MediaSession.java revision 22188f118754c3b31c13d2f94daf718f111d92af
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.net.Uri; 33import android.os.Bundle; 34import android.os.Handler; 35import android.os.Looper; 36import android.os.Message; 37import android.os.Parcel; 38import android.os.Parcelable; 39import android.os.RemoteException; 40import android.os.ResultReceiver; 41import android.os.UserHandle; 42import android.service.media.MediaBrowserService; 43import android.text.TextUtils; 44import android.util.Log; 45import android.view.KeyEvent; 46 47import java.lang.annotation.Retention; 48import java.lang.annotation.RetentionPolicy; 49import java.lang.ref.WeakReference; 50import java.util.List; 51 52/** 53 * Allows interaction with media controllers, volume keys, media buttons, and 54 * transport controls. 55 * <p> 56 * A MediaSession should be created when an app wants to publish media playback 57 * information or handle media keys. In general an app only needs one session 58 * for all playback, though multiple sessions can be created to provide finer 59 * grain controls of media. 60 * <p> 61 * Once a session is created the owner of the session may pass its 62 * {@link #getSessionToken() session token} to other processes to allow them to 63 * create a {@link MediaController} to interact with the session. 64 * <p> 65 * To receive commands, media keys, and other events a {@link Callback} must be 66 * set with {@link #setCallback(Callback)} and {@link #setActive(boolean) 67 * setActive(true)} must be called. 68 * <p> 69 * When an app is finished performing playback it must call {@link #release()} 70 * to clean up the session and notify any controllers. 71 * <p> 72 * MediaSession objects are thread safe. 73 */ 74public final class MediaSession { 75 private static final String TAG = "MediaSession"; 76 77 /** 78 * Set this flag on the session to indicate that it can handle media button 79 * events. 80 */ 81 public static final int FLAG_HANDLES_MEDIA_BUTTONS = 1 << 0; 82 83 /** 84 * Set this flag on the session to indicate that it handles transport 85 * control commands through its {@link Callback}. 86 */ 87 public static final int FLAG_HANDLES_TRANSPORT_CONTROLS = 1 << 1; 88 89 /** 90 * System only flag for a session that needs to have priority over all other 91 * sessions. This flag ensures this session will receive media button events 92 * regardless of the current ordering in the system. 93 * 94 * @hide 95 */ 96 public static final int FLAG_EXCLUSIVE_GLOBAL_PRIORITY = 1 << 16; 97 98 /** @hide */ 99 @Retention(RetentionPolicy.SOURCE) 100 @IntDef(flag = true, value = { 101 FLAG_HANDLES_MEDIA_BUTTONS, 102 FLAG_HANDLES_TRANSPORT_CONTROLS, 103 FLAG_EXCLUSIVE_GLOBAL_PRIORITY }) 104 public @interface SessionFlags { } 105 106 private final Object mLock = new Object(); 107 private final int mMaxBitmapSize; 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 mMaxBitmapSize = context.getResources().getDimensionPixelSize( 152 com.android.internal.R.dimen.config_mediaMetadataBitmapMaxSize); 153 mCbStub = new CallbackStub(this); 154 MediaSessionManager manager = (MediaSessionManager) context 155 .getSystemService(Context.MEDIA_SESSION_SERVICE); 156 try { 157 mBinder = manager.createSession(mCbStub, tag, userId); 158 mSessionToken = new Token(mBinder.getController()); 159 mController = new MediaController(context, mSessionToken); 160 } catch (RemoteException e) { 161 throw new RuntimeException("Remote error creating session.", e); 162 } 163 } 164 165 /** 166 * Set the callback to receive updates for the MediaSession. This includes 167 * media button events and transport controls. The caller's thread will be 168 * used to post updates. 169 * <p> 170 * Set the callback to null to stop receiving updates. 171 * 172 * @param callback The callback object 173 */ 174 public void setCallback(@Nullable Callback callback) { 175 setCallback(callback, null); 176 } 177 178 /** 179 * Set the callback to receive updates for the MediaSession. This includes 180 * media button events and transport controls. 181 * <p> 182 * Set the callback to null to stop receiving updates. 183 * 184 * @param callback The callback to receive updates on. 185 * @param handler The handler that events should be posted on. 186 */ 187 public void setCallback(@Nullable Callback callback, @Nullable Handler handler) { 188 synchronized (mLock) { 189 if (callback == null) { 190 if (mCallback != null) { 191 mCallback.mCallback.mSession = null; 192 } 193 mCallback = null; 194 return; 195 } 196 if (mCallback != null) { 197 // We're updating the callback, clear the session from the old 198 // one. 199 mCallback.mCallback.mSession = null; 200 } 201 if (handler == null) { 202 handler = new Handler(); 203 } 204 callback.mSession = this; 205 CallbackMessageHandler msgHandler = new CallbackMessageHandler(handler.getLooper(), 206 callback); 207 mCallback = msgHandler; 208 } 209 } 210 211 /** 212 * Set an intent for launching UI for this Session. This can be used as a 213 * quick link to an ongoing media screen. The intent should be for an 214 * activity that may be started using {@link Activity#startActivity(Intent)}. 