| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.app; |
| |
| import android.content.Loader; |
| import android.os.Bundle; |
| import android.util.DebugUtils; |
| import android.util.Log; |
| import android.util.SparseArray; |
| |
| import java.io.FileDescriptor; |
| import java.io.PrintWriter; |
| import java.lang.reflect.Modifier; |
| |
| /** |
| * Interface associated with an {@link Activity} or {@link Fragment} for managing |
| * one or more {@link android.content.Loader} instances associated with it. This |
| * helps an application manage longer-running operations in conjunction with the |
| * Activity or Fragment lifecycle; the most common use of this is with a |
| * {@link android.content.CursorLoader}, however applications are free to write |
| * their own loaders for loading other types of data. |
| * |
| * While the LoaderManager API was introduced in |
| * {@link android.os.Build.VERSION_CODES#HONEYCOMB}, a version of the API |
| * at is also available for use on older platforms through |
| * {@link android.support.v4.app.FragmentActivity}. See the blog post |
| * <a href="http://android-developers.blogspot.com/2011/03/fragments-for-all.html"> |
| * Fragments For All</a> for more details. |
| * |
| * <p>As an example, here is the full implementation of a {@link Fragment} |
| * that displays a {@link android.widget.ListView} containing the results of |
| * a query against the contacts content provider. It uses a |
| * {@link android.content.CursorLoader} to manage the query on the provider. |
| * |
| * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/LoaderCursor.java |
| * fragment_cursor} |
| * |
| * <div class="special reference"> |
| * <h3>Developer Guides</h3> |
| * <p>For more information about using loaders, read the |
| * <a href="{@docRoot}guide/topics/fundamentals/loaders.html">Loaders</a> developer guide.</p> |
| * </div> |
| * |
| * @deprecated Use the <a href="{@docRoot}tools/extras/support-library.html">Support Library</a> |
| * {@link android.support.v4.app.LoaderManager} |
| */ |
| @Deprecated |
| public abstract class LoaderManager { |
| /** |
| * Callback interface for a client to interact with the manager. |
| * |
| * @deprecated Use the <a href="{@docRoot}tools/extras/support-library.html"> |
| * Support Library</a> {@link android.support.v4.app.LoaderManager.LoaderCallbacks} |
| */ |
| @Deprecated |
| public interface LoaderCallbacks<D> { |
| /** |
| * Instantiate and return a new Loader for the given ID. |
| * |
| * @param id The ID whose loader is to be created. |
| * @param args Any arguments supplied by the caller. |
| * @return Return a new Loader instance that is ready to start loading. |
| */ |
| public Loader<D> onCreateLoader(int id, Bundle args); |
| |
| /** |
| * Called when a previously created loader has finished its load. Note |
| * that normally an application is <em>not</em> allowed to commit fragment |
| * transactions while in this call, since it can happen after an |
| * activity's state is saved. See {@link FragmentManager#beginTransaction() |
| * FragmentManager.openTransaction()} for further discussion on this. |
| * |
| * <p>This function is guaranteed to be called prior to the release of |
| * the last data that was supplied for this Loader. At this point |
| * you should remove all use of the old data (since it will be released |
| * soon), but should not do your own release of the data since its Loader |
| * owns it and will take care of that. The Loader will take care of |
| * management of its data so you don't have to. In particular: |
| * |
| * <ul> |
| * <li> <p>The Loader will monitor for changes to the data, and report |
| * them to you through new calls here. You should not monitor the |
| * data yourself. For example, if the data is a {@link android.database.Cursor} |
| * and you place it in a {@link android.widget.CursorAdapter}, use |
| * the {@link android.widget.CursorAdapter#CursorAdapter(android.content.Context, |
| * android.database.Cursor, int)} constructor <em>without</em> passing |
