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      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.text.method;
     18 
     19 import android.content.Intent;
     20 import android.net.Uri;
     21 import android.view.KeyEvent;
     22 import android.view.MotionEvent;
     23 import android.text.*;
     24 import android.text.style.*;
     25 import android.view.View;
     26 import android.widget.TextView;
     27 
     28 public class
     29 LinkMovementMethod
     30 extends ScrollingMovementMethod
     31 {
     32     private static final int CLICK = 1;
     33     private static final int UP = 2;
     34     private static final int DOWN = 3;
     35 
     36     @Override
     37     public boolean onKeyDown(TextView widget, Spannable buffer,
     38                              int keyCode, KeyEvent event) {
     39         switch (keyCode) {
     40         case KeyEvent.KEYCODE_DPAD_CENTER:
     41         case KeyEvent.KEYCODE_ENTER:
     42             if (event.getRepeatCount() == 0) {
     43                 if (action(CLICK, widget, buffer)) {
     44                     return true;
     45                 }
     46             }
     47         }
     48 
     49         return super.onKeyDown(widget, buffer, keyCode, event);
     50     }
     51 
     52     @Override
     53     protected boolean up(TextView widget, Spannable buffer) {
     54         if (action(UP, widget, buffer)) {
     55             return true;
     56         }
     57 
     58         return super.up(widget, buffer);
     59     }
     60 
     61     @Override
     62     protected boolean down(TextView widget, Spannable buffer) {
     63         if (action(DOWN, widget, buffer)) {
     64             return true;
     65         }
     66 
     67         return super.down(widget, buffer);
     68     }
     69 
     70     @Override
     71     protected boolean left(TextView widget, Spannable buffer) {
     72         if (action(UP, widget, buffer)) {
     73             return true;
     74         }
     75 
     76         return super.left(widget, buffer);
     77     }
     78 
     79     @Override
     80     protected boolean right(TextView widget, Spannable buffer) {
     81         if (action(DOWN, widget, buffer)) {
     82             return true;
     83         }
     84 
     85         return super.right(widget, buffer);
     86     }
     87 
     88     private boolean action(int what, TextView widget, Spannable buffer) {
     89         boolean handled = false;
     90 
     91         Layout layout = widget.getLayout();
     92 
     93         int padding = widget.getTotalPaddingTop() +
     94                       widget.getTotalPaddingBottom();
     95         int areatop = widget.getScrollY();
     96         int areabot = areatop + widget.getHeight() - padding;
     97 
     98         int linetop = layout.getLineForVertical(areatop);
     99         int linebot = layout.getLineForVertical(areabot);
    100 
    101         int first = layout.getLineStart(linetop);
    102         int last = layout.getLineEnd(linebot);
    103 
    104         ClickableSpan[] candidates = buffer.getSpans(first, last, ClickableSpan.class);
    105 
    106         int a = Selection.getSelectionStart(buffer);
    107         int b = Selection.getSelectionEnd(buffer);
    108 
    109         int selStart = Math.min(a, b);
    110         int selEnd = Math.max(a, b);
    111 
    112         if (selStart < 0) {
    113             if (buffer.getSpanStart(FROM_BELOW) >= 0) {
    114                 selStart = selEnd = buffer.length();
    115             }
    116         }
    117 
    118         if (selStart > last)
    119             selStart = selEnd = Integer.MAX_VALUE;
    120         if (selEnd < first)
    121             selStart = selEnd = -1;
    122 
    123         switch (what) {
    124         case CLICK:
    125             if (selStart == selEnd) {
    126                 return false;
    127             }
    128 
    129             ClickableSpan[] link = buffer.getSpans(selStart, selEnd, ClickableSpan.class);
    130 
    131             if (link.length != 1)
    132                 return false;
    133 
    134             link[0].onClick(widget);
    135             break;
    136 
    137         case UP:
    138             int beststart, bestend;
    139 
    140             beststart = -1;
    141             bestend = -1;
