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
17package com.android.launcher3;
18
19import android.content.Context;
20import android.graphics.Bitmap;
21import android.graphics.BlurMaskFilter;
22import android.graphics.Canvas;
23import android.graphics.Color;
24import android.graphics.Paint;
25import android.graphics.PorterDuff;
26import android.graphics.PorterDuffXfermode;
27import android.graphics.Rect;
28import android.graphics.Region.Op;
29
30public class HolographicOutlineHelper {
31
32    private static final Rect sTempRect = new Rect();
33
34    private final Canvas mCanvas = new Canvas();
35    private final Paint mDrawPaint = new Paint();
36    private final Paint mBlurPaint = new Paint();
37    private final Paint mErasePaint = new Paint();
38
39    private final BlurMaskFilter mMediumOuterBlurMaskFilter;
40    private final BlurMaskFilter mThinOuterBlurMaskFilter;
41    private final BlurMaskFilter mMediumInnerBlurMaskFilter;
42
43    private final BlurMaskFilter mShaowBlurMaskFilter;
44    private final int mShadowOffset;
45
46    /**
47     * Padding used when creating shadow bitmap;
48     */
49    final int shadowBitmapPadding;
50
51    static HolographicOutlineHelper INSTANCE;
52
53    private HolographicOutlineHelper(Context context) {
54        final float scale = LauncherAppState.getInstance().getScreenDensity();
55
56        mMediumOuterBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.OUTER);
57        mThinOuterBlurMaskFilter = new BlurMaskFilter(scale * 1.0f, BlurMaskFilter.Blur.OUTER);
58        mMediumInnerBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.NORMAL);
59
60        mShaowBlurMaskFilter = new BlurMaskFilter(scale * 4.0f, BlurMaskFilter.Blur.NORMAL);
61        mShadowOffset = (int) (scale * 2.0f);
62        shadowBitmapPadding = (int) (scale * 4.0f);
63
64        mDrawPaint.setFilterBitmap(true);
65        mDrawPaint.setAntiAlias(true);
66        mBlurPaint.setFilterBitmap(true);
67        mBlurPaint.setAntiAlias(true);
68        mErasePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
69        mErasePaint.setFilterBitmap(true);
70        mErasePaint.setAntiAlias(true);
71    }
72
73    public static HolographicOutlineHelper obtain(Context context) {
74        if (INSTANCE == null) {
75            INSTANCE = new HolographicOutlineHelper(context);
76        }
77        return INSTANCE;
78    }
79
80    /**
81     * Applies a more expensive and accurate outline to whatever is currently drawn in a specified
82     * bitmap.
83     */
84    void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
85            int outlineColor) {
86        applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, true);
87    }
88    void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
89            int outlineColor, boolean clipAlpha) {
90
91        // We start by removing most of the alpha channel so as to ignore shadows, and
92        // other types of partial transparency when defining the shape of the object
93        if (clipAlpha) {
94            int[] srcBuffer = new int[srcDst.getWidth() * srcDst.getHeight()];
95            srcDst.getPixels(srcBuffer,
96                    0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
97            for (int i = 0; i < srcBuffer.length; i++) {
98                final int alpha = srcBuffer[i] >>> 24;
99                if (alpha < 188) {
100                    srcBuffer[i] = 0;
101                }
102            }
103            srcDst.setPixels(srcBuffer,
104                    0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
105        }
106        Bitmap glowShape = srcDst.extractAlpha();
107
108        // calculate the outer blur first
109        mBlurPaint.setMaskFilter(mMediumOuterBlurMaskFilter);
110        int[] outerBlurOffset = new int[2];
111        Bitmap thickOuterBlur = glowShape.extractAlpha(mBlurPaint, outerBlurOffset);
112
113        mBlurPaint.setMaskFilter(mThinOuterBlurMaskFilter);