| * in either {@link android.widget.CursorAdapter#FLAG_AUTO_REQUERY} |
| * or {@link android.widget.CursorAdapter#FLAG_REGISTER_CONTENT_OBSERVER} |
| * (that is, use 0 for the flags argument). This prevents the CursorAdapter |
| * from doing its own observing of the Cursor, which is not needed since |
| * when a change happens you will get a new Cursor throw another call |
| * here. |
| * <li> The Loader will release the data once it knows the application |
| * is no longer using it. For example, if the data is |
| * a {@link android.database.Cursor} from a {@link android.content.CursorLoader}, |
| * you should not call close() on it yourself. If the Cursor is being placed in a |
| * {@link android.widget.CursorAdapter}, you should use the |
| * {@link android.widget.CursorAdapter#swapCursor(android.database.Cursor)} |
| * method so that the old Cursor is not closed. |
| * </ul> |
| * |
| * @param loader The Loader that has finished. |
| * @param data The data generated by the Loader. |
| */ |
| public void onLoadFinished(Loader<D> loader, D data); |
| |
| /** |
| * Called when a previously created loader is being reset, and thus |
| * making its data unavailable. The application should at this point |
| * remove any references it has to the Loader's data. |
| * |
| * @param loader The Loader that is being reset. |
| */ |
| public void onLoaderReset(Loader<D> loader); |
| } |
| |
| /** |
| * Ensures a loader is initialized and active. If the loader doesn't |
| * already exist, one is created and (if the activity/fragment is currently |
| * started) starts the loader. Otherwise the last created |
| * loader is re-used. |
| * |
| * <p>In either case, the given callback is associated with the loader, and |
| * will be called as the loader state changes. If at the point of call |
| * the caller is in its started state, and the requested loader |
| * already exists and has generated its data, then |
| * callback {@link LoaderCallbacks#onLoadFinished} will |
| * be called immediately (inside of this function), so you must be prepared |
| * for this to happen. |
| * |
| * @param id A unique identifier for this loader. Can be whatever you want. |
| * Identifiers are scoped to a particular LoaderManager instance. |
| * @param args Optional arguments to supply to the loader at construction. |
| * If a loader already exists (a new one does not need to be created), this |
| * parameter will be ignored and the last arguments continue to be used. |
| * @param callback Interface the LoaderManager will call to report about |
| * changes in the state of the loader. Required. |
| */ |
| public abstract <D> Loader<D> initLoader(int id, Bundle args, |
| LoaderManager.LoaderCallbacks<D> callback); |
| |
| /** |
| * Starts a new or restarts an existing {@link android.content.Loader} in |
| * this manager, registers the callbacks to it, |
| * and (if the activity/fragment is currently started) starts loading it. |
| * If a loader with the same id has previously been |
| * started it will automatically be destroyed when the new loader completes |
| * its work. The callback will be delivered before the old loader |
| * is destroyed. |
| * |
| * @param id A unique identifier for this loader. Can be whatever you want. |
| * Identifiers are scoped to a particular LoaderManager instance. |
| * @param args Optional arguments to supply to the loader at construction. |
| * @param callback Interface the LoaderManager will call to report about |
| * changes in the state of the loader. Required. |
| */ |
| public abstract <D> Loader<D> restartLoader(int id, Bundle args, |
| LoaderManager.LoaderCallbacks<D> callback); |
| |
| /** |
| * Stops and removes the loader with the given ID. If this loader |
| * had previously reported data to the client through |
| * {@link LoaderCallbacks#onLoadFinished(Loader, Object)}, a call |
| * will be made to {@link LoaderCallbacks#onLoaderReset(Loader)}. |
| */ |
| public abstract void destroyLoader(int id); |
| |
| /** |
| * Return the Loader with the given id or null if no matching Loader |