215 * 216 * @param pi The intent to launch to show UI for this Session. 217 */ 218 public void setSessionActivity(@Nullable PendingIntent pi) { 219 try { 220 mBinder.setLaunchPendingIntent(pi); 221 } catch (RemoteException e) { 222 Log.wtf(TAG, "Failure in setLaunchPendingIntent.", e); 223 } 224 } 225 226 /** 227 * Set a pending intent for your media button receiver to allow restarting 228 * playback after the session has been stopped. If your app is started in 229 * this way an {@link Intent#ACTION_MEDIA_BUTTON} intent will be sent via 230 * the pending intent. 231 * 232 * @param mbr The {@link PendingIntent} to send the media button event to. 233 */ 234 public void setMediaButtonReceiver(@Nullable PendingIntent mbr) { 235 try { 236 mBinder.setMediaButtonReceiver(mbr); 237 } catch (RemoteException e) { 238 Log.wtf(TAG, "Failure in setMediaButtonReceiver.", e); 239 } 240 } 241 242 /** 243 * Set any flags for the session. 244 * 245 * @param flags The flags to set for this session. 246 */ 247 public void setFlags(@SessionFlags int flags) { 248 try { 249 mBinder.setFlags(flags); 250 } catch (RemoteException e) { 251 Log.wtf(TAG, "Failure in setFlags.", e); 252 } 253 } 254 255 /** 256 * Set the attributes for this session's audio. This will affect the 257 * system's volume handling for this session. If 258 * {@link #setPlaybackToRemote} was previously called it will stop receiving 259 * volume commands and the system will begin sending volume changes to the 260 * appropriate stream. 261 * <p> 262 * By default sessions use attributes for media. 263 * 264 * @param attributes The {@link AudioAttributes} for this session's audio. 265 */ 266 public void setPlaybackToLocal(AudioAttributes attributes) { 267 if (attributes == null) { 268 throw new IllegalArgumentException("Attributes cannot be null for local playback."); 269 } 270 try { 271 mBinder.setPlaybackToLocal(attributes); 272 } catch (RemoteException e) { 273 Log.wtf(TAG, "Failure in setPlaybackToLocal.", e); 274 } 275 } 276 277 /** 278 * Configure this session to use remote volume handling. This must be called 279 * to receive volume button events, otherwise the system will adjust the 280 * appropriate stream volume for this session. If 281 * {@link #setPlaybackToLocal} was previously called the system will stop 282 * handling volume changes for this session and pass them to the volume 283 * provider instead. 284 * 285 * @param volumeProvider The provider that will handle volume changes. May 286 * not be null. 287 */ 288 public void setPlaybackToRemote(@NonNull VolumeProvider volumeProvider) { 289 if (volumeProvider == null) { 290 throw new IllegalArgumentException("volumeProvider may not be null!"); 291 } 292 synchronized (mLock) { 293 mVolumeProvider = volumeProvider; 294 } 295 volumeProvider.setCallback(new VolumeProvider.Callback() { 296 @Override 297 public void onVolumeChanged(VolumeProvider volumeProvider) { 298 notifyRemoteVolumeChanged(volumeProvider); 299 } 300 }); 301 302 try { 303 mBinder.setPlaybackToRemote(volumeProvider.getVolumeControl(), 304 volumeProvider.getMaxVolume()); 305 mBinder.setCurrentVolume(volumeProvider.getCurrentVolume()); 306 } catch (RemoteException e) { 307 Log.wtf(TAG, "Failure in setPlaybackToRemote.", e); 308 } 309 } 310 311 /** 312 * Set if this session is currently active and ready to receive commands. If 313 * set to false your session's controller may not be discoverable. You must 314 * set the session to active before it can start receiving media button 315 * events or transport commands. 316 * 317 * @param active Whether this session is active or not. 318 */ 319 public void setActive(boolean active) { 320 if (mActive == active) { 321 return; 322 } 323 try { 324 mBinder.setActive(active); 325 mActive = active; 326 } catch (RemoteException e) { 327 Log.wtf(TAG, "Failure in setActive.", e); 328 } 329 } 330 331 /** 332 * Get the current active state of this session. 333 * 334 * @return True if the session is active, false otherwise. 335 */ 336 public boolean isActive() { 337 return mActive; 338 } 339 340 /** 341 * Send a proprietary event to all MediaControllers listening to this 342 * Session. It's up to the Controller/Session owner to determine the meaning 343 * of any events. 344 * 345 * @param event The name of the event to send 346 * @param extras Any extras included with the event 347 */ 348 public void sendSessionEvent(@NonNull String event, @Nullable Bundle extras) { 349 if (TextUtils.isEmpty(event)) { 350 throw new IllegalArgumentException("event cannot be null or empty"); 351 } 352 try { 353 mBinder.sendEvent(event, extras); 354 } catch (RemoteException e) { 355 Log.wtf(TAG, "Error sending event", e); 356 } 357 } 358 359 /** 360 * This must be called when an app has finished performing playback. If 361 * playback is expected to start again shortly the session can be left open, 362 * but it must be released if your activity or service is being destroyed. 