LoaderManager

@MainThread
public abstract void destroyLoader(int id)

Stops and removes the loader with the given ID. If this loader had previously reported data to the client through onLoadFinished, a call will be made to onLoaderReset.

Must be called from the process's main thread.

public abstract void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args)

Print the LoaderManager's state into the given stream.

public static void enableDebugLogging(boolean enabled)

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 @NonNull LoaderManager <T extends LifecycleOwner & ViewModelStoreOwner> getInstance(@NonNull T owner)

Gets a LoaderManager associated with the given owner, such as a androidx.fragment.app.FragmentActivity or androidx.fragment.app.Fragment.

public abstract @Nullable Loader<D> <D> getLoader(int id)

Return the Loader with the given id or null if no matching Loader is found.

public boolean hasRunningLoaders()

Returns true if any loaders managed are currently running and have not returned data to the application yet.

@MainThread
public abstract @NonNull Loader<D> <D> initLoader(
    int id,
    @Nullable Bundle args,
    @NonNull LoaderManager.LoaderCallbacks<D> callback
)

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.

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 onLoadFinished will be called immediately (inside of this function), so you must be prepared for this to happen.

Must be called from the process's main thread.

public abstract void markForRedelivery()

Mark all Loaders associated with this LoaderManager for redelivery of their current data (if any), waiting for the next time the Loader is started if it is currently stopped. In cases where no data has yet been delivered, this is effectively a no-op. In cases where data has already been delivered via onLoadFinished, this will ensure that onLoadFinished is called again with the same data.

Call this only if you are implementing a LifecycleOwner where the views/elements that developers are likely to use in onLoadFinished can be created and destroyed multiple times without the LifecycleOwner itself being destroyed. Call this when the views/elements are being destroyed to ensure that the data is redelivered upon recreation.

@MainThread
public abstract @NonNull Loader<D> <D> restartLoader(
    int id,
    @Nullable Bundle args,
    @NonNull LoaderManager.LoaderCallbacks<D> callback
)

Starts a new or restarts an existing 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.

Must be called from the process's main thread.