| * is found. |
| */ |
| public abstract <D> Loader<D> getLoader(int id); |
| |
| /** |
| * Print the LoaderManager's state into the given stream. |
| * |
| * @param prefix Text to print at the front of each line. |
| * @param fd The raw file descriptor that the dump is being sent to. |
| * @param writer A PrintWriter to which the dump is to be set. |
| * @param args Additional arguments to the dump request. |
| */ |
| public abstract void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args); |
| |
| /** |
| * Control whether the framework's internal loader manager debugging |
| * logs are turned on. If enabled, you will see output in logcat as |
| * the framework performs loader operations. |
| */ |
| public static void enableDebugLogging(boolean enabled) { |
| LoaderManagerImpl.DEBUG = enabled; |
| } |
| |
| /** @hide for internal testing only */ |
| public FragmentHostCallback getFragmentHostCallback() { return null; } |
| } |
| |
| class LoaderManagerImpl extends LoaderManager { |
| static final String TAG = "LoaderManager"; |
| static boolean DEBUG = false; |
| |
| // These are the currently active loaders. A loader is here |
| // from the time its load is started until it has been explicitly |
| // stopped or restarted by the application. |
| final SparseArray<LoaderInfo> mLoaders = new SparseArray<LoaderInfo>(0); |
| |
| // These are previously run loaders. This list is maintained internally |
| // to avoid destroying a loader while an application is still using it. |
| // It allows an application to restart a loader, but continue using its |
| // previously run loader until the new loader's data is available. |
| final SparseArray<LoaderInfo> mInactiveLoaders = new SparseArray<LoaderInfo>(0); |
| |
| final String mWho; |
| |
| boolean mStarted; |
| boolean mRetaining; |
| boolean mRetainingStarted; |
| |
| boolean mCreatingLoader; |
| private FragmentHostCallback mHost; |
| |
| final class LoaderInfo implements Loader.OnLoadCompleteListener<Object>, |
| Loader.OnLoadCanceledListener<Object> { |
| final int mId; |
| final Bundle mArgs; |
| LoaderManager.LoaderCallbacks<Object> mCallbacks; |
| Loader<Object> mLoader; |
| boolean mHaveData; |
| boolean mDeliveredData; |
| Object mData; |
| boolean mStarted; |
| boolean mRetaining; |
| boolean mRetainingStarted; |
| boolean mReportNextStart; |
| boolean mDestroyed; |
| boolean mListenerRegistered; |
| |
| LoaderInfo mPendingLoader; |
| |
| public LoaderInfo(int id, Bundle args, LoaderManager.LoaderCallbacks<Object> callbacks) { |
| mId = id; |
| mArgs = args; |
| mCallbacks = callbacks; |
| } |
| |
| void start() { |
| if (mRetaining && mRetainingStarted) { |
| // Our owner is started, but we were being retained from a |
| // previous instance in the started state... so there is really |
| // nothing to do here, since the loaders are still started. |
| mStarted = true; |
| return; |
| } |
| |
| if (mStarted) { |
| // If loader already started, don't restart. |
| return; |
| } |
| |
| mStarted = true; |
| |
| if (DEBUG) Log.v(TAG, " Starting: " + this); |
| if (mLoader == null && mCallbacks != null) { |
| mLoader = mCallbacks.onCreateLoader(mId, mArgs); |
| } |
| if (mLoader != null) { |
| if (mLoader.getClass().isMemberClass() |
| && !Modifier.isStatic(mLoader.getClass().getModifiers())) { |
| throw new IllegalArgumentException( |
| "Object returned from onCreateLoader must not be a non-static inner member class: " |
| + mLoader); |
| } |
| if (!mListenerRegistered) { |
| mLoader.registerListener(mId, this); |
| mLoader.registerOnLoadCanceledListener(this); |
| mListenerRegistered = true; |
| } |
| mLoader.startLoading(); |
| } |
| } |
| |
| void retain() { |
| if (DEBUG) Log.v(TAG, " Retaining: " + this); |
| mRetaining = true; |
| mRetainingStarted = mStarted; |
| mStarted = false; |
| mCallbacks = null; |
| } |
| |
| void finishRetain() { |
| if (mRetaining) { |
| if (DEBUG) Log.v(TAG, " Finished Retaining: " + this); |
| mRetaining = false; |
| if (mStarted != mRetainingStarted) { |
| if (!mStarted) { |
