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/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.database;


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. 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. 
/**
 * A cross process cursor is an extension of a {@link Cursor} that also supports
 * usage from remote processes.
 * <p>
 * The contents of a cross process cursor are marshalled to the remote process by
 * filling {@link CursorWindow} objects using {@link #fillWindow}.  As an optimization,
 * the cursor can provide a pre-filled window to use via {@link #getWindow} thereby
 * obviating the need to copy the data to yet another cursor window.
 */
public interface CrossProcessCursor extends Cursor {
    
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.
/**
     * Returns a pre-filled window that contains the data within this cursor.
     * <p>
     * In particular, the window contains the row indicated by {@link Cursor#getPosition}.
     * The window's contents are automatically scrolled whenever the current
     * row moved outside the range covered by the window.
     * </p>
     *
     * @return The pre-filled window, or null if none.
     */
    CursorWindow getWindow();

    
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. 


Params:
  • position – The zero-based index of the first row to copy into the window.
  • window – The window to fill.
/**
     * Copies cursor data into the window.
     * <p>
     * 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.
     * </p><p>
     * 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.
     * </p><p>
     * The current position of the cursor, as returned by {@link #getPosition},
     * is not changed by this method.
     * </p>
     *
     * @param position The zero-based index of the first row to copy into the window.
     * @param window The window to fill.
     */
    void fillWindow(int position, CursorWindow window);

    
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. 


Params:
  • 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.
/**
     * 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.
     * <p>
     * This function should be called by methods such as {@link #moveToPosition(int)},
     * so it will typically not be called from outside of the cursor class itself.
     * </p>
     *
     * @param oldPosition The position that we're moving from.
     * @param newPosition The position that we're moving to.
     * @return True if the move is successful, false otherwise.
     */
    boolean onMove(int oldPosition, int newPosition); 
}