mediator.java

java patterns book

import java.awt.*;
import java.util.*;
//swing classes
import com.sun.java.swing.text.*;
import com.sun.java.swing.*;
import com.sun.java.swing.event.*;
import com.sun.java.swing.border.*;
import com.sun.java.swing.tree.*;

public class Mediator
{
   boolean startRect;
   boolean dSelected;
   Vector drawings;
   Vector undoList;
   RectButton rectButton;
   FillButton fillButton;
   CircleButton circButton;
   PickButton arrowButton;
   JPanel canvas;
   Drawing selectedDrawing;
   StateManager stMgr;

public Mediator()
{
   startRect = false;
   dSelected = false;
   drawings = new Vector();
   undoList = new Vector();
   stMgr = new StateManager(this);
}
//-------------------------------------------
public void startRectangle()
{
   stMgr.setRect();
   arrowButton.setSelected(false);
   circButton.setSelected(false);
   fillButton.setSelected(false);
 }
//---------------------------------------------
public void startCircle()
{
   stMgr.setCircle();
   rectButton.setSelected(false);
   arrowButton.setSelected(false);
   fillButton.setSelected(false);
}
//---------------------------------------------
public void startFill()
{
   stMgr.setFill();
   rectButton.setSelected(false);
   circButton.setSelected(false);
   arrowButton.setSelected(false);
   stMgr.select(selectedDrawing, Color.red);
   repaint();
}
//---------------------------------------------
public void startArrow()
{
   stMgr.setArrow();
   rectButton.setSelected(false);
   circButton.setSelected(false);
   fillButton.setSelected(false);
}
//---------------------------------------------
public Drawing getSelected()
{
   return selectedDrawing;
}
//---------------------------------------------
public void fillSelected()
{
   if(dSelected)
   {
      selectedDrawing.setFill(Color.red);
   }
}
//---------------------------------------------
public Vector getDrawings()
{
   return drawings;
}
//-------------------------------------------
public void addDrawing(Drawing d)
{
   drawings.addElement(d);
}
//-------------------------------------------
public void registerRectButton(RectButton rb)
{
   rectButton = rb;
}
public void registerCircleButton(CircleButton cb)
{
   circButton = cb;
}
public void registerArrowButton(PickButton ab)
{
   arrowButton = ab;
}
public void registerFillButton(FillButton fb)
{
   fillButton = fb;
}
//-------------------------------------------
public void registerCanvas(JPanel p)
{
   canvas = p;
}
//-------------------------------------------
public void mouseDown(int x, int y)
{
   stMgr.mouseDown(x, y);
   repaint();
}
//-------------------------------------------
public void mouseUp(int x, int y)
{
   stMgr.mouseUp(x, y);
}
//-------------------------------------------
public void unpick()
{
   dSelected = false;
   if(selectedDrawing != null)
   {
      selectedDrawing.setSelected(false);
      selectedDrawing = null;
      repaint();
   }
}
//-------------------------------------------
public void rememberPosition()
{
   if(dSelected){
   //Memento m = new Memento(d);
   //undoList.addElement(m);
   }
}
//--------------------------------------
public void setSelected(Drawing d)
{
   if(d!=null)
   {
      dSelected = true;
      selectedDrawing = d;
      d.setSelected(true);
      repaint();
   }
}
//-------------------------------------------
public void pickRect(int x, int y)
{                                                          
   
}                   
//-------------------------------------------
public void clear()
{
 drawings = new Vector();
 undoList = new Vector();
 dSelected = false;
 selectedDrawing = null;
 repaint();
}
//-------------------------------------------
private void repaint()
{
   canvas.repaint();
}
//-------------------------------------------
public void mouseDrag(int x, int y)
{
   stMgr.mouseDrag(x, y);
}
//-------------------------------------------
public void reDraw(Graphics g)
{
   g.setColor(Color.black);
   for (int i=0; i< drawings.size(); i++) 
      {
      Drawing v = (Drawing)drawings.elementAt(i);
      v.draw(g);
      }
}
//-------------------------------------------
public void undo()
{
   if(undoList.size()>0)
   {
      //get last element in undo list
      Object obj = undoList.lastElement();
      undoList.removeElement(obj);   //and remove it
      //if this is an Integer, the last action was a new rectangle
      if (obj instanceof Integer)    
      {   
         //remove last created rectangle
         Object drawObj = drawings.lastElement();
         drawings.removeElement(drawObj);
      }
      //if this is a Memento, the last action was a move
      if(obj instanceof Memento)
      {
         //get the Memento
         Memento m = (Memento)obj;
         m.restore();     //and restore the old position
      }
     repaint();
   }
 }
}