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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.graphics.Bitmap;
     21 import android.graphics.BlurMaskFilter;
     22 import android.graphics.Canvas;
     23 import android.graphics.Paint;
     24 import android.graphics.PorterDuff;
     25 import android.graphics.PorterDuffXfermode;
     26 
     27 public class HolographicOutlineHelper {
     28     private final Paint mHolographicPaint = new Paint();
     29     private final Paint mBlurPaint = new Paint();
     30     private final Paint mErasePaint = new Paint();
     31 
     32     public int mMaxOuterBlurRadius;
     33     public int mMinOuterBlurRadius;
     34 
     35     private BlurMaskFilter mExtraThickOuterBlurMaskFilter;
     36     private BlurMaskFilter mThickOuterBlurMaskFilter;
     37     private BlurMaskFilter mMediumOuterBlurMaskFilter;
     38     private BlurMaskFilter mThinOuterBlurMaskFilter;
     39     private BlurMaskFilter mThickInnerBlurMaskFilter;
     40     private BlurMaskFilter mExtraThickInnerBlurMaskFilter;
     41     private BlurMaskFilter mMediumInnerBlurMaskFilter;
     42 
     43     private static final int THICK = 0;
     44     private static final int MEDIUM = 1;
     45     private static final int EXTRA_THICK = 2;
     46 
     47     static HolographicOutlineHelper INSTANCE;
     48 
     49     private HolographicOutlineHelper(Context context) {
     50         final float scale = LauncherAppState.getInstance().getScreenDensity();
     51 
     52         mMinOuterBlurRadius = (int) (scale * 1.0f);
     53         mMaxOuterBlurRadius = (int) (scale * 12.0f);
     54 
     55         mExtraThickOuterBlurMaskFilter = new BlurMaskFilter(scale * 12.0f, BlurMaskFilter.Blur.OUTER);
     56         mThickOuterBlurMaskFilter = new BlurMaskFilter(scale * 6.0f, BlurMaskFilter.Blur.OUTER);
     57         mMediumOuterBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.OUTER);
     58         mThinOuterBlurMaskFilter = new BlurMaskFilter(scale * 1.0f, BlurMaskFilter.Blur.OUTER);
     59         mExtraThickInnerBlurMaskFilter = new BlurMaskFilter(scale * 6.0f, BlurMaskFilter.Blur.NORMAL);
     60         mThickInnerBlurMaskFilter = new BlurMaskFilter(scale * 4.0f, BlurMaskFilter.Blur.NORMAL);
     61         mMediumInnerBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.NORMAL);
     62 
     63         mHolographicPaint.setFilterBitmap(true);
     64         mHolographicPaint.setAntiAlias(true);
     65         mBlurPaint.setFilterBitmap(true);
     66         mBlurPaint.setAntiAlias(true);
     67         mErasePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
     68         mErasePaint.setFilterBitmap(true);
     69         mErasePaint.setAntiAlias(true);
     70     }
     71 
     72     public static HolographicOutlineHelper obtain(Context context) {
     73         if (INSTANCE == null) {
     74             INSTANCE = new HolographicOutlineHelper(context);
     75         }
     76         return INSTANCE;
     77     }
     78 
     79     /**
     80      * Returns the interpolated holographic highlight alpha for the effect we want when scrolling
     81      * pages.
     82      */
     83     public static float highlightAlphaInterpolator(float r) {
     84         float maxAlpha = 0.6f;
     85         return (float) Math.pow(maxAlpha * (1.0f - r), 1.5f);
     86     }
     87 
     88     /**
     89      * Returns the interpolated view alpha for the effect we want when scrolling pages.
     90      */
     91     public static float viewAlphaInterpolator(float r) {
     92         final float pivot = 0.95f;
     93         if (r < pivot) {
     94             return (float) Math.pow(r / pivot, 1.5f);
     95         } else {
     96             return 1.0f;
     97         }
     98     }
     99 
    100     /**
    101      * Applies a more expensive and accurate outline to whatever is currently drawn in a specified
    102      * bitmap.
