ShadowKeyDrawable.java revision eb5ce83cb400549dea09458e6e3908fae4457fe4 
1/*
2 * Copyright (C) 2018 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.systemui.statusbar.phone;
18
19
20import android.graphics.Bitmap;
21import android.graphics.BlurMaskFilter;
22import android.graphics.BlurMaskFilter.Blur;
23import android.graphics.Canvas;
24import android.graphics.Color;
25import android.graphics.ColorFilter;
26import android.graphics.Paint;
27import android.graphics.PixelFormat;
28import android.graphics.Rect;
29import android.graphics.drawable.Drawable;
30
31import com.android.systemui.R;
32
33/**
34 * A drawable which adds shadow around a child drawable.
35 */
36public class ShadowKeyDrawable extends Drawable {
37    private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
38
39    private final ShadowDrawableState mState;
40
41    public ShadowKeyDrawable(Drawable d) {
42        this(d, new ShadowDrawableState());
43    }
44
45    private ShadowKeyDrawable(Drawable d, ShadowDrawableState state) {
46        mState = state;
47        if (d != null) {
48            mState.mBaseHeight = d.getIntrinsicHeight();
49            mState.mBaseWidth = d.getIntrinsicWidth();
50            mState.mChangingConfigurations = d.getChangingConfigurations();
51            mState.mChildState = d.getConstantState();
52        }
53    }
54
55    public void setRotation(float degrees) {
56        if (mState.mRotateDegrees != degrees) {
57            mState.mRotateDegrees = degrees;
58            mState.mLastDrawnBitmap = null;
59            invalidateSelf();
60        }
61    }
62
63    public void setShadowProperties(int x, int y, int size, int color) {
64        if (mState.mShadowOffsetX != x || mState.mShadowOffsetY != y
65                || mState.mShadowSize != size || mState.mShadowColor != color) {
66            mState.mShadowOffsetX = x;
67            mState.mShadowOffsetY = y;
68            mState.mShadowSize = size;
69            mState.mShadowColor = color;
70            mState.mLastDrawnBitmap = null;
71            invalidateSelf();
72        }
73    }
74
75    public float getRotation() {
76        return mState.mRotateDegrees;
77    }
78
79    @Override
80    public void draw(Canvas canvas) {
81        Rect bounds = getBounds();
82        if (bounds.isEmpty()) {
83            return;
84        }
85        if (mState.mLastDrawnBitmap == null) {
86            regenerateBitmapCache();
87        }
88        canvas.drawBitmap(mState.mLastDrawnBitmap, null, bounds, mPaint);
89    }
90
91    @Override
92    public void setTint(int tintColor) {
93        super.setTint(tintColor);
94    }
95
96    @Override
97    public void setAlpha(int alpha) {
98        mPaint.setAlpha(alpha);
99        invalidateSelf();
100    }
101
102    @Override
103    public void setColorFilter(ColorFilter colorFilter) {
104        mPaint.setColorFilter(colorFilter);
105        invalidateSelf();
106    }
107
108    @Override
109    public ConstantState getConstantState() {
110        return mState;
111    }
112
113    @Override
114    public int getOpacity() {
115        return PixelFormat.TRANSLUCENT;
116    }
117
118    @Override
119    public int getIntrinsicHeight() {
120        return mState.mBaseHeight;
121    }
122
123    @Override
124    public int getIntrinsicWidth() {
125        return mState.mBaseWidth;
126    }
127
128    @Override
129    public boolean canApplyTheme() {
130        return mState.canApplyTheme();
131    }
132
133    private void regenerateBitmapCache() {
134        final int width = getIntrinsicWidth();
135        final int height = getIntrinsicHeight();
136        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
137        Canvas canvas = new Canvas(bitmap);
138        canvas.save();
139        final float radians = (float) (mState.mRotateDegrees * Math.PI / 180);
140
141        // Rotate canvas before drawing original drawable if no shadow
142        if (mState.mShadowSize == 0) {
143            canvas.rotate(mState.mRotateDegrees, width / 2, height / 2);
144        }
145
146        // Call mutate, so that the pixel allocation by the underlying vector drawable is cleared.
147        final Drawable d = mState.mChildState.newDrawable().mutate();
148        d.setBounds(0, 0, mState.mBaseWidth, mState.mBaseHeight);
149        d.draw(canvas);
150
151        if (mState.mShadowSize > 0) {
152            // Draws the shadow
153            Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
154            paint.setMaskFilter(new BlurMaskFilter(mState.mShadowSize, Blur.NORMAL));
155            int[] offset = new int[2];
156
157            final Bitmap shadow = bitmap.extractAlpha(paint, offset);
158
159            paint.setMaskFilter(null);
160            paint.setColor(mState.mShadowColor);
161            bitmap.eraseColor(Color.TRANSPARENT);
162
163            canvas.rotate(mState.mRotateDegrees, width / 2, height / 2);
164
165            final float shadowOffsetX = (float) (Math.sin(radians) * mState.mShadowOffsetY
166                    + Math.cos(radians) * mState.mShadowOffsetX);
167            final float shadowOffsetY = (float) (Math.cos(radians) * mState.mShadowOffsetY
168                    - Math.sin(radians) * mState.mShadowOffsetX);
169
170            canvas.drawBitmap(shadow, offset[0] + shadowOffsetX, offset[1] + shadowOffsetY, paint);
171            d.draw(canvas);
172        }
173
174        bitmap = bitmap.copy(Bitmap.Config.HARDWARE, false);
175        mState.mLastDrawnBitmap = bitmap;
176        canvas.restore();
177    }
178
179    private static class ShadowDrawableState extends ConstantState {
180        int mChangingConfigurations;
181        int mBaseWidth;
182        int mBaseHeight;
183        float mRotateDegrees;
184        int mShadowOffsetX;
185        int mShadowOffsetY;
186        int mShadowSize;
187        int mShadowColor;
188
189        Bitmap mLastDrawnBitmap;
190        ConstantState mChildState;
191
192        @Override
193        public Drawable newDrawable() {
194            return new ShadowKeyDrawable(null, this);
195        }
196
197        @Override
198        public int getChangingConfigurations() {
199            return mChangingConfigurations;
200        }
201
202        @Override
203        public boolean canApplyTheme() {
204            return true;
205        }
206    }
207}
208