MediaSession.java revision 305563bd6368bb650bc42267bcf71b3722a5a86b
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 android.media.session; 18 19import android.annotation.IntDef; 20import android.annotation.NonNull; 21import android.annotation.Nullable; 22import android.app.Activity; 23import android.app.PendingIntent; 24import android.content.Context; 25import android.content.Intent; 26import android.content.pm.ParceledListSlice; 27import android.media.AudioAttributes; 28import android.media.MediaDescription; 29import android.media.MediaMetadata; 30import android.media.Rating; 31import android.media.VolumeProvider; 32import android.media.routing.MediaRouter; 33import android.net.Uri; 34import android.os.Bundle; 35import android.os.Handler; 36import android.os.Looper; 37import android.os.Message; 38import android.os.Parcel; 39import android.os.Parcelable; 40import android.os.RemoteException; 41import android.os.ResultReceiver; 42import android.os.UserHandle; 43import android.service.media.MediaBrowserService; 44import android.text.TextUtils; 45import android.util.Log; 46import android.view.KeyEvent; 47 48import java.lang.annotation.Retention; 49import java.lang.annotation.RetentionPolicy; 50import java.lang.ref.WeakReference; 51import java.util.List; 52 53/** 54 * Allows interaction with media controllers, volume keys, media buttons, and 55 * transport controls. 56 * <p> 57 * A MediaSession should be created when an app wants to publish media playback 58 * information or handle media keys. In general an app only needs one session 59 * for all playback, though multiple sessions can be created to provide finer 60 * grain controls of media. 61 * <p> 62 * Once a session is created the owner of the session may pass its 63 * {@link #getSessionToken() session token} to other processes to allow them to 64 * create a {@link MediaController} to interact with the session. 65 * <p> 66 * To receive commands, media keys, and other events a {@link Callback} must be 67 * set with {@link #setCallback(Callback)} and {@link #setActive(boolean) 68 * setActive(true)} must be called. 69 * <p> 70 * When an app is finished performing playback it must call {@link #release()} 71 * to clean up the session and notify any controllers. 72 * <p> 73 * MediaSession objects are thread safe. 74 */ 75public final class MediaSession { 76 private static final String TAG = "MediaSession"; 77 78 /** 79 * Set this flag on the session to indicate that it can handle media button 80 * events. 81 */ 82 public static final int FLAG_HANDLES_MEDIA_BUTTONS = 1 << 0; 83 84 /** 85 * Set this flag on the session to indicate that it handles transport 86 * control commands through its {@link Callback}. 87 */ 88 public static final int FLAG_HANDLES_TRANSPORT_CONTROLS = 1 << 1; 89 90 /** 91 * System only flag for a session that needs to have priority over all other 92 * sessions. This flag ensures this session will receive media button events 93 * regardless of the current ordering in the system. 94 * 95 * @hide 96 */ 97 public static final int FLAG_EXCLUSIVE_GLOBAL_PRIORITY = 1 << 16; 98 99 /** @hide */ 100 @Retention(RetentionPolicy.SOURCE) 101 @IntDef(flag = true, value = { 102 FLAG_HANDLES_MEDIA_BUTTONS, 103 FLAG_HANDLES_TRANSPORT_CONTROLS, 104 FLAG_EXCLUSIVE_GLOBAL_PRIORITY }) 105 public @interface SessionFlags { } 106 107 private final Object mLock = new Object(); 108 109 private final MediaSession.Token mSessionToken; 110 private final MediaController mController; 111 private final ISession mBinder; 112 private final CallbackStub mCbStub; 113 114 private CallbackMessageHandler mCallback; 115 private VolumeProvider mVolumeProvider; 116 private PlaybackState mPlaybackState; 117 118 private boolean mActive = false; 119 120 /** 121 * Creates a new session. The session will automatically be registered with 122 * the system but will not be published until {@link #setActive(boolean) 123 * setActive(true)} is called. You must call {@link #release()} when 124 * finished with the session. 125 * 126 * @param context The context to use to create the session. 127 * @param tag A short name for debugging purposes. 128 */ 129 public MediaSession(@NonNull Context context, @NonNull String tag) { 130 this(context, tag, UserHandle.myUserId()); 131 } 132 133 /** 134 * Creates a new session as the specified user. To create a session as a 135 * user other than your own you must hold the 136 * {@link android.Manifest.permission#INTERACT_ACROSS_USERS_FULL} 137 * permission. 138 * 139 * @param context The context to use to create the session. 