VirtualDisplay.java revision 92207df753c27b094e9e0ca80d41bc0d54dc6bd5 
1/*
2 * Copyright (C) 2013 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 */
16package android.hardware.display;
17
18import android.os.IBinder;
19import android.view.Display;
20import android.view.Surface;
21
22/**
23 * Represents a virtual display. The content of a virtual display is rendered to a
24 * {@link android.view.Surface} that you must provide to {@link DisplayManager#createVirtualDisplay
25 * createVirtualDisplay()}.
26 * <p>
27 * Because a virtual display renders to a surface provided by the application, it will be
28 * released automatically when the process terminates and all remaining windows on it will
29 * be forcibly removed.  However, you should also explicitly call {@link #release} when
30 * you're done with it.
31 * </p>
32 *
33 * @see DisplayManager#createVirtualDisplay
34 */
35public final class VirtualDisplay {
36    private final DisplayManagerGlobal mGlobal;
37    private final Display mDisplay;
38    private IBinder mToken;
39    private Surface mSurface;
40
41    VirtualDisplay(DisplayManagerGlobal global, Display display, IBinder token,
42            Surface surface) {
43        mGlobal = global;
44        mDisplay = display;
45        mToken = token;
46        mSurface = surface;
47    }
48
49    /**
50     * Gets the virtual display.
51     */
52    public Display getDisplay() {
53        return mDisplay;
54    }
55
56    /**
57     * Gets the surface that backs the virtual display.
58     */
59    public Surface getSurface() {
60        return mSurface;
61    }
62
63    /**
64     * Sets the surface that backs the virtual display.
65     * <p>
66     * Detaching the surface that backs a virtual display has a similar effect to
67     * turning off the screen.
68     * </p><p>
69     * It is still the caller's responsibility to destroy the surface after it has
70     * been detached.
71     * </p>
72     *
73     * @param surface The surface to set, or null to detach the surface from the virtual display.
74     */
75    public void setSurface(Surface surface) {
76        if (mSurface != surface) {
77            mGlobal.setVirtualDisplaySurface(mToken, surface);
78            mSurface = surface;
79        }
80    }
81
82    /**
83     * Releases the virtual display and destroys its underlying surface.
84     * <p>
85     * All remaining windows on the virtual display will be forcibly removed
86     * as part of releasing the virtual display.
87     * </p>
88     */
89    public void release() {
90        if (mToken != null) {
91            mGlobal.releaseVirtualDisplay(mToken);
92            mToken = null;
93        }
94    }
95
96    @Override
97    public String toString() {
98        return "VirtualDisplay{display=" + mDisplay + ", token=" + mToken
99                + ", surface=" + mSurface + "}";
100    }
101}
102