CircularDisplayMask.java revision a04ea61db5566f05d5c783b2f62614aa03005be9 
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
20
21import android.graphics.Canvas;
22import android.graphics.Color;
23import android.graphics.Paint;
24import android.graphics.PixelFormat;
25import android.graphics.Point;
26import android.graphics.PorterDuff;
27import android.graphics.Rect;
28import android.view.Display;
29import android.view.Surface;
30import android.view.Surface.OutOfResourcesException;
31import android.view.SurfaceControl;
32import android.view.SurfaceSession;
33import android.util.Slog;
34
35class CircularDisplayMask {
36    private static final String TAG = "CircularDisplayMask";
37
38    private static final int STROKE_WIDTH = 2;
39    // size of the chin
40    private int mScreenOffset = 0;
41    // Display dimensions
42    private Point mScreenSize;
43
44    private final SurfaceControl mSurfaceControl;
45    private final Surface mSurface = new Surface();
46    private int mLastDW;
47    private int mLastDH;
48    private boolean mDrawNeeded;
49    private Paint mPaint;
50    private int mRotation;
51    private boolean mVisible;
52    private boolean mDimensionsUnequal = false;
53
54    public CircularDisplayMask(Display display, SurfaceSession session, int zOrder,
55            int screenOffset) {
56        mScreenSize = new Point();
57        display.getSize(mScreenSize);
58        if (mScreenSize.x != mScreenSize.y) {
59            Slog.w(TAG, "Screen dimensions of displayId = " + display.getDisplayId() +
60                    "are not equal, circularMask will not be drawn.");
61            mDimensionsUnequal = true;
62        }
63
64        SurfaceControl ctrl = null;
65        try {
66            ctrl = new SurfaceControl(session, "CircularDisplayMask",
67                mScreenSize.x, mScreenSize.y, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
68            ctrl.setLayerStack(display.getLayerStack());
69            ctrl.setLayer(zOrder);
70            ctrl.setPosition(0, 0);
71            ctrl.show();
72            mSurface.copyFrom(ctrl);
73        } catch (OutOfResourcesException e) {
74        }
75        mSurfaceControl = ctrl;
76        mDrawNeeded = true;
77        mPaint = new Paint();
78        mPaint.setAntiAlias(true);
79        mPaint.setStyle(Paint.Style.STROKE);
80        mPaint.setColor(Color.BLACK);
81        mPaint.setStrokeWidth(STROKE_WIDTH);
82        mScreenOffset = screenOffset;
83    }
84
85    private void drawIfNeeded() {
86        if (!mDrawNeeded || !mVisible || mDimensionsUnequal) {
87            return;
88        }
89        mDrawNeeded = false;
90
91        Rect dirty = new Rect(0, 0, mScreenSize.x, mScreenSize.y);
92        Canvas c = null;
93        try {
94            c = mSurface.lockCanvas(dirty);
95        } catch (IllegalArgumentException e) {
96        } catch (Surface.OutOfResourcesException e) {
97        }
98        if (c == null) {
99            return;
100        }
101        c.drawColor(Color.TRANSPARENT, PorterDuff.Mode.SRC);
102        switch (mRotation) {
103        case Surface.ROTATION_0:
104        case Surface.ROTATION_90:
105            // chin bottom or right
106            mSurfaceControl.setPosition(0, 0);
107            break;
108        case Surface.ROTATION_180:
109            // chin top
110            mSurfaceControl.setPosition(0, -mScreenOffset);
111            break;
112        case Surface.ROTATION_270:
113            // chin left
114            mSurfaceControl.setPosition(-mScreenOffset, 0);
115            break;
116        }
117
118        int circleRadius = mScreenSize.x / 2;
119        c.drawCircle(circleRadius, circleRadius, circleRadius, mPaint);
120        mSurface.unlockCanvasAndPost(c);
121    }
122
123    // Note: caller responsible for being inside
124    // Surface.openTransaction() / closeTransaction()
125    public void setVisibility(boolean on) {
126        if (mSurfaceControl == null) {
127            return;
128        }
129        mVisible = on;
130        drawIfNeeded();
131        if (on) {
132            mSurfaceControl.show();
133        } else {
134            mSurfaceControl.hide();
135        }
136    }
137
138    void positionSurface(int dw, int dh, int rotation) {
139        if (mLastDW == dw && mLastDH == dh && mRotation == rotation) {
140            return;
141        }
142        mLastDW = dw;
143        mLastDH = dh;
144        mDrawNeeded = true;
145        mRotation = rotation;
146        drawIfNeeded();
147    }
148
149}
150