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 PictureLayout(Context context)32 public PictureLayout(Context context) { 33 super(context); 34 } 35 PictureLayout(Context context, AttributeSet attrs)36 public PictureLayout(Context context, AttributeSet attrs) { 37 super(context, attrs); 38 } 39 40 @Override addView(View child)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 addView(View child, int index)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 addView(View child, LayoutParams params)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 addView(View child, int index, LayoutParams params)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 generateDefaultLayoutParams()77 protected LayoutParams generateDefaultLayoutParams() { 78 return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); 79 } 80 81 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)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 drawPict(Canvas canvas, int x, int y, int w, int h, float sx, float sy)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 dispatchDraw(Canvas canvas)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 invalidateChildInParent(int[] location, Rect dirty)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 onLayout(boolean changed, int l, int t, int r, int b)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