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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.android.launcher3;
18 
19 import android.content.Context;
20 import android.content.res.Resources;
21 import android.graphics.Bitmap;
22 import android.graphics.BlurMaskFilter;
23 import android.graphics.Canvas;
24 import android.graphics.Color;
25 import android.graphics.Paint;
26 import android.graphics.PorterDuff;
27 import android.graphics.PorterDuffXfermode;
28 import android.graphics.Rect;
29 import android.graphics.drawable.Drawable;
30 import android.util.SparseArray;
31 
32 /**
33  * Utility class to generate shadow and outline effect, which are used for click feedback
34  * and drag-n-drop respectively.
35  */
36 public class HolographicOutlineHelper {
37 
38     private static HolographicOutlineHelper sInstance;
39 
40     private final Canvas mCanvas = new Canvas();
41     private final Paint mDrawPaint = new Paint();
42     private final Paint mBlurPaint = new Paint();
43     private final Paint mErasePaint = new Paint();
44 
45     private final BlurMaskFilter mMediumOuterBlurMaskFilter;
46     private final BlurMaskFilter mThinOuterBlurMaskFilter;
47     private final BlurMaskFilter mMediumInnerBlurMaskFilter;
48 
49     private final BlurMaskFilter mShadowBlurMaskFilter;
50 
51     // We have 4 different icon sizes: homescreen, hotseat, folder & all-apps
52     private final SparseArray<Bitmap> mBitmapCache = new SparseArray<>(4);
53 
HolographicOutlineHelper(Context context)54     private HolographicOutlineHelper(Context context) {
55         Resources res = context.getResources();
56 
57         float mediumBlur = res.getDimension(R.dimen.blur_size_medium_outline);
58         mMediumOuterBlurMaskFilter = new BlurMaskFilter(mediumBlur, BlurMaskFilter.Blur.OUTER);
59         mMediumInnerBlurMaskFilter = new BlurMaskFilter(mediumBlur, BlurMaskFilter.Blur.NORMAL);
60 
61         mThinOuterBlurMaskFilter = new BlurMaskFilter(
62                 res.getDimension(R.dimen.blur_size_thin_outline), BlurMaskFilter.Blur.OUTER);
63 
64         mShadowBlurMaskFilter = new BlurMaskFilter(
65                 res.getDimension(R.dimen.blur_size_click_shadow), BlurMaskFilter.Blur.NORMAL);
66 
67         mDrawPaint.setFilterBitmap(true);
68         mDrawPaint.setAntiAlias(true);
69         mBlurPaint.setFilterBitmap(true);
70         mBlurPaint.setAntiAlias(true);
71         mErasePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
72         mErasePaint.setFilterBitmap(true);
73         mErasePaint.setAntiAlias(true);
74     }
75 
obtain(Context context)76     public static HolographicOutlineHelper obtain(Context context) {
77         if (sInstance == null) {
78             sInstance = new HolographicOutlineHelper(context);
79         }
80         return sInstance;
81     }
82 
83     /**
84      * Applies a more expensive and accurate outline to whatever is currently drawn in a specified
85      * bitmap.
86      */
applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color, int outlineColor)87     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
88             int outlineColor) {
89         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, true);
90     }
applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color, int outlineColor, boolean clipAlpha)91     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
92             int outlineColor, boolean clipAlpha) {
93 
94         // We start by removing most of the alpha channel so as to ignore shadows, and
95         // other types of partial transparency when defining the shape of the object
96         if (clipAlpha) {
97             int[] srcBuffer = new int[srcDst.getWidth() * srcDst.getHeight()];
98             srcDst.getPixels(srcBuffer,
99                     0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
100             for (int i = 0; i < srcBuffer.length; i++) {
101                 final int alpha = srcBuffer[i] >>> 24;
102                 if (alpha < 188) {
103                     srcBuffer[i] = 0;
104                 }
105             }
106             srcDst.setPixels(srcBuffer,
107                     0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
108         }
109         Bitmap glowShape = srcDst.extractAlpha();
110 
111         // calculate the outer blur first
112         mBlurPaint.setMaskFilter(mMediumOuterBlurMaskFilter);
113         int[] outerBlurOffset = new int[2];
114         Bitmap thickOuterBlur = glowShape.extractAlpha(mBlurPaint, outerBlurOffset);
115 
116         mBlurPaint.setMaskFilter(mThinOuterBlurMaskFilter);
117         int[] brightOutlineOffset = new int[2];
118         Bitmap brightOutline = glowShape.extractAlpha(mBlurPaint, brightOutlineOffset);
119 
120         // calculate the inner blur
121         srcDstCanvas.setBitmap(glowShape);
122         srcDstCanvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
123         mBlurPaint.setMaskFilter(mMediumInnerBlurMaskFilter);
124         int[] thickInnerBlurOffset = new int[2];
125         Bitmap thickInnerBlur = glowShape.extractAlpha(mBlurPaint, thickInnerBlurOffset);
126 
127         // mask out the inner blur
128         srcDstCanvas.setBitmap(thickInnerBlur);
129         srcDstCanvas.drawBitmap(glowShape, -thickInnerBlurOffset[0],
130                 -thickInnerBlurOffset[1], mErasePaint);
131         srcDstCanvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(),
132                 mErasePaint);
133         srcDstCanvas.drawRect(0, 0, thickInnerBlur.getWidth(), -thickInnerBlurOffset[1],
134                 mErasePaint);
135 
136         // draw the inner and outer blur
137         srcDstCanvas.setBitmap(srcDst);
138         srcDstCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
139         mDrawPaint.setColor(color);
140         srcDstCanvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
141                 mDrawPaint);
142         srcDstCanvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1],
143                 mDrawPaint);
144 
145         // draw the bright outline
146         mDrawPaint.setColor(outlineColor);
147         srcDstCanvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1],
148                 mDrawPaint);
149 
150         // cleanup
151         srcDstCanvas.setBitmap(null);
152         brightOutline.recycle();
153         thickOuterBlur.recycle();
154         thickInnerBlur.recycle();
155         glowShape.recycle();
156     }
157 
createMediumDropShadow(BubbleTextView view)158     Bitmap createMediumDropShadow(BubbleTextView view) {
159         Drawable icon = view.getIcon();
160         if (icon == null) {
161             return null;
162         }
163         Rect rect = icon.getBounds();
164 
165         int bitmapWidth = (int) (rect.width() * view.getScaleX());
166         int bitmapHeight = (int) (rect.height() * view.getScaleY());
167 
168         int key = (bitmapWidth << 16) | bitmapHeight;
169         Bitmap cache = mBitmapCache.get(key);
170         if (cache == null) {
171             cache = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
172             mCanvas.setBitmap(cache);
173             mBitmapCache.put(key, cache);
174         } else {
175             mCanvas.setBitmap(cache);
176             mCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
177         }
178 
179         mCanvas.save(Canvas.MATRIX_SAVE_FLAG);
180         mCanvas.scale(view.getScaleX(), view.getScaleY());
181         mCanvas.translate(-rect.left, -rect.top);
182         icon.draw(mCanvas);
183         mCanvas.restore();
184         mCanvas.setBitmap(null);
185 
186         mBlurPaint.setMaskFilter(mShadowBlurMaskFilter);
187         return cache.extractAlpha(mBlurPaint, null);
188     }
189 }
190