AsyncQueryHandler


public abstract class AsyncQueryHandler
extends Handler

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


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.

Inherited methods

Public constructors

AsyncQueryHandler

Added in API level 1
public AsyncQueryHandler (ContentResolver cr)

Parameters
cr ContentResolver

Public methods

cancelOperation

Added in API level 1
public final void cancelOperation (int token)

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

handleMessage

Added in API level 1
public void handleMessage (Message msg)

Subclasses must implement this to receive messages.

Parameters
msg Message: This value cannot be null.

startDelete

Added in API level 1
public final void startDelete (int token, 
                Object cookie, 
                Uri uri, 
                String selection, 
                String[] selectionArgs)

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

Parameters
token int: A token passed into onDeleteComplete(int, Object, int) to identify the delete operation.

cookie Object: An object that gets passed into onDeleteComplete(int, Object, int)

uri Uri: the Uri passed to the delete operation.

selection String: the where clause.

selectionArgs String

startInsert

Added in API level 1
public final void startInsert (int token, 
                Object cookie, 
                Uri uri, 
                ContentValues initialValues)

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

Parameters
token int: A token passed into onInsertComplete(int, Object, Uri) to identify the insert operation.

cookie Object: An object that gets passed into onInsertComplete(int, Object, Uri)

uri Uri: the Uri passed to the insert operation.

initialValues ContentValues: the ContentValues parameter passed to the insert operation.

startQuery

Added in API level 1
public void startQuery (int token, 
                Object cookie, 
                Uri uri, 
                String[] projection, 
                String selection, 
                String[] selectionArgs, 
                String orderBy)

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

Parameters
token int: A token passed into onQueryComplete(int, Object, Cursor) to identify the query.

cookie Object: An object that gets passed into onQueryComplete(int, Object, Cursor)

uri Uri: The URI, using the content:// scheme, for the content to retrieve.

projection String: 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 String: 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 String: 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 String: 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.

startUpdate

Added in API level 1
public final void startUpdate (int token, 
                Object cookie, 
                Uri uri, 
                ContentValues values, 
                String selection, 
                String[] selectionArgs)

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

Parameters
token int: A token passed into onUpdateComplete(int, Object, int) to identify the update operation.

cookie Object: An object that gets passed into onUpdateComplete(int, Object, int)

uri Uri: the Uri passed to the update operation.

values ContentValues: the ContentValues parameter passed to the update operation.

selection String

selectionArgs String

Protected methods

createHandler

Added in API level 1
protected Handler createHandler (Looper looper)

Parameters
looper Looper

Returns
Handler

onDeleteComplete

Added in API level 1
protected void onDeleteComplete (int token, 
                Object cookie, 
                int result)

Called when an asynchronous delete is completed.

Parameters
token int: the token to identify the query, passed in from startDelete(int, Object, Uri, String, String).

cookie Object: the cookie object that's passed in from startDelete(int, Object, Uri, String, String).

result int: the result returned from the delete operation

onInsertComplete

Added in API level 1
protected void onInsertComplete (int token, 
                Object cookie, 
                Uri uri)

Called when an asynchronous insert is completed.

Parameters
token int: the token to identify the query, passed in from startInsert(int, Object, Uri, ContentValues).

cookie Object: the cookie object that's passed in from startInsert(int, Object, Uri, ContentValues).

uri Uri: the uri returned from the insert operation.

onQueryComplete

Added in API level 1
protected void onQueryComplete (int token, 
                Object cookie, 
                Cursor cursor)

Called when an asynchronous query is completed.

Parameters
token int: the token to identify the query, passed in from startQuery(int, Object, Uri, String, String, String, String).

cookie Object: the cookie object passed in from startQuery(int, Object, Uri, String, String, String, String).

cursor Cursor: The cursor holding the results from the query.

onUpdateComplete

Added in API level 1
protected void onUpdateComplete (int token, 
                Object cookie, 
                int result)

Called when an asynchronous update is completed.

Parameters
token int: the token to identify the query, passed in from startUpdate(int, Object, Uri, ContentValues, String, String).

cookie Object: the cookie object that's passed in from startUpdate(int, Object, Uri, ContentValues, String, String).

result int: the result returned from the update operation