    103      */
    104     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    105             int outlineColor, int thickness) {
    106         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, true,
    107                 thickness);
    108     }
    109     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    110             int outlineColor, boolean clipAlpha, int thickness) {
    111 
    112         // We start by removing most of the alpha channel so as to ignore shadows, and
    113         // other types of partial transparency when defining the shape of the object
    114         if (clipAlpha) {
    115             int[] srcBuffer = new int[srcDst.getWidth() * srcDst.getHeight()];
    116             srcDst.getPixels(srcBuffer,
    117                     0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
    118             for (int i = 0; i < srcBuffer.length; i++) {
    119                 final int alpha = srcBuffer[i] >>> 24;
    120                 if (alpha < 188) {
    121                     srcBuffer[i] = 0;
    122                 }
    123             }
    124             srcDst.setPixels(srcBuffer,
    125                     0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
    126         }
    127         Bitmap glowShape = srcDst.extractAlpha();
    128 
    129         // calculate the outer blur first
    130         BlurMaskFilter outerBlurMaskFilter;
    131         switch (thickness) {
    132             case EXTRA_THICK:
    133                 outerBlurMaskFilter = mExtraThickOuterBlurMaskFilter;
    134                 break;
    135             case THICK:
    136                 outerBlurMaskFilter = mThickOuterBlurMaskFilter;
    137                 break;
    138             case MEDIUM:
    139                 outerBlurMaskFilter = mMediumOuterBlurMaskFilter;
    140                 break;
    141             default:
    142                 throw new RuntimeException("Invalid blur thickness");
    143         }
    144         mBlurPaint.setMaskFilter(outerBlurMaskFilter);
    145         int[] outerBlurOffset = new int[2];
    146         Bitmap thickOuterBlur = glowShape.extractAlpha(mBlurPaint, outerBlurOffset);
    147         if (thickness == EXTRA_THICK) {
    148             mBlurPaint.setMaskFilter(mMediumOuterBlurMaskFilter);
    149         } else {
    150             mBlurPaint.setMaskFilter(mThinOuterBlurMaskFilter);
    151         }
    152 
    153         int[] brightOutlineOffset = new int[2];
    154         Bitmap brightOutline = glowShape.extractAlpha(mBlurPaint, brightOutlineOffset);
    155 
    156         // calculate the inner blur
    157         srcDstCanvas.setBitmap(glowShape);
    158         srcDstCanvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
    159         BlurMaskFilter innerBlurMaskFilter;
    160         switch (thickness) {
    161             case EXTRA_THICK:
    162                 innerBlurMaskFilter = mExtraThickInnerBlurMaskFilter;
    163                 break;
    164             case THICK:
    165                 innerBlurMaskFilter = mThickInnerBlurMaskFilter;
    166                 break;
    167             case MEDIUM:
    168                 innerBlurMaskFilter = mMediumInnerBlurMaskFilter;
    169                 break;
    170             default:
    171                 throw new RuntimeException("Invalid blur thickness");
    172         }
    173         mBlurPaint.setMaskFilter(innerBlurMaskFilter);
    174         int[] thickInnerBlurOffset = new int[2];
    175         Bitmap thickInnerBlur = glowShape.extractAlpha(mBlurPaint, thickInnerBlurOffset);
    176 
    177         // mask out the inner blur
    178         srcDstCanvas.setBitmap(thickInnerBlur);
    179         srcDstCanvas.drawBitmap(glowShape, -thickInnerBlurOffset[0],
    180                 -thickInnerBlurOffset[1], mErasePaint);
    181         srcDstCanvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(),
    182                 mErasePaint);
    183         srcDstCanvas.drawRect(0, 0, thickInnerBlur.getWidth(), -thickInnerBlurOffset[1],
    184                 mErasePaint);
    185 
    186         // draw the inner and outer blur
    187         srcDstCanvas.setBitmap(srcDst);
    188         srcDstCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
    189         mHolographicPaint.setColor(color);
    190         srcDstCanvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
    191                 mHolographicPaint);
    192         srcDstCanvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1],
    193                 mHolographicPaint);
    194 
    195         // draw the bright outline
    196         mHolographicPaint.setColor(outlineColor);
    197         srcDstCanvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1],
    198                 mHolographicPaint);
    199 
    200         // cleanup
    201         srcDstCanvas.setBitmap(null);
    202         brightOutline.recycle();
    203         thickOuterBlur.recycle();
    204         thickInnerBlur.recycle();
    205         glowShape.recycle();
    206     }
    207 
    208     void applyExtraThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    209             int outlineColor) {
    210         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, EXTRA_THICK);
    211     }
    212 
    213     void applyThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    214             int outlineColor) {
    215         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, THICK);
    216     }
    217 
    218     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    219             int outlineColor, boolean clipAlpha) {
    220         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, clipAlpha,
    221                 MEDIUM);
    222     }
    223 
    224     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    225             int outlineColor) {
    226         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, MEDIUM);
    227     }
    228 
    229 }
    230