363 */ 364 public void release() { 365 try { 366 mBinder.destroy(); 367 } catch (RemoteException e) { 368 Log.wtf(TAG, "Error releasing session: ", e); 369 } 370 } 371 372 /** 373 * Retrieve a token object that can be used by apps to create a 374 * {@link MediaController} for interacting with this session. The owner of 375 * the session is responsible for deciding how to distribute these tokens. 376 * 377 * @return A token that can be used to create a MediaController for this 378 * session 379 */ 380 public @NonNull Token getSessionToken() { 381 return mSessionToken; 382 } 383 384 /** 385 * Get a controller for this session. This is a convenience method to avoid 386 * having to cache your own controller in process. 387 * 388 * @return A controller for this session. 389 */ 390 public @NonNull MediaController getController() { 391 return mController; 392 } 393 394 /** 395 * Update the current playback state. 396 * 397 * @param state The current state of playback 398 */ 399 public void setPlaybackState(@Nullable PlaybackState state) { 400 mPlaybackState = state; 401 try { 402 mBinder.setPlaybackState(state); 403 } catch (RemoteException e) { 404 Log.wtf(TAG, "Dead object in setPlaybackState.", e); 405 } 406 } 407 408 /** 409 * Update the current metadata. New metadata can be created using 410 * {@link android.media.MediaMetadata.Builder}. 411 * 412 * @param metadata The new metadata 413 */ 414 public void setMetadata(@Nullable MediaMetadata metadata) { 415 if (metadata != null ) { 416 metadata = (new MediaMetadata.Builder(metadata, mMaxBitmapSize)).build(); 417 } 418 try { 419 mBinder.setMetadata(metadata); 420 } catch (RemoteException e) { 421 Log.wtf(TAG, "Dead object in setPlaybackState.", e); 422 } 423 } 424 425 /** 426 * Update the list of items in the play queue. It is an ordered list and 427 * should contain the current item, and previous or upcoming items if they 428 * exist. Specify null if there is no current play queue. 429 * <p> 430 * The queue should be of reasonable size. If the play queue is unbounded 431 * within your app, it is better to send a reasonable amount in a sliding 432 * window instead. 433 * 434 * @param queue A list of items in the play queue. 435 */ 436 public void setQueue(@Nullable List<QueueItem> queue) { 437 try { 438 mBinder.setQueue(queue == null ? null : new ParceledListSlice<QueueItem>(queue)); 439 } catch (RemoteException e) { 440 Log.wtf("Dead object in setQueue.", e); 441 } 442 } 443 444 /** 445 * Set the title of the play queue. The UI should display this title along 446 * with the play queue itself. 447 * e.g. "Play Queue", "Now Playing", or an album name. 448 * 449 * @param title The title of the play queue. 450 */ 451 public void setQueueTitle(@Nullable CharSequence title) { 452 try { 453 mBinder.setQueueTitle(title); 454 } catch (RemoteException e) { 455 Log.wtf("Dead object in setQueueTitle.", e); 456 } 457 } 458 459 /** 460 * Set the style of rating used by this session. Apps trying to set the 461 * rating should use this style. Must be one of the following: 462 * <ul> 463 * <li>{@link Rating#RATING_NONE}</li> 464 * <li>{@link Rating#RATING_3_STARS}</li> 465 * <li>{@link Rating#RATING_4_STARS}</li> 466 * <li>{@link Rating#RATING_5_STARS}</li> 467 * <li>{@link Rating#RATING_HEART}</li> 468 * <li>{@link Rating#RATING_PERCENTAGE}</li> 469 * <li>{@link Rating#RATING_THUMB_UP_DOWN}</li> 470 * </ul> 471 */ 472 public void setRatingType(int type) { 473 try { 474 mBinder.setRatingType(type); 475 } catch (RemoteException e) { 476 Log.e(TAG, "Error in setRatingType.", e); 477 } 478 } 479 480 /** 481 * Set some extras that can be associated with the {@link MediaSession}. No assumptions should 482 * be made as to how a {@link MediaController} will handle these extras. 483 * Keys should be fully qualified (e.g. com.example.MY_EXTRA) to avoid conflicts. 484 * 485 * @param extras The extras associated with the {@link MediaSession}. 486 */ 487 public void setExtras(@Nullable Bundle extras) { 488 try { 489 mBinder.setExtras(extras); 490 } catch (RemoteException e) { 491 Log.wtf("Dead object in setExtras.", e); 492 } 493 } 494 495 /** 496 * Notify the system that the remote volume changed. 497 * 498 * @param provider The provider that is handling volume changes. 