CircularDisplayMask.java revision ea481beda699165a7050ddcc37b10841d33ed9e6 
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.PorterDuffXfermode;
28import android.graphics.Rect;
29import android.view.Display;
30import android.view.Surface;
31import android.view.Surface.OutOfResourcesException;
32import android.view.SurfaceControl;
33import android.view.SurfaceSession;
34import android.util.Slog;
35
36class CircularDisplayMask {
37    private static final String TAG = "CircularDisplayMask";
38
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            if (WindowManagerService.DEBUG_SURFACE_TRACE) {
67                ctrl = new WindowStateAnimator.SurfaceTrace(session, "CircularDisplayMask",
68                        mScreenSize.x, mScreenSize.y, PixelFormat.TRANSLUCENT,
69                        SurfaceControl.HIDDEN);
70            } else {
71                ctrl = new SurfaceControl(session, "CircularDisplayMask", mScreenSize.x,
72                        mScreenSize.y, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
73            }
74            ctrl.setLayerStack(display.getLayerStack());
75            ctrl.setLayer(zOrder);
76            ctrl.setPosition(0, 0);
77            ctrl.show();
78            mSurface.copyFrom(ctrl);
79        } catch (OutOfResourcesException e) {
80        }
81        mSurfaceControl = ctrl;
82        mDrawNeeded = true;
83        mPaint = new Paint();
84        mPaint.setAntiAlias(true);
85        mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
86        mScreenOffset = screenOffset;
87    }
88
89    private void drawIfNeeded() {
90        if (!mDrawNeeded || !mVisible || mDimensionsUnequal) {
91            return;
92        }
93        mDrawNeeded = false;
94
95        Rect dirty = new Rect(0, 0, mScreenSize.x, mScreenSize.y);
96        Canvas c = null;
97        try {
98            c = mSurface.lockCanvas(dirty);
99        } catch (IllegalArgumentException e) {
100        } catch (Surface.OutOfResourcesException e) {
101        }
102        if (c == null) {
103            return;
104        }
105        switch (mRotation) {
106        case Surface.ROTATION_0:
107        case Surface.ROTATION_90:
108            // chin bottom or right
109            mSurfaceControl.setPosition(0, 0);
110            break;
111        case Surface.ROTATION_180:
112            // chin top
113            mSurfaceControl.setPosition(0, -mScreenOffset);
114            break;
115        case Surface.ROTATION_270:
116            // chin left
117            mSurfaceControl.setPosition(-mScreenOffset, 0);
118            break;
119        }
120
121        int circleRadius = mScreenSize.x / 2;
122        c.drawColor(Color.BLACK);
123
124        // The radius is reduced by 1 to provide an anti aliasing effect on the display edges.
125        c.drawCircle(circleRadius, circleRadius, circleRadius - 1, mPaint);
126        mSurface.unlockCanvasAndPost(c);
127    }
128
129    // Note: caller responsible for being inside
130    // Surface.openTransaction() / closeTransaction()
131    public void setVisibility(boolean on) {
132        if (mSurfaceControl == null) {
133            return;
134        }
135        mVisible = on;
136        drawIfNeeded();
137        if (on) {
138            mSurfaceControl.show();
139        } else {
140            mSurfaceControl.hide();
141        }
142    }
143
144    void positionSurface(int dw, int dh, int rotation) {
145        if (mLastDW == dw && mLastDH == dh && mRotation == rotation) {
146            return;
147        }
148        mLastDW = dw;
149        mLastDH = dh;
150        mDrawNeeded = true;
151        mRotation = rotation;
152        drawIfNeeded();
153    }
154
155}
156