they want. 259 * <p> 260 * Note: When first introduced, this method could only be called before 261 * setting the adapter with {@link #setAdapter(ListAdapter)}. Starting with 262 * {@link android.os.Build.VERSION_CODES#KITKAT}, this method may be 263 * called at any time. If the ListView's adapter does not extend 264 * {@link HeaderViewListAdapter}, it will be wrapped with a supporting 265 * instance of {@link WrapperListAdapter}. 266 * 267 * @param v The view to add. 268 * @param data Data to associate with this view 269 * @param isSelectable whether the item is selectable 270 */ 271 public void addHeaderView(View v, Object data, boolean isSelectable) { 272 final FixedViewInfo info = new FixedViewInfo(); 273 info.view = v; 274 info.data = data; 275 info.isSelectable = isSelectable; 276 mHeaderViewInfos.add(info); 277 mAreAllItemsSelectable &= isSelectable; 278 279 // Wrap the adapter if it wasn't already wrapped. 280 if (mAdapter != null) { 281 if (!(mAdapter instanceof HeaderViewListAdapter)) { 282 wrapHeaderListAdapterInternal(); 283 } 284 285 // In the case of re-adding a header view, or adding one later on, 286 // we need to notify the observer. 287 if (mDataSetObserver != null) { 288 mDataSetObserver.onChanged(); 289 } 290 } 291 } 292 293 /** 294 * Add a fixed view to appear at the top of the list. If addHeaderView is 295 * called more than once, the views will appear in the order they were 296 * added. Views added using this call can take focus if they want. 297 * <p> 298 * Note: When first introduced, this method could only be called before 299 * setting the adapter with {@link #setAdapter(ListAdapter)}. Starting with 300 * {@link android.os.Build.VERSION_CODES#KITKAT}, this method may be 301 * called at any time. If the ListView's adapter does not extend 302 * {@link HeaderViewListAdapter}, it will be wrapped with a supporting 303 * instance of {@link WrapperListAdapter}. 304 * 305 * @param v The view to add. 306 */ 307 public void addHeaderView(View v) { 308 addHeaderView(v, null, true); 309 } 310 311 @Override 312 public int getHeaderViewsCount() { 313 return mHeaderViewInfos.size(); 314 } 315 316 /** 317 * Removes a previously-added header view. 318 * 319 * @param v The view to remove 320 * @return true if the view was removed, false if the view was not a header 321 * view 322 */ 323 public boolean removeHeaderView(View v) { 324 if (mHeaderViewInfos.size() > 0) { 325 boolean result = false; 326 if (mAdapter != null && ((HeaderViewListAdapter) mAdapter).removeHeader(v)) { 327 if (mDataSetObserver != null) { 328 mDataSetObserver.onChanged(); 329 } 330 result = true; 331 } 332 removeFixedViewInfo(v, mHeaderViewInfos); 333 return result; 334 } 335 return false; 336 } 337 338 private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) { 339 int len = where.size(); 340 for (int i = 0; i < len; ++i) { 341 FixedViewInfo info = where.get(i); 342 if (info.view == v) { 343 where.remove(i); 344 break; 345 } 346 } 347 } 348 349 /** 350 * Add a fixed view to appear at the bottom of the list. If addFooterView is 351 * called more than once, the views will appear in the order they were 352 * added. Views added using this call can take focus if they want. 353 * <p> 354 * Note: When first introduced, this method could only be called before 355 * setting the adapter with {@link #setAdapter(ListAdapter)}. Starting with 356 * {@link android.os.Build.VERSION_CODES#KITKAT}, this method may be 357 * called at any time. If the ListView's adapter does not extend 358 * {@link HeaderViewListAdapter}, it will be wrapped with a supporting 359 * instance of {@link WrapperListAdapter}. 360 * 361 * @param v The view to add. 362 * @param data Data to associate with this view 363 * @param isSelectable true if the footer view can be selected 364 */ 365 public void addFooterView(View v, Object data, boolean isSelectable) { 366 final FixedViewInfo info = new FixedViewInfo(); 367 info.view = v; 368 info.data = data; 369 info.isSelectable = isSelectable; 370 mFooterViewInfos.add(info); 371 mAreAllItemsSelectable &= isSelectable; 372 373 // Wrap the adapter if it wasn't already wrapped. 374 if (mAdapter != null) { 375 if (!(mAdapter instanceof HeaderViewListAdapter)) { 376 wrapHeaderListAdapterInternal(); 377 } 378 379 // In the case of re-adding a footer view, or adding one later on, 380 // we need to notify the observer. 381 if (mDataSetObserver != null) { 382 mDataSetObserver.onChanged(); 383 } 384 } 385 } 386 387 /** 388 * Add a fixed view to appear at the bottom of the list. If addFooterView is 389 * called more than once, the views will appear in the order they were 390 * added. Views added using this call can take focus if they want. 391 * <p> 392 * Note: When first introduced, this method could only be called before 393 * setting the adapter with {@link #setAdapter(ListAdapter)}. Starting with 394 * {@link android.os.Build.VERSION_CODES#KITKAT}, this method may be 395 * called at any time. If the ListView's adapter does not extend 396 * {@link HeaderViewListAdapter}, it will be wrapped with a supporting 397 * instance of {@link WrapperListAdapter}. 398 * 399 * @param v The view to add. 400 */ 401 public void addFooterView(View v) { 402 addFooterView(v, null, true); 403 } 404 405 @Override 406 public int getFooterViewsCount() { 407 return mFooterViewInfos.size(); 408 } 409 410 /** 411 * Removes a previously-added footer view. 412 * 413 * @param v The view to remove 414 * @return 415 * true if the view was removed, false if the view was not a footer view 416 */ 417 public boolean removeFooterView(View v) { 418 if (mFooterViewInfos.size() > 0) { 419 boolean result = false; 420 if (mAdapter != null && ((HeaderViewListAdapter) mAdapter).removeFooter(v)) { 421 if (mDataSetObserver != null) { 422 mDataSetObserver.onChanged(); 423 } 424 result = true; 425 } 426 removeFixedViewInfo(v, mFooterViewInfos); 427 return result; 428 } 429 return false; 430 } 431 432 /** 433 * Returns the adapter currently in use in this ListView. The returned adapter 434 * might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but 435 * might be a {@link WrapperListAdapter}. 436 * 437 * @return The adapter currently used to display data in this ListView. 438 * 439 * @see #setAdapter(ListAdapter) 440 */ 441 @Override 442 public ListAdapter getAdapter() { 443 return mAdapter; 444 } 445 446 /** 447 * Sets up this AbsListView to use a remote views adapter which connects to a RemoteViewsService 448 * through the specified intent. 449 * @param intent the intent used to identify the RemoteViewsService for the adapter to connect to. 450 */ 451 @android.view.RemotableViewMethod 452 public void setRemoteViewsAdapter(Intent intent) { 453 super.setRemoteViewsAdapter(intent); 454 } 455 456 /** 457 * Sets the data behind this ListView. 458 * 459 * The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, 460 * depending on the ListView features currently in use. For instance, adding 461 * headers and/or footers will cause the adapter to be wrapped. 462 * 463 * @param adapter The ListAdapter which is responsible for maintaining the 464 * data backing this list and for producing a view to represent an 465 * item in that data set. 466 * 467 * @see #getAdapter() 468 */ 469 @Override 470 public void setAdapter(ListAdapter adapter) { 471 if (mAdapter != null && mDataSetObserver != null) { 472 mAdapter.unregisterDataSetObserver(mDataSetObserver); 473 } 474 475 resetList(); 476 mRecycler.clear(); 477 478 if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) { 479 mAdapter = wrapHeaderListAdapterInternal(mHeaderViewInfos, mFooterViewInfos, adapter); 480 } else { 481 mAdapter = adapter; 482 } 483 484 mOldSelectedPosition = INVALID_POSITION; 485 mOldSelectedRowId = INVALID_ROW_ID; 486 487 // AbsListView#setAdapter will update choice mode states. 488 super.setAdapter(adapter); 489 490 if (mAdapter != null) { 491 mAreAllItemsSelectable = mAdapter.areAllItemsEnabled(); 492 mOldItemCount = mItemCount; 493 mItemCount = mAdapter.getCount(); 494 checkFocus(); 495 496 mDataSetObserver = new AdapterDataSetObserver(); 497 mAdapter.registerDataSetObserver(mDataSetObserver); 498 499 mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); 500 501 int position; 502 if (mStackFromBottom) { 503 position = lookForSelectablePosition(mItemCount - 1, false); 504 } else { 505 position = lookForSelectablePosition(0, true); 506 } 507 setSelectedPositionInt(position); 508 setNextSelectedPositionInt(position); 509 510 if (mItemCount == 0) { 511 // Nothing selected 512 checkSelectionChanged(); 513 } 514 } else { 515 mAreAllItemsSelectable = true; 516 checkFocus(); 517 // Nothing selected 518 checkSelectionChanged(); 519 } 520 521 requestLayout(); 522 } 523 524 /** 525 * The list is empty. Clear everything out. 526 */ 527 @Override 528 void resetList() { 529 // The parent's resetList() will remove all views from the layout so we need to 530 // cleanup the state of our footers and headers 531 clearRecycledState(mHeaderViewInfos); 532 clearRecycledState(mFooterViewInfos); 533 534 super.resetList(); 535 536 mLayoutMode = LAYOUT_NORMAL; 537 } 538 539 private void clearRecycledState(ArrayList<FixedViewInfo> infos) { 540 if (infos != null) { 541 final int count = infos.size(); 542 543 for (int i = 0; i < count; i++) { 544 final View child = infos.get(i).view; 545 final LayoutParams p = (LayoutParams) child.getLayoutParams(); 546 if (p != null) { 547 p.recycledHeaderFooter = false; 548 } 549 } 550 } 551 } 552 553 /** 554 * @return Whether the list needs to show the top fading edge 555 */ 556 private boolean showingTopFadingEdge() { 557 final int listTop = mScrollY + mListPadding.top; 558 return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop); 559 } 560 561 /** 562 * @return Whether the list needs to show the bottom fading edge 563 */ 564 private boolean showingBottomFadingEdge() { 565 final int childCount = getChildCount(); 566 final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 567 final int lastVisiblePosition = mFirstPosition + childCount - 1; 568 569 final int listBottom = mScrollY + getHeight() - mListPadding.bottom; 570 571 return (lastVisiblePosition < mItemCount - 1) 572 || (bottomOfBottomChild < listBottom); 573 } 574 575 576 @Override 577 public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { 578 579 int rectTopWithinChild = rect.top; 580 581 // offset so rect is in coordinates of the this view 582 rect.offset(child.getLeft(), child.getTop()); 583 rect.offset(-child.getScrollX(), -child.getScrollY()); 584 585 final int height = getHeight(); 586 int listUnfadedTop = getScrollY(); 587 int listUnfadedBottom = listUnfadedTop + height; 588 final int fadingEdge = getVerticalFadingEdgeLength(); 589 590 if (showingTopFadingEdge()) { 591 // leave room for top fading edge as long as rect isn't at very top 592 if ((mSelectedPosition > 0) || (rectTopWithinChild > fadingEdge)) { 593 listUnfadedTop += fadingEdge; 594 } 595 } 596 597 int childCount = getChildCount(); 598 int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 599 600 if (showingBottomFadingEdge()) { 601 // leave room for bottom fading edge as long as rect isn't at very bottom 602 if ((mSelectedPosition < mItemCount - 1) 603 || (rect.bottom < (bottomOfBottomChild - fadingEdge))) { 604 listUnfadedBottom -= fadingEdge; 605 } 606 } 607 608 int scrollYDelta = 0; 609 610 if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) { 611 // need to MOVE DOWN to get it in view: move down just enough so 612 // that the entire rectangle is in view (or at least the first 613 // screen size chunk). 614 615 if (rect.height() > height) { 616 // just enough to get screen size chunk on 617 scrollYDelta += (rect.top - listUnfadedTop); 618 } else { 619 // get entire rect at bottom of screen 620 scrollYDelta += (rect.bottom - listUnfadedBottom); 621 } 622 623 // make sure we aren't scrolling beyond the end of our children 624 int distanceToBottom = bottomOfBottomChild - listUnfadedBottom; 625 scrollYDelta = Math.min(scrollYDelta, distanceToBottom); 626 } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) { 627 // need to MOVE UP to get it in view: move up just enough so that 628 // entire rectangle is in view (or at least the first screen 629 // size chunk of it). 630 631 if (rect.height() > height) { 632 // screen size chunk 633 scrollYDelta -= (listUnfadedBottom - rect.bottom); 634 } else { 635 // entire rect at top 636 scrollYDelta -= (listUnfadedTop - rect.top); 637 } 638 639 // make sure we aren't scrolling any further than the top our children 640 int top = getChildAt(0).getTop(); 641 int deltaToTop = top - listUnfadedTop; 642 scrollYDelta = Math.max(scrollYDelta, deltaToTop); 643 } 644 645 final boolean scroll = scrollYDelta != 0; 646 if (scroll) { 647 scrollListItemsBy(-scrollYDelta); 648 positionSelector(INVALID_POSITION, child); 649 mSelectedTop = child.getTop(); 650 invalidate(); 651 } 652 return scroll; 653 } 654 655 /** 656 * {@inheritDoc} 657 */ 658 @Override 659 void fillGap(boolean down) { 660 final int count = getChildCount(); 661 if (down) { 662 int paddingTop = 0; 663 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 664 paddingTop = getListPaddingTop(); 665 } 666 final int startOffset = count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight : 667 paddingTop; 668 fillDown(mFirstPosition + count, startOffset); 669 correctTooHigh(getChildCount()); 670 } else { 671 int paddingBottom = 0; 672 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 673 paddingBottom = getListPaddingBottom(); 674 } 675 final int startOffset = count > 0 ? getChildAt(0).getTop() - mDividerHeight : 676 getHeight() - paddingBottom; 677 fillUp(mFirstPosition - 1, startOffset); 678 correctTooLow(getChildCount()); 679 } 680 } 681 682 /** 683 * Fills the list from pos down to the end of the list view. 684 * 685 * @param pos The first position to put in the list 686 * 687 * @param nextTop The location where the top of the item associated with pos 688 * should be drawn 689 * 690 * @return The view that is currently selected, if it happens to be in the 691 * range that we draw. 692 */ 693 private View fillDown(int pos, int nextTop) { 694 View selectedView = null; 695 696 int end = (mBottom - mTop); 697 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 698 end -= mListPadding.bottom; 699 } 700 701 while (nextTop < end && pos < mItemCount) { 702 // is this the selected item? 703 boolean selected = pos == mSelectedPosition; 704 View child = makeAndAddView(pos, nextTop, true, mListPadding.left, selected); 705 706 nextTop = child.getBottom() + mDividerHeight; 707 if (selected) { 708 selectedView = child; 709 } 710 pos++; 711 } 712 713 setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1); 714 return selectedView; 715 } 716 717 /** 718 * Fills the list from pos up to the top of the list view. 719 * 720 * @param pos The first position to put in the list 721 * 722 * @param nextBottom The location where the bottom of the item associated 723 * with pos should be drawn 724 * 725 * @return The view that is currently selected 726 */ 727 private View fillUp(int pos, int nextBottom) { 728 View selectedView = null; 729 730 int end = 0; 731 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 732 end = mListPadding.top; 733 } 734 735 while (nextBottom > end && pos >= 0) { 736 // is this the selected item? 737 boolean selected = pos == mSelectedPosition; 738 View child = makeAndAddView(pos, nextBottom, false, mListPadding.left, selected); 739 nextBottom = child.getTop() - mDividerHeight; 740 if (selected) { 741 selectedView = child; 742 } 743 pos--; 744 } 745 746 mFirstPosition = pos + 1; 747 setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1); 748 return selectedView; 749 } 750 751 /** 752 * Fills the list from top to bottom, starting with mFirstPosition 753 * 754 * @param nextTop The location where the top of the first item should be 755 * drawn 756 * 757 * @return The view that is currently selected 758 */ 759 private View fillFromTop(int nextTop) { 760 mFirstPosition = Math.min(mFirstPosition, mSelectedPosition); 761 mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); 762 if (mFirstPosition < 0) { 763 mFirstPosition = 0; 764 } 765 return fillDown(mFirstPosition, nextTop); 766 } 767 768 769 /** 770 * Put mSelectedPosition in the middle of the screen and then build up and 771 * down from there. This method forces mSelectedPosition to the center. 