StrictModeFlash.java revision 9158825f9c41869689d6b1786d7c7aa8bdd524ce 
1/*
2 * Copyright (C) 2010 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.PixelFormat;
23import android.graphics.Rect;
24import android.graphics.Region;
25import android.view.Display;
26import android.view.Surface.OutOfResourcesException;
27import android.view.Surface;
28import android.view.SurfaceControl;
29import android.view.SurfaceSession;
30
31class StrictModeFlash {
32    private static final String TAG = "StrictModeFlash";
33
34    private final SurfaceControl mSurfaceControl;
35    private final Surface mSurface = new Surface();
36    private int mLastDW;
37    private int mLastDH;
38    private boolean mDrawNeeded;
39    private final int mThickness = 20;
40
41    public StrictModeFlash(Display display, SurfaceSession session) {
42        SurfaceControl ctrl = null;
43        try {
44            ctrl = new SurfaceControl(session, "StrictModeFlash",
45                1, 1, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
46            ctrl.setLayerStack(display.getLayerStack());
47            ctrl.setLayer(WindowManagerService.TYPE_LAYER_MULTIPLIER * 101);  // one more than Watermark? arbitrary.
48            ctrl.setPosition(0, 0);
49            ctrl.show();
50            mSurface.copyFrom(ctrl);
51        } catch (OutOfResourcesException e) {
52        }
53        mSurfaceControl = ctrl;
54        mDrawNeeded = true;
55    }
56
57    private void drawIfNeeded() {
58        if (!mDrawNeeded) {
59            return;
60        }
61        mDrawNeeded = false;
62        final int dw = mLastDW;
63        final int dh = mLastDH;
64
65        Rect dirty = new Rect(0, 0, dw, dh);
66        Canvas c = null;
67        try {
68            c = mSurface.lockCanvas(dirty);
69        } catch (IllegalArgumentException e) {
70        } catch (Surface.OutOfResourcesException e) {
71        }
72        if (c == null) {
73            return;
74        }
75
76        // Top
77        c.clipRect(new Rect(0, 0, dw, mThickness), Region.Op.REPLACE);
78        c.drawColor(Color.RED);
79        // Left
80        c.clipRect(new Rect(0, 0, mThickness, dh), Region.Op.REPLACE);
81        c.drawColor(Color.RED);
82        // Right
83        c.clipRect(new Rect(dw - mThickness, 0, dw, dh), Region.Op.REPLACE);
84        c.drawColor(Color.RED);
85        // Bottom
86        c.clipRect(new Rect(0, dh - mThickness, dw, dh), Region.Op.REPLACE);
87        c.drawColor(Color.RED);
88
89        mSurface.unlockCanvasAndPost(c);
90    }
91
92    // Note: caller responsible for being inside
93    // Surface.openTransaction() / closeTransaction()
94    public void setVisibility(boolean on) {
95        if (mSurfaceControl == null) {
96            return;
97        }
98        drawIfNeeded();
99        if (on) {
100            mSurfaceControl.show();
101        } else {
102            mSurfaceControl.hide();
103        }
104    }
105
106    void positionSurface(int dw, int dh) {
107        if (mLastDW == dw && mLastDH == dh) {
108            return;
109        }
110        mLastDW = dw;
111        mLastDH = dh;
112        mSurfaceControl.setSize(dw, dh);
113        mDrawNeeded = true;
114    }
115
116}
117