140 * @param tag A short name for debugging purposes. 141 * @param userId The user id to create the session as. 142 * @hide 143 */ 144 public MediaSession(@NonNull Context context, @NonNull String tag, int userId) { 145 if (context == null) { 146 throw new IllegalArgumentException("context cannot be null."); 147 } 148 if (TextUtils.isEmpty(tag)) { 149 throw new IllegalArgumentException("tag cannot be null or empty"); 150 } 151 mCbStub = new CallbackStub(this); 152 MediaSessionManager manager = (MediaSessionManager) context 153 .getSystemService(Context.MEDIA_SESSION_SERVICE); 154 try { 155 mBinder = manager.createSession(mCbStub, tag, userId); 156 mSessionToken = new Token(mBinder.getController()); 157 mController = new MediaController(context, mSessionToken); 158 } catch (RemoteException e) { 159 throw new RuntimeException("Remote error creating session.", e); 160 } 161 } 162 163 /** 164 * Set the callback to receive updates for the MediaSession. This includes 165 * media button events and transport controls. The caller's thread will be 166 * used to post updates. 167 * <p> 168 * Set the callback to null to stop receiving updates. 169 * 170 * @param callback The callback object 171 */ 172 public void setCallback(@Nullable Callback callback) { 173 setCallback(callback, null); 174 } 175 176 /** 177 * Set the callback to receive updates for the MediaSession. This includes 178 * media button events and transport controls. 179 * <p> 180 * Set the callback to null to stop receiving updates. 181 * 182 * @param callback The callback to receive updates on. 183 * @param handler The handler that events should be posted on. 184 */ 185 public void setCallback(@Nullable Callback callback, @Nullable Handler handler) { 186 synchronized (mLock) { 187 if (callback == null) { 188 if (mCallback != null) { 189 mCallback.mCallback.mSession = null; 190 } 191 mCallback = null; 192 return; 193 } 194 if (mCallback != null) { 195 // We're updating the callback, clear the session from the old 196 // one. 197 mCallback.mCallback.mSession = null; 198 } 199 if (handler == null) { 200 handler = new Handler(); 201 } 202 callback.mSession = this; 203 CallbackMessageHandler msgHandler = new CallbackMessageHandler(handler.getLooper(), 204 callback); 205 mCallback = msgHandler; 206 } 207 } 208 209 /** 210 * Set an intent for launching UI for this Session. This can be used as a 211 * quick link to an ongoing media screen. The intent should be for an 212 * activity that may be started using {@link Activity#startActivity(Intent)}. 213 * 214 * @param pi The intent to launch to show UI for this Session. 215 */ 216 public void setSessionActivity(@Nullable PendingIntent pi) { 217 try { 218 mBinder.setLaunchPendingIntent(pi); 219 } catch (RemoteException e) { 220 Log.wtf(TAG, "Failure in setLaunchPendingIntent.", e); 221 } 222 } 223 224 /** 225 * Associates a {@link MediaRouter} with this session to control the destination 226 * of media content. 227 * <p> 228 * A media router may only be associated with at most one session at a time. 229 * </p> 230 * 231 * @param router The media router, or null to remove the current association. 232 */ 233 public void setMediaRouter(@Nullable MediaRouter router) { 234 try { 235 mBinder.setMediaRouter(router != null ? router.getBinder() : null); 236 } catch (RemoteException e) { 237 Log.wtf(TAG, "Failure in setMediaButtonReceiver.", e); 238 } 239 } 240 241 /** 242 * Set a pending intent for your media button receiver to allow restarting 243 * playback after the session has been stopped. If your app is started in 244 * this way an {@link Intent#ACTION_MEDIA_BUTTON} intent will be sent via 245 * the pending intent. 246 * 247 * @param mbr The {@link PendingIntent} to send the media button event to. 248 */ 249 public void setMediaButtonReceiver(@Nullable PendingIntent mbr) { 250 try { 251 mBinder.setMediaButtonReceiver(mbr); 252 } catch (RemoteException e) { 253 Log.wtf(TAG, "Failure in setMediaButtonReceiver.", e); 254 } 255 } 256 257 /** 258 * Set any flags for the session. 259 * 260 * @param flags The flags to set for this session. 261 */ 262 public void setFlags(@SessionFlags int flags) { 263 try { 264 mBinder.setFlags(flags); 265 } catch (RemoteException e) { 266 Log.wtf(TAG, "Failure in setFlags.", e); 267 } 268 } 269 270 /** 271 * Set the attributes for this session's audio. This will affect the 272 * system's volume handling for this session. If 273 * {@link #setPlaybackToRemote} was previously called it will stop receiving 274 * volume commands and the system will begin sending volume changes to the 275 * appropriate stream. 