| // This loader was retained in a started state, but |
| // at the end of retaining everything our owner is |
| // no longer started... so make it stop. |
| stop(); |
| } |
| } |
| } |
| |
| if (mStarted && mHaveData && !mReportNextStart) { |
| // This loader has retained its data, either completely across |
| // a configuration change or just whatever the last data set |
| // was after being restarted from a stop, and now at the point of |
| // finishing the retain we find we remain started, have |
| // our data, and the owner has a new callback... so |
| // let's deliver the data now. |
| callOnLoadFinished(mLoader, mData); |
| } |
| } |
| |
| void reportStart() { |
| if (mStarted) { |
| if (mReportNextStart) { |
| mReportNextStart = false; |
| if (mHaveData && !mRetaining) { |
| callOnLoadFinished(mLoader, mData); |
| } |
| } |
| } |
| } |
| |
| void stop() { |
| if (DEBUG) Log.v(TAG, " Stopping: " + this); |
| mStarted = false; |
| if (!mRetaining) { |
| if (mLoader != null && mListenerRegistered) { |
| // Let the loader know we're done with it |
| mListenerRegistered = false; |
| mLoader.unregisterListener(this); |
| mLoader.unregisterOnLoadCanceledListener(this); |
| mLoader.stopLoading(); |
| } |
| } |
| } |
| |
| boolean cancel() { |
| if (DEBUG) Log.v(TAG, " Canceling: " + this); |
| if (mStarted && mLoader != null && mListenerRegistered) { |
| final boolean cancelLoadResult = mLoader.cancelLoad(); |
| if (!cancelLoadResult) { |
| onLoadCanceled(mLoader); |
| } |
| return cancelLoadResult; |
| } |
| return false; |
| } |
| |
| void destroy() { |
| if (DEBUG) Log.v(TAG, " Destroying: " + this); |
| mDestroyed = true; |
| boolean needReset = mDeliveredData; |
| mDeliveredData = false; |
| if (mCallbacks != null && mLoader != null && mHaveData && needReset) { |
| if (DEBUG) Log.v(TAG, " Reseting: " + this); |
| String lastBecause = null; |
| if (mHost != null) { |
| lastBecause = mHost.mFragmentManager.mNoTransactionsBecause; |
| mHost.mFragmentManager.mNoTransactionsBecause = "onLoaderReset"; |
| } |
| try { |
| mCallbacks.onLoaderReset(mLoader); |
| } finally { |
| if (mHost != null) { |
| mHost.mFragmentManager.mNoTransactionsBecause = lastBecause; |
| } |
| } |
| } |
| mCallbacks = null; |
| mData = null; |
| mHaveData = false; |
| if (mLoader != null) { |
| if (mListenerRegistered) { |
| mListenerRegistered = false; |
| mLoader.unregisterListener(this); |
| mLoader.unregisterOnLoadCanceledListener(this); |
| } |
| mLoader.reset(); |
| } |
| if (mPendingLoader != null) { |
| mPendingLoader.destroy(); |
| } |
| } |
| |
| @Override |
| public void onLoadCanceled(Loader<Object> loader) { |
| if (DEBUG) Log.v(TAG, "onLoadCanceled: " + this); |
| |
| if (mDestroyed) { |
| if (DEBUG) Log.v(TAG, " Ignoring load canceled -- destroyed"); |
| return; |
| } |
| |
| if (mLoaders.get(mId) != this) { |
| // This cancellation message is not coming from the current active loader. |
| // We don't care about it. |
| if (DEBUG) Log.v(TAG, " Ignoring load canceled -- not active"); |
| return; |
| } |
| |
| LoaderInfo pending = mPendingLoader; |
| if (pending != null) { |
| // There is a new request pending and we were just |
| // waiting for the old one to cancel or complete before starting |
| // it. So now it is time, switch over to the new loader. |
| if (DEBUG) Log.v(TAG, " Switching to pending loader: " + pending); |
| mPendingLoader = null; |
| mLoaders.put(mId, null); |
| destroy(); |
| installLoader(pending); |
| } |
| } |
| |
| @Override |
| public void onLoadComplete(Loader<Object> loader, Object data) { |
| if (DEBUG) Log.v(TAG, "onLoadComplete: " + this); |
| |
| if (mDestroyed) { |
| if (DEBUG) Log.v(TAG, " Ignoring load complete -- destroyed"); |
| return; |
| } |
| |
| if (mLoaders.get(mId) != this) { |
| // This data is not coming from the current active loader. |
| // We don't care about it. |
| if (DEBUG) Log.v(TAG, " Ignoring load complete -- not active"); |
| return; |
| } |
| |
| LoaderInfo pending = mPendingLoader; |
| if (pending != null) { |
| // There is a new request pending and we were just |