772 * 773 * @param childrenTop Top of the area in which children can be drawn, as 774 * measured in pixels 775 * @param childrenBottom Bottom of the area in which children can be drawn, 776 * as measured in pixels 777 * @return Currently selected view 778 */ 779 private View fillFromMiddle(int childrenTop, int childrenBottom) { 780 int height = childrenBottom - childrenTop; 781 782 int position = reconcileSelectedPosition(); 783 784 View sel = makeAndAddView(position, childrenTop, true, 785 mListPadding.left, true); 786 mFirstPosition = position; 787 788 int selHeight = sel.getMeasuredHeight(); 789 if (selHeight <= height) { 790 sel.offsetTopAndBottom((height - selHeight) / 2); 791 } 792 793 fillAboveAndBelow(sel, position); 794 795 if (!mStackFromBottom) { 796 correctTooHigh(getChildCount()); 797 } else { 798 correctTooLow(getChildCount()); 799 } 800 801 return sel; 802 } 803 804 /** 805 * Once the selected view as been placed, fill up the visible area above and 806 * below it. 807 * 808 * @param sel The selected view 809 * @param position The position corresponding to sel 810 */ 811 private void fillAboveAndBelow(View sel, int position) { 812 final int dividerHeight = mDividerHeight; 813 if (!mStackFromBottom) { 814 fillUp(position - 1, sel.getTop() - dividerHeight); 815 adjustViewsUpOrDown(); 816 fillDown(position + 1, sel.getBottom() + dividerHeight); 817 } else { 818 fillDown(position + 1, sel.getBottom() + dividerHeight); 819 adjustViewsUpOrDown(); 820 fillUp(position - 1, sel.getTop() - dividerHeight); 821 } 822 } 823 824 825 /** 826 * Fills the grid based on positioning the new selection at a specific 827 * location. The selection may be moved so that it does not intersect the 828 * faded edges. The grid is then filled upwards and downwards from there. 829 * 830 * @param selectedTop Where the selected item should be 831 * @param childrenTop Where to start drawing children 832 * @param childrenBottom Last pixel where children can be drawn 833 * @return The view that currently has selection 834 */ 835 private View fillFromSelection(int selectedTop, int childrenTop, int childrenBottom) { 836 int fadingEdgeLength = getVerticalFadingEdgeLength(); 837 final int selectedPosition = mSelectedPosition; 838 839 View sel; 840 841 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 842 selectedPosition); 843 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 844 selectedPosition); 845 846 sel = makeAndAddView(selectedPosition, selectedTop, true, mListPadding.left, true); 847 848 849 // Some of the newly selected item extends below the bottom of the list 850 if (sel.getBottom() > bottomSelectionPixel) { 851 // Find space available above the selection into which we can scroll 852 // upwards 853 final int spaceAbove = sel.getTop() - topSelectionPixel; 854 855 // Find space required to bring the bottom of the selected item 856 // fully into view 857 final int spaceBelow = sel.getBottom() - bottomSelectionPixel; 858 final int offset = Math.min(spaceAbove, spaceBelow); 859 860 // Now offset the selected item to get it into view 861 sel.offsetTopAndBottom(-offset); 862 } else if (sel.getTop() < topSelectionPixel) { 863 // Find space required to bring the top of the selected item fully 864 // into view 865 final int spaceAbove = topSelectionPixel - sel.getTop(); 866 867 // Find space available below the selection into which we can scroll 868 // downwards 869 final int spaceBelow = bottomSelectionPixel - sel.getBottom(); 870 final int offset = Math.min(spaceAbove, spaceBelow); 871 872 // Offset the selected item to get it into view 873 sel.offsetTopAndBottom(offset); 874 } 875 876 // Fill in views above and below 877 fillAboveAndBelow(sel, selectedPosition); 878 879 if (!mStackFromBottom) { 880 correctTooHigh(getChildCount()); 881 } else { 882 correctTooLow(getChildCount()); 883 } 884 885 return sel; 886 } 887 888 /** 889 * Calculate the bottom-most pixel we can draw the selection into 890 * 891 * @param childrenBottom Bottom pixel were children can be drawn 892 * @param fadingEdgeLength Length of the fading edge in pixels, if present 893 * @param selectedPosition The position that will be selected 894 * @return The bottom-most pixel we can draw the selection into 895 */ 896 private int getBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, 897 int selectedPosition) { 898 int bottomSelectionPixel = childrenBottom; 899 if (selectedPosition != mItemCount - 1) { 900 bottomSelectionPixel -= fadingEdgeLength; 901 } 902 return bottomSelectionPixel; 903 } 904 905 /** 906 * Calculate the top-most pixel we can draw the selection into 907 * 908 * @param childrenTop Top pixel were children can be drawn 909 * @param fadingEdgeLength Length of the fading edge in pixels, if present 910 * @param selectedPosition The position that will be selected 911 * @return The top-most pixel we can draw the selection into 912 */ 913 private int getTopSelectionPixel(int childrenTop, int fadingEdgeLength, int selectedPosition) { 914 // first pixel we can draw the selection into 915 int topSelectionPixel = childrenTop; 916 if (selectedPosition > 0) { 917 topSelectionPixel += fadingEdgeLength; 918 } 919 return topSelectionPixel; 920 } 921 922 /** 923 * Smoothly scroll to the specified adapter position. The view will 924 * scroll such that the indicated position is displayed. 925 * @param position Scroll to this adapter position. 926 */ 927 @android.view.RemotableViewMethod 928 public void smoothScrollToPosition(int position) { 929 super.smoothScrollToPosition(position); 930 } 931 932 /** 933 * Smoothly scroll to the specified adapter position offset. The view will 934 * scroll such that the indicated position is displayed. 935 * @param offset The amount to offset from the adapter position to scroll to. 936 */ 937 @android.view.RemotableViewMethod 938 public void smoothScrollByOffset(int offset) { 939 super.smoothScrollByOffset(offset); 940 } 941 942 /** 943 * Fills the list based on positioning the new selection relative to the old 944 * selection. The new selection will be placed at, above, or below the 945 * location of the new selection depending on how the selection is moving. 946 * The selection will then be pinned to the visible part of the screen, 947 * excluding the edges that are faded. The list is then filled upwards and 948 * downwards from there. 949 * 950 * @param oldSel The old selected view. Useful for trying to put the new 951 * selection in the same place 952 * @param newSel The view that is to become selected. Useful for trying to 953 * put the new selection in the same place 954 * @param delta Which way we are moving 955 * @param childrenTop Where to start drawing children 956 * @param childrenBottom Last pixel where children can be drawn 957 * @return The view that currently has selection 958 */ 959 private View moveSelection(View oldSel, View newSel, int delta, int childrenTop, 960 int childrenBottom) { 961 int fadingEdgeLength = getVerticalFadingEdgeLength(); 962 final int selectedPosition = mSelectedPosition; 963 964 View sel; 965 966 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 967 selectedPosition); 968 final int bottomSelectionPixel = getBottomSelectionPixel(childrenTop, fadingEdgeLength, 969 selectedPosition); 970 971 if (delta > 0) { 972 /* 973 * Case 1: Scrolling down. 974 */ 975 976 /* 977 * Before After 978 * | | | | 979 * +-------+ +-------+ 980 * | A | | A | 981 * | 1 | => +-------+ 982 * +-------+ | B | 983 * | B | | 2 | 984 * +-------+ +-------+ 985 * | | | | 986 * 987 * Try to keep the top of the previously selected item where it was. 988 * oldSel = A 989 * sel = B 990 */ 991 992 // Put oldSel (A) where it belongs 993 oldSel = makeAndAddView(selectedPosition - 1, oldSel.getTop(), true, 994 mListPadding.left, false); 995 996 final int dividerHeight = mDividerHeight; 997 998 // Now put the new selection (B) below that 999 sel = makeAndAddView(selectedPosition, oldSel.getBottom() + dividerHeight, true, 1000 mListPadding.left, true); 1001 1002 // Some of the newly selected item extends below the bottom of the list 1003 if (sel.getBottom() > bottomSelectionPixel) { 1004 1005 // Find space available above the selection into which we can scroll upwards 1006 int spaceAbove = sel.getTop() - topSelectionPixel; 1007 1008 // Find space required to bring the bottom of the selected item fully into view 1009 int spaceBelow = sel.getBottom() - bottomSelectionPixel; 1010 1011 // Don't scroll more than half the height of the list 1012 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 1013 int offset = Math.min(spaceAbove, spaceBelow); 1014 offset = Math.min(offset, halfVerticalSpace); 1015 1016 // We placed oldSel, so offset that item 1017 oldSel.offsetTopAndBottom(-offset); 1018 // Now offset the selected item to get it into view 1019 sel.offsetTopAndBottom(-offset); 1020 } 1021 1022 // Fill in views above and below 1023 if (!mStackFromBottom) { 1024 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 1025 adjustViewsUpOrDown(); 1026 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 1027 } else { 1028 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 1029 adjustViewsUpOrDown(); 1030 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 1031 } 1032 } else if (delta < 0) { 1033 /* 1034 * Case 2: Scrolling up. 1035 */ 1036 1037 /* 1038 * Before After 1039 * | | | | 1040 * +-------+ +-------+ 1041 * | A | | A | 1042 * +-------+ => | 1 | 1043 * | B | +-------+ 1044 * | 2 | | B | 1045 * +-------+ +-------+ 1046 * | | | | 1047 * 1048 * Try to keep the top of the item about to become selected where it was. 1049 * newSel = A 1050 * olSel = B 1051 */ 1052 1053 if (newSel != null) { 1054 // Try to position the top of newSel (A) where it was before it was selected 1055 sel = makeAndAddView(selectedPosition, newSel.getTop(), true, mListPadding.left, 1056 true); 1057 } else { 1058 // If (A) was not on screen and so did not have a view, position 1059 // it above the oldSel (B) 1060 sel = makeAndAddView(selectedPosition, oldSel.getTop(), false, mListPadding.left, 1061 true); 1062 } 1063 1064 // Some of the newly selected item extends above the top of the list 1065 if (sel.getTop() < topSelectionPixel) { 1066 // Find space required to bring the top of the selected item fully into view 1067 int spaceAbove = topSelectionPixel - sel.getTop(); 1068 1069 // Find space available below the selection into which we can scroll downwards 1070 int spaceBelow = bottomSelectionPixel - sel.getBottom(); 1071 1072 // Don't scroll more than half the height of the list 1073 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 1074 int offset = Math.min(spaceAbove, spaceBelow); 1075 offset = Math.min(offset, halfVerticalSpace); 1076 1077 // Offset the selected item to get it into view 1078 sel.offsetTopAndBottom(offset); 1079 } 1080 1081 // Fill in views above and below 1082 fillAboveAndBelow(sel, selectedPosition); 1083 } else { 1084 1085 int oldTop = oldSel.getTop(); 1086 1087 /* 1088 * Case 3: Staying still 1089 */ 1090 sel = makeAndAddView(selectedPosition, oldTop, true, mListPadding.left, true); 1091 1092 // We're staying still... 1093 if (oldTop < childrenTop) { 1094 // ... but the top of the old selection was off screen. 1095 // (This can happen if the data changes size out from under us) 1096 int newBottom = sel.getBottom(); 1097 if (newBottom < childrenTop + 20) { 1098 // Not enough visible -- bring it onscreen 1099 sel.offsetTopAndBottom(childrenTop - sel.getTop()); 1100 } 1101 } 1102 1103 // Fill in views above and below 1104 fillAboveAndBelow(sel, selectedPosition); 1105 } 1106 1107 return sel; 1108 } 1109 1110 private class FocusSelector implements Runnable { 1111 // the selector is waiting to set selection on the list view 1112 private static final int STATE_SET_SELECTION = 1; 1113 // the selector set the selection on the list view, waiting for a layoutChildren pass 1114 private static final int STATE_WAIT_FOR_LAYOUT = 2; 1115 // the selector's selection has been honored and it is waiting to request focus on the 1116 // target child. 1117 private static final int STATE_REQUEST_FOCUS = 3; 1118 1119 private int mAction; 1120 private int mPosition; 1121 private int mPositionTop; 1122 1123 FocusSelector setupForSetSelection(int position, int top) { 1124 mPosition = position; 1125 mPositionTop = top; 1126 mAction = STATE_SET_SELECTION; 1127 return this; 1128 } 1129 1130 public void run() { 1131 if (mAction == STATE_SET_SELECTION) { 1132 setSelectionFromTop(mPosition, mPositionTop); 1133 mAction = STATE_WAIT_FOR_LAYOUT; 1134 } else if (mAction == STATE_REQUEST_FOCUS) { 1135 final int childIndex = mPosition - mFirstPosition; 1136 final View child = getChildAt(childIndex); 1137 if (child != null) { 1138 child.requestFocus(); 1139 } 1140 mAction = -1; 1141 } 1142 } 1143 1144 @Nullable Runnable setupFocusIfValid(int position) { 1145 if (mAction != STATE_WAIT_FOR_LAYOUT || position != mPosition) { 1146 return null; 1147 } 1148 mAction = STATE_REQUEST_FOCUS; 1149 return this; 1150 } 1151 1152 void onLayoutComplete() { 1153 if (mAction == STATE_WAIT_FOR_LAYOUT) { 1154 mAction = -1; 1155 } 1156 } 1157 } 1158 1159 @Override 1160 protected void onDetachedFromWindow() { 1161 if (mFocusSelector != null) { 1162 removeCallbacks(mFocusSelector); 1163 mFocusSelector = null; 1164 } 1165 super.onDetachedFromWindow(); 1166 } 1167 1168 @Override 1169 protected void onSizeChanged(int w, int h, int oldw, int oldh) { 1170 if (getChildCount() > 0) { 1171 View focusedChild = getFocusedChild(); 1172 if (focusedChild != null) { 1173 final int childPosition = mFirstPosition + indexOfChild(focusedChild); 1174 final int childBottom = focusedChild.getBottom(); 1175 final int offset = Math.max(0, childBottom - (h - mPaddingTop)); 1176 final int top = focusedChild.getTop() - offset; 1177 if (mFocusSelector == null) { 1178 mFocusSelector = new FocusSelector(); 1179 } 1180 post(mFocusSelector.setupForSetSelection(childPosition, top)); 1181 } 1182 } 1183 super.onSizeChanged(w, h, oldw, oldh); 1184 } 1185 1186 @Override 1187 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 1188 // Sets up mListPadding 1189 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 1190 1191 final int widthMode = MeasureSpec.getMode(widthMeasureSpec); 1192 final int heightMode = MeasureSpec.getMode(heightMeasureSpec); 1193 int widthSize = MeasureSpec.getSize(widthMeasureSpec); 1194 int heightSize = MeasureSpec.getSize(heightMeasureSpec); 1195 1196 int childWidth = 0; 1197 int childHeight = 0; 1198 int childState = 0; 1199 1200 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1201 if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED 1202 || heightMode == MeasureSpec.UNSPECIFIED)) { 1203 final View child = obtainView(0, mIsScrap); 1204 1205 // Lay out child directly against the parent measure spec so that 1206 // we can obtain exected minimum width and height. 