499 * @hide 500 */ 501 public void notifyRemoteVolumeChanged(VolumeProvider provider) { 502 synchronized (mLock) { 503 if (provider == null || provider != mVolumeProvider) { 504 Log.w(TAG, "Received update from stale volume provider"); 505 return; 506 } 507 } 508 try { 509 mBinder.setCurrentVolume(provider.getCurrentVolume()); 510 } catch (RemoteException e) { 511 Log.e(TAG, "Error in notifyVolumeChanged", e); 512 } 513 } 514 515 private void dispatchPrepare() { 516 postToCallback(CallbackMessageHandler.MSG_PREPARE); 517 } 518 519 private void dispatchPrepareFromMediaId(String mediaId, Bundle extras) { 520 postToCallback(CallbackMessageHandler.MSG_PREPARE_MEDIA_ID, mediaId, extras); 521 } 522 523 private void dispatchPrepareFromSearch(String query, Bundle extras) { 524 postToCallback(CallbackMessageHandler.MSG_PREPARE_SEARCH, query, extras); 525 } 526 527 private void dispatchPrepareFromUri(Uri uri, Bundle extras) { 528 postToCallback(CallbackMessageHandler.MSG_PREPARE_URI, uri, extras); 529 } 530 531 private void dispatchPlay() { 532 postToCallback(CallbackMessageHandler.MSG_PLAY); 533 } 534 535 private void dispatchPlayFromMediaId(String mediaId, Bundle extras) { 536 postToCallback(CallbackMessageHandler.MSG_PLAY_MEDIA_ID, mediaId, extras); 537 } 538 539 private void dispatchPlayFromSearch(String query, Bundle extras) { 540 postToCallback(CallbackMessageHandler.MSG_PLAY_SEARCH, query, extras); 541 } 542 543 private void dispatchPlayFromUri(Uri uri, Bundle extras) { 544 postToCallback(CallbackMessageHandler.MSG_PLAY_URI, uri, extras); 545 } 546 547 private void dispatchSkipToItem(long id) { 548 postToCallback(CallbackMessageHandler.MSG_SKIP_TO_ITEM, id); 549 } 550 551 private void dispatchPause() { 552 postToCallback(CallbackMessageHandler.MSG_PAUSE); 553 } 554 555 private void dispatchStop() { 556 postToCallback(CallbackMessageHandler.MSG_STOP); 557 } 558 559 private void dispatchNext() { 560 postToCallback(CallbackMessageHandler.MSG_NEXT); 561 } 562 563 private void dispatchPrevious() { 564 postToCallback(CallbackMessageHandler.MSG_PREVIOUS); 565 } 566 567 private void dispatchFastForward() { 568 postToCallback(CallbackMessageHandler.MSG_FAST_FORWARD); 569 } 570 571 private void dispatchRewind() { 572 postToCallback(CallbackMessageHandler.MSG_REWIND); 573 } 574 575 private void dispatchSeekTo(long pos) { 576 postToCallback(CallbackMessageHandler.MSG_SEEK_TO, pos); 577 } 578 579 private void dispatchRate(Rating rating) { 580 postToCallback(CallbackMessageHandler.MSG_RATE, rating); 581 } 582 583 private void dispatchCustomAction(String action, Bundle args) { 584 postToCallback(CallbackMessageHandler.MSG_CUSTOM_ACTION, action, args); 585 } 586 587 private void dispatchMediaButton(Intent mediaButtonIntent) { 588 postToCallback(CallbackMessageHandler.MSG_MEDIA_BUTTON, mediaButtonIntent); 589 } 590 591 private void dispatchAdjustVolume(int direction) { 592 postToCallback(CallbackMessageHandler.MSG_ADJUST_VOLUME, direction); 593 } 594 595 private void dispatchSetVolumeTo(int volume) { 596 postToCallback(CallbackMessageHandler.MSG_SET_VOLUME, volume); 597 } 598 599 private void postToCallback(int what) { 600 postToCallback(what, null); 601 } 602 603 private void postCommand(String command, Bundle args, ResultReceiver resultCb) { 604 Command cmd = new Command(command, args, resultCb); 605 postToCallback(CallbackMessageHandler.MSG_COMMAND, cmd); 606 } 607 608 private void postToCallback(int what, Object obj) { 609 postToCallback(what, obj, null); 610 } 611 612 private void postToCallback(int what, Object obj, Bundle extras) { 613 synchronized (mLock) { 614 if (mCallback != null) { 615 mCallback.post(what, obj, extras); 616 } 617 } 618 } 619 620 /** 621 * Return true if this is considered an active playback state. 622 * 623 * @hide 624 */ 625 public static boolean isActiveState(int state) { 626 switch (state) { 627 case PlaybackState.STATE_FAST_FORWARDING: 628 case PlaybackState.STATE_REWINDING: 629 case PlaybackState.STATE_SKIPPING_TO_PREVIOUS: 630 case PlaybackState.STATE_SKIPPING_TO_NEXT: 631 case PlaybackState.STATE_BUFFERING: 632 case PlaybackState.STATE_CONNECTING: 633 case PlaybackState.STATE_PLAYING: 634 return true; 635 } 636 return false; 637 } 638 639 /** 640 * Represents an ongoing session. This may be passed to apps by the session 641 * owner to allow them to create a {@link MediaController} to communicate with 642 * the session. 643 */ 644 public static final class Token implements Parcelable { 645 646 private ISessionController mBinder; 647 648 /** 649 * @hide 650 */ 651 public Token(ISessionController binder) { 652 mBinder = binder; 653 } 654 655 @Override 656 public int describeContents() { 657 return 0; 658 } 659 660 @Override 661 public void writeToParcel(Parcel dest, int flags) { 662 dest.writeStrongBinder(mBinder.asBinder()); 663 } 664 665 @Override 666 public int hashCode() { 667 final int prime = 31; 668 int result = 1; 669 result = prime * result + ((mBinder == null) ? 