| // waiting for the old one to complete before starting |
| // it. So now it is time, switch over to the new loader. |
| if (DEBUG) Log.v(TAG, " Switching to pending loader: " + pending); |
| mPendingLoader = null; |
| mLoaders.put(mId, null); |
| destroy(); |
| installLoader(pending); |
| return; |
| } |
| |
| // Notify of the new data so the app can switch out the old data before |
| // we try to destroy it. |
| if (mData != data || !mHaveData) { |
| mData = data; |
| mHaveData = true; |
| if (mStarted) { |
| callOnLoadFinished(loader, data); |
| } |
| } |
| |
| //if (DEBUG) Log.v(TAG, " onLoadFinished returned: " + this); |
| |
| // We have now given the application the new loader with its |
| // loaded data, so it should have stopped using the previous |
| // loader. If there is a previous loader on the inactive list, |
| // clean it up. |
| LoaderInfo info = mInactiveLoaders.get(mId); |
| if (info != null && info != this) { |
| info.mDeliveredData = false; |
| info.destroy(); |
| mInactiveLoaders.remove(mId); |
| } |
| |
| if (mHost != null && !hasRunningLoaders()) { |
| mHost.mFragmentManager.startPendingDeferredFragments(); |
| } |
| } |
| |
| void callOnLoadFinished(Loader<Object> loader, Object data) { |
| if (mCallbacks != null) { |
| String lastBecause = null; |
| if (mHost != null) { |
| lastBecause = mHost.mFragmentManager.mNoTransactionsBecause; |
| mHost.mFragmentManager.mNoTransactionsBecause = "onLoadFinished"; |
| } |
| try { |
| if (DEBUG) Log.v(TAG, " onLoadFinished in " + loader + ": " |
| + loader.dataToString(data)); |
| mCallbacks.onLoadFinished(loader, data); |
| } finally { |
| if (mHost != null) { |
| mHost.mFragmentManager.mNoTransactionsBecause = lastBecause; |
| } |
| } |
| mDeliveredData = true; |
| } |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder(64); |
| sb.append("LoaderInfo{"); |
| sb.append(Integer.toHexString(System.identityHashCode(this))); |
| sb.append(" #"); |
| sb.append(mId); |
| sb.append(" : "); |
| DebugUtils.buildShortClassTag(mLoader, sb); |
| sb.append("}}"); |
| return sb.toString(); |
| } |
| |
| public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { |
| writer.print(prefix); writer.print("mId="); writer.print(mId); |
| writer.print(" mArgs="); writer.println(mArgs); |
| writer.print(prefix); writer.print("mCallbacks="); writer.println(mCallbacks); |
| writer.print(prefix); writer.print("mLoader="); writer.println(mLoader); |
| if (mLoader != null) { |
| mLoader.dump(prefix + " ", fd, writer, args); |
| } |
| if (mHaveData || mDeliveredData) { |
| writer.print(prefix); writer.print("mHaveData="); writer.print(mHaveData); |
| writer.print(" mDeliveredData="); writer.println(mDeliveredData); |
| writer.print(prefix); writer.print("mData="); writer.println(mData); |
| } |
| writer.print(prefix); writer.print("mStarted="); writer.print(mStarted); |
| writer.print(" mReportNextStart="); writer.print(mReportNextStart); |
| writer.print(" mDestroyed="); writer.println(mDestroyed); |
| writer.print(prefix); writer.print("mRetaining="); writer.print(mRetaining); |
| writer.print(" mRetainingStarted="); writer.print(mRetainingStarted); |
| writer.print(" mListenerRegistered="); writer.println(mListenerRegistered); |
| if (mPendingLoader != null) { |
| writer.print(prefix); writer.println("Pending Loader "); |
| writer.print(mPendingLoader); writer.println(":"); |
| mPendingLoader.dump(prefix + " ", fd, writer, args); |
| } |
| } |
| } |
| |
| LoaderManagerImpl(String who, FragmentHostCallback host, boolean started) { |
| mWho = who; |
| mHost = host; |
| mStarted = started; |
| } |
| |
| void updateHostController(FragmentHostCallback host) { |
| mHost = host; |
| } |
| |
| public FragmentHostCallback getFragmentHostCallback() { |
| return mHost; |
| } |
| |
| private LoaderInfo createLoader(int id, Bundle args, |
| LoaderManager.LoaderCallbacks<Object> callback) { |
| LoaderInfo info = new LoaderInfo(id, args, (LoaderManager.LoaderCallbacks<Object>)callback); |
| Loader<Object> loader = callback.onCreateLoader(id, args); |
