811a5a4a |
1 | /* |
2 | * Copyright (C) 2011 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 | |
17 | package android.support.v2.app; |
18 | |
19 | import android.app.Activity; |
20 | import android.os.Bundle; |
21 | import android.support.v2.content.Loader; |
22 | import android.support.v2.util.DebugUtils; |
23 | import android.util.Log; |
24 | |
25 | import java.io.FileDescriptor; |
26 | import java.io.PrintWriter; |
27 | import java.lang.reflect.Modifier; |
28 | |
29 | /** |
30 | * Static library support version of the framework's {@link android.app.LoaderManager}. |
31 | * Used to write apps that run on platforms prior to Android 3.0. When running |
32 | * on Android 3.0 or above, this implementation is still used; it does not try |
33 | * to switch to the framework's implementation. See the framework SDK |
34 | * documentation for a class overview. |
35 | * |
36 | * <p>Your activity must derive from {@link FragmentActivity} to use this. |
37 | */ |
38 | public abstract class LoaderManager { |
39 | /** |
40 | * Callback interface for a client to interact with the manager. |
41 | */ |
42 | public interface LoaderCallbacks<D> { |
43 | /** |
44 | * Instantiate and return a new Loader for the given ID. |
45 | * |
46 | * @param id The ID whose loader is to be created. |
47 | * @param args Any arguments supplied by the caller. |
48 | * @return Return a new Loader instance that is ready to start loading. |
49 | */ |
50 | public Loader<D> onCreateLoader(int id, Bundle args); |
51 | |
52 | /** |
53 | * Called when a previously created loader has finished its load. Note |
54 | * that normally an application is <em>not</em> allowed to commit fragment |
55 | * transactions while in this call, since it can happen after an |
56 | * activity's state is saved. See {@link FragmentManager#beginTransaction() |
57 | * FragmentManager.openTransaction()} for further discussion on this. |
58 | * |
59 | * <p>This function is guaranteed to be called prior to the release of |
60 | * the last data that was supplied for this Loader. At this point |
61 | * you should remove all use of the old data (since it will be released |
62 | * soon), but should not do your own release of the data since its Loader |
63 | * owns it and will take care of that. The Loader will take care of |
64 | * management of its data so you don't have to. In particular: |
65 | * |
66 | * <ul> |
67 | * <li> <p>The Loader will monitor for changes to the data, and report |
68 | * them to you through new calls here. You should not monitor the |
69 | * data yourself. For example, if the data is a {@link android.database.Cursor} |
70 | * and you place it in a {@link android.widget.CursorAdapter}, use |
71 | * the {@link android.widget.CursorAdapter#CursorAdapter(android.content.Context, |
72 | * android.database.Cursor, int)} constructor <em>without</em> passing |
73 | * in either {@link android.widget.CursorAdapter#FLAG_AUTO_REQUERY} |
74 | * or {@link android.widget.CursorAdapter#FLAG_REGISTER_CONTENT_OBSERVER} |
75 | * (that is, use 0 for the flags argument). This prevents the CursorAdapter |
76 | * from doing its own observing of the Cursor, which is not needed since |
77 | * when a change happens you will get a new Cursor throw another call |
78 | * here. |
79 | * <li> The Loader will release the data once it knows the application |
80 | * is no longer using it. For example, if the data is |
81 | * a {@link android.database.Cursor} from a {@link android.content.CursorLoader}, |
82 | * you should not call close() on it yourself. If the Cursor is being placed in a |
83 | * {@link android.widget.CursorAdapter}, you should use the |
84 | * {@link android.widget.CursorAdapter#swapCursor(android.database.Cursor)} |
85 | * method so that the old Cursor is not closed. |
86 | * </ul> |
87 | * |
88 | * @param loader The Loader that has finished. |
