1 /* 2 * Copyright (C) 2014 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.view; 18 19 import com.android.resources.Density; 20 import com.android.tools.layoutlib.annotations.LayoutlibDelegate; 21 22 import android.graphics.Bitmap; 23 import android.graphics.Bitmap_Delegate; 24 import android.graphics.Canvas; 25 import android.graphics.Outline; 26 import android.graphics.Path_Delegate; 27 import android.graphics.Rect; 28 import android.graphics.Region.Op; 29 import android.view.animation.Transformation; 30 31 import java.awt.Graphics2D; 32 import java.awt.image.BufferedImage; 33 34 /** 35 * Delegate used to provide new implementation of a select few methods of {@link ViewGroup} 36 * <p/> 37 * Through the layoutlib_create tool, the original methods of ViewGroup have been replaced by calls 38 * to methods of the same name in this delegate class. 39 */ 40 public class ViewGroup_Delegate { 41 42 /** 43 * Overrides the original drawChild call in ViewGroup to draw the shadow. 44 */ 45 @LayoutlibDelegate drawChild(ViewGroup thisVG, Canvas canvas, View child, long drawingTime)46 /*package*/ static boolean drawChild(ViewGroup thisVG, Canvas canvas, View child, 47 long drawingTime) { 48 if (child.getZ() > thisVG.getZ()) { 49 // The background's bounds are set lazily. Make sure they are set correctly so that 50 // the outline obtained is correct. 51 child.setBackgroundBounds(); 52 ViewOutlineProvider outlineProvider = child.getOutlineProvider(); 53 if (outlineProvider != null) { 54 Outline outline = child.mAttachInfo.mTmpOutline; 55 outlineProvider.getOutline(child, outline); 56 if (outline.mPath != null || (outline.mRect != null && !outline.mRect.isEmpty())) { 57 int restoreTo = transformCanvas(thisVG, canvas, child); 58 drawShadow(thisVG, canvas, child, outline); 59 canvas.restoreToCount(restoreTo); 60 } 61 } 62 } 63 return thisVG.drawChild_Original(canvas, child, drawingTime); 64 } 65 drawShadow(ViewGroup parent, Canvas canvas, View child, Outline outline)66 private static void drawShadow(ViewGroup parent, Canvas canvas, View child, 67 Outline outline) { 68 float elevation = getElevation(child, parent); 69 if(outline.mMode == Outline.MODE_ROUND_RECT && outline.mRect != null) { 70 RectShadowPainter.paintShadow(outline, elevation, canvas); 71 return; 72 } 73 BufferedImage shadow = null; 74 if (outline.mPath != null) { 75 shadow = getPathShadow(outline, canvas, elevation); 76 } 77 if (shadow == null) { 78 return; 79 } 80 Bitmap bitmap = Bitmap_Delegate.createBitmap(shadow, false, 81 Density.getEnum(canvas.getDensity())); 82 Rect clipBounds = canvas.getClipBounds(); 83 Rect newBounds = new Rect(clipBounds); 84 newBounds.inset((int)-elevation, (int)-elevation); 85 canvas.clipRect(newBounds, Op.REPLACE); 86 canvas.drawBitmap(bitmap, 0, 0, null); 87 canvas.clipRect(clipBounds, Op.REPLACE); 88 } 89 getElevation(View child, ViewGroup parent)90 private static float getElevation(View child, ViewGroup parent) { 91 return child.getZ() - parent.getZ(); 92 } 93 getPathShadow(Outline outline, Canvas canvas, float elevation)94 private static BufferedImage getPathShadow(Outline outline, Canvas canvas, float elevation) { 95 Rect clipBounds = canvas.getClipBounds(); 96 if (clipBounds.isEmpty()) { 97 return null; 98 } 99 BufferedImage image = new BufferedImage(clipBounds.width(), clipBounds.height(), 100 BufferedImage.TYPE_INT_ARGB); 101 Graphics2D graphics = image.createGraphics(); 102 graphics.draw(Path_Delegate.getDelegate(outline.mPath.mNativePath).getJavaShape()); 103 graphics.dispose(); 104 return ShadowPainter.createDropShadow(image, (int) elevation); 105 } 106 107 // Copied from android.view.View#draw(Canvas, ViewGroup, long) and removed code paths 108 // which were never taken. Ideally, we should hook up the shadow code in the same method so 109 // that we don't have to transform the canvas twice. transformCanvas(ViewGroup thisVG, Canvas canvas, View child)110 private static int transformCanvas(ViewGroup thisVG, Canvas canvas, View child) { 111 final int restoreTo = canvas.save(); 112 final boolean childHasIdentityMatrix = child.hasIdentityMatrix(); 113 int flags = thisVG.mGroupFlags; 114 Transformation transformToApply = null; 115 boolean concatMatrix = false; 116 if ((flags & ViewGroup.FLAG_SUPPORT_STATIC_TRANSFORMATIONS) != 0) { 117 final Transformation t = thisVG.getChildTransformation(); 118 final boolean hasTransform = thisVG.getChildStaticTransformation(child, t); 119 if (hasTransform) { 120 final int transformType = t.getTransformationType(); 121 transformToApply = transformType != Transformation.TYPE_IDENTITY ? t : null; 122 concatMatrix = (transformType & Transformation.TYPE_MATRIX) != 0; 123 } 124 } 125 concatMatrix |= childHasIdentityMatrix; 126 127 child.computeScroll(); 128 int sx = child.mScrollX; 129 int sy = child.mScrollY; 130 131 canvas.translate(child.mLeft - sx, child.mTop - sy); 132 float alpha = child.getAlpha() * child.getTransitionAlpha(); 133 134 if (transformToApply != null || alpha < 1 || !childHasIdentityMatrix) { 135 if (transformToApply != null || !childHasIdentityMatrix) { 136 int transX = -sx; 137 int transY = -sy; 138 139 if (transformToApply != null) { 140 if (concatMatrix) { 141 // Undo the scroll translation, apply the transformation matrix, 142 // then redo the scroll translate to get the correct result. 143 canvas.translate(-transX, -transY); 144 canvas.concat(transformToApply.getMatrix()); 145 canvas.translate(transX, transY); 146 } 147 if (!childHasIdentityMatrix) { 148 canvas.translate(-transX, -transY); 149 canvas.concat(child.getMatrix()); 150 canvas.translate(transX, transY); 151 } 152 } 153 154 } 155 } 156 return restoreTo; 157 } 158 } 159