figure.java

来自「eclipse 的程序源码」· Java 代码 · 共 39 行

/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.examples.paint;


import org.eclipse.swt.graphics.*;

/**
 * Superinterface for all drawing objects.
 * All drawing objects know how to render themselved to the screen and can draw a
 * temporary version of themselves for previewing the general appearance of the
 * object onscreen before it gets committed.
 */
public abstract class Figure {
	/**
	 * Draws this object.
	 * 
	 * @param fdc a parameter block specifying drawing-related information
	 */
	public abstract void draw(FigureDrawContext fdc);

	/**
	 * Computes the damaged screen region caused by drawing this object (imprecise), then
	 * appends it to the supplied region.
	 * 
	 * @param fdc a parameter block specifying drawing-related information
	 * @param region a region to which additional damage areas will be added
	 */
	public abstract void addDamagedRegion(FigureDrawContext fdc, Region region);
}