89 | * @param data The data generated by the Loader. |
90 | */ |
91 | public void onLoadFinished(Loader<D> loader, D data); |
92 | |
93 | /** |
94 | * Called when a previously created loader is being reset, and thus |
95 | * making its data unavailable. The application should at this point |
96 | * remove any references it has to the Loader's data. |
97 | * |
98 | * @param loader The Loader that is being reset. |
99 | */ |
100 | public void onLoaderReset(Loader<D> loader); |
101 | } |
102 | |
103 | /** |
104 | * Ensures a loader is initialized and active. If the loader doesn't |
105 | * already exist, one is created and (if the activity/fragment is currently |
106 | * started) starts the loader. Otherwise the last created |
107 | * loader is re-used. |
108 | * |
109 | * <p>In either case, the given callback is associated with the loader, and |
110 | * will be called as the loader state changes. If at the point of call |
111 | * the caller is in its started state, and the requested loader |
112 | * already exists and has generated its data, then |
113 | * callback {@link LoaderCallbacks#onLoadFinished} will |
114 | * be called immediately (inside of this function), so you must be prepared |
115 | * for this to happen. |
116 | * |
117 | * @param id A unique identifier for this loader. Can be whatever you want. |
118 | * Identifiers are scoped to a particular LoaderManager instance. |
119 | * @param args Optional arguments to supply to the loader at construction. |
120 | * If a loader already exists (a new one does not need to be created), this |
121 | * parameter will be ignored and the last arguments continue to be used. |
122 | * @param callback Interface the LoaderManager will call to report about |
123 | * changes in the state of the loader. Required. |
124 | */ |
125 | public abstract <D> Loader<D> initLoader(int id, Bundle args, |
126 | LoaderManager.LoaderCallbacks<D> callback); |
127 | |
128 | /** |
129 | * Starts a new or restarts an existing {@link android.content.Loader} in |
130 | * this manager, registers the callbacks to it, |
131 | * and (if the activity/fragment is currently started) starts loading it. |
132 | * If a loader with the same id has previously been |
133 | * started it will automatically be destroyed when the new loader completes |
134 | * its work. The callback will be delivered before the old loader |
135 | * is destroyed. |
136 | * |
137 | * @param id A unique identifier for this loader. Can be whatever you want. |
138 | * Identifiers are scoped to a particular LoaderManager instance. |
139 | * @param args Optional arguments to supply to the loader at construction. |
140 | * @param callback Interface the LoaderManager will call to report about |
141 | * changes in the state of the loader. Required. |
142 | */ |
143 | public abstract <D> Loader<D> restartLoader(int id, Bundle args, |
144 | LoaderManager.LoaderCallbacks<D> callback); |
145 | |
146 | /** |
147 | * Stops and removes the loader with the given ID. If this loader |
148 | * had previously reported data to the client through |
149 | * {@link LoaderCallbacks#onLoadFinished(Loader, Object)}, a call |
150 | * will be made to {@link LoaderCallbacks#onLoaderReset(Loader)}. |
151 | */ |
152 | public abstract void destroyLoader(int id); |
153 | |
154 | /** |
155 | * Return the Loader with the given id or null if no matching Loader |
156 | * is found. |
157 | */ |
158 | public abstract <D> Loader<D> getLoader(int id); |
159 | |
160 | /** |
161 | * Print the LoaderManager's state into the given stream. |
162 | * |
163 | * @param prefix Text to print at the front of each line. |
164 | * @param fd The raw file descriptor that the dump is being sent to. |
165 | * @param writer A PrintWriter to which the dump is to be set. |
166 | * @param args Additional arguments to the dump request. |
167 | */ |