| info.mLoader = (Loader<Object>)loader; |
| return info; |
| } |
| |
| private LoaderInfo createAndInstallLoader(int id, Bundle args, |
| LoaderManager.LoaderCallbacks<Object> callback) { |
| try { |
| mCreatingLoader = true; |
| LoaderInfo info = createLoader(id, args, callback); |
| installLoader(info); |
| return info; |
| } finally { |
| mCreatingLoader = false; |
| } |
| } |
| |
| void installLoader(LoaderInfo info) { |
| mLoaders.put(info.mId, info); |
| if (mStarted) { |
| // The activity will start all existing loaders in it's onStart(), |
| // so only start them here if we're past that point of the activitiy's |
| // life cycle |
| info.start(); |
| } |
| } |
| |
| /** |
| * Call to initialize a particular ID with a Loader. If this ID already |
| * has a Loader associated with it, it is left unchanged and any previous |
| * callbacks replaced with the newly provided ones. If there is not currently |
| * a Loader for the ID, a new one is created and started. |
| * |
| * <p>This function should generally be used when a component is initializing, |
| * to ensure that a Loader it relies on is created. This allows it to re-use |
| * an existing Loader's data if there already is one, so that for example |
| * when an {@link Activity} is re-created after a configuration change it |
| * does not need to re-create its loaders. |
| * |
| * <p>Note that in the case where an existing Loader is re-used, the |
| * <var>args</var> given here <em>will be ignored</em> because you will |
| * continue using the previous Loader. |
| * |
| * @param id A unique (to this LoaderManager instance) identifier under |
| * which to manage the new Loader. |
| * @param args Optional arguments that will be propagated to |
| * {@link LoaderCallbacks#onCreateLoader(int, Bundle) LoaderCallbacks.onCreateLoader()}. |
| * @param callback Interface implementing management of this Loader. Required. |
| * Its onCreateLoader() method will be called while inside of the function to |
| * instantiate the Loader object. |
| */ |
| @SuppressWarnings("unchecked") |
| public <D> Loader<D> initLoader(int id, Bundle args, LoaderManager.LoaderCallbacks<D> callback) { |
| if (mCreatingLoader) { |
| throw new IllegalStateException("Called while creating a loader"); |
| } |
| |
| LoaderInfo info = mLoaders.get(id); |
| |
| if (DEBUG) Log.v(TAG, "initLoader in " + this + ": args=" + args); |
| |
| if (info == null) { |
| // Loader doesn't already exist; create. |
| info = createAndInstallLoader(id, args, (LoaderManager.LoaderCallbacks<Object>)callback); |
| if (DEBUG) Log.v(TAG, " Created new loader " + info); |
| } else { |
| if (DEBUG) Log.v(TAG, " Re-using existing loader " + info); |
| info.mCallbacks = (LoaderManager.LoaderCallbacks<Object>)callback; |
| } |
| |
| if (info.mHaveData && mStarted) { |
| // If the loader has already generated its data, report it now. |
| info.callOnLoadFinished(info.mLoader, info.mData); |
| } |
| |
| return (Loader<D>)info.mLoader; |
| } |
| |
| /** |
| * Call to re-create the Loader associated with a particular ID. If there |
| * is currently a Loader associated with this ID, it will be |
| * canceled/stopped/destroyed as appropriate. A new Loader with the given |
| * arguments will be created and its data delivered to you once available. |
| * |
| * <p>This function does some throttling of Loaders. If too many Loaders |
| * have been created for the given ID but not yet generated their data, |
| * new calls to this function will create and return a new Loader but not |
| * actually start it until some previous loaders have completed. |
| * |
| * <p>After calling this function, any previous Loaders associated with |
| * this ID will be considered invalid, and you will receive no further |
| * data updates from them. |
| * |
| * @param id A unique (to this LoaderManager instance) identifier under |
| * which to manage the new Loader. |
| * @param args Optional arguments that will be propagated to |
| * {@link LoaderCallbacks#onCreateLoader(int, Bundle) LoaderCallbacks.onCreateLoader()}. |
