Loader

Loader

Loader (Context context)

Stores away the application context associated with context. Since Loaders can be used across multiple activities it's dangerous to store the context directly; always use getContext() to retrieve the Loader's Context, don't use the constructor argument directly. The Context returned by getContext() is safe to use across Activity instances.

abandon

void abandon ()

This function will normally be called for you automatically by LoaderManager when restarting a Loader. When using a Loader with LoaderManager, you must not call this method yourself, or you will conflict with its management of the Loader. Tell the Loader that it is being abandoned. This is called prior to reset() to have it retain its current data but not report any new data.

Must be called from the process's main thread.

cancelLoad

boolean cancelLoad ()

Attempt to cancel the current load task. Must be called on the main thread of the process.

Cancellation is not an immediate operation, since the load is performed in a background thread. If there is currently a load in progress, this method requests that the load be canceled, and notes this is the case; once the background thread has completed its work its remaining state will be cleared. If another load request comes in during this time, it will be held until the canceled load is complete.

commitContentChanged

void commitContentChanged ()

Commit that you have actually fully processed a content change that was returned by takeContentChanged(). This is for use with rollbackContentChanged() to handle situations where a load is cancelled. Call this when you have completely processed a load without it being cancelled.

dataToString

String dataToString (D data)

For debugging, converts an instance of the Loader's data class to a string that can be printed. Must handle a null data.

deliverCancellation

void deliverCancellation ()

Informs the registered Loader.OnLoadCanceledListener that the load has been canceled. Should only be called by subclasses. Must be called from the process's main thread.

deliverResult

void deliverResult (D data)

Sends the result of the load to the registered listener. Should only be called by subclasses. Must be called from the process's main thread.

dump

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

Print the Loader's state into the given stream.

forceLoad

void forceLoad ()

Force an asynchronous load. Unlike startLoading() this will ignore a previously loaded data set and load a new one. This simply calls through to the implementation's onForceLoad(). You generally should only call this when the loader is started -- that is, isStarted() returns true.

Must be called from the process's main thread.

getContext

Context getContext ()

getId

int getId ()

isAbandoned

boolean isAbandoned ()

Return whether this loader has been abandoned. In this state, the loader must not report any new data, and must keep its last reported data valid until it is finally reset.

isReset

boolean isReset ()

Return whether this load has been reset. That is, either the loader has not yet been started for the first time, or its reset() has been called.

isStarted

boolean isStarted ()

Return whether this load has been started. That is, its startLoading() has been called and no calls to stopLoading() or reset() have yet been made.

onContentChanged

void onContentChanged ()

Called when Loader.ForceLoadContentObserver detects a change. The default implementation checks to see if the loader is currently started; if so, it simply calls forceLoad(); otherwise, it sets a flag so that takeContentChanged() returns true.

Must be called from the process's main thread.

registerListener

void registerListener (int id, 
                OnLoadCompleteListener<D> listener)

Registers a class that will receive callbacks when a load is complete. The callback will be called on the process's main thread so it's safe to pass the results to widgets.

Must be called from the process's main thread.