168 | public abstract void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args); |
169 | |
170 | /** |
171 | * Control whether the framework's internal loader manager debugging |
172 | * logs are turned on. If enabled, you will see output in logcat as |
173 | * the framework performs loader operations. |
174 | */ |
175 | public static void enableDebugLogging(boolean enabled) { |
176 | LoaderManagerImpl.DEBUG = enabled; |
177 | } |
178 | } |
179 | |
180 | class LoaderManagerImpl extends LoaderManager { |
181 | static final String TAG = "LoaderManager"; |
182 | static boolean DEBUG = false; |
183 | |
184 | // These are the currently active loaders. A loader is here |
185 | // from the time its load is started until it has been explicitly |
186 | // stopped or restarted by the application. |
187 | final HCSparseArray<LoaderInfo> mLoaders = new HCSparseArray<LoaderInfo>(); |
188 | |
189 | // These are previously run loaders. This list is maintained internally |
190 | // to avoid destroying a loader while an application is still using it. |
191 | // It allows an application to restart a loader, but continue using its |
192 | // previously run loader until the new loader's data is available. |
193 | final HCSparseArray<LoaderInfo> mInactiveLoaders = new HCSparseArray<LoaderInfo>(); |
194 | |
195 | FragmentActivity mActivity; |
196 | boolean mStarted; |
197 | boolean mRetaining; |
198 | boolean mRetainingStarted; |
199 | |
200 | boolean mCreatingLoader; |
201 | |
202 | final class LoaderInfo implements Loader.OnLoadCompleteListener<Object> { |
203 | final int mId; |
204 | final Bundle mArgs; |
205 | LoaderManager.LoaderCallbacks<Object> mCallbacks; |
206 | Loader<Object> mLoader; |
207 | boolean mHaveData; |
208 | boolean mDeliveredData; |
209 | Object mData; |
210 | boolean mStarted; |
211 | boolean mRetaining; |
212 | boolean mRetainingStarted; |
213 | boolean mDestroyed; |
214 | boolean mListenerRegistered; |
215 | |
216 | LoaderInfo mPendingLoader; |
217 | |
218 | public LoaderInfo(int id, Bundle args, LoaderManager.LoaderCallbacks<Object> callbacks) { |
219 | mId = id; |
220 | mArgs = args; |
221 | mCallbacks = callbacks; |
222 | } |
223 | |
224 | void start() { |
225 | if (mRetaining && mRetainingStarted) { |
226 | // Our owner is started, but we were being retained from a |
227 | // previous instance in the started state... so there is really |
228 | // nothing to do here, since the loaders are still started. |
229 | mStarted = true; |
230 | return; |
231 | } |
232 | |
233 | if (mStarted) { |
234 | // If loader already started, don't restart. |
235 | return; |
236 | } |
237 | |
238 | mStarted = true; |
239 | |
240 | if (DEBUG) Log.v(TAG, " Starting: " + this); |
241 | if (mLoader == null && mCallbacks != null) { |
242 | mLoader = mCallbacks.onCreateLoader(mId, mArgs); |
243 | } |
244 | if (mLoader != null) { |
245 | if (mLoader.getClass().isMemberClass() |
246 | && !Modifier.isStatic(mLoader.getClass().getModifiers())) { |
247 | throw new IllegalArgumentException( |
248 | "Object returned from onCreateLoader must not be a non-static inner member class: " |
249 | + mLoader); |
250 | } |
251 | if (!mListenerRegistered) { |
252 | mLoader.registerListener(mId, this); |
253 | mListenerRegistered = true; |
254 | } |
255 | mLoader.startLoading(); |
256 | } |
257 | } |
258 | |
259 | void retain() { |
260 | if (DEBUG) Log.v(TAG, " Retaining: " + this); |
261 | mRetaining = true; |
262 | mRetainingStarted = mStarted; |
263 | mStarted = false; |
264 | mCallbacks = null; |
265 | } |
266 | |
267 | void finishRetain() { |
268 | if (mRetaining) { |
269 | if (DEBUG) Log.v(TAG, " Finished Retaining: " + this); |
270 | mRetaining = false; |
271 | if (mStarted != mRetainingStarted) { |
272 | if (!mStarted) { |
273 | // This loader was retained in a started state, but |
274 | // at the end of retaining everything our owner is |
