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 static com.android.server.wm.WindowManagerDebugConfig.DEBUG_SURFACE_TRACE;
21import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
22import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
23
24import android.graphics.Canvas;
25import android.graphics.Color;
26import android.graphics.Paint;
27import android.graphics.PixelFormat;
28import android.graphics.Point;
29import android.graphics.PorterDuff;
30import android.graphics.PorterDuffXfermode;
31import android.graphics.Rect;
32import android.util.Slog;
33import android.view.Display;
34import android.view.Surface;
35import android.view.Surface.OutOfResourcesException;
36import android.view.SurfaceControl;
37import android.view.SurfaceSession;
38
39class CircularDisplayMask {
40    private static final String TAG = TAG_WITH_CLASS_NAME ? "CircularDisplayMask" : TAG_WM;
41
42    // size of the chin
43    private int mScreenOffset = 0;
44    // Display dimensions
45    private Point mScreenSize;
46
47    private final SurfaceControl mSurfaceControl;
48    private final Surface mSurface = new Surface();
49    private int mLastDW;
50    private int mLastDH;
51    private boolean mDrawNeeded;
52    private Paint mPaint;
53    private int mRotation;
54    private boolean mVisible;
55    private boolean mDimensionsUnequal = false;
56    private int mMaskThickness;
57
58    public CircularDisplayMask(Display display, SurfaceSession session, int zOrder,
59            int screenOffset, int maskThickness) {
60        mScreenSize = new Point();
61        display.getSize(mScreenSize);
62        if (mScreenSize.x != mScreenSize.y + screenOffset) {
63            Slog.w(TAG, "Screen dimensions of displayId = " + display.getDisplayId() +
64                    "are not equal, circularMask will not be drawn.");
65            mDimensionsUnequal = true;
66        }
67
68        SurfaceControl ctrl = null;
69        try {
70            if (DEBUG_SURFACE_TRACE) {
71                ctrl = new WindowSurfaceController.SurfaceTrace(session, "CircularDisplayMask",
72                        mScreenSize.x, mScreenSize.y, PixelFormat.TRANSLUCENT,
73                        SurfaceControl.HIDDEN);
74            } else {
75                ctrl = new SurfaceControl(session, "CircularDisplayMask", mScreenSize.x,
76                        mScreenSize.y, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
77            }
78            ctrl.setLayerStack(display.getLayerStack());
79            ctrl.setLayer(zOrder);
80            ctrl.setPosition(0, 0);
81            ctrl.show();
82            mSurface.copyFrom(ctrl);
83        } catch (OutOfResourcesException e) {
84        }
85        mSurfaceControl = ctrl;
86        mDrawNeeded = true;
87        mPaint = new Paint();
88        mPaint.setAntiAlias(true);
89        mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
90        mScreenOffset = screenOffset;
91        mMaskThickness = maskThickness;
92    }
93
94    private void drawIfNeeded() {
95        if (!mDrawNeeded || !mVisible || mDimensionsUnequal) {
96            return;
97        }
98        mDrawNeeded = false;
99
100        Rect dirty = new Rect(0, 0, mScreenSize.x, mScreenSize.y);
101        Canvas c = null;
102        try {
103            c = mSurface.lockCanvas(dirty);
104        } catch (IllegalArgumentException e) {
105        } catch (Surface.OutOfResourcesException e) {
106        }
107        if (c == null) {
108            return;
109        }
110        switch (mRotation) {
111        case Surface.ROTATION_0:
112        case Surface.ROTATION_90:
113            // chin bottom or right
114            mSurfaceControl.setPosition(0, 0);
115            break;
116        case Surface.ROTATION_180:
117            // chin top
118            mSurfaceControl.setPosition(0, -mScreenOffset);
119            break;
120        case Surface.ROTATION_270:
121            // chin left
122            mSurfaceControl.setPosition(-mScreenOffset, 0);
123            break;
124        }
125
126        int circleRadius = mScreenSize.x / 2;
127        c.drawColor(Color.BLACK);
128
129        // The radius is reduced by mMaskThickness to provide an anti aliasing effect on the display edges.
130        c.drawCircle(circleRadius, circleRadius, circleRadius - mMaskThickness, mPaint);
131        mSurface.unlockCanvasAndPost(c);
132    }
133
134    // Note: caller responsible for being inside
135    // Surface.openTransaction() / closeTransaction()
136    public void setVisibility(boolean on) {
137        if (mSurfaceControl == null) {
138            return;
139        }
140        mVisible = on;
141        drawIfNeeded();
142        if (on) {
143            mSurfaceControl.show();
144        } else {
145            mSurfaceControl.hide();
146        }
147    }
148
149    void positionSurface(int dw, int dh, int rotation) {
150        if (mLastDW == dw && mLastDH == dh && mRotation == rotation) {
151            return;
152        }
153        mLastDW = dw;
154        mLastDH = dh;
155        mDrawNeeded = true;
156        mRotation = rotation;
157        drawIfNeeded();
158    }
159
160}
161