public class

ContentQueryMap

extends Observable
java.lang.Object
   ↳ java.util.Observable
     ↳ android.content.ContentQueryMap

Class Overview

Caches the contents of a cursor into a Map of String->ContentValues and optionally keeps the cache fresh by registering for updates on the content backing the cursor. The column of the database that is to be used as the key of the map is user-configurable, and the ContentValues contains all columns other than the one that is designated the key.

The cursor data is accessed by row key and column name via getValue().

Summary

Public Constructors
ContentQueryMap(Cursor cursor, String columnNameOfKey, boolean keepUpdated, Handler handlerForUpdateNotifications)
Creates a ContentQueryMap that caches the content backing the cursor
Public Methods
synchronized void close()
synchronized Map<String, ContentValues> getRows()
synchronized ContentValues getValues(String rowName)
Access the ContentValues for the row specified by rowName
void requery()
Requeries the cursor and reads the contents into the cache
void setKeepUpdated(boolean keepUpdated)
Change whether or not the ContentQueryMap will register with the cursor's ContentProvider for change notifications.
Protected Methods
void finalize()
Is called before the object's memory is being reclaimed by the VM.
[Expand]
Inherited Methods
From class java.util.Observable
From class java.lang.Object

Public Constructors

public ContentQueryMap (Cursor cursor, String columnNameOfKey, boolean keepUpdated, Handler handlerForUpdateNotifications)

Creates a ContentQueryMap that caches the content backing the cursor

Parameters
cursor the cursor whose contents should be cached
columnNameOfKey the column that is to be used as the key of the values map
keepUpdated true if the cursor's ContentProvider should be monitored for changes and the map updated when changes do occur
handlerForUpdateNotifications the Handler that should be used to receive notifications of changes (if requested). Normally you pass null here, but if you know that the thread that is creating this isn't a thread that can receive messages then you can create your own handler and use that here.

Public Methods

public synchronized void close ()

public synchronized Map<String, ContentValues> getRows ()

public synchronized ContentValues getValues (String rowName)

Access the ContentValues for the row specified by rowName

Parameters
rowName which row to read
Returns
  • the ContentValues for the row, or null if the row wasn't present in the cursor

public void requery ()

Requeries the cursor and reads the contents into the cache

public void setKeepUpdated (boolean keepUpdated)

Change whether or not the ContentQueryMap will register with the cursor's ContentProvider for change notifications. If you use a ContentQueryMap in an activity you should call this with false in onPause(), which means you need to call it with true in onResume() if want it to be kept updated.

Parameters
keepUpdated if true the ContentQueryMap should be registered with the cursor's ContentProvider, false otherwise

Protected Methods

protected void finalize ()

Is called before the object's memory is being reclaimed by the VM. This can only happen once the VM has detected, during a run of the garbage collector, that the object is no longer reachable by any thread of the running application.

The method can be used to free system resources or perform other cleanup before the object is garbage collected. The default implementation of the method is empty, which is also expected by the VM, but subclasses can override finalize() as required. Uncaught exceptions which are thrown during the execution of this method cause it to terminate immediately but are otherwise ignored.

Note that the VM does guarantee that finalize() is called at most once for any object, but it doesn't guarantee when (if at all) finalize() will be called. For example, object B's finalize() can delay the execution of object A's finalize() method and therefore it can delay the reclamation of A's memory. To be safe, use a ReferenceQueue, because it provides more control over the way the VM deals with references during garbage collection.

Throws
Throwable