1207 measureScrapChild(child, 0, widthMeasureSpec, heightSize); 1208 1209 childWidth = child.getMeasuredWidth(); 1210 childHeight = child.getMeasuredHeight(); 1211 childState = combineMeasuredStates(childState, child.getMeasuredState()); 1212 1213 if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( 1214 ((LayoutParams) child.getLayoutParams()).viewType)) { 1215 mRecycler.addScrapView(child, 0); 1216 } 1217 } 1218 1219 if (widthMode == MeasureSpec.UNSPECIFIED) { 1220 widthSize = mListPadding.left + mListPadding.right + childWidth + 1221 getVerticalScrollbarWidth(); 1222 } else { 1223 widthSize |= (childState & MEASURED_STATE_MASK); 1224 } 1225 1226 if (heightMode == MeasureSpec.UNSPECIFIED) { 1227 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1228 getVerticalFadingEdgeLength() * 2; 1229 } 1230 1231 if (heightMode == MeasureSpec.AT_MOST) { 1232 // TODO: after first layout we should maybe start at the first visible position, not 0 1233 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); 1234 } 1235 1236 setMeasuredDimension(widthSize, heightSize); 1237 1238 mWidthMeasureSpec = widthMeasureSpec; 1239 } 1240 1241 private void measureScrapChild(View child, int position, int widthMeasureSpec, int heightHint) { 1242 LayoutParams p = (LayoutParams) child.getLayoutParams(); 1243 if (p == null) { 1244 p = (AbsListView.LayoutParams) generateDefaultLayoutParams(); 1245 child.setLayoutParams(p); 1246 } 1247 p.viewType = mAdapter.getItemViewType(position); 1248 p.isEnabled = mAdapter.isEnabled(position); 1249 p.forceAdd = true; 1250 1251 final int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, 1252 mListPadding.left + mListPadding.right, p.width); 1253 final int lpHeight = p.height; 1254 final int childHeightSpec; 1255 if (lpHeight > 0) { 1256 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1257 } else { 1258 childHeightSpec = MeasureSpec.makeSafeMeasureSpec(heightHint, MeasureSpec.UNSPECIFIED); 1259 } 1260 child.measure(childWidthSpec, childHeightSpec); 1261 1262 // Since this view was measured directly aginst the parent measure 1263 // spec, we must measure it again before reuse. 1264 child.forceLayout(); 1265 } 1266 1267 /** 1268 * @return True to recycle the views used to measure this ListView in 1269 * UNSPECIFIED/AT_MOST modes, false otherwise. 1270 * @hide 1271 */ 1272 @ViewDebug.ExportedProperty(category = "list") 1273 protected boolean recycleOnMeasure() { 1274 return true; 1275 } 1276 1277 /** 1278 * Measures the height of the given range of children (inclusive) and 1279 * returns the height with this ListView's padding and divider heights 1280 * included. If maxHeight is provided, the measuring will stop when the 1281 * current height reaches maxHeight. 1282 * 1283 * @param widthMeasureSpec The width measure spec to be given to a child's 1284 * {@link View#measure(int, int)}. 1285 * @param startPosition The position of the first child to be shown. 1286 * @param endPosition The (inclusive) position of the last child to be 1287 * shown. Specify {@link #NO_POSITION} if the last child should be 1288 * the last available child from the adapter. 1289 * @param maxHeight The maximum height that will be returned (if all the 1290 * children don't fit in this value, this value will be 1291 * returned). 1292 * @param disallowPartialChildPosition In general, whether the returned 1293 * height should only contain entire children. This is more 1294 * powerful--it is the first inclusive position at which partial 1295 * children will not be allowed. Example: it looks nice to have 1296 * at least 3 completely visible children, and in portrait this 1297 * will most likely fit; but in landscape there could be times 1298 * when even 2 children can not be completely shown, so a value 1299 * of 2 (remember, inclusive) would be good (assuming 1300 * startPosition is 0). 1301 * @return The height of this ListView with the given children. 1302 */ 1303 final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, 1304 int maxHeight, int disallowPartialChildPosition) { 1305 final ListAdapter adapter = mAdapter; 1306 if (adapter == null) { 1307 return mListPadding.top + mListPadding.bottom; 1308 } 1309 1310 // Include the padding of the list 1311 int returnedHeight = mListPadding.top + mListPadding.bottom; 1312 final int dividerHeight = mDividerHeight; 1313 // The previous height value that was less than maxHeight and contained 1314 // no partial children 1315 int prevHeightWithoutPartialChild = 0; 1316 int i; 1317 View child; 1318 1319 // mItemCount - 1 since endPosition parameter is inclusive 1320 endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; 1321 final AbsListView.RecycleBin recycleBin = mRecycler; 1322 final boolean recyle = recycleOnMeasure(); 1323 final boolean[] isScrap = mIsScrap; 1324 1325 for (i = startPosition; i <= endPosition; ++i) { 1326 child = obtainView(i, isScrap); 1327 1328 measureScrapChild(child, i, widthMeasureSpec, maxHeight); 1329 1330 if (i > 0) { 1331 // Count the divider for all but one child 1332 returnedHeight += dividerHeight; 1333 } 1334 1335 // Recycle the view before we possibly return from the method 1336 if (recyle && recycleBin.shouldRecycleViewType( 1337 ((LayoutParams) child.getLayoutParams()).viewType)) { 1338 recycleBin.addScrapView(child, -1); 1339 } 1340 1341 returnedHeight += child.getMeasuredHeight(); 1342 1343 if (returnedHeight >= maxHeight) { 1344 // We went over, figure out which height to return. If returnedHeight > maxHeight, 1345 // then the i'th position did not fit completely. 1346 return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) 1347 && (i > disallowPartialChildPosition) // We've past the min pos 1348 && (prevHeightWithoutPartialChild > 0) // We have a prev height 1349 && (returnedHeight != maxHeight) // i'th child did not fit completely 1350 ? prevHeightWithoutPartialChild 1351 : maxHeight; 1352 } 1353 1354 if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { 1355 prevHeightWithoutPartialChild = returnedHeight; 1356 } 1357 } 1358 1359 // At this point, we went through the range of children, and they each 1360 // completely fit, so return the returnedHeight 1361 return returnedHeight; 1362 } 1363 1364 @Override 1365 int findMotionRow(int y) { 1366 int childCount = getChildCount(); 1367 if (childCount > 0) { 1368 if (!mStackFromBottom) { 1369 for (int i = 0; i < childCount; i++) { 1370 View v = getChildAt(i); 1371 if (y <= v.getBottom()) { 1372 return mFirstPosition + i; 1373 } 1374 } 1375 } else { 1376 for (int i = childCount - 1; i >= 0; i--) { 1377 View v = getChildAt(i); 1378 if (y >= v.getTop()) { 1379 return mFirstPosition + i; 1380 } 1381 } 1382 } 1383 } 1384 return INVALID_POSITION; 1385 } 1386 1387 /** 1388 * Put a specific item at a specific location on the screen and then build 1389 * up and down from there. 1390 * 1391 * @param position The reference view to use as the starting point 1392 * @param top Pixel offset from the top of this view to the top of the 1393 * reference view. 1394 * 1395 * @return The selected view, or null if the selected view is outside the 1396 * visible area. 1397 */ 1398 private View fillSpecific(int position, int top) { 1399 boolean tempIsSelected = position == mSelectedPosition; 1400 View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected); 1401 // Possibly changed again in fillUp if we add rows above this one. 1402 mFirstPosition = position; 1403 1404 View above; 1405 View below; 1406 1407 final int dividerHeight = mDividerHeight; 1408 if (!mStackFromBottom) { 1409 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1410 // This will correct for the top of the first view not touching the top of the list 1411 adjustViewsUpOrDown(); 1412 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1413 int childCount = getChildCount(); 1414 if (childCount > 0) { 1415 correctTooHigh(childCount); 1416 } 1417 } else { 1418 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1419 // This will correct for the bottom of the last view not touching the bottom of the list 1420 adjustViewsUpOrDown(); 1421 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1422 int childCount = getChildCount(); 1423 if (childCount > 0) { 1424 correctTooLow(childCount); 1425 } 1426 } 1427 1428 if (tempIsSelected) { 1429 return temp; 1430 } else if (above != null) { 1431 return above; 1432 } else { 1433 return below; 1434 } 1435 } 1436 1437 /** 1438 * Check if we have dragged the bottom of the list too high (we have pushed the 1439 * top element off the top of the screen when we did not need to). Correct by sliding 1440 * everything back down. 1441 * 1442 * @param childCount Number of children 1443 */ 1444 private void correctTooHigh(int childCount) { 1445 // First see if the last item is visible. If it is not, it is OK for the 1446 // top of the list to be pushed up. 1447 int lastPosition = mFirstPosition + childCount - 1; 1448 if (lastPosition == mItemCount - 1 && childCount > 0) { 1449 1450 // Get the last child ... 1451 final View lastChild = getChildAt(childCount - 1); 1452 1453 // ... and its bottom edge 1454 final int lastBottom = lastChild.getBottom(); 1455 1456 // This is bottom of our drawable area 1457 final int end = (mBottom - mTop) - mListPadding.bottom; 1458 1459 // This is how far the bottom edge of the last view is from the bottom of the 1460 // drawable area 1461 int bottomOffset = end - lastBottom; 1462 View firstChild = getChildAt(0); 1463 final int firstTop = firstChild.getTop(); 1464 1465 // Make sure we are 1) Too high, and 2) Either there are more rows above the 1466 // first row or the first row is scrolled off the top of the drawable area 1467 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 1468 if (mFirstPosition == 0) { 1469 // Don't pull the top too far down 1470 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 1471 } 1472 // Move everything down 1473 offsetChildrenTopAndBottom(bottomOffset); 1474 if (mFirstPosition > 0) { 1475 // Fill the gap that was opened above mFirstPosition with more rows, if 1476 // possible 1477 fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight); 1478 // Close up the remaining gap 1479 adjustViewsUpOrDown(); 1480 } 1481 1482 } 1483 } 1484 } 1485 1486 /** 1487 * Check if we have dragged the bottom of the list too low (we have pushed the 1488 * bottom element off the bottom of the screen when we did not need to). Correct by sliding 1489 * everything back up. 1490 * 1491 * @param childCount Number of children 1492 */ 1493 private void correctTooLow(int childCount) { 1494 // First see if the first item is visible. If it is not, it is OK for the 1495 // bottom of the list to be pushed down. 1496 if (mFirstPosition == 0 && childCount > 0) { 1497 1498 // Get the first child ... 1499 final View firstChild = getChildAt(0); 1500 1501 // ... and its top edge 1502 final int firstTop = firstChild.getTop(); 1503 1504 // This is top of our drawable area 1505 final int start = mListPadding.top; 1506 1507 // This is bottom of our drawable area 1508 final int end = (mBottom - mTop) - mListPadding.bottom; 1509 1510 // This is how far the top edge of the first view is from the top of the 1511 // drawable area 1512 int topOffset = firstTop - start; 1513 View lastChild = getChildAt(childCount - 1); 1514 final int lastBottom = lastChild.getBottom(); 1515 int lastPosition = mFirstPosition + childCount - 1; 1516 1517 // Make sure we are 1) Too low, and 2) Either there are more rows below the 1518 // last row or the last row is scrolled off the bottom of the drawable area 1519 if (topOffset > 0) { 1520 if (lastPosition < mItemCount - 1 || lastBottom > end) { 1521 if (lastPosition == mItemCount - 1) { 1522 // Don't pull the bottom too far up 1523 topOffset = Math.min(topOffset, lastBottom - end); 1524 } 1525 // Move everything up 1526 offsetChildrenTopAndBottom(-topOffset); 1527 if (lastPosition < mItemCount - 1) { 1528 // Fill the gap that was opened below the last position with more rows, if 1529 // possible 1530 fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight); 1531 // Close up the remaining gap 1532 adjustViewsUpOrDown(); 1533 } 1534 } else if (lastPosition == mItemCount - 1) { 1535 adjustViewsUpOrDown(); 1536 } 1537 } 1538 } 1539 } 1540 1541 @Override 1542 protected void layoutChildren() { 1543 final boolean blockLayoutRequests = mBlockLayoutRequests; 1544 if (blockLayoutRequests) { 1545 return; 1546 } 1547 1548 mBlockLayoutRequests = true; 1549 1550 try { 1551 super.layoutChildren(); 1552 1553 invalidate(); 1554 1555 if (mAdapter == null) { 1556 resetList(); 1557 invokeOnItemScrollListener(); 1558 return; 1559 } 1560 1561 final int childrenTop = mListPadding.top; 1562 final int childrenBottom = mBottom - mTop - mListPadding.bottom; 1563 final int childCount = getChildCount(); 1564 1565 int index = 0; 1566 int delta = 0; 1567 1568 View sel; 1569 View oldSel = null; 1570 View oldFirst = null; 1571 View newSel = null; 1572 1573 // Remember stuff we will need down below 1574 switch (mLayoutMode) { 1575 case LAYOUT_SET_SELECTION: 1576 index = mNextSelectedPosition - mFirstPosition; 1577 if (index >= 0 && index < childCount) { 1578 newSel = getChildAt(index); 1579 } 1580 break; 1581 case LAYOUT_FORCE_TOP: 1582 case LAYOUT_FORCE_BOTTOM: 1583 case LAYOUT_SPECIFIC: 1584 case LAYOUT_SYNC: 1585 break; 1586 case LAYOUT_MOVE_SELECTION: 1587 default: 1588 // Remember the previously selected view 1589 index = mSelectedPosition - mFirstPosition; 1590 if (index >= 0 && index < childCount) { 1591 oldSel = getChildAt(index); 1592 } 1593 1594 // Remember the previous first child 1595 oldFirst = getChildAt(0); 1596 1597 if (mNextSelectedPosition >= 0) { 1598 delta = mNextSelectedPosition - mSelectedPosition; 1599 } 1600 1601 // Caution: newSel might be null 1602 newSel = getChildAt(index + delta); 1603 } 1604 1605 1606 boolean dataChanged = mDataChanged; 1607 if (dataChanged) { 1608 handleDataChanged(); 1609 } 1610 1611 // Handle the empty set by removing all views that are visible 1612 // and calling it a day 1613 if (mItemCount == 0) { 1614 resetList(); 1615 invokeOnItemScrollListener(); 1616 return; 1617 } else if (mItemCount != mAdapter.getCount()) { 1618 throw new IllegalStateException("The content of the adapter has changed but " 1619 + "ListView did not receive a notification. Make sure the content of " 1620 + "your adapter is not modified from a background thread, but only from " 1621 + "the UI thread. Make sure your adapter calls notifyDataSetChanged() " 1622 + "when its content changes. [in ListView(" + getId() + ", " + getClass() 1623 + ") with Adapter(" + mAdapter.getClass() + ")]"); 1624 } 1625 1626 setSelectedPositionInt(mNextSelectedPosition); 1627 1628 AccessibilityNodeInfo accessibilityFocusLayoutRestoreNode = null; 1629 View accessibilityFocusLayoutRestoreView = null; 1630 int accessibilityFocusPosition = INVALID_POSITION; 1631 1632 // Remember which child, if any, had accessibility focus. This must 1633 // occur before recycling any views, since that will clear 1634 // accessibility focus. 1635 final ViewRootImpl viewRootImpl = getViewRootImpl(); 1636 if (viewRootImpl != null) { 1637 final View focusHost = viewRootImpl.getAccessibilityFocusedHost(); 1638 if (focusHost != null) { 1639 final View focusChild = getAccessibilityFocusedChild(focusHost); 1640 if (focusChild != null) { 1641 if (!dataChanged || isDirectChildHeaderOrFooter(focusChild) 1642 || focusChild.hasTransientState() || mAdapterHasStableIds) { 1643 // The views won't be changing, so try to maintain 1644 // focus on the current host and virtual view. 1645 accessibilityFocusLayoutRestoreView = focusHost; 1646 accessibilityFocusLayoutRestoreNode = viewRootImpl 1647 .getAccessibilityFocusedVirtualView(); 1648 } 1649 1650 // If all else fails, maintain focus at the same 1651 // position. 1652 accessibilityFocusPosition = getPositionForView(focusChild); 1653 } 1654 } 1655 } 1656 1657 View focusLayoutRestoreDirectChild = null; 1658 View focusLayoutRestoreView = null; 1659 1660 // Take focus back to us temporarily to avoid the eventual call to 1661 // clear focus when removing the focused child below from messing 1662 // things up when ViewAncestor assigns focus back to someone else. 1663 final View focusedChild = getFocusedChild(); 1664 if (focusedChild != null) { 1665 // TODO: in some cases focusedChild.getParent() == null 1666 1667 // We can remember the focused view to restore after re-layout 1668 // if the data hasn't changed, or if the focused position is a 1669 // header or footer. 1670 if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild) 1671 || focusedChild.hasTransientState() || mAdapterHasStableIds) { 1672 focusLayoutRestoreDirectChild = focusedChild; 1673 // Remember the specific view that had focus. 1674 focusLayoutRestoreView = findFocus(); 1675 if (focusLayoutRestoreView != null) { 1676 // Tell it we are going to mess with it. 1677 focusLayoutRestoreView.dispatchStartTemporaryDetach(); 1678 } 1679 } 1680 requestFocus(); 1681 } 1682 1683 // Pull all children into the RecycleBin. 