StrictModeFlash.java revision 784707187d96b731df5256c1c2adb0aaf9037239 
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.util.DisplayMetrics;
26import android.util.Slog;
27import android.view.Display;
28import android.view.Surface;
29import android.view.SurfaceSession;
30
31class StrictModeFlash {
32    private static final String TAG = "StrictModeFlash";
33
34    Surface mSurface;
35    int mLastDW;
36    int mLastDH;
37    boolean mDrawNeeded;
38    final int mThickness = 20;
39
40    public StrictModeFlash(Display display, SurfaceSession session) {
41        final DisplayMetrics dm = new DisplayMetrics();
42        display.getRealMetrics(dm);
43
44        try {
45            mSurface = new Surface(session, 0, "StrictModeFlash", -1, 1, 1, PixelFormat.TRANSLUCENT, 0);
46        } catch (Surface.OutOfResourcesException e) {
47            return;
48        }
49
50        mSurface.setLayer(WindowManagerService.TYPE_LAYER_MULTIPLIER * 101);  // one more than Watermark? arbitrary.
51        mSurface.setPosition(0, 0);
52        mDrawNeeded = true;
53    }
54
55    private void drawIfNeeded() {
56        if (!mDrawNeeded) {
57            return;
58        }
59        mDrawNeeded = false;
60        final int dw = mLastDW;
61        final int dh = mLastDH;
62
63        Rect dirty = new Rect(0, 0, dw, dh);
64        Canvas c = null;
65        try {
66            c = mSurface.lockCanvas(dirty);
67        } catch (IllegalArgumentException e) {
68        } catch (Surface.OutOfResourcesException e) {
69        }
70        if (c == null) {
71            return;
72        }
73
74        // Top
75        c.clipRect(new Rect(0, 0, dw, mThickness), Region.Op.REPLACE);
76        c.drawColor(Color.RED);
77        // Left
78        c.clipRect(new Rect(0, 0, mThickness, dh), Region.Op.REPLACE);
79        c.drawColor(Color.RED);
80        // Right
81        c.clipRect(new Rect(dw - mThickness, 0, dw, dh), Region.Op.REPLACE);
82        c.drawColor(Color.RED);
83        // Bottom
84        c.clipRect(new Rect(0, dh - mThickness, dw, dh), Region.Op.REPLACE);
85        c.drawColor(Color.RED);
86
87        mSurface.unlockCanvasAndPost(c);
88    }
89
90    // Note: caller responsible for being inside
91    // Surface.openTransaction() / closeTransaction()
92    public void setVisibility(boolean on) {
93        if (mSurface == null) {
94            return;
95        }
96        drawIfNeeded();
97        if (on) {
98            mSurface.show();
99        } else {
100            mSurface.hide();
101        }
102    }
103
104    void positionSurface(int dw, int dh) {
105        if (mLastDW == dw && mLastDH == dh) {
106            return;
107        }
108        mLastDW = dw;
109        mLastDH = dh;
110        mSurface.setSize(dw, dh);
111        mDrawNeeded = true;
112    }
113
114}
115