276 * <p> 277 * By default sessions use attributes for media. 278 * 279 * @param attributes The {@link AudioAttributes} for this session's audio. 280 */ 281 public void setPlaybackToLocal(AudioAttributes attributes) { 282 if (attributes == null) { 283 throw new IllegalArgumentException("Attributes cannot be null for local playback."); 284 } 285 try { 286 mBinder.setPlaybackToLocal(attributes); 287 } catch (RemoteException e) { 288 Log.wtf(TAG, "Failure in setPlaybackToLocal.", e); 289 } 290 } 291 292 /** 293 * Configure this session to use remote volume handling. This must be called 294 * to receive volume button events, otherwise the system will adjust the 295 * appropriate stream volume for this session. If 296 * {@link #setPlaybackToLocal} was previously called the system will stop 297 * handling volume changes for this session and pass them to the volume 298 * provider instead. 299 * 300 * @param volumeProvider The provider that will handle volume changes. May 301 * not be null. 302 */ 303 public void setPlaybackToRemote(@NonNull VolumeProvider volumeProvider) { 304 if (volumeProvider == null) { 305 throw new IllegalArgumentException("volumeProvider may not be null!"); 306 } 307 mVolumeProvider = volumeProvider; 308 volumeProvider.setCallback(new VolumeProvider.Callback() { 309 @Override 310 public void onVolumeChanged(VolumeProvider volumeProvider) { 311 notifyRemoteVolumeChanged(volumeProvider); 312 } 313 }); 314 315 try { 316 mBinder.setPlaybackToRemote(volumeProvider.getVolumeControl(), 317 volumeProvider.getMaxVolume()); 318 mBinder.setCurrentVolume(volumeProvider.getCurrentVolume()); 319 } catch (RemoteException e) { 320 Log.wtf(TAG, "Failure in setPlaybackToRemote.", e); 321 } 322 } 323 324 /** 325 * Set if this session is currently active and ready to receive commands. If 326 * set to false your session's controller may not be discoverable. You must 327 * set the session to active before it can start receiving media button 328 * events or transport commands. 329 * 330 * @param active Whether this session is active or not. 331 */ 332 public void setActive(boolean active) { 333 if (mActive == active) { 334 return; 335 } 336 try { 337 mBinder.setActive(active); 338 mActive = active; 339 } catch (RemoteException e) { 340 Log.wtf(TAG, "Failure in setActive.", e); 341 } 342 } 343 344 /** 345 * Get the current active state of this session. 346 * 347 * @return True if the session is active, false otherwise. 348 */ 349 public boolean isActive() { 350 return mActive; 351 } 352 353 /** 354 * Send a proprietary event to all MediaControllers listening to this 355 * Session. It's up to the Controller/Session owner to determine the meaning 356 * of any events. 357 * 358 * @param event The name of the event to send 359 * @param extras Any extras included with the event 360 */ 361 public void sendSessionEvent(@NonNull String event, @Nullable Bundle extras) { 362 if (TextUtils.isEmpty(event)) { 363 throw new IllegalArgumentException("event cannot be null or empty"); 364 } 365 try { 366 mBinder.sendEvent(event, extras); 367 } catch (RemoteException e) { 368 Log.wtf(TAG, "Error sending event", e); 369 } 370 } 371 372 /** 373 * This must be called when an app has finished performing playback. If 374 * playback is expected to start again shortly the session can be left open, 375 * but it must be released if your activity or service is being destroyed. 376 */ 377 public void release() { 378 try { 379 mBinder.destroy(); 380 } catch (RemoteException e) { 381 Log.wtf(TAG, "Error releasing session: ", e); 382 } 383 } 384 385 /** 386 * Retrieve a token object that can be used by apps to create a 387 * {@link MediaController} for interacting with this session. The owner of 388 * the session is responsible for deciding how to distribute these tokens. 389 * 390 * @return A token that can be used to create a MediaController for this 391 * session 392 */ 393 public @NonNull Token getSessionToken() { 394 return mSessionToken; 395 } 396 397 /** 398 * Get a controller for this session. This is a convenience method to avoid 399 * having to cache your own controller in process. 400 * 401 * @return A controller for this session. 402 */ 403 public @NonNull MediaController getController() { 404 return mController; 405 } 406 407 /** 408 * Update the current playback state. 