1684 // These views will be reused if possible 1685 final int firstPosition = mFirstPosition; 1686 final RecycleBin recycleBin = mRecycler; 1687 if (dataChanged) { 1688 for (int i = 0; i < childCount; i++) { 1689 recycleBin.addScrapView(getChildAt(i), firstPosition+i); 1690 } 1691 } else { 1692 recycleBin.fillActiveViews(childCount, firstPosition); 1693 } 1694 1695 // Clear out old views 1696 detachAllViewsFromParent(); 1697 recycleBin.removeSkippedScrap(); 1698 1699 switch (mLayoutMode) { 1700 case LAYOUT_SET_SELECTION: 1701 if (newSel != null) { 1702 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1703 } else { 1704 sel = fillFromMiddle(childrenTop, childrenBottom); 1705 } 1706 break; 1707 case LAYOUT_SYNC: 1708 sel = fillSpecific(mSyncPosition, mSpecificTop); 1709 break; 1710 case LAYOUT_FORCE_BOTTOM: 1711 sel = fillUp(mItemCount - 1, childrenBottom); 1712 adjustViewsUpOrDown(); 1713 break; 1714 case LAYOUT_FORCE_TOP: 1715 mFirstPosition = 0; 1716 sel = fillFromTop(childrenTop); 1717 adjustViewsUpOrDown(); 1718 break; 1719 case LAYOUT_SPECIFIC: 1720 final int selectedPosition = reconcileSelectedPosition(); 1721 sel = fillSpecific(selectedPosition, mSpecificTop); 1722 /** 1723 * When ListView is resized, FocusSelector requests an async selection for the 1724 * previously focused item to make sure it is still visible. If the item is not 1725 * selectable, it won't regain focus so instead we call FocusSelector 1726 * to directly request focus on the view after it is visible. 1727 */ 1728 if (sel == null && mFocusSelector != null) { 1729 final Runnable focusRunnable = mFocusSelector 1730 .setupFocusIfValid(selectedPosition); 1731 if (focusRunnable != null) { 1732 post(focusRunnable); 1733 } 1734 } 1735 break; 1736 case LAYOUT_MOVE_SELECTION: 1737 sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom); 1738 break; 1739 default: 1740 if (childCount == 0) { 1741 if (!mStackFromBottom) { 1742 final int position = lookForSelectablePosition(0, true); 1743 setSelectedPositionInt(position); 1744 sel = fillFromTop(childrenTop); 1745 } else { 1746 final int position = lookForSelectablePosition(mItemCount - 1, false); 1747 setSelectedPositionInt(position); 1748 sel = fillUp(mItemCount - 1, childrenBottom); 1749 } 1750 } else { 1751 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1752 sel = fillSpecific(mSelectedPosition, 1753 oldSel == null ? childrenTop : oldSel.getTop()); 1754 } else if (mFirstPosition < mItemCount) { 1755 sel = fillSpecific(mFirstPosition, 1756 oldFirst == null ? childrenTop : oldFirst.getTop()); 1757 } else { 1758 sel = fillSpecific(0, childrenTop); 1759 } 1760 } 1761 break; 1762 } 1763 1764 // Flush any cached views that did not get reused above 1765 recycleBin.scrapActiveViews(); 1766 1767 // remove any header/footer that has been temp detached and not re-attached 1768 removeUnusedFixedViews(mHeaderViewInfos); 1769 removeUnusedFixedViews(mFooterViewInfos); 1770 1771 if (sel != null) { 1772 // The current selected item should get focus if items are 1773 // focusable. 1774 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) { 1775 final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild && 1776 focusLayoutRestoreView != null && 1777 focusLayoutRestoreView.requestFocus()) || sel.requestFocus(); 1778 if (!focusWasTaken) { 1779 // Selected item didn't take focus, but we still want to 1780 // make sure something else outside of the selected view 1781 // has focus. 1782 final View focused = getFocusedChild(); 1783 if (focused != null) { 1784 focused.clearFocus(); 1785 } 1786 positionSelector(INVALID_POSITION, sel); 1787 } else { 1788 sel.setSelected(false); 1789 mSelectorRect.setEmpty(); 1790 } 1791 } else { 1792 positionSelector(INVALID_POSITION, sel); 1793 } 1794 mSelectedTop = sel.getTop(); 1795 } else { 1796 final boolean inTouchMode = mTouchMode == TOUCH_MODE_TAP 1797 || mTouchMode == TOUCH_MODE_DONE_WAITING; 1798 if (inTouchMode) { 1799 // If the user's finger is down, select the motion position. 1800 final View child = getChildAt(mMotionPosition - mFirstPosition); 1801 if (child != null) { 1802 positionSelector(mMotionPosition, child); 1803 } 1804 } else if (mSelectorPosition != INVALID_POSITION) { 1805 // If we had previously positioned the selector somewhere, 1806 // put it back there. It might not match up with the data, 1807 // but it's transitioning out so it's not a big deal. 1808 final View child = getChildAt(mSelectorPosition - mFirstPosition); 1809 if (child != null) { 1810 positionSelector(mSelectorPosition, child); 1811 } 1812 } else { 1813 // Otherwise, clear selection. 1814 mSelectedTop = 0; 1815 mSelectorRect.setEmpty(); 1816 } 1817 1818 // Even if there is not selected position, we may need to 1819 // restore focus (i.e. something focusable in touch mode). 1820 if (hasFocus() && focusLayoutRestoreView != null) { 1821 focusLayoutRestoreView.requestFocus(); 1822 } 1823 } 1824 1825 // Attempt to restore accessibility focus, if necessary. 1826 if (viewRootImpl != null) { 1827 final View newAccessibilityFocusedView = viewRootImpl.getAccessibilityFocusedHost(); 1828 if (newAccessibilityFocusedView == null) { 1829 if (accessibilityFocusLayoutRestoreView != null 1830 && accessibilityFocusLayoutRestoreView.isAttachedToWindow()) { 1831 final AccessibilityNodeProvider provider = 1832 accessibilityFocusLayoutRestoreView.getAccessibilityNodeProvider(); 1833 if (accessibilityFocusLayoutRestoreNode != null && provider != null) { 1834 final int virtualViewId = AccessibilityNodeInfo.getVirtualDescendantId( 1835 accessibilityFocusLayoutRestoreNode.getSourceNodeId()); 1836 provider.performAction(virtualViewId, 1837 AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS, null); 1838 } else { 1839 accessibilityFocusLayoutRestoreView.requestAccessibilityFocus(); 1840 } 1841 } else if (accessibilityFocusPosition != INVALID_POSITION) { 1842 // Bound the position within the visible children. 1843 final int position = MathUtils.constrain( 1844 accessibilityFocusPosition - mFirstPosition, 0, 1845 getChildCount() - 1); 1846 final View restoreView = getChildAt(position); 1847 if (restoreView != null) { 1848 restoreView.requestAccessibilityFocus(); 1849 } 1850 } 1851 } 1852 } 1853 1854 // Tell focus view we are done mucking with it, if it is still in 1855 // our view hierarchy. 1856 if (focusLayoutRestoreView != null 1857 && focusLayoutRestoreView.getWindowToken() != null) { 1858 focusLayoutRestoreView.dispatchFinishTemporaryDetach(); 1859 } 1860 1861 mLayoutMode = LAYOUT_NORMAL; 1862 mDataChanged = false; 1863 if (mPositionScrollAfterLayout != null) { 1864 post(mPositionScrollAfterLayout); 1865 mPositionScrollAfterLayout = null; 1866 } 1867 mNeedSync = false; 1868 setNextSelectedPositionInt(mSelectedPosition); 1869 1870 updateScrollIndicators(); 1871 1872 if (mItemCount > 0) { 1873 checkSelectionChanged(); 1874 } 1875 1876 invokeOnItemScrollListener(); 1877 } finally { 1878 if (mFocusSelector != null) { 1879 mFocusSelector.onLayoutComplete(); 1880 } 1881 if (!blockLayoutRequests) { 1882 mBlockLayoutRequests = false; 1883 } 1884 } 1885 } 1886 1887 @Override 1888 boolean trackMotionScroll(int deltaY, int incrementalDeltaY) { 1889 final boolean result = super.trackMotionScroll(deltaY, incrementalDeltaY); 1890 removeUnusedFixedViews(mHeaderViewInfos); 1891 removeUnusedFixedViews(mFooterViewInfos); 1892 return result; 1893 } 1894 1895 /** 1896 * Header and Footer views are not scrapped / recycled like other views but they are still 1897 * detached from the ViewGroup. After a layout operation, call this method to remove such views. 1898 * 1899 * @param infoList The info list to be traversed 1900 */ 1901 private void removeUnusedFixedViews(@Nullable List<FixedViewInfo> infoList) { 1902 if (infoList == null) { 1903 return; 1904 } 1905 for (int i = infoList.size() - 1; i >= 0; i--) { 1906 final FixedViewInfo fixedViewInfo = infoList.get(i); 1907 final View view = fixedViewInfo.view; 1908 final LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1909 if (view.getParent() == null && lp != null && lp.recycledHeaderFooter) { 1910 removeDetachedView(view, false); 1911 lp.recycledHeaderFooter = false; 1912 } 1913 1914 } 1915 } 1916 1917 /** 1918 * @param child a direct child of this list. 1919 * @return Whether child is a header or footer view. 1920 */ 1921 private boolean isDirectChildHeaderOrFooter(View child) { 1922 final ArrayList<FixedViewInfo> headers = mHeaderViewInfos; 1923 final int numHeaders = headers.size(); 1924 for (int i = 0; i < numHeaders; i++) { 1925 if (child == headers.get(i).view) { 1926 return true; 1927 } 1928 } 1929 1930 final ArrayList<FixedViewInfo> footers = mFooterViewInfos; 1931 final int numFooters = footers.size(); 1932 for (int i = 0; i < numFooters; i++) { 1933 if (child == footers.get(i).view) { 1934 return true; 1935 } 1936 } 1937 1938 return false; 1939 } 1940 1941 /** 1942 * Obtains the view and adds it to our list of children. The view can be 1943 * made fresh, converted from an unused view, or used as is if it was in 1944 * the recycle bin. 1945 * 1946 * @param position logical position in the list 1947 * @param y top or bottom edge of the view to add 1948 * @param flow {@code true} to align top edge to y, {@code false} to align 1949 * bottom edge to y 1950 * @param childrenLeft left edge where children should be positioned 1951 * @param selected {@code true} if the position is selected, {@code false} 1952 * otherwise 1953 * @return the view that was added 1954 */ 1955 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1956 boolean selected) { 1957 if (!mDataChanged) { 1958 // Try to use an existing view for this position. 1959 final View activeView = mRecycler.getActiveView(position); 1960 if (activeView != null) { 1961 // Found it. We're reusing an existing child, so it just needs 1962 // to be positioned like a scrap view. 1963 setupChild(activeView, position, y, flow, childrenLeft, selected, true); 1964 return activeView; 1965 } 1966 } 1967 1968 // Make a new view for this position, or convert an unused view if 1969 // possible. 1970 final View child = obtainView(position, mIsScrap); 1971 1972 // This needs to be positioned and measured. 1973 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0]); 1974 1975 return child; 1976 } 1977 1978 /** 1979 * Adds a view as a child and make sure it is measured (if necessary) and 1980 * positioned properly. 1981 * 1982 * @param child the view to add 1983 * @param position the position of this child 1984 * @param y the y position relative to which this view will be positioned 1985 * @param flowDown {@code true} to align top edge to y, {@code false} to 1986 * align bottom edge to y 1987 * @param childrenLeft left edge where children should be positioned 1988 * @param selected {@code true} if the position is selected, {@code false} 1989 * otherwise 1990 * @param isAttachedToWindow {@code true} if the view is already attached 1991 * to the window, e.g. whether it was reused, or 1992 * {@code false} otherwise 1993 */ 1994 private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, 1995 boolean selected, boolean isAttachedToWindow) { 1996 Trace.traceBegin(Trace.TRACE_TAG_VIEW, "setupListItem"); 1997 1998 final boolean isSelected = selected && shouldShowSelector(); 1999 final boolean updateChildSelected = isSelected != child.isSelected(); 2000 final int mode = mTouchMode; 2001 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL 2002 && mMotionPosition == position; 2003 final boolean updateChildPressed = isPressed != child.isPressed(); 2004 final boolean needToMeasure = !isAttachedToWindow || updateChildSelected 2005 || child.isLayoutRequested(); 2006 2007 // Respect layout params that are already in the view. Otherwise make 2008 // some up... 2009 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 2010 if (p == null) { 2011 p = (AbsListView.LayoutParams) generateDefaultLayoutParams(); 2012 } 2013 p.viewType = mAdapter.getItemViewType(position); 2014 p.isEnabled = mAdapter.isEnabled(position); 2015 2016 // Set up view state before attaching the view, since we may need to 2017 // rely on the jumpDrawablesToCurrentState() call that occurs as part 2018 // of view attachment. 2019 if (updateChildSelected) { 2020 child.setSelected(isSelected); 2021 } 2022 2023 if (updateChildPressed) { 2024 child.setPressed(isPressed); 2025 } 2026 2027 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 2028 if (child instanceof Checkable) { 2029 ((Checkable) child).setChecked(mCheckStates.get(position)); 2030 } else if (getContext().getApplicationInfo().targetSdkVersion 2031 >= android.os.Build.VERSION_CODES.HONEYCOMB) { 2032 child.setActivated(mCheckStates.get(position)); 2033 } 2034 } 2035 2036 if ((isAttachedToWindow && !p.forceAdd) || (p.recycledHeaderFooter 2037 && p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { 2038 attachViewToParent(child, flowDown ? -1 : 0, p); 2039 2040 // If the view was previously attached for a different position, 2041 // then manually jump the drawables. 2042 if (isAttachedToWindow 2043 && (((AbsListView.LayoutParams) child.getLayoutParams()).scrappedFromPosition) 2044 != position) { 2045 child.jumpDrawablesToCurrentState(); 2046 } 2047 } else { 2048 p.forceAdd = false; 2049 if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { 2050 p.recycledHeaderFooter = true; 2051 } 2052 addViewInLayout(child, flowDown ? -1 : 0, p, true); 2053 // add view in layout will reset the RTL properties. We have to re-resolve them 2054 child.resolveRtlPropertiesIfNeeded(); 2055 } 2056 2057 if (needToMeasure) { 2058 final int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2059 mListPadding.left + mListPadding.right, p.width); 2060 final int lpHeight = p.height; 2061 final int childHeightSpec; 2062 if (lpHeight > 0) { 2063 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2064 } else { 2065 childHeightSpec = MeasureSpec.makeSafeMeasureSpec(getMeasuredHeight(), 2066 MeasureSpec.UNSPECIFIED); 2067 } 2068 child.measure(childWidthSpec, childHeightSpec); 2069 } else { 2070 cleanupLayoutState(child); 2071 } 2072 2073 final int w = child.getMeasuredWidth(); 2074 final int h = child.getMeasuredHeight(); 2075 final int childTop = flowDown ? y : y - h; 2076 2077 if (needToMeasure) { 2078 final int childRight = childrenLeft + w; 2079 final int childBottom = childTop + h; 2080 child.layout(childrenLeft, childTop, childRight, childBottom); 2081 } else { 2082 child.offsetLeftAndRight(childrenLeft - child.getLeft()); 2083 child.offsetTopAndBottom(childTop - child.getTop()); 2084 } 2085 2086 if (mCachingStarted && !child.isDrawingCacheEnabled()) { 2087 child.setDrawingCacheEnabled(true); 2088 } 2089 2090 Trace.traceEnd(Trace.TRACE_TAG_VIEW); 2091 } 2092 2093 @Override 2094 protected boolean canAnimate() { 2095 return super.canAnimate() && mItemCount > 0; 2096 } 2097 2098 /** 2099 * Sets the currently selected item. If in touch mode, the item will not be selected 2100 * but it will still be positioned appropriately. If the specified selection position 2101 * is less than 0, then the item at position 0 will be selected. 2102 * 2103 * @param position Index (starting at 0) of the data item to be selected. 2104 */ 2105 @Override 2106 public void setSelection(int position) { 2107 setSelectionFromTop(position, 0); 2108 } 2109 2110 /** 2111 * Makes the item at the supplied position selected. 2112 * 2113 * @param position the position of the item to select 2114 */ 2115 @Override 2116 void setSelectionInt(int position) { 2117 setNextSelectedPositionInt(position); 2118 boolean awakeScrollbars = false; 2119 2120 final int selectedPosition = mSelectedPosition; 2121 2122 if (selectedPosition >= 0) { 2123 if (position == selectedPosition - 1) { 2124 awakeScrollbars = true; 2125 } else if (position == selectedPosition + 1) { 2126 awakeScrollbars = true; 2127 } 2128 } 2129 2130 if (mPositionScroller != null) { 2131 mPositionScroller.stop(); 2132 } 2133 2134 layoutChildren(); 2135 2136 if (awakeScrollbars) { 2137 awakenScrollBars(); 2138 } 2139 } 2140 2141 /** 2142 * Find a position that can be selected (i.e., is not a separator). 