/* * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* **************************************************************** ****************************************************************** ****************************************************************** *** COPYRIGHT (c) Eastman Kodak Company, 1997 *** As an unpublished work pursuant to Title 17 of the United *** States Code. All rights reserved. ****************************************************************** ****************************************************************** ******************************************************************/ package java.awt.image; import java.awt.Point; /** * WritableRenderedImage is a common interface for objects which * contain or can produce image data in the form of Rasters and * which can be modified and/or written over. The image * data may be stored/produced as a single tile or a regular array * of tiles. *
* WritableRenderedImage provides notification to other interested * objects when a tile is checked out for writing (via the * getWritableTile method) and when the last writer of a particular * tile relinquishes its access (via a call to releaseWritableTile). * Additionally, it allows any caller to determine whether any tiles * are currently checked out (via hasTileWriters), and to obtain a * list of such tiles (via getWritableTileIndices, in the form of a Vector * of Point objects). *
* Objects wishing to be notified of changes in tile writability must * implement the TileObserver interface, and are added by a * call to addTileObserver. Multiple calls to * addTileObserver for the same object will result in multiple * notifications. An existing observer may reduce its notifications * by calling removeTileObserver; if the observer had no * notifications the operation is a no-op. *
* It is necessary for a WritableRenderedImage to ensure that
* notifications occur only when the first writer acquires a tile and
* the last writer releases it.
*
*/
public interface WritableRenderedImage extends RenderedImage
{
/**
* Adds an observer. If the observer is already present,
* it will receive multiple notifications.
* @param to the specified TileObserver
*/
public void addTileObserver(TileObserver to);
/**
* Removes an observer. If the observer was not registered,
* nothing happens. If the observer was registered for multiple
* notifications, it will now be registered for one fewer.
* @param to the specified TileObserver
*/
public void removeTileObserver(TileObserver to);
/**
* Checks out a tile for writing.
*
* The WritableRenderedImage is responsible for notifying all
* of its TileObservers when a tile goes from having
* no writers to having one writer.
*
* @param tileX the X index of the tile.
* @param tileY the Y index of the tile.
* @return a writable tile.
*/
public WritableRaster getWritableTile(int tileX, int tileY);
/**
* Relinquishes the right to write to a tile. If the caller
* continues to write to the tile, the results are undefined.
* Calls to this method should only appear in matching pairs
* with calls to getWritableTile; any other use will lead
* to undefined results.
*
* The WritableRenderedImage is responsible for notifying all of
* its TileObservers when a tile goes from having one writer
* to having no writers.
*
* @param tileX the X index of the tile.
* @param tileY the Y index of the tile.
*/
public void releaseWritableTile(int tileX, int tileY);
/**
* Returns whether a tile is currently checked out for writing.
*
* @param tileX the X index of the tile.
* @param tileY the Y index of the tile.
* @return true
if specified tile is checked out
* for writing; false
otherwise.
*/
public boolean isTileWritable(int tileX, int tileY);
/**
* Returns an array of Point objects indicating which tiles
* are checked out for writing. Returns null if none are
* checked out.
* @return an array containing the locations of tiles that are
* checked out for writing.
*/
public Point[] getWritableTileIndices();
/**
* Returns whether any tile is checked out for writing.
* Semantically equivalent to (getWritableTileIndices() != null).
* @return true
if any tiles are checked out for
* writing; false
otherwise.
*/
public boolean hasTileWriters();
/**
* Sets a rect of the image to the contents of the Raster r, which is
* assumed to be in the same coordinate space as the WritableRenderedImage.
* The operation is clipped to the bounds of the WritableRenderedImage.
* @param r the specified Raster
*/
public void setData(Raster r);
}