409 * 410 * @param state The current state of playback 411 */ 412 public void setPlaybackState(@Nullable PlaybackState state) { 413 mPlaybackState = state; 414 try { 415 mBinder.setPlaybackState(state); 416 } catch (RemoteException e) { 417 Log.wtf(TAG, "Dead object in setPlaybackState.", e); 418 } 419 } 420 421 /** 422 * Update the current metadata. New metadata can be created using 423 * {@link android.media.MediaMetadata.Builder}. 424 * 425 * @param metadata The new metadata 426 */ 427 public void setMetadata(@Nullable MediaMetadata metadata) { 428 try { 429 mBinder.setMetadata(metadata); 430 } catch (RemoteException e) { 431 Log.wtf(TAG, "Dead object in setPlaybackState.", e); 432 } 433 } 434 435 /** 436 * Update the list of items in the play queue. It is an ordered list and 437 * should contain the current item, and previous or upcoming items if they 438 * exist. Specify null if there is no current play queue. 439 * <p> 440 * The queue should be of reasonable size. If the play queue is unbounded 441 * within your app, it is better to send a reasonable amount in a sliding 442 * window instead. 443 * 444 * @param queue A list of items in the play queue. 445 */ 446 public void setQueue(@Nullable List<QueueItem> queue) { 447 try { 448 mBinder.setQueue(queue == null ? null : new ParceledListSlice<QueueItem>(queue)); 449 } catch (RemoteException e) { 450 Log.wtf("Dead object in setQueue.", e); 451 } 452 } 453 454 /** 455 * Set the title of the play queue. The UI should display this title along 456 * with the play queue itself. 457 * e.g. "Play Queue", "Now Playing", or an album name. 458 * 459 * @param title The title of the play queue. 460 */ 461 public void setQueueTitle(@Nullable CharSequence title) { 462 try { 463 mBinder.setQueueTitle(title); 464 } catch (RemoteException e) { 465 Log.wtf("Dead object in setQueueTitle.", e); 466 } 467 } 468 469 /** 470 * Set the style of rating used by this session. Apps trying to set the 471 * rating should use this style. Must be one of the following: 472 * <ul> 473 * <li>{@link Rating#RATING_NONE}</li> 474 * <li>{@link Rating#RATING_3_STARS}</li> 475 * <li>{@link Rating#RATING_4_STARS}</li> 476 * <li>{@link Rating#RATING_5_STARS}</li> 477 * <li>{@link Rating#RATING_HEART}</li> 478 * <li>{@link Rating#RATING_PERCENTAGE}</li> 479 * <li>{@link Rating#RATING_THUMB_UP_DOWN}</li> 480 * </ul> 481 */ 482 public void setRatingType(int type) { 483 try { 484 mBinder.setRatingType(type); 485 } catch (RemoteException e) { 486 Log.e(TAG, "Error in setRatingType.", e); 487 } 488 } 489 490 /** 491 * Set some extras that can be associated with the {@link MediaSession}. No assumptions should 492 * be made as to how a {@link MediaController} will handle these extras. 493 * Keys should be fully qualified (e.g. com.example.MY_EXTRA) to avoid conflicts. 494 * 495 * @param extras The extras associated with the {@link MediaSession}. 496 */ 497 public void setExtras(@Nullable Bundle extras) { 498 try { 499 mBinder.setExtras(extras); 500 } catch (RemoteException e) { 501 Log.wtf("Dead object in setExtras.", e); 502 } 503 } 504 505 /** 506 * Notify the system that the remote volume changed. 507 * 508 * @param provider The provider that is handling volume changes. 509 * @hide 510 */ 511 public void notifyRemoteVolumeChanged(VolumeProvider provider) { 512 if (provider == null || provider != mVolumeProvider) { 513 Log.w(TAG, "Received update from stale volume provider"); 514 return; 515 } 516 try { 517 mBinder.setCurrentVolume(provider.getCurrentVolume()); 518 } catch (RemoteException e) { 519 Log.e(TAG, "Error in notifyVolumeChanged", e); 520 } 521 } 522 523 private void dispatchPlay() { 524 postToCallback(CallbackMessageHandler.MSG_PLAY); 525 } 526 527 private void dispatchPlayFromMediaId(String mediaId, Bundle extras) { 528 postToCallback(CallbackMessageHandler.MSG_PLAY_MEDIA_ID, mediaId, extras); 529 } 530 531 private void dispatchPlayFromSearch(String query, Bundle extras) { 532 postToCallback(CallbackMessageHandler.MSG_PLAY_SEARCH, query, extras); 533 } 534 535 private void dispatchSkipToItem(long id) { 536 postToCallback(CallbackMessageHandler.MSG_SKIP_TO_ITEM, id); 537 } 538 539 private void dispatchPause() { 540 postToCallback(CallbackMessageHandler.MSG_PAUSE); 541 } 542 543 private void dispatchStop() { 544 postToCallback(CallbackMessageHandler.MSG_STOP); 545 } 546 547 private void dispatchNext() { 548 postToCallback(CallbackMessageHandler.MSG_NEXT); 549 } 550 551 private void dispatchPrevious() { 552 postToCallback(CallbackMessageHandler.MSG_PREVIOUS); 553 } 554 555 private void dispatchFastForward() { 556 postToCallback(CallbackMessageHandler.MSG_FAST_FORWARD); 557 } 558 559 private void dispatchRewind() { 560 postToCallback(CallbackMessageHandler.MSG_REWIND); 