2143 * 2144 * @param position The starting position to look at. 2145 * @param lookDown Whether to look down for other positions. 2146 * @return The next selectable position starting at position and then searching either up or 2147 * down. Returns {@link #INVALID_POSITION} if nothing can be found. 2148 */ 2149 @Override 2150 int lookForSelectablePosition(int position, boolean lookDown) { 2151 final ListAdapter adapter = mAdapter; 2152 if (adapter == null || isInTouchMode()) { 2153 return INVALID_POSITION; 2154 } 2155 2156 final int count = adapter.getCount(); 2157 if (!mAreAllItemsSelectable) { 2158 if (lookDown) { 2159 position = Math.max(0, position); 2160 while (position < count && !adapter.isEnabled(position)) { 2161 position++; 2162 } 2163 } else { 2164 position = Math.min(position, count - 1); 2165 while (position >= 0 && !adapter.isEnabled(position)) { 2166 position--; 2167 } 2168 } 2169 } 2170 2171 if (position < 0 || position >= count) { 2172 return INVALID_POSITION; 2173 } 2174 2175 return position; 2176 } 2177 2178 /** 2179 * Find a position that can be selected (i.e., is not a separator). If there 2180 * are no selectable positions in the specified direction from the starting 2181 * position, searches in the opposite direction from the starting position 2182 * to the current position. 2183 * 2184 * @param current the current position 2185 * @param position the starting position 2186 * @param lookDown whether to look down for other positions 2187 * @return the next selectable position, or {@link #INVALID_POSITION} if 2188 * nothing can be found 2189 */ 2190 int lookForSelectablePositionAfter(int current, int position, boolean lookDown) { 2191 final ListAdapter adapter = mAdapter; 2192 if (adapter == null || isInTouchMode()) { 2193 return INVALID_POSITION; 2194 } 2195 2196 // First check after the starting position in the specified direction. 2197 final int after = lookForSelectablePosition(position, lookDown); 2198 if (after != INVALID_POSITION) { 2199 return after; 2200 } 2201 2202 // Then check between the starting position and the current position. 2203 final int count = adapter.getCount(); 2204 current = MathUtils.constrain(current, -1, count - 1); 2205 if (lookDown) { 2206 position = Math.min(position - 1, count - 1); 2207 while ((position > current) && !adapter.isEnabled(position)) { 2208 position--; 2209 } 2210 if (position <= current) { 2211 return INVALID_POSITION; 2212 } 2213 } else { 2214 position = Math.max(0, position + 1); 2215 while ((position < current) && !adapter.isEnabled(position)) { 2216 position++; 2217 } 2218 if (position >= current) { 2219 return INVALID_POSITION; 2220 } 2221 } 2222 2223 return position; 2224 } 2225 2226 /** 2227 * setSelectionAfterHeaderView set the selection to be the first list item 2228 * after the header views. 2229 */ 2230 public void setSelectionAfterHeaderView() { 2231 final int count = getHeaderViewsCount(); 2232 if (count > 0) { 2233 mNextSelectedPosition = 0; 2234 return; 2235 } 2236 2237 if (mAdapter != null) { 2238 setSelection(count); 2239 } else { 2240 mNextSelectedPosition = count; 2241 mLayoutMode = LAYOUT_SET_SELECTION; 2242 } 2243 2244 } 2245 2246 @Override 2247 public boolean dispatchKeyEvent(KeyEvent event) { 2248 // Dispatch in the normal way 2249 boolean handled = super.dispatchKeyEvent(event); 2250 if (!handled) { 2251 // If we didn't handle it... 2252 View focused = getFocusedChild(); 2253 if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) { 2254 // ... and our focused child didn't handle it 2255 // ... give it to ourselves so we can scroll if necessary 2256 handled = onKeyDown(event.getKeyCode(), event); 2257 } 2258 } 2259 return handled; 2260 } 2261 2262 @Override 2263 public boolean onKeyDown(int keyCode, KeyEvent event) { 2264 return commonKey(keyCode, 1, event); 2265 } 2266 2267 @Override 2268 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 2269 return commonKey(keyCode, repeatCount, event); 2270 } 2271 2272 @Override 2273 public boolean onKeyUp(int keyCode, KeyEvent event) { 2274 return commonKey(keyCode, 1, event); 2275 } 2276 2277 private boolean commonKey(int keyCode, int count, KeyEvent event) { 2278 if (mAdapter == null || !isAttachedToWindow()) { 2279 return false; 2280 } 2281 2282 if (mDataChanged) { 2283 layoutChildren(); 2284 } 2285 2286 boolean handled = false; 2287 int action = event.getAction(); 2288 if (KeyEvent.isConfirmKey(keyCode) 2289 && event.hasNoModifiers() && action != KeyEvent.ACTION_UP) { 2290 handled = resurrectSelectionIfNeeded(); 2291 if (!handled && event.getRepeatCount() == 0 && getChildCount() > 0) { 2292 keyPressed(); 2293 handled = true; 2294 } 2295 } 2296 2297 2298 if (!handled && action != KeyEvent.ACTION_UP) { 2299 switch (keyCode) { 2300 case KeyEvent.KEYCODE_DPAD_UP: 2301 if (event.hasNoModifiers()) { 2302 handled = resurrectSelectionIfNeeded(); 2303 if (!handled) { 2304 while (count-- > 0) { 2305 if (arrowScroll(FOCUS_UP)) { 2306 handled = true; 2307 } else { 2308 break; 2309 } 2310 } 2311 } 2312 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 2313 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP); 2314 } 2315 break; 2316 2317 case KeyEvent.KEYCODE_DPAD_DOWN: 2318 if (event.hasNoModifiers()) { 2319 handled = resurrectSelectionIfNeeded(); 2320 if (!handled) { 2321 while (count-- > 0) { 2322 if (arrowScroll(FOCUS_DOWN)) { 2323 handled = true; 2324 } else { 2325 break; 2326 } 2327 } 2328 } 2329 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 2330 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN); 2331 } 2332 break; 2333 2334 case KeyEvent.KEYCODE_DPAD_LEFT: 2335 if (event.hasNoModifiers()) { 2336 handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT); 2337 } 2338 break; 2339 2340 case KeyEvent.KEYCODE_DPAD_RIGHT: 2341 if (event.hasNoModifiers()) { 2342 handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT); 2343 } 2344 break; 2345 2346 case KeyEvent.KEYCODE_PAGE_UP: 2347 if (event.hasNoModifiers()) { 2348 handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_UP); 2349 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 2350 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP); 2351 } 2352 break; 2353 2354 case KeyEvent.KEYCODE_PAGE_DOWN: 2355 if (event.hasNoModifiers()) { 2356 handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_DOWN); 2357 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 2358 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN); 2359 } 2360 break; 2361 2362 case KeyEvent.KEYCODE_MOVE_HOME: 2363 if (event.hasNoModifiers()) { 2364 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP); 2365 } 2366 break; 2367 2368 case KeyEvent.KEYCODE_MOVE_END: 2369 if (event.hasNoModifiers()) { 2370 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN); 2371 } 2372 break; 2373 2374 case KeyEvent.KEYCODE_TAB: 2375 // This creates an asymmetry in TAB navigation order. At some 2376 // point in the future we may decide that it's preferable to 2377 // force the list selection to the top or bottom when receiving 2378 // TAB focus from another widget, but for now this is adequate. 2379 if (event.hasNoModifiers()) { 2380 handled = resurrectSelectionIfNeeded() || arrowScroll(FOCUS_DOWN); 2381 } else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) { 2382 handled = resurrectSelectionIfNeeded() || arrowScroll(FOCUS_UP); 2383 } 2384 break; 2385 } 2386 } 2387 2388 if (handled) { 2389 return true; 2390 } 2391 2392 if (sendToTextFilter(keyCode, count, event)) { 2393 return true; 2394 } 2395 2396 switch (action) { 2397 case KeyEvent.ACTION_DOWN: 2398 return super.onKeyDown(keyCode, event); 2399 2400 case KeyEvent.ACTION_UP: 2401 return super.onKeyUp(keyCode, event); 2402 2403 case KeyEvent.ACTION_MULTIPLE: 2404 return super.onKeyMultiple(keyCode, count, event); 2405 2406 default: // shouldn't happen 2407 return false; 2408 } 2409 } 2410 2411 /** 2412 * Scrolls up or down by the number of items currently present on screen. 2413 * 2414 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2415 * @return whether selection was moved 2416 */ 2417 boolean pageScroll(int direction) { 2418 final int nextPage; 2419 final boolean down; 2420 2421 if (direction == FOCUS_UP) { 2422 nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1); 2423 down = false; 2424 } else if (direction == FOCUS_DOWN) { 2425 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1); 2426 down = true; 2427 } else { 2428 return false; 2429 } 2430 2431 if (nextPage >= 0) { 2432 final int position = lookForSelectablePositionAfter(mSelectedPosition, nextPage, down); 2433 if (position >= 0) { 2434 mLayoutMode = LAYOUT_SPECIFIC; 2435 mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength(); 2436 2437 if (down && (position > (mItemCount - getChildCount()))) { 2438 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2439 } 2440 2441 if (!down && (position < getChildCount())) { 2442 mLayoutMode = LAYOUT_FORCE_TOP; 2443 } 2444 2445 setSelectionInt(position); 2446 invokeOnItemScrollListener(); 2447 if (!awakenScrollBars()) { 2448 invalidate(); 2449 } 2450 2451 return true; 2452 } 2453 } 2454 2455 return false; 2456 } 2457 2458 /** 2459 * Go to the last or first item if possible (not worrying about panning 2460 * across or navigating within the internal focus of the currently selected 2461 * item.) 2462 * 2463 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2464 * @return whether selection was moved 2465 */ 2466 boolean fullScroll(int direction) { 2467 boolean moved = false; 2468 if (direction == FOCUS_UP) { 2469 if (mSelectedPosition != 0) { 2470 final int position = lookForSelectablePositionAfter(mSelectedPosition, 0, true); 2471 if (position >= 0) { 2472 mLayoutMode = LAYOUT_FORCE_TOP; 2473 setSelectionInt(position); 2474 invokeOnItemScrollListener(); 2475 } 2476 moved = true; 2477 } 2478 } else if (direction == FOCUS_DOWN) { 2479 final int lastItem = (mItemCount - 1); 2480 if (mSelectedPosition < lastItem) { 2481 final int position = lookForSelectablePositionAfter( 2482 mSelectedPosition, lastItem, false); 2483 if (position >= 0) { 2484 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2485 setSelectionInt(position); 2486 invokeOnItemScrollListener(); 2487 } 2488 moved = true; 2489 } 2490 } 2491 2492 if (moved && !awakenScrollBars()) { 2493 awakenScrollBars(); 2494 invalidate(); 2495 } 2496 2497 return moved; 2498 } 2499 2500 /** 2501 * To avoid horizontal focus searches changing the selected item, we 2502 * manually focus search within the selected item (as applicable), and 2503 * prevent focus from jumping to something within another item. 2504 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT} 2505 * @return Whether this consumes the key event. 2506 */ 2507 private boolean handleHorizontalFocusWithinListItem(int direction) { 2508 if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT) { 2509 throw new IllegalArgumentException("direction must be one of" 2510 + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}"); 2511 } 2512 2513 final int numChildren = getChildCount(); 2514 if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) { 2515 final View selectedView = getSelectedView(); 2516 if (selectedView != null && selectedView.hasFocus() && 2517 selectedView instanceof ViewGroup) { 2518 2519 final View currentFocus = selectedView.findFocus(); 2520 final View nextFocus = FocusFinder.getInstance().findNextFocus( 2521 (ViewGroup) selectedView, currentFocus, direction); 2522 if (nextFocus != null) { 2523 // do the math to get interesting rect in next focus' coordinates 2524 Rect focusedRect = mTempRect; 2525 if (currentFocus != null) { 2526 currentFocus.getFocusedRect(focusedRect); 2527 offsetDescendantRectToMyCoords(currentFocus, focusedRect); 2528 offsetRectIntoDescendantCoords(nextFocus, focusedRect); 2529 } else { 2530 focusedRect = null; 2531 } 2532 if (nextFocus.requestFocus(direction, focusedRect)) { 2533 return true; 2534 } 2535 } 2536 // we are blocking the key from being handled (by returning true) 2537 // if the global result is going to be some other view within this 2538 // list. this is to acheive the overall goal of having 2539 // horizontal d-pad navigation remain in the current item. 2540 final View globalNextFocus = FocusFinder.getInstance().findNextFocus( 2541 (ViewGroup) getRootView(), currentFocus, direction); 2542 if (globalNextFocus != null) { 2543 return isViewAncestorOf(globalNextFocus, this); 2544 } 2545 } 2546 } 2547 return false; 2548 } 2549 2550 /** 2551 * Scrolls to the next or previous item if possible. 2552 * 2553 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2554 * 2555 * @return whether selection was moved 2556 */ 2557 boolean arrowScroll(int direction) { 2558 try { 2559 mInLayout = true; 2560 final boolean handled = arrowScrollImpl(direction); 2561 if (handled) { 2562 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 2563 } 2564 return handled; 2565 } finally { 2566 mInLayout = false; 2567 } 2568 } 2569 2570 /** 2571 * Used by {@link #arrowScrollImpl(int)} to help determine the next selected position 2572 * to move to. This return a position in the direction given if the selected item 2573 * is fully visible. 2574 * 2575 * @param selectedView Current selected view to move from 2576 * @param selectedPos Current selected position to move from 2577 * @param direction Direction to move in 2578 * @return Desired selected position after moving in the given direction 2579 */ 2580 private final int nextSelectedPositionForDirection( 2581 View selectedView, int selectedPos, int direction) { 2582 int nextSelected; 2583 2584 if (direction == View.FOCUS_DOWN) { 2585 final int listBottom = getHeight() - mListPadding.bottom; 2586 if (selectedView != null && selectedView.getBottom() <= listBottom) { 2587 nextSelected = selectedPos != INVALID_POSITION && selectedPos >= mFirstPosition ? 2588 selectedPos + 1 : 2589 mFirstPosition; 2590 } else { 2591 return INVALID_POSITION; 2592 } 2593 } else { 2594 final int listTop = mListPadding.top; 2595 if (selectedView != null && selectedView.getTop() >= listTop) { 2596 final int lastPos = mFirstPosition + getChildCount() - 1; 2597 nextSelected = selectedPos != INVALID_POSITION && selectedPos <= lastPos ? 2598 selectedPos - 1 : 2599 lastPos; 2600 } else { 2601 return INVALID_POSITION; 2602 } 2603 } 2604 2605 if (nextSelected < 0 || nextSelected >= mAdapter.getCount()) { 2606 return INVALID_POSITION; 2607 } 2608 return lookForSelectablePosition(nextSelected, direction == View.FOCUS_DOWN); 2609 } 2610 2611 /** 2612 * Handle an arrow scroll going up or down. Take into account whether items are selectable, 2613 * whether there are focusable items etc. 2614 * 2615 * @param direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}. 2616 * @return Whether any scrolling, selection or focus change occured. 2617 */ 2618 private boolean arrowScrollImpl(int direction) { 2619 if (getChildCount() <= 0) { 2620 return false; 2621 } 2622 2623 View selectedView = getSelectedView(); 2624 int selectedPos = mSelectedPosition; 2625 2626 int nextSelectedPosition = nextSelectedPositionForDirection(selectedView, selectedPos, direction); 2627 int amountToScroll = amountToScroll(direction, nextSelectedPosition); 2628 2629 // if we are moving focus, we may OVERRIDE the default behavior 2630 final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null; 2631 if (focusResult != null) { 2632 nextSelectedPosition = focusResult.getSelectedPosition(); 2633 amountToScroll = focusResult.getAmountToScroll(); 2634 } 2635 2636 boolean needToRedraw = focusResult != null; 2637 if (nextSelectedPosition != INVALID_POSITION) { 2638 handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null); 2639 setSelectedPositionInt(nextSelectedPosition); 2640 setNextSelectedPositionInt(nextSelectedPosition); 2641 selectedView = getSelectedView(); 2642 selectedPos = nextSelectedPosition; 2643 if (mItemsCanFocus && focusResult == null) { 2644 // there was no new view found to take focus, make sure we 2645 // don't leave focus with the old selection 2646 final View focused = getFocusedChild(); 2647 if (focused != null) { 2648 focused.clearFocus(); 2649 } 2650 } 2651 needToRedraw = true; 2652 checkSelectionChanged(); 2653 } 2654 2655 if (amountToScroll > 0) { 2656 scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll); 2657 needToRedraw = true; 2658 } 2659 2660 // if we didn't find a new focusable, make sure any existing focused 2661 // item that was panned off screen gives up focus. 