CircularDisplayMask.java revision 8b275ca9d34792ba525771e0c1865b3262e569c9 
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
17package com.android.server.wm;
18
19
20import android.graphics.Canvas;
21import android.graphics.Color;
22import android.graphics.Paint;
23import android.graphics.PixelFormat;
24import android.graphics.Rect;
25import android.view.Display;
26import android.view.Surface;
27import android.view.Surface.OutOfResourcesException;
28import android.view.SurfaceControl;
29import android.view.SurfaceSession;
30
31class CircularDisplayMask {
32    private static final String TAG = "CircularDisplayMask";
33
34    private static final int STROKE_WIDTH = 2;
35
36    private final SurfaceControl mSurfaceControl;
37    private final Surface mSurface = new Surface();
38    private int mLastDW;
39    private int mLastDH;
40    private boolean mDrawNeeded;
41    private Paint mPaint;
42    private int mRotation;
43
44    public CircularDisplayMask(Display display, SurfaceSession session, int zOrder) {
45        SurfaceControl ctrl = null;
46        try {
47            ctrl = new SurfaceControl(session, "CircularDisplayMask",
48                320, 290, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
49            ctrl.setLayerStack(display.getLayerStack());
50            ctrl.setLayer(zOrder);
51            ctrl.setPosition(0, 0);
52            ctrl.show();
53            mSurface.copyFrom(ctrl);
54        } catch (OutOfResourcesException e) {
55        }
56        mSurfaceControl = ctrl;
57        mDrawNeeded = true;
58        mPaint = new Paint();
59        mPaint.setAntiAlias(true);
60        mPaint.setStyle(Paint.Style.STROKE);
61        mPaint.setColor(Color.BLACK);
62        mPaint.setStrokeWidth(STROKE_WIDTH);
63    }
64
65    private void drawIfNeeded() {
66        if (!mDrawNeeded) {
67            return;
68        }
69        mDrawNeeded = false;
70
71        Rect dirty = new Rect(0, 0, mLastDW, mLastDH);
72        Canvas c = null;
73        try {
74            c = mSurface.lockCanvas(dirty);
75        } catch (IllegalArgumentException e) {
76        } catch (Surface.OutOfResourcesException e) {
77        }
78        if (c == null) {
79            return;
80        }
81        int cx = 160;
82        int cy = 160;
83        switch (mRotation) {
84            case Surface.ROTATION_0:
85            case Surface.ROTATION_90:
86                // chin bottom or right
87                cx = 160;
88                cy = 160;
89                break;
90            case Surface.ROTATION_180:
91                // chin top
92                cx = 160;
93                cy = 145;
94                break;
95            case Surface.ROTATION_270:
96                cx = 145;
97                cy = 160;
98                break;
99        }
100        c.drawCircle(cx, cy, 160, mPaint);
101
102        mSurface.unlockCanvasAndPost(c);
103    }
104
105    // Note: caller responsible for being inside
106    // Surface.openTransaction() / closeTransaction()
107    public void setVisibility(boolean on) {
108        if (mSurfaceControl == null) {
109            return;
110        }
111        drawIfNeeded();
112        if (on) {
113            mSurfaceControl.show();
114        } else {
115            mSurfaceControl.hide();
116        }
117    }
118
119    void positionSurface(int dw, int dh, int rotation) {
120        if (mLastDW == dw && mLastDH == dh) {
121            return;
122        }
123        mLastDW = dw;
124        mLastDH = dh;
125        mSurfaceControl.setSize(dw, dh);
126        mDrawNeeded = true;
127        mRotation = rotation;
128    }
129
130}
131