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 */
16
17package android.support.v4.media;
18
19/**
20 * Base interface to controlling a media transport.  This is the
21 * interface for implementing things like on-screen controls: it
22 * allows them to request changes in playback, retrieve the current
23 * playback state, and monitor for changes to the playback state.
24 */
25public abstract class TransportController {
26    /**
27     * Start listening to changes in playback state.
28     */
29    public abstract void registerStateListener(TransportStateListener listener);
30
31    /**
32     * Stop listening to changes in playback state.
33     */
34    public abstract void unregisterStateListener(TransportStateListener listener);
35
36    /**
37     * Request that the player start its playback at its current position.
38     */
39    public abstract void startPlaying();
40
41    /**
42     * Request that the player pause its playback and stay at its current position.
43     */
44    public abstract void pausePlaying();
45
46    /**
47     * Request that the player stop its playback; it may clear its state in whatever
48     * way is appropriate.
49     */
50    public abstract void stopPlaying();
51
52    /**
53     * Retrieve the total duration of the media stream, in milliseconds.
54     */
55    public abstract long getDuration();
56
57    /**
58     * Retrieve the current playback location in the media stream, in milliseconds.
59     */
60    public abstract long getCurrentPosition();
61
62    /**
63     * Move to a new location in the media stream.
64     * @param pos Position to move to, in milliseconds.
65     */
66    public abstract void seekTo(long pos);
67
68    /**
69     * Return whether the player is currently playing its stream.
70     */
71    public abstract boolean isPlaying();
72
73    /**
74     * Retrieve amount, in percentage (0-100), that the media stream has been buffered
75     * on to the local device.  Return 100 if the stream is always local.
76     */
77    public abstract int getBufferPercentage();
78
79    /**
80     * Retrieve the flags for the media transport control buttons that this transport supports.
81     * Result is a combination of the following flags:
82     *      {@link TransportMediator#FLAG_KEY_MEDIA_PREVIOUS},
83     *      {@link TransportMediator#FLAG_KEY_MEDIA_REWIND},
84     *      {@link TransportMediator#FLAG_KEY_MEDIA_PLAY},
85     *      {@link TransportMediator#FLAG_KEY_MEDIA_PLAY_PAUSE},
86     *      {@link TransportMediator#FLAG_KEY_MEDIA_PAUSE},
87     *      {@link TransportMediator#FLAG_KEY_MEDIA_STOP},
88     *      {@link TransportMediator#FLAG_KEY_MEDIA_FAST_FORWARD},
89     *      {@link TransportMediator#FLAG_KEY_MEDIA_NEXT}
90     */
91    public abstract int getTransportControlFlags();
92}
93