imageproxy.java

mywork是rcp开发的很好的例子

package net.sf.component.simplenote;

import java.io.File;
import java.io.FileOutputStream;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.PaintObjectEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.ImageLoader;
import org.eclipse.swt.graphics.PaletteData;
import org.eclipse.swt.widgets.Composite;

/**
 * 定义图片信息
 * 也可由形如<img src=aaa.jpg width=120 height=160></img>的字串构成
 * @author levin
 */
public class ImageProxy extends ElementProxy {
	private ImageData imageData;
	public ImageProxy(String src, int width,int height) {
		super();
		this.src = src;
		this.width = width;
		this.height = height;
	}
	
	public ImageProxy(ImageData imageData) {
		super();
		this.imageData = imageData;
		this.width = imageData.width;
		this.height = imageData.height;
	}

	public ImageProxy(String html){
		//防止解析出错
		this("",10,10);
		try{
			Pattern p=Pattern.compile("<img\\s+src=([a-z\\.A-Z/0-9]*)\\s+width=([0-9]*)\\s+height=([0-9]*)></img>");
			Matcher m=p.matcher(html);
			if(m.find()){
				this.src=m.group(1);
				this.width=Integer.parseInt(m.group(2));
				this.height=Integer.parseInt(m.group(3));
			}
		}catch(Exception ex){
			ex.printStackTrace();
		}
	}
	
	public ImageProxy() {
	}

	//取定义的html
	@Override
	public String getHtml(){
		return "<img src="+src+" width="+width+" height="+height+"></img>";
	}
	
	public int[] getMetrics(){
		return new int[]{height,0,width};
	}
	
	public void save(String basePath){
		try {
			File imageFile=createEmbedFile(basePath,".png");
			ImageLoader loader=new ImageLoader();
			loader.data=new ImageData[]{getImageData(basePath)};
			loader.save(new FileOutputStream(imageFile), SWT.IMAGE_PNG);
			//设置imageProxy的src属性
			src="embed/"+imageFile.getName();
		} catch (Exception e) {
			e.printStackTrace();
		}		
	}

	public void draw(String basePath,PaintObjectEvent event,Composite parent){
		Image image = new Image(parent.getDisplay(),getImageData(basePath));
		int x = event.x;
		int y = event.y + event.ascent - event.style.metrics.ascent;						
		event.gc.drawImage(image, x, y);
		image.dispose();
	}
	public void dispose(){
	}
	
	public String getPlaceholder(){
		return "\uFFFC";
	}
	
	private ImageData getImageData(String basePath) {
		if(imageData == null && src != null){
			try{
				imageData=new ImageData(basePath+"/"+src);
			}catch(Exception ex){
				//图片不存在
				imageData=new ImageData(width,height,8,new PaletteData(0xFF0000, 0xFF00, 0xFF));
				imageData.transparentPixel=0x00;
				for(int i=0;i<width;i++){
					for(int j=0;j<height;j++){
						//绘制边框
						if(i==0 || j==0 || i==width-1 || j== height-1 )
							imageData.setPixel(i, j, 0xff);
						else
							imageData.setPixel(i, j, 0x00);
					}
				}
				//用对称直线画法，绘制一条对角线
				{
					int x1 = 0; // 起点x
					int y1 = 0; // 起点y
					int x2 = width-1; // 终点x
					int y2 = height-1; // 终点y
					int dx = x2 - x1;
					int dy = y2 - y1;
					int dx2 = dx << 1;
					int dy2 = dy << 1;
					int e = dy2 - dx; // 决策量
					int half = (dx + 1) >> 1;
					for (int i = 0; i < half; i++)
					{
						imageData.setPixel(x1, y1, 0xff);
						imageData.setPixel(x2, y2, 0xff);
						if (e > 0) // 当e>0时，始端y向加1，末端y向减1
						{
							y1++;
							y2--;
							e -= dx2;
						}
						//始端x向加1，末端x向减1
						x1++;
						x2--;
						e += dy2;
					}
				}
			}
		}
		return imageData;
	}
}