561 } 562 563 private void dispatchSeekTo(long pos) { 564 postToCallback(CallbackMessageHandler.MSG_SEEK_TO, pos); 565 } 566 567 private void dispatchRate(Rating rating) { 568 postToCallback(CallbackMessageHandler.MSG_RATE, rating); 569 } 570 571 private void dispatchCustomAction(String action, Bundle args) { 572 postToCallback(CallbackMessageHandler.MSG_CUSTOM_ACTION, action, args); 573 } 574 575 private void dispatchMediaButton(Intent mediaButtonIntent) { 576 postToCallback(CallbackMessageHandler.MSG_MEDIA_BUTTON, mediaButtonIntent); 577 } 578 579 private void postToCallback(int what) { 580 postToCallback(what, null); 581 } 582 583 private void postCommand(String command, Bundle args, ResultReceiver resultCb) { 584 Command cmd = new Command(command, args, resultCb); 585 postToCallback(CallbackMessageHandler.MSG_COMMAND, cmd); 586 } 587 588 private void postToCallback(int what, Object obj) { 589 postToCallback(what, obj, null); 590 } 591 592 private void postToCallback(int what, Object obj, Bundle extras) { 593 synchronized (mLock) { 594 if (mCallback != null) { 595 mCallback.post(what, obj, extras); 596 } 597 } 598 } 599 600 /** 601 * Return true if this is considered an active playback state. 602 * 603 * @hide 604 */ 605 public static boolean isActiveState(int state) { 606 switch (state) { 607 case PlaybackState.STATE_FAST_FORWARDING: 608 case PlaybackState.STATE_REWINDING: 609 case PlaybackState.STATE_SKIPPING_TO_PREVIOUS: 610 case PlaybackState.STATE_SKIPPING_TO_NEXT: 611 case PlaybackState.STATE_BUFFERING: 612 case PlaybackState.STATE_CONNECTING: 613 case PlaybackState.STATE_PLAYING: 614 return true; 615 } 616 return false; 617 } 618 619 /** 620 * Represents an ongoing session. This may be passed to apps by the session 621 * owner to allow them to create a {@link MediaController} to communicate with 622 * the session. 623 */ 624 public static final class Token implements Parcelable { 625 626 private ISessionController mBinder; 627 628 /** 629 * @hide 630 */ 631 public Token(ISessionController binder) { 632 mBinder = binder; 633 } 634 635 @Override 636 public int describeContents() { 637 return 0; 638 } 639 640 @Override 641 public void writeToParcel(Parcel dest, int flags) { 642 dest.writeStrongBinder(mBinder.asBinder()); 643 } 644 645 @Override 646 public int hashCode() { 647 final int prime = 31; 648 int result = 1; 649 result = prime * result + ((mBinder == null) ? 0 : mBinder.asBinder().hashCode()); 650 return result; 651 } 652 653 @Override 654 public boolean equals(Object obj) { 655 if (this == obj) 656 return true; 657 if (obj == null) 658 return false; 659 if (getClass() != obj.getClass()) 660 return false; 661 Token other = (Token) obj; 662 if (mBinder == null) { 663 if (other.mBinder != null) 664 return false; 665 } else if (!mBinder.asBinder().equals(other.mBinder.asBinder())) 666 return false; 667 return true; 668 } 669 670 ISessionController getBinder() { 671 return mBinder; 672 } 673 674 public static final Parcelable.Creator<Token> CREATOR 675 = new Parcelable.Creator<Token>() { 676 @Override 677 public Token createFromParcel(Parcel in) { 678 return new Token(ISessionController.Stub.asInterface(in.readStrongBinder())); 679 } 680 681 @Override 682 public Token[] newArray(int size) { 683 return new Token[size]; 684 } 685 }; 686 } 687 688 /** 689 * Receives media buttons, transport controls, and commands from controllers 690 * and the system. A callback may be set using {@link #setCallback}. 691 */ 692 public abstract static class Callback { 693 private MediaSession mSession; 694 695 public Callback() { 696 } 697 698 /** 699 * Called when a controller has sent a command to this session. 700 * The owner of the session may handle custom commands but is not 701 * required to. 702 * 703 * @param command The command name. 704 * @param args Optional parameters for the command, may be null. 705 * @param cb A result receiver to which a result may be sent by the command, may be null. 706 */ 707 public void onCommand(@NonNull String command, @Nullable Bundle args, 708 @Nullable ResultReceiver cb) { 709 } 710 711 /** 712 * Called when a media button is pressed and this session has the 713 * highest priority or a controller sends a media button event to the 714 * session. The default behavior will call the relevant method if the 715 * action for it was set. 716 * <p> 717 * The intent will be of type {@link Intent#ACTION_MEDIA_BUTTON} with a 718 * KeyEvent in {@link Intent#EXTRA_KEY_EVENT} 719 * 720 * @param mediaButtonIntent an intent containing the KeyEvent as an 721 * extra 722 * @return True if the event was handled, false otherwise. 