275 | // no longer started... so make it stop. |
276 | stop(); |
277 | } |
278 | } |
279 | } |
280 | |
281 | if (mStarted && mHaveData) { |
282 | // This loader has retained its data, either completely across |
283 | // a configuration change or just whatever the last data set |
284 | // was after being restarted from a stop, and now at the point of |
285 | // finishing the retain we find we remain started, have |
286 | // our data, and the owner has a new callback... so |
287 | // let's deliver the data now. |
288 | callOnLoadFinished(mLoader, mData); |
289 | } |
290 | } |
291 | |
292 | void stop() { |
293 | if (DEBUG) Log.v(TAG, " Stopping: " + this); |
294 | mStarted = false; |
295 | if (!mRetaining) { |
296 | if (mLoader != null && mListenerRegistered) { |
297 | // Let the loader know we're done with it |
298 | mListenerRegistered = false; |
299 | mLoader.unregisterListener(this); |
300 | mLoader.stopLoading(); |
301 | } |
302 | } |
303 | } |
304 | |
305 | void destroy() { |
306 | if (DEBUG) Log.v(TAG, " Destroying: " + this); |
307 | mDestroyed = true; |
308 | boolean needReset = mDeliveredData; |
309 | mDeliveredData = false; |
310 | if (mCallbacks != null && mLoader != null && mHaveData && needReset) { |
311 | if (DEBUG) Log.v(TAG, " Reseting: " + this); |
312 | String lastBecause = null; |
313 | if (mActivity != null) { |
314 | lastBecause = mActivity.mFragments.mNoTransactionsBecause; |
315 | mActivity.mFragments.mNoTransactionsBecause = "onLoaderReset"; |
316 | } |
317 | try { |
318 | mCallbacks.onLoaderReset(mLoader); |
319 | } finally { |
320 | if (mActivity != null) { |
321 | mActivity.mFragments.mNoTransactionsBecause = lastBecause; |
322 | } |
323 | } |
324 | } |
325 | mCallbacks = null; |
326 | mData = null; |
327 | mHaveData = false; |
328 | if (mLoader != null) { |
329 | if (mListenerRegistered) { |
330 | mListenerRegistered = false; |
331 | mLoader.unregisterListener(this); |
332 | } |
333 | mLoader.reset(); |
334 | } |
335 | if (mPendingLoader != null) { |
336 | mPendingLoader.destroy(); |
337 | } |
338 | } |
339 | |
340 | @Override public void onLoadComplete(Loader<Object> loader, Object data) { |
341 | if (DEBUG) Log.v(TAG, "onLoadComplete: " + this); |
342 | |
343 | if (mDestroyed) { |
344 | if (DEBUG) Log.v(TAG, " Ignoring load complete -- destroyed"); |
345 | return; |
346 | } |
347 | |
348 | if (mLoaders.get(mId) != this) { |
349 | // This data is not coming from the current active loader. |
350 | // We don't care about it. |
351 | if (DEBUG) Log.v(TAG, " Ignoring load complete -- not active"); |
352 | return; |
353 | } |
354 | |
355 | LoaderInfo pending = mPendingLoader; |
356 | if (pending != null) { |
357 | // There is a new request pending and we were just |
358 | // waiting for the old one to complete before starting |
359 | // it. So now it is time, switch over to the new loader. |
360 | if (DEBUG) Log.v(TAG, " Switching to pending loader: " + pending); |
361 | mPendingLoader = null; |
362 | mLoaders.put(mId, null); |
363 | destroy(); |
364 | installLoader(pending); |
365 | return; |
366 | } |
367 | |
368 | // Notify of the new data so the app can switch out the old data before |
369 | // we try to destroy it. |
370 | if (mData != data || !mHaveData) { |
371 | mData = data; |
372 | mHaveData = true; |
373 | if (mStarted) { |
374 | callOnLoadFinished(loader, data); |
375 | } |
376 | } |
377 | |
378 | //if (DEBUG) Log.v(TAG, " onLoadFinished returned: " + this); |
379 | |
380 | // We have now given the application the new loader with its |
381 | // loaded data, so it should have stopped using the previous |
382 | // loader. If there is a previous loader on the inactive list, |
383 | // clean it up. |
384 | LoaderInfo info = mInactiveLoaders.get(mId); |
385 | if (info != null && info != this) { |
386 | info.mDeliveredData = false; |
387 | info.destroy(); |
388 | mInactiveLoaders.remove(mId); |
