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