Æliens

  public interface widget { 
   widget  
  
  public String path();
  
  public void eval(String cmd);
  
  public void pack(String s);
  
  public void bind(handler h,String s);
  public void bind(String p, handler h,String s);
  
  public void configure(String cmd);
  public void geometry(int x, int y);
  
  public void xscroll(widget w);
  public void yscroll(widget w);
  
  public widget self(); // to define compound widgets
  public void redirect(widget inner);
  }; 
  
  

  import hush.dv.api.event;
  import hush.dv.widgets.canvas;
  
  class draw extends canvas { 
   draw   go.java    
  boolean dragging;
  
  public draw(String path) {
  	super(path); 
  	dragging = false;
  	bind(this);
  	}
  
  public void press(event ev) {
  	dragging = true;
  	}
  
  public void release(event ev) {
  	dragging = false;
  	}
  
  public void motion(event ev) {
  	if (dragging)
  		circle(ev.x(),ev.y(),2,"-fill black");
  	}
  };
  

  import hush.dv.api.*;
  import hush.dv.widgets.frame;
  
  public class toolbox extends frame {  
   toolbox  
  
  tablet tablet;
  
  public toolbox(widget w, tablet t) {
      super(w,"toolbox");
      tablet = t;
      new toolbutton(this,"draw");
      new toolbutton(this,"move");
      new toolbutton(this,"box");
      new toolbutton(this,"circle");
      new toolbutton(this,"arrow");
  }
  
  public int operator() {
          tablet.mode(_event.arg(1)); // reset tablet mode
          return OK;
          }
  
  };
  

  import hush.dv.api.*;
  import hush.dv.widgets.*;
  
  public class tablet extends canvas { 
   tablet  
  
  int _mode;
  canvas canvas;
  handler[] handlers;
  
  final int DRAW = 0;
  final int MOVE = 1;
  final int CIRCLE = 2;
  final int BOX = 3;
  final int ARROW = 5;
  
  public tablet(widget w, String name, String options) {
  
  	super(w,name,"*");
  
  	handlers = new handler[12];
  
          init(options);
          redirect(canvas); // to delegate to canvas
          bind(this); // to intercept user actions 
  	
          handlers[DRAW] = new DrawHandler(canvas);
          handlers[MOVE] = new MoveHandler(canvas);
          handlers[BOX] = new BoxHandler(canvas);
          handlers[CIRCLE] = new CircleHandler(canvas);
          handlers[ARROW] = new ArrowHandler(canvas);
  
          _mode = 0; // drawmode.draw;
          }
  
  public int operator() { 
  	handlers [mode].dispatch(_event);
  	return OK;
  	}
  
  public int mode(String s) { 
  	int m = -1;
  	if ("draw".equals(s)) m = DRAW; 
  	if ("move".equals(s)) m = MOVE; 
  	if ("box".equals(s)) m = BOX; 
  	if ("circle".equals(s)) m = CIRCLE;
  	if ("arrow".equals(s)) m = ARROW; 
  	if (m >= 0) _mode = m;
  	return _mode;
  	}
  
  void init(String options) {
  
          widget root = new frame(path(),"-class tablet");
  
  	canvas = new canvas(root,"canvas",options);
  	canvas.configure("-relief sunken -background white");
  	canvas.geometry(200,100);
  	
  	scrollbar scrollx = new Scrollbar(root,"scrollx");
  	scrollx.orient("horizontal");
  	scrollx.pack("-side bottom -fill x -expand 0");
  	
  	scrollbar scrolly = new Scrollbar(root,"scrolly");
  	
  	scrolly.orient("vertical");
  	scrolly.pack("-side right -fill y -expand 0");
  	
  	canvas.pack("-side top -fill both -expand 1");
  	
  	canvas.xscroll(scrollx); scrollx.xview(canvas);
  	canvas.yscroll(scrolly); scrolly.yview(canvas);
  	}
  
  };
  

  import hush.dv.api.*;
  import hush.dv.widgets.frame;
  import hush.dv.widgets.canvas;
  
  public class drawtool extends canvas { 
   drawtool  
  
  widget root;
  tablet tablet;
  
  public drawtool() { System.out.println("meta handler created"); } 
  
  public drawtool(String p, String options) {
          super(p,"*");                 // create empty tablet
  	init(options);
  	}
  
  public int operator() {
  	System.out.println("Calling drawtool:" + _event.args(0) );
  	String[] argv = _event.argv();
  	if ("self".equals(argv[1])) tk.result(self().path());
  	else if ("drawtool".equals(argv[0]))
  		create(argv[1],_event.args(2)); 
  	else if ("path".equals(argv[1])) tk.result(path()); 
  	else if ("pack".equals(argv[1])) pack(_event.args(2));
  	else self().eval( _event.args(1) );  // send through
  	return OK;
  	}
  
  void create(String name, String options) {
  	drawtool m = new drawtool(name,options);
  	}
  
  void init(String options) {
  	root = new frame(path(),"-class Meta");
  
  	frame frame = new frame(root,"frame");
  
  	tablet = new tablet(frame,"tablet",options);
  
  	toolbox toolbox = new toolbox(frame,tablet);
  	menubar menubar = new menubar(root,tablet,toolbox);
  
          toolbox.pack("-side left -fill y -expand 0");
  	tablet.pack("-side left -fill both -expand 1");
  
  	menubar.pack();
  	frame.pack("-expand 1 -fill both");
  
  
  	redirect( tablet );  // the widget of interest
  	}
  };