723 */ 724 public boolean onMediaButtonEvent(@NonNull Intent mediaButtonIntent) { 725 if (mSession != null 726 && Intent.ACTION_MEDIA_BUTTON.equals(mediaButtonIntent.getAction())) { 727 KeyEvent ke = mediaButtonIntent.getParcelableExtra(Intent.EXTRA_KEY_EVENT); 728 if (ke != null && ke.getAction() == KeyEvent.ACTION_DOWN) { 729 PlaybackState state = mSession.mPlaybackState; 730 long validActions = state == null ? 0 : state.getActions(); 731 switch (ke.getKeyCode()) { 732 case KeyEvent.KEYCODE_MEDIA_PLAY: 733 if ((validActions & PlaybackState.ACTION_PLAY) != 0) { 734 onPlay(); 735 return true; 736 } 737 break; 738 case KeyEvent.KEYCODE_MEDIA_PAUSE: 739 if ((validActions & PlaybackState.ACTION_PAUSE) != 0) { 740 onPause(); 741 return true; 742 } 743 break; 744 case KeyEvent.KEYCODE_MEDIA_NEXT: 745 if ((validActions & PlaybackState.ACTION_SKIP_TO_NEXT) != 0) { 746 onSkipToNext(); 747 return true; 748 } 749 break; 750 case KeyEvent.KEYCODE_MEDIA_PREVIOUS: 751 if ((validActions & PlaybackState.ACTION_SKIP_TO_PREVIOUS) != 0) { 752 onSkipToPrevious(); 753 return true; 754 } 755 break; 756 case KeyEvent.KEYCODE_MEDIA_STOP: 757 if ((validActions & PlaybackState.ACTION_STOP) != 0) { 758 onStop(); 759 return true; 760 } 761 break; 762 case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD: 763 if ((validActions & PlaybackState.ACTION_FAST_FORWARD) != 0) { 764 onFastForward(); 765 return true; 766 } 767 break; 768 case KeyEvent.KEYCODE_MEDIA_REWIND: 769 if ((validActions & PlaybackState.ACTION_REWIND) != 0) { 770 onRewind(); 771 return true; 772 } 773 break; 774 case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE: 775 case KeyEvent.KEYCODE_HEADSETHOOK: 776 boolean isPlaying = state == null ? false 777 : state.getState() == PlaybackState.STATE_PLAYING; 778 boolean canPlay = (validActions & (PlaybackState.ACTION_PLAY_PAUSE 779 | PlaybackState.ACTION_PLAY)) != 0; 780 boolean canPause = (validActions & (PlaybackState.ACTION_PLAY_PAUSE 781 | PlaybackState.ACTION_PAUSE)) != 0; 782 if (isPlaying && canPause) { 783 onPause(); 784 return true; 785 } else if (!isPlaying && canPlay) { 786 onPlay(); 787 return true; 788 } 789 break; 790 } 791 } 792 } 793 return false; 794 } 795 796 /** 797 * Override to handle requests to begin playback. 798 */ 799 public void onPlay() { 800 } 801 802 /** 803 * Override to handle requests to play a specific mediaId that was 804 * provided by your app's {@link MediaBrowserService}. 805 */ 806 public void onPlayFromMediaId(String mediaId, Bundle extras) { 807 } 808 809 /** 810 * Override to handle requests to begin playback from a search query. An 811 * empty query indicates that the app may play any music. The 812 * implementation should attempt to make a smart choice about what to 813 * play. 814 */ 815 public void onPlayFromSearch(String query, Bundle extras) { 816 } 817 818 /** 819 * Override to handle requests to play an item with a given id from the 820 * play queue. 821 */ 822 public void onSkipToQueueItem(long id) { 823 } 824 825 /** 826 * Override to handle requests to pause playback. 827 */ 828 public void onPause() { 829 } 830 831 /** 832 * Override to handle requests to skip to the next media item. 833 */ 834 public void onSkipToNext() { 835 } 836 837 /** 838 * Override to handle requests to skip to the previous media item. 839 */ 840 public void onSkipToPrevious() { 841 } 842 843 /** 844 * Override to handle requests to fast forward. 845 */ 846 public void onFastForward() { 847 } 848 849 /** 850 * Override to handle requests to rewind. 851 */ 852 public void onRewind() { 853 } 854 855 /** 856 * Override to handle requests to stop playback. 857 */ 858 public void onStop() { 859 } 860 861 /** 862 * Override to handle requests to seek to a specific position in ms. 863 * 864 * @param pos New position to move to, in milliseconds. 865 */ 866 public void onSeekTo(long pos) { 867 } 868 869 /** 870 * Override to handle the item being rated. 871 * 872 * @param rating 873 */ 874 public void onSetRating(@NonNull Rating rating) { 875 } 876 877 /** 878 * Called when a {@link MediaController} wants a {@link PlaybackState.CustomAction} to be 879 * performed. 880 * 881 * @param action The action that was originally sent in the 882 * {@link PlaybackState.CustomAction}. 883 * @param extras Optional extras specified by the {@link MediaController}. 