    142 
    143             for (int i = 0; i < candidates.length; i++) {
    144                 int end = buffer.getSpanEnd(candidates[i]);
    145 
    146                 if (end < selEnd || selStart == selEnd) {
    147                     if (end > bestend) {
    148                         beststart = buffer.getSpanStart(candidates[i]);
    149                         bestend = end;
    150                     }
    151                 }
    152             }
    153 
    154             if (beststart >= 0) {
    155                 Selection.setSelection(buffer, bestend, beststart);
    156                 return true;
    157             }
    158 
    159             break;
    160 
    161         case DOWN:
    162             beststart = Integer.MAX_VALUE;
    163             bestend = Integer.MAX_VALUE;
    164 
    165             for (int i = 0; i < candidates.length; i++) {
    166                 int start = buffer.getSpanStart(candidates[i]);
    167 
    168                 if (start > selStart || selStart == selEnd) {
    169                     if (start < beststart) {
    170                         beststart = start;
    171                         bestend = buffer.getSpanEnd(candidates[i]);
    172                     }
    173                 }
    174             }
    175 
    176             if (bestend < Integer.MAX_VALUE) {
    177                 Selection.setSelection(buffer, beststart, bestend);
    178                 return true;
    179             }
    180 
    181             break;
    182         }
    183 
    184         return false;
    185     }
    186 
    187     public boolean onKeyUp(TextView widget, Spannable buffer,
    188                            int keyCode, KeyEvent event) {
    189         return false;
    190     }
    191 
    192     @Override
    193     public boolean onTouchEvent(TextView widget, Spannable buffer,
    194                                 MotionEvent event) {
    195         int action = event.getAction();
    196 
    197         if (action == MotionEvent.ACTION_UP ||
    198             action == MotionEvent.ACTION_DOWN) {
    199             int x = (int) event.getX();
    200             int y = (int) event.getY();
    201 
    202             x -= widget.getTotalPaddingLeft();
    203             y -= widget.getTotalPaddingTop();
    204 
    205             x += widget.getScrollX();
    206             y += widget.getScrollY();
    207 
    208             Layout layout = widget.getLayout();
    209             int line = layout.getLineForVertical(y);
    210             int off = layout.getOffsetForHorizontal(line, x);
    211 
    212             ClickableSpan[] link = buffer.getSpans(off, off, ClickableSpan.class);
    213 
    214             if (link.length != 0) {
    215                 if (action == MotionEvent.ACTION_UP) {
    216                     link[0].onClick(widget);
    217                 } else if (action == MotionEvent.ACTION_DOWN) {
    218                     Selection.setSelection(buffer,
    219                                            buffer.getSpanStart(link[0]),
    220                                            buffer.getSpanEnd(link[0]));
    221                 }
    222 
    223                 return true;
    224             } else {
    225                 Selection.removeSelection(buffer);
    226             }
    227         }
    228 
    229         return super.onTouchEvent(widget, buffer, event);
    230     }
    231 
    232     public void initialize(TextView widget, Spannable text) {
    233         Selection.removeSelection(text);
    234         text.removeSpan(FROM_BELOW);
    235     }
    236 
    237     public void onTakeFocus(TextView view, Spannable text, int dir) {
    238         Selection.removeSelection(text);
    239 
    240         if ((dir & View.FOCUS_BACKWARD) != 0) {
    241             text.setSpan(FROM_BELOW, 0, 0, Spannable.SPAN_POINT_POINT);
    242         } else {
    243             text.removeSpan(FROM_BELOW);
    244         }
    245     }
    246 
    247     public static MovementMethod getInstance() {
    248         if (sInstance == null)
    249             sInstance = new LinkMovementMethod();
    250 
    251         return sInstance;
    252     }
    253 
    254     private static LinkMovementMethod sInstance;
    255     private static Object FROM_BELOW = new NoCopySpan.Concrete();
    256 }
    257