added in version 22.1.0
belongs to Maven artifact com.android.support:loader:28.0.0-alpha1

Summary: Ctors | Methods | Protected Methods | Inherited Methods | [Expand All]

CursorLoader

This package is part of the Android support library which is no longer maintained. The support library has been superseded by AndroidX which is part of Jetpack. We recommend using the AndroidX libraries in all new projects. You should also consider migrating existing projects to AndroidX. To find the AndroidX class that maps to this deprecated class, see the AndroidX support library class mappings.

public class CursorLoader
extends AsyncTaskLoader<Cursor>

java.lang.Object
↳	android.support.v4.content.Loader<android.database.Cursor>
	↳	android.support.v4.content.AsyncTaskLoader<android.database.Cursor>
		↳	android.support.v4.content.CursorLoader

---

Static library support version of the framework's CursorLoader. Used to write apps that run on platforms prior to Android 3.0. When running on Android 3.0 or above, this implementation is still used; it does not try to switch to the framework's implementation. See the framework SDK documentation for a class overview.

Summary

Public constructors
CursorLoader(Context context) Creates an empty unspecified CursorLoader.
CursorLoader(Context context, Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) Creates a fully-specified CursorLoader.

Public methods
void	cancelLoadInBackground() Called on the main thread to abort a load in progress.
void	deliverResult(Cursor cursor) Sends the result of the load to the registered listener.
void	dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) Print the Loader's state into the given stream.
String[]	getProjection()
String	getSelection()
String[]	getSelectionArgs()
String	getSortOrder()
Uri	getUri()
Cursor	loadInBackground() Called on a worker thread to perform the actual load and to return the result of the load operation.
void	onCanceled(Cursor cursor) Called if the task was canceled before it was completed.
void	setProjection(String[] projection)
void	setSelection(String selection)
void	setSelectionArgs(String[] selectionArgs)
void	setSortOrder(String sortOrder)
void	setUri(Uri uri)

Protected methods
void	onReset() Subclasses must implement this to take care of resetting their loader, as per reset().
void	onStartLoading() Starts an asynchronous load of the contacts list data.
void	onStopLoading() Must be called from the UI thread

Inherited methods
From class android.support.v4.content.AsyncTaskLoader void cancelLoadInBackground() Called on the main thread to abort a load in progress. void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) Print the Loader's state into the given stream. boolean isLoadInBackgroundCanceled() Returns true if the current invocation of loadInBackground() is being canceled. abstract Cursor loadInBackground() Called on a worker thread to perform the actual load and to return the result of the load operation. boolean onCancelLoad() Subclasses must implement this to take care of requests to cancelLoad(). void onCanceled(Cursor data) Called if the task was canceled before it was completed. void onForceLoad() Subclasses must implement this to take care of requests to forceLoad(). Cursor onLoadInBackground() Calls loadInBackground(). void setUpdateThrottle(long delayMS) Set amount to throttle updates by.
From class android.support.v4.content.Loader void abandon() This function will normally be called for you automatically by LoaderManager when restarting a Loader. boolean cancelLoad() Attempt to cancel the current load task. void commitContentChanged() Commit that you have actually fully processed a content change that was returned by takeContentChanged(). String dataToString(Cursor data) For debugging, converts an instance of the Loader's data class to a string that can be printed. void deliverCancellation() Informs the registered Loader.OnLoadCanceledListener that the load has been canceled. void deliverResult(Cursor data) Sends the result of the load to the registered listener. void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) Print the Loader's state into the given stream. void forceLoad() Force an asynchronous load. Context getContext() int getId() boolean isAbandoned() Return whether this loader has been abandoned. boolean isReset() Return whether this load has been reset. boolean isStarted() Return whether this load has been started. void onAbandon() Subclasses implement this to take care of being abandoned. boolean onCancelLoad() Subclasses must implement this to take care of requests to cancelLoad(). void onContentChanged() Called when Loader.ForceLoadContentObserver detects a change. void onForceLoad() Subclasses must implement this to take care of requests to forceLoad(). void onReset() Subclasses must implement this to take care of resetting their loader, as per reset(). void onStartLoading() Subclasses must implement this to take care of loading their data, as per startLoading(). void onStopLoading() Subclasses must implement this to take care of stopping their loader, as per stopLoading(). void registerListener(int id, OnLoadCompleteListener<Cursor> listener) Registers a class that will receive callbacks when a load is complete. void registerOnLoadCanceledListener(OnLoadCanceledListener<Cursor> listener) Registers a listener that will receive callbacks when a load is canceled. void reset() This function will normally be called for you automatically by LoaderManager when destroying a Loader. void rollbackContentChanged() Report that you have abandoned the processing of a content change that was returned by takeContentChanged() and would like to rollback to the state where there is again a pending content change. final void startLoading() This function will normally be called for you automatically by LoaderManager when the associated fragment/activity is being started. void stopLoading() This function will normally be called for you automatically by LoaderManager when the associated fragment/activity is being stopped. boolean takeContentChanged() Take the current flag indicating whether the loader's content had changed while it was stopped. String toString() void unregisterListener(OnLoadCompleteListener<Cursor> listener) Remove a listener that was previously added with registerListener(int, Loader.OnLoadCompleteListener). void unregisterOnLoadCanceledListener(OnLoadCanceledListener<Cursor> listener) Unregisters a listener that was previously added with registerOnLoadCanceledListener(Loader.OnLoadCanceledListener).
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait(long arg0, int arg1) final void wait(long arg0) final void wait()

Public constructors

CursorLoader

added in version 22.1.0

CursorLoader (Context context)

Creates an empty unspecified CursorLoader. You must follow this with calls to setUri(Uri), setSelection(String), etc to specify the query to perform.