2662 if (mItemsCanFocus && (focusResult == null) 2663 && selectedView != null && selectedView.hasFocus()) { 2664 final View focused = selectedView.findFocus(); 2665 if (focused != null) { 2666 if (!isViewAncestorOf(focused, this) || distanceToView(focused) > 0) { 2667 focused.clearFocus(); 2668 } 2669 } 2670 } 2671 2672 // if the current selection is panned off, we need to remove the selection 2673 if (nextSelectedPosition == INVALID_POSITION && selectedView != null 2674 && !isViewAncestorOf(selectedView, this)) { 2675 selectedView = null; 2676 hideSelector(); 2677 2678 // but we don't want to set the ressurect position (that would make subsequent 2679 // unhandled key events bring back the item we just scrolled off!) 2680 mResurrectToPosition = INVALID_POSITION; 2681 } 2682 2683 if (needToRedraw) { 2684 if (selectedView != null) { 2685 positionSelectorLikeFocus(selectedPos, selectedView); 2686 mSelectedTop = selectedView.getTop(); 2687 } 2688 if (!awakenScrollBars()) { 2689 invalidate(); 2690 } 2691 invokeOnItemScrollListener(); 2692 return true; 2693 } 2694 2695 return false; 2696 } 2697 2698 /** 2699 * When selection changes, it is possible that the previously selected or the 2700 * next selected item will change its size. If so, we need to offset some folks, 2701 * and re-layout the items as appropriate. 2702 * 2703 * @param selectedView The currently selected view (before changing selection). 2704 * should be <code>null</code> if there was no previous selection. 2705 * @param direction Either {@link android.view.View#FOCUS_UP} or 2706 * {@link android.view.View#FOCUS_DOWN}. 2707 * @param newSelectedPosition The position of the next selection. 2708 * @param newFocusAssigned whether new focus was assigned. This matters because 2709 * when something has focus, we don't want to show selection (ugh). 2710 */ 2711 private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition, 2712 boolean newFocusAssigned) { 2713 if (newSelectedPosition == INVALID_POSITION) { 2714 throw new IllegalArgumentException("newSelectedPosition needs to be valid"); 2715 } 2716 2717 // whether or not we are moving down or up, we want to preserve the 2718 // top of whatever view is on top: 2719 // - moving down: the view that had selection 2720 // - moving up: the view that is getting selection 2721 View topView; 2722 View bottomView; 2723 int topViewIndex, bottomViewIndex; 2724 boolean topSelected = false; 2725 final int selectedIndex = mSelectedPosition - mFirstPosition; 2726 final int nextSelectedIndex = newSelectedPosition - mFirstPosition; 2727 if (direction == View.FOCUS_UP) { 2728 topViewIndex = nextSelectedIndex; 2729 bottomViewIndex = selectedIndex; 2730 topView = getChildAt(topViewIndex); 2731 bottomView = selectedView; 2732 topSelected = true; 2733 } else { 2734 topViewIndex = selectedIndex; 2735 bottomViewIndex = nextSelectedIndex; 2736 topView = selectedView; 2737 bottomView = getChildAt(bottomViewIndex); 2738 } 2739 2740 final int numChildren = getChildCount(); 2741 2742 // start with top view: is it changing size? 2743 if (topView != null) { 2744 topView.setSelected(!newFocusAssigned && topSelected); 2745 measureAndAdjustDown(topView, topViewIndex, numChildren); 2746 } 2747 2748 // is the bottom view changing size? 2749 if (bottomView != null) { 2750 bottomView.setSelected(!newFocusAssigned && !topSelected); 2751 measureAndAdjustDown(bottomView, bottomViewIndex, numChildren); 2752 } 2753 } 2754 2755 /** 2756 * Re-measure a child, and if its height changes, lay it out preserving its 2757 * top, and adjust the children below it appropriately. 2758 * @param child The child 2759 * @param childIndex The view group index of the child. 2760 * @param numChildren The number of children in the view group. 2761 */ 2762 private void measureAndAdjustDown(View child, int childIndex, int numChildren) { 2763 int oldHeight = child.getHeight(); 2764 measureItem(child); 2765 if (child.getMeasuredHeight() != oldHeight) { 2766 // lay out the view, preserving its top 2767 relayoutMeasuredItem(child); 2768 2769 // adjust views below appropriately 2770 final int heightDelta = child.getMeasuredHeight() - oldHeight; 2771 for (int i = childIndex + 1; i < numChildren; i++) { 2772 getChildAt(i).offsetTopAndBottom(heightDelta); 2773 } 2774 } 2775 } 2776 2777 /** 2778 * Measure a particular list child. 2779 * TODO: unify with setUpChild. 2780 * @param child The child. 2781 */ 2782 private void measureItem(View child) { 2783 ViewGroup.LayoutParams p = child.getLayoutParams(); 2784 if (p == null) { 2785 p = new ViewGroup.LayoutParams( 2786 ViewGroup.LayoutParams.MATCH_PARENT, 2787 ViewGroup.LayoutParams.WRAP_CONTENT); 2788 } 2789 2790 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2791 mListPadding.left + mListPadding.right, p.width); 2792 int lpHeight = p.height; 2793 int childHeightSpec; 2794 if (lpHeight > 0) { 2795 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2796 } else { 2797 childHeightSpec = MeasureSpec.makeSafeMeasureSpec(getMeasuredHeight(), 2798 MeasureSpec.UNSPECIFIED); 2799 } 2800 child.measure(childWidthSpec, childHeightSpec); 2801 } 2802 2803 /** 2804 * Layout a child that has been measured, preserving its top position. 2805 * TODO: unify with setUpChild. 2806 * @param child The child. 2807 */ 2808 private void relayoutMeasuredItem(View child) { 2809 final int w = child.getMeasuredWidth(); 2810 final int h = child.getMeasuredHeight(); 2811 final int childLeft = mListPadding.left; 2812 final int childRight = childLeft + w; 2813 final int childTop = child.getTop(); 2814 final int childBottom = childTop + h; 2815 child.layout(childLeft, childTop, childRight, childBottom); 2816 } 2817 2818 /** 2819 * @return The amount to preview next items when arrow srolling. 2820 */ 2821 private int getArrowScrollPreviewLength() { 2822 return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength()); 2823 } 2824 2825 /** 2826 * Determine how much we need to scroll in order to get the next selected view 2827 * visible, with a fading edge showing below as applicable. The amount is 2828 * capped at {@link #getMaxScrollAmount()} . 2829 * 2830 * @param direction either {@link android.view.View#FOCUS_UP} or 2831 * {@link android.view.View#FOCUS_DOWN}. 2832 * @param nextSelectedPosition The position of the next selection, or 2833 * {@link #INVALID_POSITION} if there is no next selectable position 2834 * @return The amount to scroll. Note: this is always positive! Direction 2835 * needs to be taken into account when actually scrolling. 2836 */ 2837 private int amountToScroll(int direction, int nextSelectedPosition) { 2838 final int listBottom = getHeight() - mListPadding.bottom; 2839 final int listTop = mListPadding.top; 2840 2841 int numChildren = getChildCount(); 2842 2843 if (direction == View.FOCUS_DOWN) { 2844 int indexToMakeVisible = numChildren - 1; 2845 if (nextSelectedPosition != INVALID_POSITION) { 2846 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2847 } 2848 while (numChildren <= indexToMakeVisible) { 2849 // Child to view is not attached yet. 2850 addViewBelow(getChildAt(numChildren - 1), mFirstPosition + numChildren - 1); 2851 numChildren++; 2852 } 2853 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2854 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2855 2856 int goalBottom = listBottom; 2857 if (positionToMakeVisible < mItemCount - 1) { 2858 goalBottom -= getArrowScrollPreviewLength(); 2859 } 2860 2861 if (viewToMakeVisible.getBottom() <= goalBottom) { 2862 // item is fully visible. 2863 return 0; 2864 } 2865 2866 if (nextSelectedPosition != INVALID_POSITION 2867 && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) { 2868 // item already has enough of it visible, changing selection is good enough 2869 return 0; 2870 } 2871 2872 int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom); 2873 2874 if ((mFirstPosition + numChildren) == mItemCount) { 2875 // last is last in list -> make sure we don't scroll past it 2876 final int max = getChildAt(numChildren - 1).getBottom() - listBottom; 2877 amountToScroll = Math.min(amountToScroll, max); 2878 } 2879 2880 return Math.min(amountToScroll, getMaxScrollAmount()); 2881 } else { 2882 int indexToMakeVisible = 0; 2883 if (nextSelectedPosition != INVALID_POSITION) { 2884 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2885 } 2886 while (indexToMakeVisible < 0) { 2887 // Child to view is not attached yet. 2888 addViewAbove(getChildAt(0), mFirstPosition); 2889 mFirstPosition--; 2890 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2891 } 2892 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2893 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2894 int goalTop = listTop; 2895 if (positionToMakeVisible > 0) { 2896 goalTop += getArrowScrollPreviewLength(); 2897 } 2898 if (viewToMakeVisible.getTop() >= goalTop) { 2899 // item is fully visible. 2900 return 0; 2901 } 2902 2903 if (nextSelectedPosition != INVALID_POSITION && 2904 (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) { 2905 // item already has enough of it visible, changing selection is good enough 2906 return 0; 2907 } 2908 2909 int amountToScroll = (goalTop - viewToMakeVisible.getTop()); 2910 if (mFirstPosition == 0) { 2911 // first is first in list -> make sure we don't scroll past it 2912 final int max = listTop - getChildAt(0).getTop(); 2913 amountToScroll = Math.min(amountToScroll, max); 2914 } 2915 return Math.min(amountToScroll, getMaxScrollAmount()); 2916 } 2917 } 2918 2919 /** 2920 * Holds results of focus aware arrow scrolling. 2921 */ 2922 static private class ArrowScrollFocusResult { 2923 private int mSelectedPosition; 2924 private int mAmountToScroll; 2925 2926 /** 2927 * How {@link android.widget.ListView#arrowScrollFocused} returns its values. 2928 */ 2929 void populate(int selectedPosition, int amountToScroll) { 2930 mSelectedPosition = selectedPosition; 2931 mAmountToScroll = amountToScroll; 2932 } 2933 2934 public int getSelectedPosition() { 2935 return mSelectedPosition; 2936 } 2937 2938 public int getAmountToScroll() { 2939 return mAmountToScroll; 2940 } 2941 } 2942 2943 /** 2944 * @param direction either {@link android.view.View#FOCUS_UP} or 2945 * {@link android.view.View#FOCUS_DOWN}. 2946 * @return The position of the next selectable position of the views that 2947 * are currently visible, taking into account the fact that there might 2948 * be no selection. Returns {@link #INVALID_POSITION} if there is no 2949 * selectable view on screen in the given direction. 2950 */ 2951 private int lookForSelectablePositionOnScreen(int direction) { 2952 final int firstPosition = mFirstPosition; 2953 if (direction == View.FOCUS_DOWN) { 2954 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2955 mSelectedPosition + 1 : 2956 firstPosition; 2957 if (startPos >= mAdapter.getCount()) { 2958 return INVALID_POSITION; 2959 } 2960 if (startPos < firstPosition) { 2961 startPos = firstPosition; 2962 } 2963 2964 final int lastVisiblePos = getLastVisiblePosition(); 2965 final ListAdapter adapter = getAdapter(); 2966 for (int pos = startPos; pos <= lastVisiblePos; pos++) { 2967 if (adapter.isEnabled(pos) 2968 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2969 return pos; 2970 } 2971 } 2972 } else { 2973 int last = firstPosition + getChildCount() - 1; 2974 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2975 mSelectedPosition - 1 : 2976 firstPosition + getChildCount() - 1; 2977 if (startPos < 0 || startPos >= mAdapter.getCount()) { 2978 return INVALID_POSITION; 2979 } 2980 if (startPos > last) { 2981 startPos = last; 2982 } 2983 2984 final ListAdapter adapter = getAdapter(); 2985 for (int pos = startPos; pos >= firstPosition; pos--) { 2986 if (adapter.isEnabled(pos) 2987 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2988 return pos; 2989 } 2990 } 2991 } 2992 return INVALID_POSITION; 2993 } 2994 2995 /** 2996 * Do an arrow scroll based on focus searching. If a new view is 2997 * given focus, return the selection delta and amount to scroll via 2998 * an {@link ArrowScrollFocusResult}, otherwise, return null. 2999 * 3000 * @param direction either {@link android.view.View#FOCUS_UP} or 3001 * {@link android.view.View#FOCUS_DOWN}. 3002 * @return The result if focus has changed, or <code>null</code>. 3003 */ 3004 private ArrowScrollFocusResult arrowScrollFocused(final int direction) { 3005 final View selectedView = getSelectedView(); 3006 View newFocus; 3007 if (selectedView != null && selectedView.hasFocus()) { 3008 View oldFocus = selectedView.findFocus(); 3009 newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction); 3010 } else { 3011 if (direction == View.FOCUS_DOWN) { 3012 final boolean topFadingEdgeShowing = (mFirstPosition > 0); 3013 final int listTop = mListPadding.top + 3014 (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 3015 final int ySearchPoint = 3016 (selectedView != null && selectedView.getTop() > listTop) ? 3017 selectedView.getTop() : 3018 listTop; 3019 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 3020 } else { 3021 final boolean bottomFadingEdgeShowing = 3022 (mFirstPosition + getChildCount() - 1) < mItemCount; 3023 final int listBottom = getHeight() - mListPadding.bottom - 3024 (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 3025 final int ySearchPoint = 3026 (selectedView != null && selectedView.getBottom() < listBottom) ? 3027 selectedView.getBottom() : 3028 listBottom; 3029 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 3030 } 3031 newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction); 3032 } 3033 3034 if (newFocus != null) { 3035 final int positionOfNewFocus = positionOfNewFocus(newFocus); 3036 3037 // if the focus change is in a different new position, make sure 3038 // we aren't jumping over another selectable position 3039 if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) { 3040 final int selectablePosition = lookForSelectablePositionOnScreen(direction); 3041 if (selectablePosition != INVALID_POSITION && 3042 ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || 3043 (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) { 3044 return null; 3045 } 3046 } 3047 3048 int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus); 3049 3050 final int maxScrollAmount = getMaxScrollAmount(); 3051 if (focusScroll < maxScrollAmount) { 3052 // not moving too far, safe to give next view focus 3053 newFocus.requestFocus(direction); 3054 mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll); 3055 return mArrowScrollFocusResult; 3056 } else if (distanceToView(newFocus) < maxScrollAmount){ 3057 // Case to consider: 3058 // too far to get entire next focusable on screen, but by going 3059 // max scroll amount, we are getting it at least partially in view, 3060 // so give it focus and scroll the max ammount. 3061 newFocus.requestFocus(direction); 3062 mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount); 3063 return mArrowScrollFocusResult; 3064 } 3065 } 3066 return null; 3067 } 3068 3069 /** 3070 * @param newFocus The view that would have focus. 3071 * @return the position that contains newFocus 3072 */ 3073 private int positionOfNewFocus(View newFocus) { 3074 final int numChildren = getChildCount(); 3075 for (int i = 0; i < numChildren; i++) { 3076 final View child = getChildAt(i); 3077 if (isViewAncestorOf(newFocus, child)) { 3078 return mFirstPosition + i; 3079 } 3080 } 3081 throw new IllegalArgumentException("newFocus is not a child of any of the" 3082 + " children of the list!"); 3083 } 3084 3085 /** 3086 * Return true if child is an ancestor of parent, (or equal to the parent). 