| * @param callback Interface implementing management of this Loader. Required. |
| * Its onCreateLoader() method will be called while inside of the function to |
| * instantiate the Loader object. |
| */ |
| @SuppressWarnings("unchecked") |
| public <D> Loader<D> restartLoader(int id, Bundle args, LoaderManager.LoaderCallbacks<D> callback) { |
| if (mCreatingLoader) { |
| throw new IllegalStateException("Called while creating a loader"); |
| } |
| |
| LoaderInfo info = mLoaders.get(id); |
| if (DEBUG) Log.v(TAG, "restartLoader in " + this + ": args=" + args); |
| if (info != null) { |
| LoaderInfo inactive = mInactiveLoaders.get(id); |
| if (inactive != null) { |
| if (info.mHaveData) { |
| // This loader now has data... we are probably being |
| // called from within onLoadComplete, where we haven't |
| // yet destroyed the last inactive loader. So just do |
| // that now. |
| if (DEBUG) Log.v(TAG, " Removing last inactive loader: " + info); |
| inactive.mDeliveredData = false; |
| inactive.destroy(); |
| info.mLoader.abandon(); |
| mInactiveLoaders.put(id, info); |
| } else { |
| // We already have an inactive loader for this ID that we are |
| // waiting for! Try to cancel; if this returns true then the task is still |
| // running and we have more work to do. |
| if (!info.cancel()) { |
| // The current Loader has not been started or was successfully canceled, |
| // we thus have no reason to keep it around. Remove it and a new |
| // LoaderInfo will be created below. |
| if (DEBUG) Log.v(TAG, " Current loader is stopped; replacing"); |
| mLoaders.put(id, null); |
| info.destroy(); |
| } else { |
| // Now we have three active loaders... we'll queue |
| // up this request to be processed once one of the other loaders |
| // finishes. |
| if (DEBUG) Log.v(TAG, |
| " Current loader is running; configuring pending loader"); |
| if (info.mPendingLoader != null) { |
| if (DEBUG) Log.v(TAG, " Removing pending loader: " + info.mPendingLoader); |
| info.mPendingLoader.destroy(); |
| info.mPendingLoader = null; |
| } |
| if (DEBUG) Log.v(TAG, " Enqueuing as new pending loader"); |
| info.mPendingLoader = createLoader(id, args, |
| (LoaderManager.LoaderCallbacks<Object>)callback); |
| return (Loader<D>)info.mPendingLoader.mLoader; |
| } |
| } |
| } else { |
| // Keep track of the previous instance of this loader so we can destroy |
| // it when the new one completes. |
| if (DEBUG) Log.v(TAG, " Making last loader inactive: " + info); |
| info.mLoader.abandon(); |
| mInactiveLoaders.put(id, info); |
| } |
| } |
| |
| info = createAndInstallLoader(id, args, (LoaderManager.LoaderCallbacks<Object>)callback); |
| return (Loader<D>)info.mLoader; |
| } |
| |
| /** |
| * Rip down, tear apart, shred to pieces a current Loader ID. After returning |
| * from this function, any Loader objects associated with this ID are |
| * destroyed. Any data associated with them is destroyed. You better not |
| * be using it when you do this. |
| * @param id Identifier of the Loader to be destroyed. |
| */ |
| public void destroyLoader(int id) { |
| if (mCreatingLoader) { |
| throw new IllegalStateException("Called while creating a loader"); |
| } |
| |
| if (DEBUG) Log.v(TAG, "destroyLoader in " + this + " of " + id); |
| int idx = mLoaders.indexOfKey(id); |
| if (idx >= 0) { |
| LoaderInfo info = mLoaders.valueAt(idx); |
| mLoaders.removeAt(idx); |
| info.destroy(); |
| } |
| idx = mInactiveLoaders.indexOfKey(id); |
| if (idx >= 0) { |
| LoaderInfo info = mInactiveLoaders.valueAt(idx); |
| mInactiveLoaders.removeAt(idx); |
| info.destroy(); |
| } |
| if (mHost != null && !hasRunningLoaders()) { |
| mHost.mFragmentManager.startPendingDeferredFragments(); |
| } |
| } |
| |
| /** |
| * Return the most recent Loader object associated with the |
| * given ID. |
| */ |
| @SuppressWarnings("unchecked") |
| public <D> Loader<D> getLoader(int id) { |
| if (mCreatingLoader) { |
| throw new IllegalStateException("Called while creating a loader"); |
| } |
| |
| LoaderInfo loaderInfo = mLoaders.get(id); |
