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Android APIs
public abstract class

AsyncQueryHandler

extends Handler
java.lang.Object
   ↳ android.os.Handler
     ↳ android.content.AsyncQueryHandler

Class Overview

A helper class to help make handling asynchronous ContentResolver queries easier.

Summary

Nested Classes
class AsyncQueryHandler.WorkerArgs  
class AsyncQueryHandler.WorkerHandler  
Public Constructors
AsyncQueryHandler(ContentResolver cr)
Public Methods
final void cancelOperation(int token)
Attempts to cancel operation that has not already started.
void handleMessage(Message msg)
Subclasses must implement this to receive messages.
final void startDelete(int token, Object cookie, Uri uri, String selection, String[] selectionArgs)
This method begins an asynchronous delete.
final void startInsert(int token, Object cookie, Uri uri, ContentValues initialValues)
This method begins an asynchronous insert.
void startQuery(int token, Object cookie, Uri uri, String[] projection, String selection, String[] selectionArgs, String orderBy)
This method begins an asynchronous query.
final void startUpdate(int token, Object cookie, Uri uri, ContentValues values, String selection, String[] selectionArgs)
This method begins an asynchronous update.
Protected Methods
Handler createHandler(Looper looper)
void onDeleteComplete(int token, Object cookie, int result)
Called when an asynchronous delete is completed.
void onInsertComplete(int token, Object cookie, Uri uri)
Called when an asynchronous insert is completed.
void onQueryComplete(int token, Object cookie, Cursor cursor)
Called when an asynchronous query is completed.
void onUpdateComplete(int token, Object cookie, int result)
Called when an asynchronous update is completed.
[Expand]
Inherited Methods
From class android.os.Handler
From class java.lang.Object

Public Constructors

public AsyncQueryHandler (ContentResolver cr)

Since: API Level 1

Public Methods

public final void cancelOperation (int token)

Since: API Level 1

Attempts to cancel operation that has not already started. Note that there is no guarantee that the operation will be canceled. They still may result in a call to on[Query/Insert/Update/Delete]Complete after this call has completed.

Parameters
token The token representing the operation to be canceled. If multiple operations have the same token they will all be canceled.

public void handleMessage (Message msg)

Since: API Level 1

Subclasses must implement this to receive messages.

public final void startDelete (int token, Object cookie, Uri uri, String selection, String[] selectionArgs)

Since: API Level 1

This method begins an asynchronous delete. When the delete operation is done onDeleteComplete(int, Object, int) is called.

Parameters
token A token passed into onDeleteComplete(int, Object, int) to identify the delete operation.
cookie An object that gets passed into onDeleteComplete(int, Object, int)
uri the Uri passed to the delete operation.
selection the where clause.

public final void startInsert (int token, Object cookie, Uri uri, ContentValues initialValues)

Since: API Level 1

This method begins an asynchronous insert. When the insert operation is done onInsertComplete(int, Object, Uri) is called.

Parameters
token A token passed into onInsertComplete(int, Object, Uri) to identify the insert operation.
cookie An object that gets passed into onInsertComplete(int, Object, Uri)
uri the Uri passed to the insert operation.
initialValues the ContentValues parameter passed to the insert operation.

public void startQuery (int token, Object cookie, Uri uri, String[] projection, String selection, String[] selectionArgs, String orderBy)

Since: API Level 1

This method begins an asynchronous query. When the query is done onQueryComplete(int, Object, Cursor) is called.

Parameters
token A token passed into onQueryComplete(int, Object, Cursor) to identify the query.
cookie An object that gets passed into onQueryComplete(int, Object, Cursor)
uri The URI, using the content:// scheme, for the content to retrieve.
projection A list of which columns to return. Passing null will return all columns, which is discouraged to prevent reading data from storage that isn't going to be used.
selection A filter declaring which rows to return, formatted as an SQL WHERE clause (excluding the WHERE itself). Passing null will return all rows for the given URI.
selectionArgs You may include ?s in selection, which will be replaced by the values from selectionArgs, in the order that they appear in the selection. The values will be bound as Strings.
orderBy How to order the rows, formatted as an SQL ORDER BY clause (excluding the ORDER BY itself). Passing null will use the default sort order, which may be unordered.

public final void startUpdate (int token, Object cookie, Uri uri, ContentValues values, String selection, String[] selectionArgs)

Since: API Level 1

This method begins an asynchronous update. When the update operation is done onUpdateComplete(int, Object, int) is called.

Parameters
token A token passed into onUpdateComplete(int, Object, int) to identify the update operation.
cookie An object that gets passed into onUpdateComplete(int, Object, int)
uri the Uri passed to the update operation.
values the ContentValues parameter passed to the update operation.

Protected Methods

protected Handler createHandler (Looper looper)

Since: API Level 1

protected void onDeleteComplete (int token, Object cookie, int result)

Since: API Level 1

Called when an asynchronous delete is completed.

Parameters
token the token to identify the query, passed in from startDelete(int, Object, Uri, String, String[]).
cookie the cookie object that's passed in from startDelete(int, Object, Uri, String, String[]).
result the result returned from the delete operation

protected void onInsertComplete (int token, Object cookie, Uri uri)

Since: API Level 1

Called when an asynchronous insert is completed.

Parameters
token the token to identify the query, passed in from startInsert(int, Object, Uri, ContentValues).
cookie the cookie object that's passed in from startInsert(int, Object, Uri, ContentValues).
uri the uri returned from the insert operation.

protected void onQueryComplete (int token, Object cookie, Cursor cursor)

Since: API Level 1

Called when an asynchronous query is completed.

Parameters
token the token to identify the query, passed in from startQuery(int, Object, Uri, String[], String, String[], String).
cookie the cookie object passed in from startQuery(int, Object, Uri, String[], String, String[], String).
cursor The cursor holding the results from the query.

protected void onUpdateComplete (int token, Object cookie, int result)

Since: API Level 1

Called when an asynchronous update is completed.

Parameters
token the token to identify the query, passed in from startUpdate(int, Object, Uri, ContentValues, String, String[]).
cookie the cookie object that's passed in from startUpdate(int, Object, Uri, ContentValues, String, String[]).
result the result returned from the update operation