1 /* 2 * Copyright (C) 2011 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 com.android.launcher3; 18 19 import android.animation.ObjectAnimator; 20 import android.animation.PropertyValuesHolder; 21 import android.content.Context; 22 import android.graphics.Canvas; 23 import android.util.AttributeSet; 24 import android.util.Pair; 25 import android.view.View; 26 27 import com.android.launcher3.util.Thunk; 28 29 public class FocusIndicatorView extends View implements View.OnFocusChangeListener { 30 31 // It can be any number >0. The view is resized using scaleX and scaleY. 32 static final int DEFAULT_LAYOUT_SIZE = 100; 33 34 private static final float MIN_VISIBLE_ALPHA = 0.2f; 35 private static final long ANIM_DURATION = 150; 36 37 private final int[] mIndicatorPos = new int[2]; 38 private final int[] mTargetViewPos = new int[2]; 39 40 private ObjectAnimator mCurrentAnimation; 41 private ViewAnimState mTargetState; 42 43 private View mLastFocusedView; 44 private boolean mInitiated; 45 private final OnFocusChangeListener mHideIndicatorOnFocusListener; 46 47 private Pair<View, Boolean> mPendingCall; 48 49 public FocusIndicatorView(Context context) { 50 this(context, null); 51 } 52 53 public FocusIndicatorView(Context context, AttributeSet attrs) { 54 super(context, attrs); 55 setAlpha(0); 56 setBackgroundColor(getResources().getColor(R.color.focused_background)); 57 58 mHideIndicatorOnFocusListener = new OnFocusChangeListener() { 59 @Override 60 public void onFocusChange(View v, boolean hasFocus) { 61 if (hasFocus) { 62 endCurrentAnimation(); 63 setAlpha(0); 64 } 65 } 66 }; 67 } 68 69 @Override 70 protected void onSizeChanged(int w, int h, int oldw, int oldh) { 71 super.onSizeChanged(w, h, oldw, oldh); 72 73 // Redraw if it is already showing. This avoids a bug where the height changes by a small 74 // amount on connecting/disconnecting a bluetooth keyboard. 75 if (mLastFocusedView != null) { 76 mPendingCall = Pair.create(mLastFocusedView, Boolean.TRUE); 77 invalidate(); 78 } 79 } 80 81 /** 82 * Sets the alpha of this FocusIndicatorView to 0 when a view with this listener receives focus. 83 */ 84 public View.OnFocusChangeListener getHideIndicatorOnFocusListener() { 85 return mHideIndicatorOnFocusListener; 86 } 87 88 @Override 89 public void onFocusChange(View v, boolean hasFocus) { 90 mPendingCall = null; 91 if (!mInitiated && (getWidth() == 0)) { 92 // View not yet laid out. Wait until the view is ready to be drawn, so that be can 93 // get the location on screen. 94 mPendingCall = Pair.create(v, hasFocus); 95 invalidate(); 96 return; 97 } 98 99 if (!mInitiated) { 100 // The parent view should always the a parent of the target view. 101 computeLocationRelativeToParent(this, (View) getParent(), mIndicatorPos); 102 mInitiated = true; 103 } 104 105 if (hasFocus) { 106 int indicatorWidth = getWidth(); 107 int indicatorHeight = getHeight(); 108 109 endCurrentAnimation(); 110 ViewAnimState nextState = new ViewAnimState(); 111 nextState.scaleX = v.getScaleX() * v.getWidth() / indicatorWidth; 112 nextState.scaleY = v.getScaleY() * v.getHeight() / indicatorHeight; 113 114 computeLocationRelativeToParent(v, (View) getParent(), mTargetViewPos); 115 nextState.x = mTargetViewPos[0] - mIndicatorPos[0] - (1 - nextState.scaleX) * indicatorWidth / 2; 116 nextState.y = mTargetViewPos[1] - mIndicatorPos[1] - (1 - nextState.scaleY) * indicatorHeight / 2; 117 118 if (getAlpha() > MIN_VISIBLE_ALPHA) { 119 mTargetState = nextState; 120 mCurrentAnimation = LauncherAnimUtils.ofPropertyValuesHolder(this, 121 PropertyValuesHolder.ofFloat(View.ALPHA, 1), 122 PropertyValuesHolder.ofFloat(View.TRANSLATION_X, mTargetState.x), 123 PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, mTargetState.y), 124 PropertyValuesHolder.ofFloat(View.SCALE_X, mTargetState.scaleX), 125 PropertyValuesHolder.ofFloat(View.SCALE_Y, mTargetState.scaleY)); 126 } else { 127 applyState(nextState); 128 mCurrentAnimation = LauncherAnimUtils.ofPropertyValuesHolder(this, 129 PropertyValuesHolder.ofFloat(View.ALPHA, 1)); 130 } 131 mLastFocusedView = v; 132 } else { 133 if (mLastFocusedView == v) { 134 mLastFocusedView = null; 135 endCurrentAnimation(); 136 mCurrentAnimation = LauncherAnimUtils.ofPropertyValuesHolder(this, 137 PropertyValuesHolder.ofFloat(View.ALPHA, 0)); 138 } 139 } 140 if (mCurrentAnimation != null) { 141 mCurrentAnimation.setDuration(ANIM_DURATION).start(); 142 } 143 } 144 145 private void endCurrentAnimation() { 146 if (mCurrentAnimation != null) { 147 mCurrentAnimation.cancel(); 148 mCurrentAnimation = null; 149 } 150 if (mTargetState != null) { 151 applyState(mTargetState); 152 mTargetState = null; 153 } 154 } 155 156 private void applyState(ViewAnimState state) { 157 setTranslationX(state.x); 158 setTranslationY(state.y); 159 setScaleX(state.scaleX); 160 setScaleY(state.scaleY); 161 } 162 163 @Override 164 protected void onDraw(Canvas canvas) { 165 if (mPendingCall != null) { 166 onFocusChange(mPendingCall.first, mPendingCall.second); 167 } 168 } 169 170 /** 171 * Computes the location of a view relative to {@param parent}, off-setting 172 * any shift due to page view scroll. 173 * @param pos an array of two integers in which to hold the coordinates 174 */ 175 private static void computeLocationRelativeToParent(View v, View parent, int[] pos) { 176 pos[0] = pos[1] = 0; 177 computeLocationRelativeToParentHelper(v, parent, pos); 178 179 // If a view is scaled, its position will also shift accordingly. For optimization, only 180 // consider this for the last node. 181 pos[0] += (1 - v.getScaleX()) * v.getWidth() / 2; 182 pos[1] += (1 - v.getScaleY()) * v.getHeight() / 2; 183 } 184 185 private static void computeLocationRelativeToParentHelper(View child, 186 View commonParent, int[] shift) { 187 View parent = (View) child.getParent(); 188 shift[0] += child.getLeft(); 189 shift[1] += child.getTop(); 190 if (parent instanceof PagedView) { 191 PagedView page = (PagedView) parent; 192 shift[0] -= page.getScrollForPage(page.indexOfChild(child)); 193 } 194 195 if (parent != commonParent) { 196 computeLocationRelativeToParentHelper(parent, commonParent, shift); 197 } 198 } 199 200 @Thunk static final class ViewAnimState { 201 float x, y, scaleX, scaleY; 202 } 203 } 204
