Package android.database

Interface CrossProcessCursor

All Superinterfaces:

AutoCloseable, Closeable, Cursor

All Known Implementing Classes:

AbstractCursor, AbstractWindowedCursor, MatrixCursor, MergeCursor, SQLiteCursor

public interface CrossProcessCursor
extends Cursor

A cross process cursor is an extension of a Cursor that also supports usage from remote processes.

The contents of a cross process cursor are marshalled to the remote process by filling CursorWindow objects using fillWindow(int, android.database.CursorWindow). As an optimization, the cursor can provide a pre-filled window to use via getWindow() thereby obviating the need to copy the data to yet another cursor window.

Field Summary

Fields inherited from interface android.database.Cursor

FIELD_TYPE_BLOB, FIELD_TYPE_FLOAT, FIELD_TYPE_INTEGER, FIELD_TYPE_NULL, FIELD_TYPE_STRING

Method Summary

Modifier and Type	Method	Description
void	fillWindow(int position, CursorWindow window)	Copies cursor data into the window.
CursorWindow	getWindow()	Returns a pre-filled window that contains the data within this cursor.
boolean	onMove(int oldPosition, int newPosition)	This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have.

Methods inherited from interface android.database.Cursor

close, copyStringToBuffer, deactivate, getBlob, getColumnCount, getColumnIndex, getColumnIndexOrThrow, getColumnName, getColumnNames, getCount, getDouble, getExtras, getFloat, getInt, getLong, getPosition, getShort, getString, getType, getWantsAllOnMoveCalls, isAfterLast, isBeforeFirst, isClosed, isFirst, isLast, isNull, move, moveToFirst, moveToLast, moveToNext, moveToPosition, moveToPrevious, registerDataSetObserver, requery, respond, setExtras, unregisterDataSetObserver

Method Detail

getWindow

CursorWindow getWindow()

Returns a pre-filled window that contains the data within this cursor.

In particular, the window contains the row indicated by Cursor.getPosition(). The window's contents are automatically scrolled whenever the current row moved outside the range covered by the window.

Returns:

The pre-filled window, or null if none.

fillWindow

void fillWindow(int position,
                CursorWindow window)

Copies cursor data into the window.

Clears the window and fills it with data beginning at the requested row position until all of the data in the cursor is exhausted or the window runs out of space.

The filled window uses the same row indices as the original cursor. For example, if you fill a window starting from row 5 from the cursor, you can query the contents of row 5 from the window just by asking it for row 5 because there is a direct correspondence between the row indices used by the cursor and the window.

The current position of the cursor, as returned by Cursor.getPosition(), is not changed by this method.

Parameters:

position - The zero-based index of the first row to copy into the window.

window - The window to fill.

onMove

boolean onMove(int oldPosition,
               int newPosition)

This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have. If it returns false the move function will also do so and the cursor will scroll to the beforeFirst position.

This function should be called by methods such as Cursor.moveToPosition(int), so it will typically not be called from outside of the cursor class itself.

Parameters:

oldPosition - The position that we're moving from.

newPosition - The position that we're moving to.

Returns:

True if the move is successful, false otherwise.