389 | } |
390 | } |
391 | |
392 | void callOnLoadFinished(Loader<Object> loader, Object data) { |
393 | if (mCallbacks != null) { |
394 | String lastBecause = null; |
395 | if (mActivity != null) { |
396 | lastBecause = mActivity.mFragments.mNoTransactionsBecause; |
397 | mActivity.mFragments.mNoTransactionsBecause = "onLoadFinished"; |
398 | } |
399 | try { |
400 | if (DEBUG) Log.v(TAG, " onLoadFinished in " + loader + ": " |
401 | + loader.dataToString(data)); |
402 | mCallbacks.onLoadFinished(loader, data); |
403 | } finally { |
404 | if (mActivity != null) { |
405 | mActivity.mFragments.mNoTransactionsBecause = lastBecause; |
406 | } |
407 | } |
408 | mDeliveredData = true; |
409 | } |
410 | } |
411 | |
412 | @Override |
413 | public String toString() { |
414 | StringBuilder sb = new StringBuilder(64); |
415 | sb.append("LoaderInfo{"); |
416 | sb.append(Integer.toHexString(System.identityHashCode(this))); |
417 | sb.append(" #"); |
418 | sb.append(mId); |
419 | sb.append(" : "); |
420 | DebugUtils.buildShortClassTag(mLoader, sb); |
421 | sb.append("}}"); |
422 | return sb.toString(); |
423 | } |
424 | |
425 | public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { |
426 | writer.print(prefix); writer.print("mId="); writer.print(mId); |
427 | writer.print(" mArgs="); writer.println(mArgs); |
428 | writer.print(prefix); writer.print("mCallbacks="); writer.println(mCallbacks); |
429 | writer.print(prefix); writer.print("mLoader="); writer.println(mLoader); |
430 | if (mLoader != null) { |
431 | mLoader.dump(prefix + " ", fd, writer, args); |
432 | } |
433 | if (mHaveData || mDeliveredData) { |
434 | writer.print(prefix); writer.print("mHaveData="); writer.print(mHaveData); |
435 | writer.print(" mDeliveredData="); writer.println(mDeliveredData); |
436 | writer.print(prefix); writer.print("mData="); writer.println(mData); |
437 | } |
438 | writer.print(prefix); writer.print("mStarted="); writer.print(mStarted); |
439 | writer.print(" mRetaining="); writer.print(mRetaining); |
440 | writer.print(" mDestroyed="); writer.println(mDestroyed); |
441 | writer.print(prefix); writer.print("mListenerRegistered="); |
442 | writer.println(mListenerRegistered); |
443 | if (mPendingLoader != null) { |
444 | writer.print(prefix); writer.println("Pending Loader "); |
445 | writer.print(mPendingLoader); writer.println(":"); |
446 | mPendingLoader.dump(prefix + " ", fd, writer, args); |
447 | } |
448 | } |
449 | } |
450 | |
451 | LoaderManagerImpl(FragmentActivity activity, boolean started) { |
452 | mActivity = activity; |
453 | mStarted = started; |
454 | } |
455 | |
456 | void updateActivity(FragmentActivity activity) { |
457 | mActivity = activity; |
458 | } |
459 | |
460 | private LoaderInfo createLoader(int id, Bundle args, |
461 | LoaderManager.LoaderCallbacks<Object> callback) { |
462 | LoaderInfo info = new LoaderInfo(id, args, (LoaderManager.LoaderCallbacks<Object>)callback); |
463 | Loader<Object> loader = callback.onCreateLoader(id, args); |
464 | info.mLoader = (Loader<Object>)loader; |
465 | return info; |
466 | } |
467 | |
468 | private LoaderInfo createAndInstallLoader(int id, Bundle args, |
469 | LoaderManager.LoaderCallbacks<Object> callback) { |
470 | try { |
471 | mCreatingLoader = true; |
472 | LoaderInfo info = createLoader(id, args, callback); |
473 | installLoader(info); |
474 | return info; |
475 | } finally { |
476 | mCreatingLoader = false; |
477 | } |
478 | } |
479 | |
480 | void installLoader(LoaderInfo info) { |
481 | mLoaders.put(info.mId, info); |
482 | if (mStarted) { |
483 | // The activity will start all existing loaders in it's onStart(), |
484 | // so only start them here if we're past that point of the activitiy's |
485 | // life cycle |
486 | info.start(); |
487 | } |
488 | } |
489 | |
490 | /** |
491 | * Call to initialize a particular ID with a Loader. If this ID already |