884 */ 885 public void onCustomAction(@NonNull String action, @Nullable Bundle extras) { 886 } 887 } 888 889 /** 890 * @hide 891 */ 892 public static class CallbackStub extends ISessionCallback.Stub { 893 private WeakReference<MediaSession> mMediaSession; 894 895 public CallbackStub(MediaSession session) { 896 mMediaSession = new WeakReference<MediaSession>(session); 897 } 898 899 @Override 900 public void onCommand(String command, Bundle args, ResultReceiver cb) { 901 MediaSession session = mMediaSession.get(); 902 if (session != null) { 903 session.postCommand(command, args, cb); 904 } 905 } 906 907 @Override 908 public void onMediaButton(Intent mediaButtonIntent, int sequenceNumber, 909 ResultReceiver cb) { 910 MediaSession session = mMediaSession.get(); 911 try { 912 if (session != null) { 913 session.dispatchMediaButton(mediaButtonIntent); 914 } 915 } finally { 916 if (cb != null) { 917 cb.send(sequenceNumber, null); 918 } 919 } 920 } 921 922 @Override 923 public void onPlay() { 924 MediaSession session = mMediaSession.get(); 925 if (session != null) { 926 session.dispatchPlay(); 927 } 928 } 929 930 @Override 931 public void onPlayFromMediaId(String mediaId, Bundle extras) { 932 MediaSession session = mMediaSession.get(); 933 if (session != null) { 934 session.dispatchPlayFromMediaId(mediaId, extras); 935 } 936 } 937 938 @Override 939 public void onPlayFromSearch(String query, Bundle extras) { 940 MediaSession session = mMediaSession.get(); 941 if (session != null) { 942 session.dispatchPlayFromSearch(query, extras); 943 } 944 } 945 946 @Override 947 public void onSkipToTrack(long id) { 948 MediaSession session = mMediaSession.get(); 949 if (session != null) { 950 session.dispatchSkipToItem(id); 951 } 952 } 953 954 @Override 955 public void onPause() { 956 MediaSession session = mMediaSession.get(); 957 if (session != null) { 958 session.dispatchPause(); 959 } 960 } 961 962 @Override 963 public void onStop() { 964 MediaSession session = mMediaSession.get(); 965 if (session != null) { 966 session.dispatchStop(); 967 } 968 } 969 970 @Override 971 public void onNext() { 972 MediaSession session = mMediaSession.get(); 973 if (session != null) { 974 session.dispatchNext(); 975 } 976 } 977 978 @Override 979 public void onPrevious() { 980 MediaSession session = mMediaSession.get(); 981 if (session != null) { 982 session.dispatchPrevious(); 983 } 984 } 985 986 @Override 987 public void onFastForward() { 988 MediaSession session = mMediaSession.get(); 989 if (session != null) { 990 session.dispatchFastForward(); 991 } 992 } 993 994 @Override 995 public void onRewind() { 996 MediaSession session = mMediaSession.get(); 997 if (session != null) { 998 session.dispatchRewind(); 999 } 1000 } 1001 1002 @Override 1003 public void onSeekTo(long pos) { 1004 MediaSession session = mMediaSession.get(); 1005 if (session != null) { 1006 session.dispatchSeekTo(pos); 1007 } 1008 } 1009 1010 @Override 1011 public void onRate(Rating rating) { 1012 MediaSession session = mMediaSession.get(); 1013 if (session != null) { 1014 session.dispatchRate(rating); 1015 } 1016 } 1017 1018 @Override 1019 public void onCustomAction(String action, Bundle args) { 1020 MediaSession session = mMediaSession.get(); 1021 if (session != null) { 1022 session.dispatchCustomAction(action, args); 1023 } 1024 } 1025 1026 @Override 1027 public void onAdjustVolume(int direction) { 1028 MediaSession session = mMediaSession.get(); 1029 if (session != null) { 1030 if (session.mVolumeProvider != null) { 1031 session.mVolumeProvider.onAdjustVolume(direction); 1032 } 1033 } 1034 } 1035 1036 @Override 1037 public void onSetVolumeTo(int value) { 1038 MediaSession session = mMediaSession.get(); 1039 if (session != null) { 1040 if (session.mVolumeProvider != null) { 1041 session.mVolumeProvider.onSetVolumeTo(value); 1042 } 1043 } 1044 } 1045 1046 } 1047 1048 /** 1049 * A single item that is part of the play queue. It contains a description 1050 * of the item and its id in the queue. 1051 */ 1052 public static final class QueueItem implements Parcelable { 1053 /** 1054 * This id is reserved. No items can be explicitly asigned this id. 1055 */ 1056 public static final int UNKNOWN_ID = -1; 1057 1058 private final MediaDescription mDescription; 1059 private final long mId; 1060 1061 /** 1062 * Create a new {@link MediaSession.QueueItem}. 1063 * 1064 * @param description The {@link MediaDescription} for this item. 1065 * @param id An identifier for this item. It must be unique within the 1066 * play queue and cannot be {@link #UNKNOWN_ID}. 