1 /* 2 * Copyright (C) 2008 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.example.android.apis.graphics; 18 19 import android.content.Context; 20 import android.graphics.Canvas; 21 import android.graphics.Picture; 22 import android.graphics.Rect; 23 import android.graphics.drawable.Drawable; 24 import android.util.AttributeSet; 25 import android.view.View; 26 import android.view.ViewGroup; 27 import android.view.ViewParent; 28 29 30 public class PictureLayout extends ViewGroup { 31 private final Picture mPicture = new Picture(); 32 33 public PictureLayout(Context context) { 34 super(context); 35 } 36 37 public PictureLayout(Context context, AttributeSet attrs) { 38 super(context, attrs); 39 } 40 41 @Override 42 public void addView(View child) { 43 if (getChildCount() > 1) { 44 throw new IllegalStateException("PictureLayout can host only one direct child"); 45 } 46 47 super.addView(child); 48 } 49 50 @Override 51 public void addView(View child, int index) { 52 if (getChildCount() > 1) { 53 throw new IllegalStateException("PictureLayout can host only one direct child"); 54 } 55 56 super.addView(child, index); 57 } 58 59 @Override 60 public void addView(View child, LayoutParams params) { 61 if (getChildCount() > 1) { 62 throw new IllegalStateException("PictureLayout can host only one direct child"); 63 } 64 65 super.addView(child, params); 66 } 67 68 @Override 69 public void addView(View child, int index, LayoutParams params) { 70 if (getChildCount() > 1) { 71 throw new IllegalStateException("PictureLayout can host only one direct child"); 72 } 73 74 super.addView(child, index, params); 75 } 76 77 @Override 78 protected LayoutParams generateDefaultLayoutParams() { 79 return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); 80 } 81 82 @Override 83 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 84 final int count = getChildCount(); 85 86 int maxHeight = 0; 87 int maxWidth = 0; 88 89 for (int i = 0; i < count; i++) { 90 final View child = getChildAt(i); 91 if (child.getVisibility() != GONE) { 92 measureChild(child, widthMeasureSpec, heightMeasureSpec); 93 } 94 } 95 96 maxWidth += getPaddingLeft() + getPaddingRight(); 97 maxHeight += getPaddingTop() + getPaddingBottom(); 98 99 Drawable drawable = getBackground(); 100 if (drawable != null) { 101 maxHeight = Math.max(maxHeight, drawable.getMinimumHeight()); 102 maxWidth = Math.max(maxWidth, drawable.getMinimumWidth()); 103 } 104 105 setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec), 106 resolveSize(maxHeight, heightMeasureSpec)); 107 } 108 109 private void drawPict(Canvas canvas, int x, int y, int w, int h, 110 float sx, float sy) { 111 canvas.save(); 112 canvas.translate(x, y); 113 canvas.clipRect(0, 0, w, h); 114 canvas.scale(0.5f, 0.5f); 115 canvas.scale(sx, sy, w, h); 116 canvas.drawPicture(mPicture); 117 canvas.restore(); 118 } 119 120 @Override 121 protected void dispatchDraw(Canvas canvas) { 122 super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight())); 123 mPicture.endRecording(); 124 125 int x = getWidth()/2; 126 int y = getHeight()/2; 127 128 if (false) { 129 canvas.drawPicture(mPicture); 130 } else { 131 drawPict(canvas, 0, 0, x, y, 1, 1); 132 drawPict(canvas, x, 0, x, y, -1, 1); 133 drawPict(canvas, 0, y, x, y, 1, -1); 134 drawPict(canvas, x, y, x, y, -1, -1); 135 } 136 } 137 138 @Override 139 public ViewParent invalidateChildInParent(int[] location, Rect dirty) { 140 location[0] = getLeft(); 141 location[1] = getTop(); 142 dirty.set(0, 0, getWidth(), getHeight()); 143 return getParent(); 144 } 145 146 @Override 147 protected void onLayout(boolean changed, int l, int t, int r, int b) { 148 final int count = super.getChildCount(); 149 150 for (int i = 0; i < count; i++) { 151 final View child = getChildAt(i); 152 if (child.getVisibility() != GONE) { 153 final int childLeft = getPaddingLeft(); 154 final int childTop = getPaddingTop(); 155 child.layout(childLeft, childTop, 156 childLeft + child.getMeasuredWidth(), 157 childTop + child.getMeasuredHeight()); 158 159 } 160 } 161 } 162 } 163