492 | * has a Loader associated with it, it is left unchanged and any previous |
493 | * callbacks replaced with the newly provided ones. If there is not currently |
494 | * a Loader for the ID, a new one is created and started. |
495 | * |
496 | * <p>This function should generally be used when a component is initializing, |
497 | * to ensure that a Loader it relies on is created. This allows it to re-use |
498 | * an existing Loader's data if there already is one, so that for example |
499 | * when an {@link Activity} is re-created after a configuration change it |
500 | * does not need to re-create its loaders. |
501 | * |
502 | * <p>Note that in the case where an existing Loader is re-used, the |
503 | * <var>args</var> given here <em>will be ignored</em> because you will |
504 | * continue using the previous Loader. |
505 | * |
506 | * @param id A unique (to this LoaderManager instance) identifier under |
507 | * which to manage the new Loader. |
508 | * @param args Optional arguments that will be propagated to |
509 | * {@link LoaderCallbacks#onCreateLoader(int, Bundle) LoaderCallbacks.onCreateLoader()}. |
510 | * @param callback Interface implementing management of this Loader. Required. |
511 | * Its onCreateLoader() method will be called while inside of the function to |
512 | * instantiate the Loader object. |
513 | */ |
514 | @SuppressWarnings("unchecked") |
515 | public <D> Loader<D> initLoader(int id, Bundle args, LoaderManager.LoaderCallbacks<D> callback) { |
516 | if (mCreatingLoader) { |
517 | throw new IllegalStateException("Called while creating a loader"); |
518 | } |
519 | |
520 | LoaderInfo info = mLoaders.get(id); |
521 | |
522 | if (DEBUG) Log.v(TAG, "initLoader in " + this + ": args=" + args); |
523 | |
524 | if (info == null) { |
525 | // Loader doesn't already exist; create. |
526 | info = createAndInstallLoader(id, args, (LoaderManager.LoaderCallbacks<Object>)callback); |
527 | if (DEBUG) Log.v(TAG, " Created new loader " + info); |
528 | } else { |
529 | if (DEBUG) Log.v(TAG, " Re-using existing loader " + info); |
530 | info.mCallbacks = (LoaderManager.LoaderCallbacks<Object>)callback; |
531 | } |
532 | |
533 | if (info.mHaveData && mStarted) { |
534 | // If the loader has already generated its data, report it now. |
535 | info.callOnLoadFinished(info.mLoader, info.mData); |
536 | } |
537 | |
538 | return (Loader<D>)info.mLoader; |
539 | } |
540 | |
541 | /** |
542 | * Call to re-create the Loader associated with a particular ID. If there |
543 | * is currently a Loader associated with this ID, it will be |
544 | * canceled/stopped/destroyed as appropriate. A new Loader with the given |
545 | * arguments will be created and its data delivered to you once available. |
546 | * |
547 | * <p>This function does some throttling of Loaders. If too many Loaders |
548 | * have been created for the given ID but not yet generated their data, |
549 | * new calls to this function will create and return a new Loader but not |
550 | * actually start it until some previous loaders have completed. |
551 | * |
552 | * <p>After calling this function, any previous Loaders associated with |
553 | * this ID will be considered invalid, and you will receive no further |
554 | * data updates from them. |
555 | * |
556 | * @param id A unique (to this LoaderManager instance) identifier under |
557 | * which to manage the new Loader. |
558 | * @param args Optional arguments that will be propagated to |
559 | * {@link LoaderCallbacks#onCreateLoader(int, Bundle) LoaderCallbacks.onCreateLoader()}. |
560 | * @param callback Interface implementing management of this Loader. Required. |
561 | * Its onCreateLoader() method will be called while inside of the function to |
562 | * instantiate the Loader object. |
563 | */ |
564 | @SuppressWarnings("unchecked") |