1067 */ 1068 public QueueItem(MediaDescription description, long id) { 1069 if (description == null) { 1070 throw new IllegalArgumentException("Description cannot be null."); 1071 } 1072 if (id == UNKNOWN_ID) { 1073 throw new IllegalArgumentException("Id cannot be QueueItem.UNKNOWN_ID"); 1074 } 1075 mDescription = description; 1076 mId = id; 1077 } 1078 1079 private QueueItem(Parcel in) { 1080 mDescription = MediaDescription.CREATOR.createFromParcel(in); 1081 mId = in.readLong(); 1082 } 1083 1084 /** 1085 * Get the description for this item. 1086 */ 1087 public MediaDescription getDescription() { 1088 return mDescription; 1089 } 1090 1091 /** 1092 * Get the queue id for this item. 1093 */ 1094 public long getQueueId() { 1095 return mId; 1096 } 1097 1098 @Override 1099 public void writeToParcel(Parcel dest, int flags) { 1100 mDescription.writeToParcel(dest, flags); 1101 dest.writeLong(mId); 1102 } 1103 1104 @Override 1105 public int describeContents() { 1106 return 0; 1107 } 1108 1109 public static final Creator<MediaSession.QueueItem> CREATOR = new Creator<MediaSession.QueueItem>() { 1110 1111 @Override 1112 public MediaSession.QueueItem createFromParcel(Parcel p) { 1113 return new MediaSession.QueueItem(p); 1114 } 1115 1116 @Override 1117 public MediaSession.QueueItem[] newArray(int size) { 1118 return new MediaSession.QueueItem[size]; 1119 } 1120 }; 1121 1122 @Override 1123 public String toString() { 1124 return "MediaSession.QueueItem {" + 1125 "Description=" + mDescription + 1126 ", Id=" + mId + " }"; 1127 } 1128 } 1129 1130 private static final class Command { 1131 public final String command; 1132 public final Bundle extras; 1133 public final ResultReceiver stub; 1134 1135 public Command(String command, Bundle extras, ResultReceiver stub) { 1136 this.command = command; 1137 this.extras = extras; 1138 this.stub = stub; 1139 } 1140 } 1141 1142 private class CallbackMessageHandler extends Handler { 1143 1144 private static final int MSG_PLAY = 1; 1145 private static final int MSG_PLAY_MEDIA_ID = 2; 1146 private static final int MSG_PLAY_SEARCH = 3; 1147 private static final int MSG_SKIP_TO_ITEM = 4; 1148 private static final int MSG_PAUSE = 5; 1149 private static final int MSG_STOP = 6; 1150 private static final int MSG_NEXT = 7; 1151 private static final int MSG_PREVIOUS = 8; 1152 private static final int MSG_FAST_FORWARD = 9; 1153 private static final int MSG_REWIND = 10; 1154 private static final int MSG_SEEK_TO = 11; 1155 private static final int MSG_RATE = 12; 1156 private static final int MSG_CUSTOM_ACTION = 13; 1157 private static final int MSG_MEDIA_BUTTON = 14; 1158 private static final int MSG_COMMAND = 15; 1159 1160 private MediaSession.Callback mCallback; 1161 1162 public CallbackMessageHandler(Looper looper, MediaSession.Callback callback) { 1163 super(looper, null, true); 1164 mCallback = callback; 1165 } 1166 1167 public void post(int what, Object obj, Bundle bundle) { 1168 Message msg = obtainMessage(what, obj); 1169 msg.setData(bundle); 1170 msg.sendToTarget(); 1171 } 1172 1173 public void post(int what, Object obj) { 1174 obtainMessage(what, obj).sendToTarget(); 1175 } 1176 1177 public void post(int what) { 1178 post(what, null); 1179 } 1180 1181 public void post(int what, Object obj, int arg1) { 1182 obtainMessage(what, arg1, 0, obj).sendToTarget(); 1183 } 1184 1185 @Override 1186 public void handleMessage(Message msg) { 1187 switch (msg.what) { 1188 case MSG_PLAY: 1189 mCallback.onPlay(); 1190 break; 1191 case MSG_PLAY_MEDIA_ID: 1192 mCallback.onPlayFromMediaId((String) msg.obj, msg.getData()); 1193 break; 1194 case MSG_PLAY_SEARCH: 1195 mCallback.onPlayFromSearch((String) msg.obj, msg.getData()); 1196 break; 1197 case MSG_SKIP_TO_ITEM: 1198 mCallback.onSkipToQueueItem((Long) msg.obj); 1199 break; 1200 case MSG_PAUSE: 1201 mCallback.onPause(); 1202 break; 1203 case MSG_STOP: 1204 mCallback.onStop(); 1205 break; 1206 case MSG_NEXT: 1207 mCallback.onSkipToNext(); 1208 break; 1209 case MSG_PREVIOUS: 1210 mCallback.onSkipToPrevious(); 1211 break; 1212 case MSG_FAST_FORWARD: 1213 mCallback.onFastForward(); 1214 break; 1215 case MSG_REWIND: 1216 mCallback.onRewind(); 1217 break; 1218 case MSG_SEEK_TO: 1219 mCallback.onSeekTo((Long) msg.obj); 1220 break; 1221 case MSG_RATE: 1222 mCallback.onSetRating((Rating) msg.obj); 1223 break; 1224 case MSG_CUSTOM_ACTION: 1225 mCallback.onCustomAction((String) msg.obj, msg.getData()); 1226 break; 1227 case MSG_MEDIA_BUTTON: 1228 mCallback.onMediaButtonEvent((Intent) msg.obj); 1229 break; 1230 case MSG_COMMAND: 1231 Command cmd = (Command) msg.obj; 1232 mCallback.onCommand(cmd.command, cmd.extras, cmd.stub); 1233 break; 1234 } 1235 } 1236 } 1237} 1238