import java.util.*;
import java.awt.*;
import java.awt.image.*;
import java.applet.Applet;

public class Updater{
	Image imBuf;
	Graphics grBuf;
	Color bakCol;
	Dimension sz;

	Rects rlst;
	DrawerVec dv;
	CropImg cropImg;

	public Updater(Applet ap){
		imBuf = EzImg.create(ap);
		grBuf = imBuf.getGraphics();
		bakCol = ap.getBackground();
		sz = ap.size();

		rlst = new Rects();
		dv = new DrawerVec();
		cropImg = new CropImg(imBuf);
		setAll();
	}
	public void set(Rectangle r){
		rlst.add(r);
	}
	public void setAll(){
		set(new Rectangle(sz));
	}
	public void add(Drawer d, int z){
		dv.add(d, z);
	}
	public void del(Drawer d){
		dv.del(d);
	}
	public void update(Graphics g){
		if(rlst.size()<=0) return;
		synchronized(rlst){
			//clear();
			clearAll();
			for(int i=0;i<dv.size(); i++){
				update(dv.getDrawer(i));
			}
			//copy(g);
			copyAll(g);
			rlst.removeAllElements();
		}
	}		
	void clear(){
		Enumeration e = rlst.elements();
		while(e.hasMoreElements()){
			Rectangle r = (Rectangle)e.nextElement();
			grBuf.setColor(bakCol);
			grBuf.clearRect(r.x, r.y, r.width, r.height);
		}
	}
	void clearAll(){
		grBuf.setColor(bakCol);
		grBuf.clearRect(0,0,sz.width,sz.height);
	}
	void update(Drawer d){
		d.begin();
		Enumeration e = rlst.elements();
		while(e.hasMoreElements()){
			Rectangle r = (Rectangle)e.nextElement();
			d.draw(grBuf, r);
		}
		d.end();
	}
	void copy(Graphics g){
		Enumeration e = rlst.elements();
		while(e.hasMoreElements()){
			Rectangle r = (Rectangle)e.nextElement();
			g.drawImage(cropImg.crop(r), r.x, r.y, null);
		}
	}
	void copyAll(Graphics g){
		g.drawImage(imBuf, 0, 0, null);
	}
}

class DrawerInf{
	public Drawer d;
	public int z;
	public DrawerInf(Drawer d, int z){
		this.d = d;
		this.z = z;
	}
}
class DrawerVec extends Vector{
	public void add(DrawerInf di){
		int i;
		for(i=0;i<size();i++){
			if(di.z < get(i).z) break;
		}
		insertElementAt(di, i);
	}
	public void add(Drawer d, int z){
		add(new DrawerInf(d, z));
	}
	public void del(Drawer d){
		int i;
		for(i=0;i<size();i++){
			if(get(i).d == d) break;
		}
		if(i>=size()) return;
		removeElement(get(i));
	}
	public DrawerInf get(int i){
		return (DrawerInf)elementAt(i);
	}
	public Drawer getDrawer(int i){
		return get(i).d;
	}
}

// EOF