3087 */ 3088 private boolean isViewAncestorOf(View child, View parent) { 3089 if (child == parent) { 3090 return true; 3091 } 3092 3093 final ViewParent theParent = child.getParent(); 3094 return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent); 3095 } 3096 3097 /** 3098 * Determine how much we need to scroll in order to get newFocus in view. 3099 * @param direction either {@link android.view.View#FOCUS_UP} or 3100 * {@link android.view.View#FOCUS_DOWN}. 3101 * @param newFocus The view that would take focus. 3102 * @param positionOfNewFocus The position of the list item containing newFocus 3103 * @return The amount to scroll. Note: this is always positive! Direction 3104 * needs to be taken into account when actually scrolling. 3105 */ 3106 private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) { 3107 int amountToScroll = 0; 3108 newFocus.getDrawingRect(mTempRect); 3109 offsetDescendantRectToMyCoords(newFocus, mTempRect); 3110 if (direction == View.FOCUS_UP) { 3111 if (mTempRect.top < mListPadding.top) { 3112 amountToScroll = mListPadding.top - mTempRect.top; 3113 if (positionOfNewFocus > 0) { 3114 amountToScroll += getArrowScrollPreviewLength(); 3115 } 3116 } 3117 } else { 3118 final int listBottom = getHeight() - mListPadding.bottom; 3119 if (mTempRect.bottom > listBottom) { 3120 amountToScroll = mTempRect.bottom - listBottom; 3121 if (positionOfNewFocus < mItemCount - 1) { 3122 amountToScroll += getArrowScrollPreviewLength(); 3123 } 3124 } 3125 } 3126 return amountToScroll; 3127 } 3128 3129 /** 3130 * Determine the distance to the nearest edge of a view in a particular 3131 * direction. 3132 * 3133 * @param descendant A descendant of this list. 3134 * @return The distance, or 0 if the nearest edge is already on screen. 3135 */ 3136 private int distanceToView(View descendant) { 3137 int distance = 0; 3138 descendant.getDrawingRect(mTempRect); 3139 offsetDescendantRectToMyCoords(descendant, mTempRect); 3140 final int listBottom = mBottom - mTop - mListPadding.bottom; 3141 if (mTempRect.bottom < mListPadding.top) { 3142 distance = mListPadding.top - mTempRect.bottom; 3143 } else if (mTempRect.top > listBottom) { 3144 distance = mTempRect.top - listBottom; 3145 } 3146 return distance; 3147 } 3148 3149 3150 /** 3151 * Scroll the children by amount, adding a view at the end and removing 3152 * views that fall off as necessary. 3153 * 3154 * @param amount The amount (positive or negative) to scroll. 3155 */ 3156 private void scrollListItemsBy(int amount) { 3157 offsetChildrenTopAndBottom(amount); 3158 3159 final int listBottom = getHeight() - mListPadding.bottom; 3160 final int listTop = mListPadding.top; 3161 final AbsListView.RecycleBin recycleBin = mRecycler; 3162 3163 if (amount < 0) { 3164 // shifted items up 3165 3166 // may need to pan views into the bottom space 3167 int numChildren = getChildCount(); 3168 View last = getChildAt(numChildren - 1); 3169 while (last.getBottom() < listBottom) { 3170 final int lastVisiblePosition = mFirstPosition + numChildren - 1; 3171 if (lastVisiblePosition < mItemCount - 1) { 3172 last = addViewBelow(last, lastVisiblePosition); 3173 numChildren++; 3174 } else { 3175 break; 3176 } 3177 } 3178 3179 // may have brought in the last child of the list that is skinnier 3180 // than the fading edge, thereby leaving space at the end. need 3181 // to shift back 3182 if (last.getBottom() < listBottom) { 3183 offsetChildrenTopAndBottom(listBottom - last.getBottom()); 3184 } 3185 3186 // top views may be panned off screen 3187 View first = getChildAt(0); 3188 while (first.getBottom() < listTop) { 3189 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); 3190 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 3191 recycleBin.addScrapView(first, mFirstPosition); 3192 } 3193 detachViewFromParent(first); 3194 first = getChildAt(0); 3195 mFirstPosition++; 3196 } 3197 } else { 3198 // shifted items down 3199 View first = getChildAt(0); 3200 3201 // may need to pan views into top 3202 while ((first.getTop() > listTop) && (mFirstPosition > 0)) { 3203 first = addViewAbove(first, mFirstPosition); 3204 mFirstPosition--; 3205 } 3206 3207 // may have brought the very first child of the list in too far and 3208 // need to shift it back 3209 if (first.getTop() > listTop) { 3210 offsetChildrenTopAndBottom(listTop - first.getTop()); 3211 } 3212 3213 int lastIndex = getChildCount() - 1; 3214 View last = getChildAt(lastIndex); 3215 3216 // bottom view may be panned off screen 3217 while (last.getTop() > listBottom) { 3218 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); 3219 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 3220 recycleBin.addScrapView(last, mFirstPosition+lastIndex); 3221 } 3222 detachViewFromParent(last); 3223 last = getChildAt(--lastIndex); 3224 } 3225 } 3226 recycleBin.fullyDetachScrapViews(); 3227 removeUnusedFixedViews(mHeaderViewInfos); 3228 removeUnusedFixedViews(mFooterViewInfos); 3229 } 3230 3231 private View addViewAbove(View theView, int position) { 3232 int abovePosition = position - 1; 3233 View view = obtainView(abovePosition, mIsScrap); 3234 int edgeOfNewChild = theView.getTop() - mDividerHeight; 3235 setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, 3236 false, mIsScrap[0]); 3237 return view; 3238 } 3239 3240 private View addViewBelow(View theView, int position) { 3241 int belowPosition = position + 1; 3242 View view = obtainView(belowPosition, mIsScrap); 3243 int edgeOfNewChild = theView.getBottom() + mDividerHeight; 3244 setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, 3245 false, mIsScrap[0]); 3246 return view; 3247 } 3248 3249 /** 3250 * Indicates that the views created by the ListAdapter can contain focusable 3251 * items. 3252 * 3253 * @param itemsCanFocus true if items can get focus, false otherwise 3254 */ 3255 public void setItemsCanFocus(boolean itemsCanFocus) { 3256 mItemsCanFocus = itemsCanFocus; 3257 if (!itemsCanFocus) { 3258 setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); 3259 } 3260 } 3261 3262 /** 3263 * @return Whether the views created by the ListAdapter can contain focusable 3264 * items. 3265 */ 3266 public boolean getItemsCanFocus() { 3267 return mItemsCanFocus; 3268 } 3269 3270 @Override 3271 public boolean isOpaque() { 3272 boolean retValue = (mCachingActive && mIsCacheColorOpaque && mDividerIsOpaque && 3273 hasOpaqueScrollbars()) || super.isOpaque(); 3274 if (retValue) { 3275 // only return true if the list items cover the entire area of the view 3276 final int listTop = mListPadding != null ? mListPadding.top : mPaddingTop; 3277 View first = getChildAt(0); 3278 if (first == null || first.getTop() > listTop) { 3279 return false; 3280 } 3281 final int listBottom = getHeight() - 3282 (mListPadding != null ? mListPadding.bottom : mPaddingBottom); 3283 View last = getChildAt(getChildCount() - 1); 3284 if (last == null || last.getBottom() < listBottom) { 3285 return false; 3286 } 3287 } 3288 return retValue; 3289 } 3290 3291 @Override 3292 public void setCacheColorHint(int color) { 3293 final boolean opaque = (color >>> 24) == 0xFF; 3294 mIsCacheColorOpaque = opaque; 3295 if (opaque) { 3296 if (mDividerPaint == null) { 3297 mDividerPaint = new Paint(); 3298 } 3299 mDividerPaint.setColor(color); 3300 } 3301 super.setCacheColorHint(color); 3302 } 3303 3304 void drawOverscrollHeader(Canvas canvas, Drawable drawable, Rect bounds) { 3305 final int height = drawable.getMinimumHeight(); 3306 3307 canvas.save(); 3308 canvas.clipRect(bounds); 3309 3310 final int span = bounds.bottom - bounds.top; 3311 if (span < height) { 3312 bounds.top = bounds.bottom - height; 3313 } 3314 3315 drawable.setBounds(bounds); 3316 drawable.draw(canvas); 3317 3318 canvas.restore(); 3319 } 3320 3321 void drawOverscrollFooter(Canvas canvas, Drawable drawable, Rect bounds) { 3322 final int height = drawable.getMinimumHeight(); 3323 3324 canvas.save(); 3325 canvas.clipRect(bounds); 3326 3327 final int span = bounds.bottom - bounds.top; 3328 if (span < height) { 3329 bounds.bottom = bounds.top + height; 3330 } 3331 3332 drawable.setBounds(bounds); 3333 drawable.draw(canvas); 3334 3335 canvas.restore(); 3336 } 3337 3338 @Override 3339 protected void dispatchDraw(Canvas canvas) { 3340 if (mCachingStarted) { 3341 mCachingActive = true; 3342 } 3343 3344 // Draw the dividers 3345 final int dividerHeight = mDividerHeight; 3346 final Drawable overscrollHeader = mOverScrollHeader; 3347 final Drawable overscrollFooter = mOverScrollFooter; 3348 final boolean drawOverscrollHeader = overscrollHeader != null; 3349 final boolean drawOverscrollFooter = overscrollFooter != null; 3350 final boolean drawDividers = dividerHeight > 0 && mDivider != null; 3351 3352 if (drawDividers || drawOverscrollHeader || drawOverscrollFooter) { 3353 // Only modify the top and bottom in the loop, we set the left and right here 3354 final Rect bounds = mTempRect; 3355 bounds.left = mPaddingLeft; 3356 bounds.right = mRight - mLeft - mPaddingRight; 3357 3358 final int count = getChildCount(); 3359 final int headerCount = getHeaderViewsCount(); 3360 final int itemCount = mItemCount; 3361 final int footerLimit = (itemCount - mFooterViewInfos.size()); 3362 final boolean headerDividers = mHeaderDividersEnabled; 3363 final boolean footerDividers = mFooterDividersEnabled; 3364 final int first = mFirstPosition; 3365 final boolean areAllItemsSelectable = mAreAllItemsSelectable; 3366 final ListAdapter adapter = mAdapter; 3367 // If the list is opaque *and* the background is not, we want to 3368 // fill a rect where the dividers would be for non-selectable items 3369 // If the list is opaque and the background is also opaque, we don't 3370 // need to draw anything since the background will do it for us 3371 final boolean fillForMissingDividers = isOpaque() && !super.isOpaque(); 3372 3373 if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { 3374 mDividerPaint = new Paint(); 3375 mDividerPaint.setColor(getCacheColorHint()); 3376 } 3377 final Paint paint = mDividerPaint; 3378 3379 int effectivePaddingTop = 0; 3380 int effectivePaddingBottom = 0; 3381 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 3382 effectivePaddingTop = mListPadding.top; 3383 effectivePaddingBottom = mListPadding.bottom; 3384 } 3385 3386 final int listBottom = mBottom - mTop - effectivePaddingBottom + mScrollY; 3387 if (!mStackFromBottom) { 3388 int bottom = 0; 3389 3390 // Draw top divider or header for overscroll 3391 final int scrollY = mScrollY; 3392 if (count > 0 && scrollY < 0) { 3393 if (drawOverscrollHeader) { 3394 bounds.bottom = 0; 3395 bounds.top = scrollY; 3396 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3397 } else if (drawDividers) { 3398 bounds.bottom = 0; 3399 bounds.top = -dividerHeight; 3400 drawDivider(canvas, bounds, -1); 3401 } 3402 } 3403 3404 for (int i = 0; i < count; i++) { 3405 final int itemIndex = (first + i); 3406 final boolean isHeader = (itemIndex < headerCount); 3407 final boolean isFooter = (itemIndex >= footerLimit); 3408 if ((headerDividers || !isHeader) && (footerDividers || !isFooter)) { 3409 final View child = getChildAt(i); 3410 bottom = child.getBottom(); 3411 final boolean isLastItem = (i == (count - 1)); 3412 3413 if (drawDividers && (bottom < listBottom) 3414 && !(drawOverscrollFooter && isLastItem)) { 3415 final int nextIndex = (itemIndex + 1); 3416 // Draw dividers between enabled items, headers 3417 // and/or footers when enabled and requested, and 3418 // after the last enabled item. 3419 if (adapter.isEnabled(itemIndex) && (headerDividers || !isHeader 3420 && (nextIndex >= headerCount)) && (isLastItem 3421 || adapter.isEnabled(nextIndex) && (footerDividers || !isFooter 3422 && (nextIndex < footerLimit)))) { 3423 bounds.top = bottom; 3424 bounds.bottom = bottom + dividerHeight; 3425 drawDivider(canvas, bounds, i); 3426 } else if (fillForMissingDividers) { 3427 bounds.top = bottom; 3428 bounds.bottom = bottom + dividerHeight; 3429 canvas.drawRect(bounds, paint); 3430 } 3431 } 3432 } 3433 } 3434 3435 final int overFooterBottom = mBottom + mScrollY; 3436 if (drawOverscrollFooter && first + count == itemCount && 3437 overFooterBottom > bottom) { 3438 bounds.top = bottom; 3439 bounds.bottom = overFooterBottom; 3440 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3441 } 3442 } else { 3443 int top; 3444 3445 final int scrollY = mScrollY; 3446 3447 if (count > 0 && drawOverscrollHeader) { 3448 bounds.top = scrollY; 3449 bounds.bottom = getChildAt(0).getTop(); 3450 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3451 } 3452 3453 final int start = drawOverscrollHeader ? 1 : 0; 3454 for (int i = start; i < count; i++) { 3455 final int itemIndex = (first + i); 3456 final boolean isHeader = (itemIndex < headerCount); 3457 final boolean isFooter = (itemIndex >= footerLimit); 3458 if ((headerDividers || !isHeader) && (footerDividers || !isFooter)) { 3459 final View child = getChildAt(i); 3460 top = child.getTop(); 3461 if (drawDividers && (top > effectivePaddingTop)) { 3462 final boolean isFirstItem = (i == start); 3463 final int previousIndex = (itemIndex - 1); 3464 // Draw dividers between enabled items, headers 3465 // and/or footers when enabled and requested, and 3466 // before the first enabled item. 3467 if (adapter.isEnabled(itemIndex) && (headerDividers || !isHeader 3468 && (previousIndex >= headerCount)) && (isFirstItem || 3469 adapter.isEnabled(previousIndex) && (footerDividers || !isFooter 3470 && (previousIndex < footerLimit)))) { 3471 bounds.top = top - dividerHeight; 3472 bounds.bottom = top; 3473 // Give the method the child ABOVE the divider, 3474 // so we subtract one from our child position. 3475 // Give -1 when there is no child above the 3476 // divider. 3477 drawDivider(canvas, bounds, i - 1); 3478 } else if (fillForMissingDividers) { 3479 bounds.top = top - dividerHeight; 3480 bounds.bottom = top; 3481 canvas.drawRect(bounds, paint); 3482 } 3483 } 3484 } 3485 } 3486 3487 if (count > 0 && scrollY > 0) { 3488 if (drawOverscrollFooter) { 3489 final int absListBottom = mBottom; 3490 bounds.top = absListBottom; 3491 bounds.bottom = absListBottom + scrollY; 3492 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3493 } else if (drawDividers) { 3494 bounds.top = listBottom; 3495 bounds.bottom = listBottom + dividerHeight; 3496 drawDivider(canvas, bounds, -1); 3497 } 3498 } 3499 } 3500 } 3501 3502 // Draw the indicators (these should be drawn above the dividers) and children 3503 super.dispatchDraw(canvas); 3504 } 3505 3506 @Override 3507 protected boolean drawChild(Canvas canvas, View child, long drawingTime) { 3508 boolean more = super.drawChild(canvas, child, drawingTime); 3509 if (mCachingActive && child.mCachingFailed) { 3510 mCachingActive = false; 3511 } 3512 return more; 3513 } 3514 3515 /** 3516 * Draws a divider for the given child in the given bounds. 3517 * 3518 * @param canvas The canvas to draw to. 3519 * @param bounds The bounds of the divider. 3520 * @param childIndex The index of child (of the View) above the divider. 3521 * This will be -1 if there is no child above the divider to be 3522 * drawn. 3523 */ 3524 void drawDivider(Canvas canvas, Rect bounds, int childIndex) { 3525 // This widget draws the same divider for all children 3526 final Drawable divider = mDivider; 3527 3528 divider.setBounds(bounds); 3529 divider.draw(canvas); 3530 } 3531 3532 /** 3533 * Returns the drawable that will be drawn between each item in the list. 3534 * 3535 * @return the current drawable drawn between list elements 3536 * @attr ref R.styleable#ListView_divider 3537 */ 3538 @Nullable 3539 public Drawable getDivider() { 3540 return mDivider; 3541 } 3542 3543 /** 3544 * Sets the drawable that will be drawn between each item in the list. 3545 * <p> 3546 * <strong>Note:</strong> If the drawable does not have an intrinsic 3547 * height, you should also call {@link #setDividerHeight(int)}. 