content: /*
   * 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 {@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.
       * <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.
       * <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.
       * <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); 
  }
  