114        int[] brightOutlineOffset = new int[2];
115        Bitmap brightOutline = glowShape.extractAlpha(mBlurPaint, brightOutlineOffset);
116
117        // calculate the inner blur
118        srcDstCanvas.setBitmap(glowShape);
119        srcDstCanvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
120        mBlurPaint.setMaskFilter(mMediumInnerBlurMaskFilter);
121        int[] thickInnerBlurOffset = new int[2];
122        Bitmap thickInnerBlur = glowShape.extractAlpha(mBlurPaint, thickInnerBlurOffset);
123
124        // mask out the inner blur
125        srcDstCanvas.setBitmap(thickInnerBlur);
126        srcDstCanvas.drawBitmap(glowShape, -thickInnerBlurOffset[0],
127                -thickInnerBlurOffset[1], mErasePaint);
128        srcDstCanvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(),
129                mErasePaint);
130        srcDstCanvas.drawRect(0, 0, thickInnerBlur.getWidth(), -thickInnerBlurOffset[1],
131                mErasePaint);
132
133        // draw the inner and outer blur
134        srcDstCanvas.setBitmap(srcDst);
135        srcDstCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
136        mDrawPaint.setColor(color);
137        srcDstCanvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
138                mDrawPaint);
139        srcDstCanvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1],
140                mDrawPaint);
141
142        // draw the bright outline
143        mDrawPaint.setColor(outlineColor);
144        srcDstCanvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1],
145                mDrawPaint);
146
147        // cleanup
148        srcDstCanvas.setBitmap(null);
149        brightOutline.recycle();
150        thickOuterBlur.recycle();
151        thickInnerBlur.recycle();
152        glowShape.recycle();
153    }
154
155    Bitmap createMediumDropShadow(BubbleTextView view) {
156        final Bitmap result = Bitmap.createBitmap(
157                view.getWidth() + shadowBitmapPadding + shadowBitmapPadding,
158                view.getHeight() + shadowBitmapPadding + shadowBitmapPadding + mShadowOffset,
159                Bitmap.Config.ARGB_8888);
160
161        mCanvas.setBitmap(result);
162
163        final Rect clipRect = sTempRect;
164        view.getDrawingRect(sTempRect);
165        // adjust the clip rect so that we don't include the text label
166        clipRect.bottom = view.getExtendedPaddingTop() - (int) BubbleTextView.PADDING_V
167                + view.getLayout().getLineTop(0);
168
169        // Draw the View into the bitmap.
170        // The translate of scrollX and scrollY is necessary when drawing TextViews, because
171        // they set scrollX and scrollY to large values to achieve centered text
172        mCanvas.save();
173        mCanvas.scale(view.getScaleX(), view.getScaleY(),
174                view.getWidth() / 2 + shadowBitmapPadding,
175                view.getHeight() / 2 + shadowBitmapPadding);
176        mCanvas.translate(-view.getScrollX() + shadowBitmapPadding,
177                -view.getScrollY() + shadowBitmapPadding);
178        mCanvas.clipRect(clipRect, Op.REPLACE);
179        view.draw(mCanvas);
180        mCanvas.restore();
181
182        int[] blurOffst = new int[2];
183        mBlurPaint.setMaskFilter(mShaowBlurMaskFilter);
184        Bitmap blurBitmap = result.extractAlpha(mBlurPaint, blurOffst);
185
186        mCanvas.save();
187        mCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
188        mCanvas.translate(blurOffst[0], blurOffst[1]);
189
190        mDrawPaint.setColor(Color.BLACK);
191        mDrawPaint.setAlpha(30);
192        mCanvas.drawBitmap(blurBitmap, 0, 0, mDrawPaint);
193
194        mDrawPaint.setAlpha(60);
195        mCanvas.drawBitmap(blurBitmap, 0, mShadowOffset, mDrawPaint);
196        mCanvas.restore();
197
198        mCanvas.setBitmap(null);
199        blurBitmap.recycle();
200
201        return result;
202    }
203}
204