import java.awt.*;
import java.util.*;

public class ScPanel extends Panel{
	public Scrollbar h, v;
	public ViewPanel view;

	public ScPanel(Component cmp, boolean cmp_mouseEv){
		view = new ViewPanel(this, cmp, cmp_mouseEv);
		h = new Scrollbar(Scrollbar.HORIZONTAL);
		v = new Scrollbar(Scrollbar.VERTICAL);
		setLayout(new BorderLayout());
		add("Center", view);
		add("South", h);
		add("East", v);
	}
	public ScPanel(Component cmp){
		this(cmp, true);
	}
	public Point p(){
		return new Point(h.getValue(), v.getValue());
	}
	public Point view2cmp(Point p){
		return Pts.add(p, this.p());
	}
	public Point cmp2view(Point p){
		return Pts.sub(p, this.p());
	}
	void setSc(){
		Point p = this.p();
		h.setValues(p.x, view.size().width, 0, view.cmp_size().width);
		v.setValues(p.y, view.size().height, 0, view.cmp_size().height);
		Point hlf = Pts.cen(view.size());
		h.setPageIncrement(hlf.x);
		v.setPageIncrement(hlf.y);
	}
	public void reshape(int x, int y, int w, int h){
		super.reshape(x,y,w,h);
		layout();
		setSc();
	}
	public boolean handleEvent(Event e){
		if(chkScEvt(e) && (e.target == h || e.target == v)){
			view.cmp_move();
			return true;
		}
		return false;
	}
	boolean chkScEvt(Event e){
		switch(e.id){
		case Event.SCROLL_LINE_UP:
		case Event.SCROLL_LINE_DOWN:
		case Event.SCROLL_PAGE_UP:
		case Event.SCROLL_PAGE_DOWN:
		case Event.SCROLL_ABSOLUTE:
			return true;
		}
		return false;
	}
	public Point viewCen2cmp(){
		return view2cmp(Pts.cen(view.size()));
	}
	public void scrollCenter(Point cmp_pt){
		Point dif = Pts.sub(cmp_pt,viewCen2cmp());
		h.setValue(h.getValue()+dif.x);
		v.setValue(v.getValue()+dif.y);
		view.cmp_move();
	}
}

// EOF