3548 * 3549 * @param divider the drawable to use 3550 * @attr ref R.styleable#ListView_divider 3551 */ 3552 public void setDivider(@Nullable Drawable divider) { 3553 if (divider != null) { 3554 mDividerHeight = divider.getIntrinsicHeight(); 3555 } else { 3556 mDividerHeight = 0; 3557 } 3558 mDivider = divider; 3559 mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; 3560 requestLayout(); 3561 invalidate(); 3562 } 3563 3564 /** 3565 * @return Returns the height of the divider that will be drawn between each item in the list. 3566 */ 3567 public int getDividerHeight() { 3568 return mDividerHeight; 3569 } 3570 3571 /** 3572 * Sets the height of the divider that will be drawn between each item in the list. Calling 3573 * this will override the intrinsic height as set by {@link #setDivider(Drawable)} 3574 * 3575 * @param height The new height of the divider in pixels. 3576 */ 3577 public void setDividerHeight(int height) { 3578 mDividerHeight = height; 3579 requestLayout(); 3580 invalidate(); 3581 } 3582 3583 /** 3584 * Enables or disables the drawing of the divider for header views. 3585 * 3586 * @param headerDividersEnabled True to draw the headers, false otherwise. 3587 * 3588 * @see #setFooterDividersEnabled(boolean) 3589 * @see #areHeaderDividersEnabled() 3590 * @see #addHeaderView(android.view.View) 3591 */ 3592 public void setHeaderDividersEnabled(boolean headerDividersEnabled) { 3593 mHeaderDividersEnabled = headerDividersEnabled; 3594 invalidate(); 3595 } 3596 3597 /** 3598 * @return Whether the drawing of the divider for header views is enabled 3599 * 3600 * @see #setHeaderDividersEnabled(boolean) 3601 */ 3602 public boolean areHeaderDividersEnabled() { 3603 return mHeaderDividersEnabled; 3604 } 3605 3606 /** 3607 * Enables or disables the drawing of the divider for footer views. 3608 * 3609 * @param footerDividersEnabled True to draw the footers, false otherwise. 3610 * 3611 * @see #setHeaderDividersEnabled(boolean) 3612 * @see #areFooterDividersEnabled() 3613 * @see #addFooterView(android.view.View) 3614 */ 3615 public void setFooterDividersEnabled(boolean footerDividersEnabled) { 3616 mFooterDividersEnabled = footerDividersEnabled; 3617 invalidate(); 3618 } 3619 3620 /** 3621 * @return Whether the drawing of the divider for footer views is enabled 3622 * 3623 * @see #setFooterDividersEnabled(boolean) 3624 */ 3625 public boolean areFooterDividersEnabled() { 3626 return mFooterDividersEnabled; 3627 } 3628 3629 /** 3630 * Sets the drawable that will be drawn above all other list content. 3631 * This area can become visible when the user overscrolls the list. 3632 * 3633 * @param header The drawable to use 3634 */ 3635 public void setOverscrollHeader(Drawable header) { 3636 mOverScrollHeader = header; 3637 if (mScrollY < 0) { 3638 invalidate(); 3639 } 3640 } 3641 3642 /** 3643 * @return The drawable that will be drawn above all other list content 3644 */ 3645 public Drawable getOverscrollHeader() { 3646 return mOverScrollHeader; 3647 } 3648 3649 /** 3650 * Sets the drawable that will be drawn below all other list content. 3651 * This area can become visible when the user overscrolls the list, 3652 * or when the list's content does not fully fill the container area. 3653 * 3654 * @param footer The drawable to use 3655 */ 3656 public void setOverscrollFooter(Drawable footer) { 3657 mOverScrollFooter = footer; 3658 invalidate(); 3659 } 3660 3661 /** 3662 * @return The drawable that will be drawn below all other list content 3663 */ 3664 public Drawable getOverscrollFooter() { 3665 return mOverScrollFooter; 3666 } 3667 3668 @Override 3669 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 3670 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 3671 3672 final ListAdapter adapter = mAdapter; 3673 int closetChildIndex = -1; 3674 int closestChildTop = 0; 3675 if (adapter != null && gainFocus && previouslyFocusedRect != null) { 3676 previouslyFocusedRect.offset(mScrollX, mScrollY); 3677 3678 // Don't cache the result of getChildCount or mFirstPosition here, 3679 // it could change in layoutChildren. 3680 if (adapter.getCount() < getChildCount() + mFirstPosition) { 3681 mLayoutMode = LAYOUT_NORMAL; 3682 layoutChildren(); 3683 } 3684 3685 // figure out which item should be selected based on previously 3686 // focused rect 3687 Rect otherRect = mTempRect; 3688 int minDistance = Integer.MAX_VALUE; 3689 final int childCount = getChildCount(); 3690 final int firstPosition = mFirstPosition; 3691 3692 for (int i = 0; i < childCount; i++) { 3693 // only consider selectable views 3694 if (!adapter.isEnabled(firstPosition + i)) { 3695 continue; 3696 } 3697 3698 View other = getChildAt(i); 3699 other.getDrawingRect(otherRect); 3700 offsetDescendantRectToMyCoords(other, otherRect); 3701 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 3702 3703 if (distance < minDistance) { 3704 minDistance = distance; 3705 closetChildIndex = i; 3706 closestChildTop = other.getTop(); 3707 } 3708 } 3709 } 3710 3711 if (closetChildIndex >= 0) { 3712 setSelectionFromTop(closetChildIndex + mFirstPosition, closestChildTop); 3713 } else { 3714 requestLayout(); 3715 } 3716 } 3717 3718 3719 /* 3720 * (non-Javadoc) 3721 * 3722 * Children specified in XML are assumed to be header views. After we have 3723 * parsed them move them out of the children list and into mHeaderViews. 3724 */ 3725 @Override 3726 protected void onFinishInflate() { 3727 super.onFinishInflate(); 3728 3729 int count = getChildCount(); 3730 if (count > 0) { 3731 for (int i = 0; i < count; ++i) { 3732 addHeaderView(getChildAt(i)); 3733 } 3734 removeAllViews(); 3735 } 3736 } 3737 3738 /* (non-Javadoc) 3739 * @see android.view.View#findViewById(int) 3740 * First look in our children, then in any header and footer views that may be scrolled off. 3741 */ 3742 @Override 3743 protected View findViewTraversal(@IdRes int id) { 3744 View v; 3745 v = super.findViewTraversal(id); 3746 if (v == null) { 3747 v = findViewInHeadersOrFooters(mHeaderViewInfos, id); 3748 if (v != null) { 3749 return v; 3750 } 3751 v = findViewInHeadersOrFooters(mFooterViewInfos, id); 3752 if (v != null) { 3753 return v; 3754 } 3755 } 3756 return v; 3757 } 3758 3759 /* (non-Javadoc) 3760 * 3761 * Look in the passed in list of headers or footers for the view. 3762 */ 3763 View findViewInHeadersOrFooters(ArrayList<FixedViewInfo> where, int id) { 3764 if (where != null) { 3765 int len = where.size(); 3766 View v; 3767 3768 for (int i = 0; i < len; i++) { 3769 v = where.get(i).view; 3770 3771 if (!v.isRootNamespace()) { 3772 v = v.findViewById(id); 3773 3774 if (v != null) { 3775 return v; 3776 } 3777 } 3778 } 3779 } 3780 return null; 3781 } 3782 3783 /* (non-Javadoc) 3784 * @see android.view.View#findViewWithTag(Object) 3785 * First look in our children, then in any header and footer views that may be scrolled off. 3786 */ 3787 @Override 3788 protected View findViewWithTagTraversal(Object tag) { 3789 View v; 3790 v = super.findViewWithTagTraversal(tag); 3791 if (v == null) { 3792 v = findViewWithTagInHeadersOrFooters(mHeaderViewInfos, tag); 3793 if (v != null) { 3794 return v; 3795 } 3796 3797 v = findViewWithTagInHeadersOrFooters(mFooterViewInfos, tag); 3798 if (v != null) { 3799 return v; 3800 } 3801 } 3802 return v; 3803 } 3804 3805 /* (non-Javadoc) 3806 * 3807 * Look in the passed in list of headers or footers for the view with the tag. 3808 */ 3809 View findViewWithTagInHeadersOrFooters(ArrayList<FixedViewInfo> where, Object tag) { 3810 if (where != null) { 3811 int len = where.size(); 3812 View v; 3813 3814 for (int i = 0; i < len; i++) { 3815 v = where.get(i).view; 3816 3817 if (!v.isRootNamespace()) { 3818 v = v.findViewWithTag(tag); 3819 3820 if (v != null) { 3821 return v; 3822 } 3823 } 3824 } 3825 } 3826 return null; 3827 } 3828 3829 /** 3830 * @hide 3831 * @see android.view.View#findViewByPredicate(Predicate) 3832 * First look in our children, then in any header and footer views that may be scrolled off. 3833 */ 3834 @Override 3835 protected View findViewByPredicateTraversal(Predicate<View> predicate, View childToSkip) { 3836 View v; 3837 v = super.findViewByPredicateTraversal(predicate, childToSkip); 3838 if (v == null) { 3839 v = findViewByPredicateInHeadersOrFooters(mHeaderViewInfos, predicate, childToSkip); 3840 if (v != null) { 3841 return v; 3842 } 3843 3844 v = findViewByPredicateInHeadersOrFooters(mFooterViewInfos, predicate, childToSkip); 3845 if (v != null) { 3846 return v; 3847 } 3848 } 3849 return v; 3850 } 3851 3852 /* (non-Javadoc) 3853 * 3854 * Look in the passed in list of headers or footers for the first view that matches 3855 * the predicate. 3856 */ 3857 View findViewByPredicateInHeadersOrFooters(ArrayList<FixedViewInfo> where, 3858 Predicate<View> predicate, View childToSkip) { 3859 if (where != null) { 3860 int len = where.size(); 3861 View v; 3862 3863 for (int i = 0; i < len; i++) { 3864 v = where.get(i).view; 3865 3866 if (v != childToSkip && !v.isRootNamespace()) { 3867 v = v.findViewByPredicate(predicate); 3868 3869 if (v != null) { 3870 return v; 3871 } 3872 } 3873 } 3874 } 3875 return null; 3876 } 3877 3878 /** 3879 * Returns the set of checked items ids. The result is only valid if the 3880 * choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3881 * 3882 * @return A new array which contains the id of each checked item in the 3883 * list. 3884 * 3885 * @deprecated Use {@link #getCheckedItemIds()} instead. 3886 */ 3887 @Deprecated 3888 public long[] getCheckItemIds() { 3889 // Use new behavior that correctly handles stable ID mapping. 3890 if (mAdapter != null && mAdapter.hasStableIds()) { 3891 return getCheckedItemIds(); 3892 } 3893 3894 // Old behavior was buggy, but would sort of work for adapters without stable IDs. 3895 // Fall back to it to support legacy apps. 3896 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null && mAdapter != null) { 3897 final SparseBooleanArray states = mCheckStates; 3898 final int count = states.size(); 3899 final long[] ids = new long[count]; 3900 final ListAdapter adapter = mAdapter; 3901 3902 int checkedCount = 0; 3903 for (int i = 0; i < count; i++) { 3904 if (states.valueAt(i)) { 3905 ids[checkedCount++] = adapter.getItemId(states.keyAt(i)); 3906 } 3907 } 3908 3909 // Trim array if needed. mCheckStates may contain false values 3910 // resulting in checkedCount being smaller than count. 3911 if (checkedCount == count) { 3912 return ids; 3913 } else { 3914 final long[] result = new long[checkedCount]; 3915 System.arraycopy(ids, 0, result, 0, checkedCount); 3916 3917 return result; 3918 } 3919 } 3920 return new long[0]; 3921 } 3922 3923 @Override 3924 int getHeightForPosition(int position) { 3925 final int height = super.getHeightForPosition(position); 3926 if (shouldAdjustHeightForDivider(position)) { 3927 return height + mDividerHeight; 3928 } 3929 return height; 3930 } 3931 3932 private boolean shouldAdjustHeightForDivider(int itemIndex) { 3933 final int dividerHeight = mDividerHeight; 3934 final Drawable overscrollHeader = mOverScrollHeader; 3935 final Drawable overscrollFooter = mOverScrollFooter; 3936 final boolean drawOverscrollHeader = overscrollHeader != null; 3937 final boolean drawOverscrollFooter = overscrollFooter != null; 3938 final boolean drawDividers = dividerHeight > 0 && mDivider != null; 3939 3940 if (drawDividers) { 3941 final boolean fillForMissingDividers = isOpaque() && !super.isOpaque(); 3942 final int itemCount = mItemCount; 3943 final int headerCount = getHeaderViewsCount(); 3944 final int footerLimit = (itemCount - mFooterViewInfos.size()); 3945 final boolean isHeader = (itemIndex < headerCount); 3946 final boolean isFooter = (itemIndex >= footerLimit); 3947 final boolean headerDividers = mHeaderDividersEnabled; 3948 final boolean footerDividers = mFooterDividersEnabled; 3949 if ((headerDividers || !isHeader) && (footerDividers || !isFooter)) { 3950 final ListAdapter adapter = mAdapter; 3951 if (!mStackFromBottom) { 3952 final boolean isLastItem = (itemIndex == (itemCount - 1)); 3953 if (!drawOverscrollFooter || !isLastItem) { 3954 final int nextIndex = itemIndex + 1; 3955 // Draw dividers between enabled items, headers 3956 // and/or footers when enabled and requested, and 3957 // after the last enabled item. 3958 if (adapter.isEnabled(itemIndex) && (headerDividers || !isHeader 3959 && (nextIndex >= headerCount)) && (isLastItem 3960 || adapter.isEnabled(nextIndex) && (footerDividers || !isFooter 3961 && (nextIndex < footerLimit)))) { 3962 return true; 3963 } else if (fillForMissingDividers) { 3964 return true; 3965 } 3966 } 3967 } else { 3968 final int start = drawOverscrollHeader ? 1 : 0; 3969 final boolean isFirstItem = (itemIndex == start); 3970 if (!isFirstItem) { 3971 final int previousIndex = (itemIndex - 1); 3972 // Draw dividers between enabled items, headers 3973 // and/or footers when enabled and requested, and 3974 // before the first enabled item. 3975 if (adapter.isEnabled(itemIndex) && (headerDividers || !isHeader 3976 && (previousIndex >= headerCount)) && (isFirstItem || 3977 adapter.isEnabled(previousIndex) && (footerDividers || !isFooter 3978 && (previousIndex < footerLimit)))) { 3979 return true; 3980 } else if (fillForMissingDividers) { 3981 return true; 3982 } 3983 } 3984 } 3985 } 3986 } 3987 3988 return false; 3989 } 3990 3991 @Override 3992 public CharSequence getAccessibilityClassName() { 3993 return ListView.class.getName(); 3994 } 3995 3996 /** @hide */ 3997 @Override 3998 public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) { 3999 super.onInitializeAccessibilityNodeInfoInternal(info); 4000 4001 final int rowsCount = getCount(); 4002 final int selectionMode = getSelectionModeForAccessibility(); 4003 final CollectionInfo collectionInfo = CollectionInfo.obtain( 4004 rowsCount, 1, false, selectionMode); 4005 info.setCollectionInfo(collectionInfo); 4006 4007 if (rowsCount > 0) { 4008 info.addAction(AccessibilityAction.ACTION_SCROLL_TO_POSITION); 4009 } 4010 } 4011 4012 /** @hide */ 4013 @Override 4014 public boolean performAccessibilityActionInternal(int action, Bundle arguments) { 4015 if (super.performAccessibilityActionInternal(action, arguments)) { 4016 return true; 4017 } 4018 4019 switch (action) { 4020 case R.id.accessibilityActionScrollToPosition: { 4021 final int row = arguments.getInt(AccessibilityNodeInfo.ACTION_ARGUMENT_ROW_INT, -1); 4022 final int position = Math.min(row, getCount() - 1); 4023 if (row >= 0) { 4024 // The accessibility service gets data asynchronously, so 4025 // we'll be a little lenient by clamping the last position. 4026 smoothScrollToPosition(position); 4027 return true; 4028 } 4029 } break; 4030 } 4031 4032 return false; 4033 } 4034 4035 @Override 4036 public void onInitializeAccessibilityNodeInfoForItem( 4037 View view, int position, AccessibilityNodeInfo info) { 4038 super.onInitializeAccessibilityNodeInfoForItem(view, position, info); 4039 4040 final LayoutParams lp = (LayoutParams) view.getLayoutParams(); 4041 final boolean isHeading = lp != null && lp.viewType == ITEM_VIEW_TYPE_HEADER_OR_FOOTER; 4042 final boolean isSelected = isItemChecked(position); 4043 final CollectionItemInfo itemInfo = CollectionItemInfo.obtain( 4044 position, 1, 0, 1, isHeading, isSelected); 4045 info.setCollectionItemInfo(itemInfo); 4046 } 4047 4048 /** @hide */ 4049 @Override 4050 protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) { 4051 super.encodeProperties(encoder); 4052 4053 encoder.addProperty("recycleOnMeasure", recycleOnMeasure()); 4054 } 4055 4056 /** @hide */ 4057 protected HeaderViewListAdapter wrapHeaderListAdapterInternal( 4058 ArrayList<ListView.FixedViewInfo> headerViewInfos, 4059 ArrayList<ListView.FixedViewInfo> footerViewInfos, 4060 ListAdapter adapter) { 4061 return new HeaderViewListAdapter(headerViewInfos, footerViewInfos, adapter); 4062 } 4063 4064 /** @hide */ 4065 protected void wrapHeaderListAdapterInternal() { 4066 mAdapter = wrapHeaderListAdapterInternal(mHeaderViewInfos, mFooterViewInfos, mAdapter); 4067 } 4068 4069 /** @hide */ 4070 protected void dispatchDataSetObserverOnChangedInternal() { 4071 if (mDataSetObserver != null) { 4072 mDataSetObserver.onChanged(); 4073 } 4074 } 4075 } 4076