565 | public <D> Loader<D> restartLoader(int id, Bundle args, LoaderManager.LoaderCallbacks<D> callback) { |
566 | if (mCreatingLoader) { |
567 | throw new IllegalStateException("Called while creating a loader"); |
568 | } |
569 | |
570 | LoaderInfo info = mLoaders.get(id); |
571 | if (DEBUG) Log.v(TAG, "restartLoader in " + this + ": args=" + args); |
572 | if (info != null) { |
573 | LoaderInfo inactive = mInactiveLoaders.get(id); |
574 | if (inactive != null) { |
575 | if (info.mHaveData) { |
576 | // This loader now has data... we are probably being |
577 | // called from within onLoadComplete, where we haven't |
578 | // yet destroyed the last inactive loader. So just do |
579 | // that now. |
580 | if (DEBUG) Log.v(TAG, " Removing last inactive loader: " + info); |
581 | inactive.mDeliveredData = false; |
582 | inactive.destroy(); |
583 | info.mLoader.abandon(); |
584 | mInactiveLoaders.put(id, info); |
585 | } else { |
586 | // We already have an inactive loader for this ID that we are |
587 | // waiting for! What to do, what to do... |
588 | if (!info.mStarted) { |
589 | // The current Loader has not been started... we thus |
590 | // have no reason to keep it around, so bam, slam, |
591 | // thank-you-ma'am. |
592 | if (DEBUG) Log.v(TAG, " Current loader is stopped; replacing"); |
593 | mLoaders.put(id, null); |
594 | info.destroy(); |
595 | } else { |
596 | // Now we have three active loaders... we'll queue |
597 | // up this request to be processed once one of the other loaders |
598 | // finishes. |
599 | if (info.mPendingLoader != null) { |
600 | if (DEBUG) Log.v(TAG, " Removing pending loader: " + info.mPendingLoader); |
601 | info.mPendingLoader.destroy(); |
602 | info.mPendingLoader = null; |
603 | } |
604 | if (DEBUG) Log.v(TAG, " Enqueuing as new pending loader"); |
605 | info.mPendingLoader = createLoader(id, args, |
606 | (LoaderManager.LoaderCallbacks<Object>)callback); |
607 | return (Loader<D>)info.mPendingLoader.mLoader; |
608 | } |
609 | } |
610 | } else { |
611 | // Keep track of the previous instance of this loader so we can destroy |
612 | // it when the new one completes. |
613 | if (DEBUG) Log.v(TAG, " Making last loader inactive: " + info); |
614 | info.mLoader.abandon(); |
615 | mInactiveLoaders.put(id, info); |
616 | } |
617 | } |
618 | |
619 | info = createAndInstallLoader(id, args, (LoaderManager.LoaderCallbacks<Object>)callback); |
620 | return (Loader<D>)info.mLoader; |
621 | } |
622 | |
623 | /** |
624 | * Rip down, tear apart, shred to pieces a current Loader ID. After returning |
625 | * from this function, any Loader objects associated with this ID are |
626 | * destroyed. Any data associated with them is destroyed. You better not |
627 | * be using it when you do this. |
628 | * @param id Identifier of the Loader to be destroyed. |
629 | */ |
630 | public void destroyLoader(int id) { |
631 | if (mCreatingLoader) { |
632 | throw new IllegalStateException("Called while creating a loader"); |
633 | } |
634 | |
635 | if (DEBUG) Log.v(TAG, "destroyLoader in " + this + " of " + id); |
636 | int idx = mLoaders.indexOfKey(id); |
637 | if (idx >= 0) { |
638 | LoaderInfo info = mLoaders.valueAt(idx); |
639 | mLoaders.removeAt(idx); |
640 | info.destroy(); |
641 | } |
642 | idx = mInactiveLoaders.indexOfKey(id); |
643 | if (idx >= 0) { |
644 | LoaderInfo info = mInactiveLoaders.valueAt(idx); |
645 | mInactiveLoaders.removeAt(idx); |
646 | info.destroy(); |
647 | } |
648 | } |
649 | |
650 | /** |
651 | * Return the most recent Loader object associated with the |
652 | * given ID. |
653 | */ |
654 | @SuppressWarnings("unchecked") |
655 | public <D> Loader<D> getLoader(int id) { |
656 | if (mCreatingLoader) { |
657 | throw new IllegalStateException("Called while creating a loader"); |
658 | } |
659 | |
660 | LoaderInfo loaderInfo = mLoaders.get(id); |
661 | if (loaderInfo != null) { |
662 | if (loaderInfo.mPendingLoader != null) { |