0 : mBinder.asBinder().hashCode()); 670 return result; 671 } 672 673 @Override 674 public boolean equals(Object obj) { 675 if (this == obj) 676 return true; 677 if (obj == null) 678 return false; 679 if (getClass() != obj.getClass()) 680 return false; 681 Token other = (Token) obj; 682 if (mBinder == null) { 683 if (other.mBinder != null) 684 return false; 685 } else if (!mBinder.asBinder().equals(other.mBinder.asBinder())) 686 return false; 687 return true; 688 } 689 690 ISessionController getBinder() { 691 return mBinder; 692 } 693 694 public static final Parcelable.Creator<Token> CREATOR 695 = new Parcelable.Creator<Token>() { 696 @Override 697 public Token createFromParcel(Parcel in) { 698 return new Token(ISessionController.Stub.asInterface(in.readStrongBinder())); 699 } 700 701 @Override 702 public Token[] newArray(int size) { 703 return new Token[size]; 704 } 705 }; 706 } 707 708 /** 709 * Receives media buttons, transport controls, and commands from controllers 710 * and the system. A callback may be set using {@link #setCallback}. 711 */ 712 public abstract static class Callback { 713 private MediaSession mSession; 714 715 public Callback() { 716 } 717 718 /** 719 * Called when a controller has sent a command to this session. 720 * The owner of the session may handle custom commands but is not 721 * required to. 722 * 723 * @param command The command name. 724 * @param args Optional parameters for the command, may be null. 725 * @param cb A result receiver to which a result may be sent by the command, may be null. 726 */ 727 public void onCommand(@NonNull String command, @Nullable Bundle args, 728 @Nullable ResultReceiver cb) { 729 } 730 731 /** 732 * Called when a media button is pressed and this session has the 733 * highest priority or a controller sends a media button event to the 734 * session. The default behavior will call the relevant method if the 735 * action for it was set. 736 * <p> 737 * The intent will be of type {@link Intent#ACTION_MEDIA_BUTTON} with a 738 * KeyEvent in {@link Intent#EXTRA_KEY_EVENT} 739 * 740 * @param mediaButtonIntent an intent containing the KeyEvent as an 741 * extra 742 * @return True if the event was handled, false otherwise. 743 */ 744 public boolean onMediaButtonEvent(@NonNull Intent mediaButtonIntent) { 745 if (mSession != null 746 && Intent.ACTION_MEDIA_BUTTON.equals(mediaButtonIntent.getAction())) { 747 KeyEvent ke = mediaButtonIntent.getParcelableExtra(Intent.EXTRA_KEY_EVENT); 748 if (ke != null && ke.getAction() == KeyEvent.ACTION_DOWN) { 749 PlaybackState state = mSession.mPlaybackState; 750 long validActions = state == null ? 0 : state.getActions(); 751 switch (ke.getKeyCode()) { 752 case KeyEvent.KEYCODE_MEDIA_PLAY: 753 if ((validActions & PlaybackState.ACTION_PLAY) != 0) { 754 onPlay(); 755 return true; 756 } 757 break; 758 case KeyEvent.KEYCODE_MEDIA_PAUSE: 759 if ((validActions & PlaybackState.ACTION_PAUSE) != 0) { 760 onPause(); 761 return true; 762 } 763 break; 764 case KeyEvent.KEYCODE_MEDIA_NEXT: 765 if ((validActions & PlaybackState.ACTION_SKIP_TO_NEXT) != 0) { 766 onSkipToNext(); 767 return true; 768 } 769 break; 770 case KeyEvent.KEYCODE_MEDIA_PREVIOUS: 771 if ((validActions & PlaybackState.ACTION_SKIP_TO_PREVIOUS) != 0) { 772 onSkipToPrevious(); 773 return true; 774 } 775 break; 776 case KeyEvent.KEYCODE_MEDIA_STOP: 777 if ((validActions & PlaybackState.ACTION_STOP) != 0) { 778 onStop(); 779 return true; 780 } 781 break; 782 case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD: 783 if ((validActions & PlaybackState.ACTION_FAST_FORWARD) != 0) { 784 onFastForward(); 785 return true; 786 } 787 break; 788 case KeyEvent.KEYCODE_MEDIA_REWIND: 789 if ((validActions & PlaybackState.ACTION_REWIND) != 0) { 790 onRewind(); 791 return true; 792 } 793 break; 794 case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE: 795 case KeyEvent.KEYCODE_HEADSETHOOK: 796 boolean isPlaying = state == null ? false 797 : state.getState() == PlaybackState.STATE_PLAYING; 798 boolean canPlay = (validActions & (PlaybackState.ACTION_PLAY_PAUSE 799 | PlaybackState.ACTION_PLAY)) != 0; 800 boolean canPause = (validActions & (PlaybackState.ACTION_PLAY_PAUSE 801 | PlaybackState.ACTION_PAUSE)) != 0; 802 if (isPlaying && canPause) { 803 onPause(); 804 return true; 805 } else if (!isPlaying && canPlay) { 806 onPlay(); 807 return true; 808 } 809 break; 810 } 811 } 812 } 813 return false; 814 } 815 816 /** 817 * Override to handle requests to prepare playback. The state of playback should be updated 818 * to {@link PlaybackState#STATE_PAUSED} after the preparation is done. Override 819 * {@link #onPlay} to handle requests for starting playback of prepared content. 820 */ 821 public void onPrepare() { 822 } 823 824 /** 825 * Override to handle requests to prepare for playing a specific mediaId that was provided 826 * by your app's {@link MediaBrowserService}. The state of playback should be updated 827 * to {@link PlaybackState#STATE_PAUSED} after the preparation is done. The playback of 828 * the prepared content should start in the implementation of {@link #onPlay}. Override 829 * {@link #onPlayFromMediaId} to handle requests for starting playback without preparation. 