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.view.MotionEvent; 20 import android.text.*; 21 import android.widget.TextView; 22 import android.view.View; 23 24 /** 25 * A movement method that interprets movement keys by scrolling the text buffer. 26 */ 27 public class ScrollingMovementMethod extends BaseMovementMethod implements MovementMethod { 28 @Override 29 protected boolean left(TextView widget, Spannable buffer) { 30 return scrollLeft(widget, buffer, 1); 31 } 32 33 @Override 34 protected boolean right(TextView widget, Spannable buffer) { 35 return scrollRight(widget, buffer, 1); 36 } 37 38 @Override 39 protected boolean up(TextView widget, Spannable buffer) { 40 return scrollUp(widget, buffer, 1); 41 } 42 43 @Override 44 protected boolean down(TextView widget, Spannable buffer) { 45 return scrollDown(widget, buffer, 1); 46 } 47 48 @Override 49 protected boolean pageUp(TextView widget, Spannable buffer) { 50 return scrollPageUp(widget, buffer); 51 } 52 53 @Override 54 protected boolean pageDown(TextView widget, Spannable buffer) { 55 return scrollPageDown(widget, buffer); 56 } 57 58 @Override 59 protected boolean top(TextView widget, Spannable buffer) { 60 return scrollTop(widget, buffer); 61 } 62 63 @Override 64 protected boolean bottom(TextView widget, Spannable buffer) { 65 return scrollBottom(widget, buffer); 66 } 67 68 @Override 69 protected boolean lineStart(TextView widget, Spannable buffer) { 70 return scrollLineStart(widget, buffer); 71 } 72 73 @Override 74 protected boolean lineEnd(TextView widget, Spannable buffer) { 75 return scrollLineEnd(widget, buffer); 76 } 77 78 @Override 79 protected boolean home(TextView widget, Spannable buffer) { 80 return top(widget, buffer); 81 } 82 83 @Override 84 protected boolean end(TextView widget, Spannable buffer) { 85 return bottom(widget, buffer); 86 } 87 88 @Override 89 public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event) { 90 return Touch.onTouchEvent(widget, buffer, event); 91 } 92 93 @Override 94 public void onTakeFocus(TextView widget, Spannable text, int dir) { 95 Layout layout = widget.getLayout(); 96 97 if (layout != null && (dir & View.FOCUS_FORWARD) != 0) { 98 widget.scrollTo(widget.getScrollX(), 99 layout.getLineTop(0)); 100 } 101 if (layout != null && (dir & View.FOCUS_BACKWARD) != 0) { 102 int padding = widget.getTotalPaddingTop() + 103 widget.getTotalPaddingBottom(); 104 int line = layout.getLineCount() - 1; 105 106 widget.scrollTo(widget.getScrollX(), 107 layout.getLineTop(line+1) - 108 (widget.getHeight() - padding)); 109 } 110 } 111 112 public static MovementMethod getInstance() { 113 if (sInstance == null) 114 sInstance = new ScrollingMovementMethod(); 115 116 return sInstance; 117 } 118 119 private static ScrollingMovementMethod sInstance; 120 } 121