663 | return (Loader<D>)loaderInfo.mPendingLoader.mLoader; |
664 | } |
665 | return (Loader<D>)loaderInfo.mLoader; |
666 | } |
667 | return null; |
668 | } |
669 | |
670 | void doStart() { |
671 | if (DEBUG) Log.v(TAG, "Starting in " + this); |
672 | if (mStarted) { |
673 | RuntimeException e = new RuntimeException("here"); |
674 | e.fillInStackTrace(); |
675 | Log.w(TAG, "Called doStart when already started: " + this, e); |
676 | return; |
677 | } |
678 | |
679 | mStarted = true; |
680 | |
681 | // Call out to sub classes so they can start their loaders |
682 | // Let the existing loaders know that we want to be notified when a load is complete |
683 | for (int i = mLoaders.size()-1; i >= 0; i--) { |
684 | mLoaders.valueAt(i).start(); |
685 | } |
686 | } |
687 | |
688 | void doStop() { |
689 | if (DEBUG) Log.v(TAG, "Stopping in " + this); |
690 | if (!mStarted) { |
691 | RuntimeException e = new RuntimeException("here"); |
692 | e.fillInStackTrace(); |
693 | Log.w(TAG, "Called doStop when not started: " + this, e); |
694 | return; |
695 | } |
696 | |
697 | for (int i = mLoaders.size()-1; i >= 0; i--) { |
698 | mLoaders.valueAt(i).stop(); |
699 | } |
700 | mStarted = false; |
701 | } |
702 | |
703 | void doRetain() { |
704 | if (DEBUG) Log.v(TAG, "Retaining in " + this); |
705 | if (!mStarted) { |
706 | RuntimeException e = new RuntimeException("here"); |
707 | e.fillInStackTrace(); |
708 | Log.w(TAG, "Called doRetain when not started: " + this, e); |
709 | return; |
710 | } |
711 | |
712 | mRetaining = true; |
713 | mStarted = false; |
714 | for (int i = mLoaders.size()-1; i >= 0; i--) { |
715 | mLoaders.valueAt(i).retain(); |
716 | } |
717 | } |
718 | |
719 | void finishRetain() { |
720 | if (mRetaining) { |
721 | if (DEBUG) Log.v(TAG, "Finished Retaining in " + this); |
722 | |
723 | mRetaining = false; |
724 | for (int i = mLoaders.size()-1; i >= 0; i--) { |
725 | mLoaders.valueAt(i).finishRetain(); |
726 | } |
727 | } |
728 | } |
729 | |
730 | void doDestroy() { |
731 | if (!mRetaining) { |
732 | if (DEBUG) Log.v(TAG, "Destroying Active in " + this); |
733 | for (int i = mLoaders.size()-1; i >= 0; i--) { |
734 | mLoaders.valueAt(i).destroy(); |
735 | } |
736 | } |
737 | |
738 | if (DEBUG) Log.v(TAG, "Destroying Inactive in " + this); |
739 | for (int i = mInactiveLoaders.size()-1; i >= 0; i--) { |
740 | mInactiveLoaders.valueAt(i).destroy(); |
741 | } |
742 | mInactiveLoaders.clear(); |
743 | } |
744 | |
745 | @Override |
746 | public String toString() { |
747 | StringBuilder sb = new StringBuilder(128); |
748 | sb.append("LoaderManager{"); |
749 | sb.append(Integer.toHexString(System.identityHashCode(this))); |
750 | sb.append(" in "); |
751 | DebugUtils.buildShortClassTag(mActivity, sb); |
752 | sb.append("}}"); |
753 | return sb.toString(); |
754 | } |
755 | |
756 | @Override |
757 | public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { |
758 | if (mLoaders.size() > 0) { |
759 | writer.print(prefix); writer.println("Active Loaders:"); |
760 | String innerPrefix = prefix + " "; |
761 | for (int i=0; i < mLoaders.size(); i++) { |
762 | LoaderInfo li = mLoaders.valueAt(i); |
763 | writer.print(prefix); writer.print(" #"); writer.print(mLoaders.keyAt(i)); |
764 | writer.print(": "); writer.println(li.toString()); |
765 | li.dump(innerPrefix, fd, writer, args); |
766 | } |
767 | } |
768 | if (mInactiveLoaders.size() > 0) { |
769 | writer.print(prefix); writer.println("Inactive Loaders:"); |
770 | String innerPrefix = prefix + " "; |
771 | for (int i=0; i < mInactiveLoaders.size(); i++) { |
772 | LoaderInfo li = mInactiveLoaders.valueAt(i); |
773 | writer.print(prefix); writer.print(" #"); writer.print(mInactiveLoaders.keyAt(i)); |
774 | writer.print(": "); writer.println(li.toString()); |
775 | li.dump(innerPrefix, fd, writer, args); |
776 | } |
777 | } |
778 | } |
779 | } |