Parameters
context	Context

CursorLoader

added in version 22.1.0

CursorLoader (Context context, 
                Uri uri, 
                String[] projection, 
                String selection, 
                String[] selectionArgs, 
                String sortOrder)

Creates a fully-specified CursorLoader. See ContentResolver.query() for documentation on the meaning of the parameters. These will be passed as-is to that call.

Parameters
context	Context
uri	Uri
projection	String
selection	String
selectionArgs	String
sortOrder	String

Public methods

cancelLoadInBackground

added in version 24.1.0

void cancelLoadInBackground ()

Called on the main thread to abort a load in progress. Override this method to abort the current invocation of loadInBackground() that is running in the background on a worker thread. This method should do nothing if loadInBackground() has not started running or if it has already finished.

deliverResult

added in version 22.1.0

void deliverResult (Cursor cursor)

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.

Parameters
cursor	Cursor: the result of the load

dump

added in version 22.1.0

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

Print the Loader's state into the given stream.

Parameters
prefix	String: Text to print at the front of each line.
fd	FileDescriptor: The raw file descriptor that the dump is being sent to.
writer	PrintWriter: A PrintWriter to which the dump is to be set.
args	String: Additional arguments to the dump request.

getProjection

added in version 22.1.0

String[] getProjection ()

Returns
String[]

getSelection

added in version 22.1.0

String getSelection ()

Returns
String

getSelectionArgs

added in version 22.1.0

String[] getSelectionArgs ()

Returns
String[]

getSortOrder

added in version 22.1.0

String getSortOrder ()

Returns
String

getUri

added in version 22.1.0

Uri getUri ()

Returns
Uri

loadInBackground

added in version 22.1.0

Cursor loadInBackground ()

Called on a worker thread to perform the actual load and to return the result of the load operation. Implementations should not deliver the result directly, but should return them from this method, which will eventually end up calling deliverResult(D) on the UI thread. If implementations need to process the results on the UI thread they may override deliverResult(D) and do so there. To support cancellation, this method should periodically check the value of isLoadInBackgroundCanceled() and terminate when it returns true. Subclasses may also override cancelLoadInBackground() to interrupt the load directly instead of polling isLoadInBackgroundCanceled(). When the load is canceled, this method may either return normally or throw OperationCanceledException. In either case, the Loader will call onCanceled(D) to perform post-cancellation cleanup and to dispose of the result object, if any.

Returns
Cursor	The result of the load operation.

onCanceled

added in version 22.1.0

void onCanceled (Cursor cursor)

Called if the task was canceled before it was completed. Gives the class a chance to clean up post-cancellation and to properly dispose of the result.

Parameters
cursor	Cursor: The value that was returned by loadInBackground(), or null if the task threw OperationCanceledException.

setProjection

added in version 22.1.0

void setProjection (String[] projection)

Parameters
projection	String

setSelection

added in version 22.1.0

void setSelection (String selection)

Parameters
selection	String

setSelectionArgs

added in version 22.1.0

void setSelectionArgs (String[] selectionArgs)

Parameters
selectionArgs	String

setSortOrder

added in version 22.1.0

void setSortOrder (String sortOrder)

Parameters
sortOrder	String

setUri

added in version 22.1.0

void setUri (Uri uri)

Parameters
uri	Uri

Protected methods

onReset

added in version 22.1.0

void onReset ()

Subclasses must implement this to take care of resetting their loader, as per reset(). This is not called by clients directly, but as a result of a call to reset(). This will always be called from the process's main thread.

onStartLoading

added in version 22.1.0

void onStartLoading ()

Starts an asynchronous load of the contacts list data. When the result is ready the callbacks will be called on the UI thread. If a previous load has been completed and is still valid the result may be passed to the callbacks immediately. Must be called from the UI thread

onStopLoading

added in version 22.1.0

void onStopLoading ()

Must be called from the UI thread

• Interfaces

  • Loader.OnLoadCanceledListener
  • Loader.OnLoadCompleteListener

• Classes

  • AsyncTaskLoader
  • ContentResolverCompat
  • ContextCompat
  • CursorLoader
  • FileProvider
  • IntentCompat
  • Loader
  • Loader.ForceLoadContentObserver
  • LocalBroadcastManager
  • MimeTypeFilter
  • PermissionChecker
  • SharedPreferencesCompat
  • SharedPreferencesCompat.EditorCompat
  • WakefulBroadcastReceiver