830 */ 831 public void onPrepareFromMediaId(String mediaId, Bundle extras) { 832 } 833 834 /** 835 * Override to handle requests to prepare playback from a search query. An 836 * empty query indicates that the app may prepare any music. The 837 * implementation should attempt to make a smart choice about what to 838 * play. The state of playback should be updated to {@link PlaybackState#STATE_PAUSED} 839 * after the preparation is done. The playback of the prepared content should start 840 * in the implementation of {@link #onPlay}. Override {@link #onPlayFromSearch} 841 * to handle requests for starting playback without preparation. 842 */ 843 public void onPrepareFromSearch(String query, Bundle extras) { 844 } 845 846 /** 847 * Override to handle requests to prepare a specific media item represented by a URI. 848 * The state of playback should be updated to {@link PlaybackState#STATE_PAUSED} 849 * after the preparation is done. The playback of the prepared content should start in 850 * the implementation of {@link #onPlay}. Override {@link #onPlayFromUri} to handle requests 851 * for starting playback without preparation. 852 */ 853 public void onPrepareFromUri(Uri uri, Bundle extras) { 854 } 855 856 /** 857 * Override to handle requests to begin playback. 858 */ 859 public void onPlay() { 860 } 861 862 /** 863 * Override to handle requests to begin playback from a search query. An 864 * empty query indicates that the app may play any music. The 865 * implementation should attempt to make a smart choice about what to 866 * play. 867 */ 868 public void onPlayFromSearch(String query, Bundle extras) { 869 } 870 871 /** 872 * Override to handle requests to play a specific mediaId that was 873 * provided by your app's {@link MediaBrowserService}. 874 */ 875 public void onPlayFromMediaId(String mediaId, Bundle extras) { 876 } 877 878 /** 879 * Override to handle requests to play a specific media item represented by a URI. 880 */ 881 public void onPlayFromUri(Uri uri, Bundle extras) { 882 } 883 884 /** 885 * Override to handle requests to play an item with a given id from the 886 * play queue. 887 */ 888 public void onSkipToQueueItem(long id) { 889 } 890 891 /** 892 * Override to handle requests to pause playback. 893 */ 894 public void onPause() { 895 } 896 897 /** 898 * Override to handle requests to skip to the next media item. 899 */ 900 public void onSkipToNext() { 901 } 902 903 /** 904 * Override to handle requests to skip to the previous media item. 905 */ 906 public void onSkipToPrevious() { 907 } 908 909 /** 910 * Override to handle requests to fast forward. 911 */ 912 public void onFastForward() { 913 } 914 915 /** 916 * Override to handle requests to rewind. 917 */ 918 public void onRewind() { 919 } 920 921 /** 922 * Override to handle requests to stop playback. 923 */ 924 public void onStop() { 925 } 926 927 /** 928 * Override to handle requests to seek to a specific position in ms. 929 * 930 * @param pos New position to move to, in milliseconds. 931 */ 932 public void onSeekTo(long pos) { 933 } 934 935 /** 936 * Override to handle the item being rated. 937 * 938 * @param rating 939 */ 940 public void onSetRating(@NonNull Rating rating) { 941 } 942 943 /** 944 * Called when a {@link MediaController} wants a {@link PlaybackState.CustomAction} to be 945 * performed. 946 * 947 * @param action The action that was originally sent in the 948 * {@link PlaybackState.CustomAction}. 949 * @param extras Optional extras specified by the {@link MediaController}. 950 */ 951 public void onCustomAction(@NonNull String action, @Nullable Bundle extras) { 952 } 953 } 954 955 /** 956 * @hide 957 */ 958 public static class CallbackStub extends ISessionCallback.Stub { 959 private WeakReference<MediaSession> mMediaSession; 960 961 public CallbackStub(MediaSession session) { 962 mMediaSession = new WeakReference<MediaSession>(session); 963 } 964 965 @Override 966 public void onCommand(String command, Bundle args, ResultReceiver cb) { 967 MediaSession session = mMediaSession.get(); 968 if (session != null) { 969 session.postCommand(command, args, cb); 970 } 971 } 972 973 @Override 974 public void onMediaButton(Intent mediaButtonIntent, int sequenceNumber, 975 ResultReceiver cb) { 976 MediaSession session = mMediaSession.get(); 977 try { 978 if (session != null) { 979 session.dispatchMediaButton(mediaButtonIntent); 980 } 981 } finally { 982 if (cb != null) { 983 cb.send(sequenceNumber, null); 984 } 985 } 986 } 987 988 @Override 989 public void onPrepare() { 990 MediaSession session = mMediaSession.get(); 991 if (session != null) { 992 session.dispatchPrepare(); 993 } 994 } 995 996 @Override 997 public void onPrepareFromMediaId(String mediaId, Bundle extras) { 998 MediaSession session = mMediaSession.get(); 999 if (session != null) { 1000 session.dispatchPrepareFromMediaId(mediaId, extras); 1001 } 1002 } 1003 1004 @Override 1005 public void onPrepareFromSearch(String query, Bundle extras) { 1006 MediaSession session = mMediaSession.get(); 1007 if (session != null) { 1008 session.dispatchPrepareFromSearch(query, extras); 1009 } 1010 } 1011 1012 @Override 