elementproxy.java

mywork是rcp开发的很好的例子

package net.sf.component.simplenote;

import java.io.File;

import org.eclipse.swt.custom.PaintObjectEvent;
import org.eclipse.swt.widgets.Composite;

/**
 * 抽取了一个image和file的父类
 * @author levin
 * 2007.03.15
 */
public abstract class ElementProxy {

	public String src;
	public int width;
	public int height;

	public ElementProxy() {
	}

	public ElementProxy(String html) {
	}

	//取html表示
	public abstract String getHtml();
	//取metrics:ascent,descent,width
	public abstract int[] getMetrics();
	//保存
	public abstract void save(String basePath);
	//绘制
	public abstract void draw(String basePath,PaintObjectEvent event,Composite parent);
	//清场
	public abstract void dispose();
	//取占位符
	public abstract String getPlaceholder();
	
	public String toString(){
		return getHtml();
	}
	
	//取文件名，不重复
	protected synchronized File createEmbedFile(String basePath,String fileSuffix) {
		long currentTime = System.currentTimeMillis();
		File parent=new File(basePath,"embed");
		if(! parent.exists() || ! parent.isDirectory())
			parent.mkdir();
		File file = null;
		do {
			file = new File(parent, Long.toHexString(currentTime) + fileSuffix);
			currentTime++;
		} while (file.exists());
		return file;
	}	
	
	//一个工厂方法
	public static ElementProxy getInstance(String html){
		if(html.startsWith("<img"))
			return new ImageProxy(html);
		else
			return new FileProxy(html);
	}
	
}