| if (loaderInfo != null) { |
| if (loaderInfo.mPendingLoader != null) { |
| return (Loader<D>)loaderInfo.mPendingLoader.mLoader; |
| } |
| return (Loader<D>)loaderInfo.mLoader; |
| } |
| return null; |
| } |
| |
| void doStart() { |
| if (DEBUG) Log.v(TAG, "Starting in " + this); |
| if (mStarted) { |
| RuntimeException e = new RuntimeException("here"); |
| e.fillInStackTrace(); |
| Log.w(TAG, "Called doStart when already started: " + this, e); |
| return; |
| } |
| |
| mStarted = true; |
| |
| // Call out to sub classes so they can start their loaders |
| // Let the existing loaders know that we want to be notified when a load is complete |
| for (int i = mLoaders.size()-1; i >= 0; i--) { |
| mLoaders.valueAt(i).start(); |
| } |
| } |
| |
| void doStop() { |
| if (DEBUG) Log.v(TAG, "Stopping in " + this); |
| if (!mStarted) { |
| RuntimeException e = new RuntimeException("here"); |
| e.fillInStackTrace(); |
| Log.w(TAG, "Called doStop when not started: " + this, e); |
| return; |
| } |
| |
| for (int i = mLoaders.size()-1; i >= 0; i--) { |
| mLoaders.valueAt(i).stop(); |
| } |
| mStarted = false; |
| } |
| |
| void doRetain() { |
| if (DEBUG) Log.v(TAG, "Retaining in " + this); |
| if (!mStarted) { |
| RuntimeException e = new RuntimeException("here"); |
| e.fillInStackTrace(); |
| Log.w(TAG, "Called doRetain when not started: " + this, e); |
| return; |
| } |
| |
| mRetaining = true; |
| mStarted = false; |
| for (int i = mLoaders.size()-1; i >= 0; i--) { |
| mLoaders.valueAt(i).retain(); |
| } |
| } |
| |
| void finishRetain() { |
| if (mRetaining) { |
| if (DEBUG) Log.v(TAG, "Finished Retaining in " + this); |
| |
| mRetaining = false; |
| for (int i = mLoaders.size()-1; i >= 0; i--) { |
| mLoaders.valueAt(i).finishRetain(); |
| } |
| } |
| } |
| |
| void doReportNextStart() { |
| for (int i = mLoaders.size()-1; i >= 0; i--) { |
| mLoaders.valueAt(i).mReportNextStart = true; |
| } |
| } |
| |
| void doReportStart() { |
| for (int i = mLoaders.size()-1; i >= 0; i--) { |
| mLoaders.valueAt(i).reportStart(); |
| } |
| } |
| |
| void doDestroy() { |
| if (!mRetaining) { |
| if (DEBUG) Log.v(TAG, "Destroying Active in " + this); |
| for (int i = mLoaders.size()-1; i >= 0; i--) { |
| mLoaders.valueAt(i).destroy(); |
| } |
| mLoaders.clear(); |
| } |
| |
| if (DEBUG) Log.v(TAG, "Destroying Inactive in " + this); |
| for (int i = mInactiveLoaders.size()-1; i >= 0; i--) { |
| mInactiveLoaders.valueAt(i).destroy(); |
| } |
| mInactiveLoaders.clear(); |
| mHost = null; |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder(128); |
| sb.append("LoaderManager{"); |
| sb.append(Integer.toHexString(System.identityHashCode(this))); |
| sb.append(" in "); |
| DebugUtils.buildShortClassTag(mHost, sb); |
| sb.append("}}"); |
| return sb.toString(); |
| } |
| |
| @Override |
| public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { |
| if (mLoaders.size() > 0) { |
| writer.print(prefix); writer.println("Active Loaders:"); |
| String innerPrefix = prefix + " "; |
| for (int i=0; i < mLoaders.size(); i++) { |
| LoaderInfo li = mLoaders.valueAt(i); |
| writer.print(prefix); writer.print(" #"); writer.print(mLoaders.keyAt(i)); |
| writer.print(": "); writer.println(li.toString()); |
| li.dump(innerPrefix, fd, writer, args); |
| } |
| } |
| if (mInactiveLoaders.size() > 0) { |
| writer.print(prefix); writer.println("Inactive Loaders:"); |
| String innerPrefix = prefix + " "; |
| for (int i=0; i < mInactiveLoaders.size(); i++) { |
| LoaderInfo li = mInactiveLoaders.valueAt(i); |
| writer.print(prefix); writer.print(" #"); writer.print(mInactiveLoaders.keyAt(i)); |
| writer.print(": "); writer.println(li.toString()); |
| li.dump(innerPrefix, fd, writer, args); |
| } |
| } |
| } |
| |
| public boolean hasRunningLoaders() { |
| boolean loadersRunning = false; |
| final int count = mLoaders.size(); |
| for (int i = 0; i < count; i++) { |
| final LoaderInfo li = mLoaders.valueAt(i); |
| loadersRunning |= li.mStarted && !li.mDeliveredData; |
| } |
| return loadersRunning; |
| } |
| } |