1013 public void onPrepareFromUri(Uri uri, Bundle extras) { 1014 MediaSession session = mMediaSession.get(); 1015 if (session != null) { 1016 session.dispatchPrepareFromUri(uri, extras); 1017 } 1018 } 1019 1020 @Override 1021 public void onPlay() { 1022 MediaSession session = mMediaSession.get(); 1023 if (session != null) { 1024 session.dispatchPlay(); 1025 } 1026 } 1027 1028 @Override 1029 public void onPlayFromMediaId(String mediaId, Bundle extras) { 1030 MediaSession session = mMediaSession.get(); 1031 if (session != null) { 1032 session.dispatchPlayFromMediaId(mediaId, extras); 1033 } 1034 } 1035 1036 @Override 1037 public void onPlayFromSearch(String query, Bundle extras) { 1038 MediaSession session = mMediaSession.get(); 1039 if (session != null) { 1040 session.dispatchPlayFromSearch(query, extras); 1041 } 1042 } 1043 1044 @Override 1045 public void onPlayFromUri(Uri uri, Bundle extras) { 1046 MediaSession session = mMediaSession.get(); 1047 if (session != null) { 1048 session.dispatchPlayFromUri(uri, extras); 1049 } 1050 } 1051 1052 @Override 1053 public void onSkipToTrack(long id) { 1054 MediaSession session = mMediaSession.get(); 1055 if (session != null) { 1056 session.dispatchSkipToItem(id); 1057 } 1058 } 1059 1060 @Override 1061 public void onPause() { 1062 MediaSession session = mMediaSession.get(); 1063 if (session != null) { 1064 session.dispatchPause(); 1065 } 1066 } 1067 1068 @Override 1069 public void onStop() { 1070 MediaSession session = mMediaSession.get(); 1071 if (session != null) { 1072 session.dispatchStop(); 1073 } 1074 } 1075 1076 @Override 1077 public void onNext() { 1078 MediaSession session = mMediaSession.get(); 1079 if (session != null) { 1080 session.dispatchNext(); 1081 } 1082 } 1083 1084 @Override 1085 public void onPrevious() { 1086 MediaSession session = mMediaSession.get(); 1087 if (session != null) { 1088 session.dispatchPrevious(); 1089 } 1090 } 1091 1092 @Override 1093 public void onFastForward() { 1094 MediaSession session = mMediaSession.get(); 1095 if (session != null) { 1096 session.dispatchFastForward(); 1097 } 1098 } 1099 1100 @Override 1101 public void onRewind() { 1102 MediaSession session = mMediaSession.get(); 1103 if (session != null) { 1104 session.dispatchRewind(); 1105 } 1106 } 1107 1108 @Override 1109 public void onSeekTo(long pos) { 1110 MediaSession session = mMediaSession.get(); 1111 if (session != null) { 1112 session.dispatchSeekTo(pos); 1113 } 1114 } 1115 1116 @Override 1117 public void onRate(Rating rating) { 1118 MediaSession session = mMediaSession.get(); 1119 if (session != null) { 1120 session.dispatchRate(rating); 1121 } 1122 } 1123 1124 @Override 1125 public void onCustomAction(String action, Bundle args) { 1126 MediaSession session = mMediaSession.get(); 1127 if (session != null) { 1128 session.dispatchCustomAction(action, args); 1129 } 1130 } 1131 1132 @Override 1133 public void onAdjustVolume(int direction) { 1134 MediaSession session = mMediaSession.get(); 1135 if (session != null) { 1136 session.dispatchAdjustVolume(direction); 1137 } 1138 } 1139 1140 @Override 1141 public void onSetVolumeTo(int value) { 1142 MediaSession session = mMediaSession.get(); 1143 if (session != null) { 1144 session.dispatchSetVolumeTo(value); 1145 } 1146 } 1147 1148 } 1149 1150 /** 1151 * A single item that is part of the play queue. It contains a description 1152 * of the item and its id in the queue. 1153 */ 1154 public static final class QueueItem implements Parcelable { 1155 /** 1156 * This id is reserved. No items can be explicitly asigned this id. 1157 */ 1158 public static final int UNKNOWN_ID = -1; 1159 1160 private final MediaDescription mDescription; 1161 private final long mId; 1162 1163 /** 1164 * Create a new {@link MediaSession.QueueItem}. 1165 * 1166 * @param description The {@link MediaDescription} for this item. 1167 * @param id An identifier for this item. It must be unique within the 1168 * play queue and cannot be {@link #UNKNOWN_ID}. 1169 */ 1170 public QueueItem(MediaDescription description, long id) { 1171 if (description == null) { 1172 throw new IllegalArgumentException("Description cannot be null."); 1173 } 1174 if (id == UNKNOWN_ID) { 1175 throw new IllegalArgumentException("Id cannot be QueueItem.UNKNOWN_ID"); 1176 } 1177 mDescription = description; 1178 mId = id; 1179 } 1180 1181 private QueueItem(Parcel in) { 1182 mDescription = MediaDescription.CREATOR.createFromParcel(in); 1183 mId = in.readLong(); 1184 } 1185 1186 /** 1187 * Get the description for this item. 1188 */ 1189 public MediaDescription getDescription() { 1190 return mDescription; 1191 } 1192 1193 /** 1194 * Get the queue id for this item. 1195 */ 1196 public long getQueueId() { 1197 return mId; 1198 } 1199 1200 @Override 1201 public void writeToParcel(Parcel dest, int flags) { 1202 mDescription.writeToParcel(dest, flags); 1203 dest.writeLong(mId); 1204 } 1205 1206 @Override 1207 public int describeContents() { 1208 return 0; 1209 } 1210 1211 public static final Creator<MediaSession.QueueItem> CREATOR = new Creator<MediaSession.QueueItem>() { 1212 1213 @Override 1214 public MediaSession.QueueItem createFromParcel(Parcel p) { 1215 return new MediaSession.QueueItem(p); 1216 } 1217 1218 @Override 1219 public MediaSession.QueueItem[] newArray(int size) { 1220 return new MediaSession.QueueItem[size]; 1221 } 1222 }; 1223 1224 @Override 1225 public String toString() { 1226 return "MediaSession.QueueItem {" + 1227 "Description=" + mDescription + 1228 ", Id=" + mId + " }"; 1229 } 1230 } 1231 1232 private static final class Command { 1233 public final String command; 1234 public final Bundle extras; 1235 public final ResultReceiver stub; 1236 1237 public Command(String command, Bundle extras, ResultReceiver stub) { 1238 this.command = command; 1239 this.extras = extras; 1240 this.stub = stub; 1241 } 1242 } 1243 1244 private class CallbackMessageHandler extends Handler { 1245 1246 private static final int MSG_COMMAND = 1; 1247 private static final int MSG_MEDIA_BUTTON = 2; 1248 private static final int MSG_PREPARE = 3; 1249 private static final int MSG_PREPARE_MEDIA_ID = 4; 1250 private static final int MSG_PREPARE_SEARCH = 5; 1251 private static final int MSG_PREPARE_URI = 6; 1252 private static final int MSG_PLAY = 7; 1253 private static final int MSG_PLAY_MEDIA_ID = 8; 1254 private static final int MSG_PLAY_SEARCH = 9; 1255 private static final int MSG_PLAY_URI = 10; 1256 private static final int MSG_SKIP_TO_ITEM = 11; 1257 private static final int MSG_PAUSE = 12; 1258 private static final int MSG_STOP = 13; 1259 private static final int MSG_NEXT = 14; 1260 private static final int MSG_PREVIOUS = 15; 1261 private static final int MSG_FAST_FORWARD = 16; 1262 private static final int MSG_REWIND = 17; 1263 private static final int MSG_SEEK_TO = 18; 1264 private static final int MSG_RATE = 19; 1265 private static final int MSG_CUSTOM_ACTION = 20; 1266 private static final int MSG_ADJUST_VOLUME = 21; 1267 private static final int MSG_SET_VOLUME = 22; 1268 1269 private MediaSession.Callback mCallback; 1270 1271 public CallbackMessageHandler(Looper looper, MediaSession.Callback callback) { 1272 super(looper, null, true); 1273 mCallback = callback; 1274 } 1275 1276 public void post(int what, Object obj, Bundle bundle) { 1277 Message msg = obtainMessage(what, obj); 1278 msg.setData(bundle); 1279 msg.sendToTarget(); 1280 } 1281 1282 public void post(int what, Object obj) { 1283 obtainMessage(what, obj).sendToTarget(); 1284 } 1285 1286 public void post(int what) { 1287 post(what, null); 1288 } 1289 1290 public void post(int what, Object obj, int arg1) { 1291 obtainMessage(what, arg1, 0, obj).sendToTarget(); 1292 } 1293 1294 @Override 1295 public void handleMessage(Message msg) { 1296 VolumeProvider vp; 1297 switch (msg.what) { 1298 case MSG_COMMAND: 1299 Command cmd = (Command) msg.obj; 1300 mCallback.onCommand(cmd.command, cmd.extras, cmd.stub); 1301 break; 1302 case MSG_MEDIA_BUTTON: 1303 mCallback.onMediaButtonEvent((Intent) msg.obj); 1304 break; 1305 case MSG_PREPARE: 1306 mCallback.onPrepare(); 1307 break; 1308 case MSG_PREPARE_MEDIA_ID: 1309 mCallback.onPrepareFromMediaId((String) msg.obj, msg.getData()); 1310 break; 1311 case MSG_PREPARE_SEARCH: 1312 mCallback.onPrepareFromSearch((String) msg.obj, msg.getData()); 1313 break; 1314 case MSG_PREPARE_URI: 1315 mCallback.onPrepareFromUri((Uri) msg.obj, msg.getData()); 1316 break; 1317 case MSG_PLAY: 1318 mCallback.onPlay(); 1319 break; 1320 case MSG_PLAY_MEDIA_ID: 1321 mCallback.onPlayFromMediaId((String) msg.obj, msg.getData()); 1322 break; 1323 case MSG_PLAY_SEARCH: 1324 mCallback.onPlayFromSearch((String) msg.obj, msg.getData()); 1325 break; 1326 case MSG_PLAY_URI: 1327 mCallback.onPlayFromUri((Uri) msg.obj, msg.getData()); 1328 break; 1329 case MSG_SKIP_TO_ITEM: 1330 mCallback.onSkipToQueueItem((Long) msg.obj); 1331 break; 1332 case MSG_PAUSE: 1333 mCallback.onPause(); 1334 break; 1335 case MSG_STOP: 1336 mCallback.onStop(); 1337 break; 1338 case MSG_NEXT: 1339 mCallback.onSkipToNext(); 1340 break; 1341 case MSG_PREVIOUS: 1342 mCallback.onSkipToPrevious(); 1343 break; 1344 case MSG_FAST_FORWARD: 1345 mCallback.onFastForward(); 1346 break; 1347 case MSG_REWIND: 1348 mCallback.onRewind(); 1349 break; 1350 case MSG_SEEK_TO: 1351 mCallback.onSeekTo((Long) msg.obj); 1352 break; 1353 case MSG_RATE: 1354 mCallback.onSetRating((Rating) msg.obj); 1355 break; 1356 case MSG_CUSTOM_ACTION: 1357 mCallback.onCustomAction((String) msg.obj, msg.getData()); 1358 break; 1359 case MSG_ADJUST_VOLUME: 1360 synchronized (mLock) { 1361 vp = mVolumeProvider; 1362 } 1363 if (vp != null) { 1364 vp.onAdjustVolume((int) msg.obj); 1365 } 1366 break; 1367 case MSG_SET_VOLUME: 1368 synchronized (mLock) { 1369 vp = mVolumeProvider; 1370 } 1371 if (vp != null) { 1372 vp.onSetVolumeTo((int) msg.obj); 1373 } 1374 break; 1375 } 1376 } 1377 } 1378} 1379