/*
   * The contents of this file are subject to the BT "ZEUS" Open Source 
   * Licence (L77741), Version 1.0 (the "Licence"); you may not use this file 
   * except in compliance with the Licence. You may obtain a copy of the Licence
   * from $ZEUS_INSTALL/licence.html or alternatively from
   * http://www.labs.bt.com/projects/agents/zeus/licence.htm
   * 
   * Except as stated in Clause 7 of the Licence, software distributed under the
   * Licence is distributed WITHOUT WARRANTY OF ANY KIND, either express or 
  * implied. See the Licence for the specific language governing rights and 
  * limitations under the Licence.
  * 
  * The Original Code is within the package zeus.*.
  * The Initial Developer of the Original Code is British Telecommunications
  * public limited company, whose registered office is at 81 Newgate Street, 
  * London, EC1A 7AJ, England. Portions created by British Telecommunications 
  * public limited company are Copyright 1996-9. All Rights Reserved.
  * 
  * THIS NOTICE MUST BE INCLUDED ON ANY COPY OF THIS FILE
  */
  
  
  
  package zeus.gui.graph;
  
  import java.awt.*;
  import java.awt.event.*;
  import javax.swing.*;
  
  import java.util.*;
  
  public class SelectPanel extends JPanel
                           implements MouseListener, MouseMotionListener {
  
      // protected Dimension psize = new Dimension(400,400);
  
      protected Point anchor    = new Point(0,0);
      protected Point stretched = new Point(0,0);
      protected Point last      = new Point(0,0);
      protected Point end       = new Point(0,0);
  
      protected boolean   firstStretch = true;
      protected boolean   regionSelected = false;
      protected Rectangle region = new Rectangle(0,0,0,0);
      protected Vector    items = new Vector();
  
      public SelectPanel() {
         super(true);
         this.addMouseListener(this);
         this.addMouseMotionListener(this);
         // setSize(psize);
         // validate();
      }
      public SelectPanel(Dimension dim) {
         this();
         // psize = new Dimension(dim); setSize(dim);
         setMaximumSize(dim);
         // validate();
      }
      public SelectPanel(int w, int h) {
         this();
         //psize = new Dimension(w,h); setSize(w,h);
         //validate();
      }
  
      public void mouseClicked(MouseEvent evt) {}
      public void mouseEntered(MouseEvent evt) {}
      public void mouseExited(MouseEvent evt) {}
      public void mouseMoved(MouseEvent evt) {}
  
      boolean source_ok = false;
      public void mousePressed(MouseEvent evt) {
         source_ok = (evt.getSource() == this);
  
         if ( !source_ok ) return;
         if ( SwingUtilities.isLeftMouseButton(evt) )
            this.anchor(evt.getPoint());
      }
      public void mouseDragged(MouseEvent evt) {
         if ( !source_ok ) return;
         if ( SwingUtilities.isLeftMouseButton(evt) )
            this.stretch(evt.getPoint());
      }
      public void mouseReleased(MouseEvent evt) {
         if ( !source_ok ) return;
         if ( SwingUtilities.isLeftMouseButton(evt) )
            this.end(evt.getPoint());
         source_ok = false;
      }
  
      public void drawRegion(Graphics graphics) {
         graphics.drawRect(region.x, region.y, region.width, region.height);
      }
  
      public void clearRegion(Graphics graphics) {
         Color c = graphics.getColor();
         graphics.setColor(this.getBackground());
         graphics.drawRect(region.x, region.y, region.width, region.height);
         graphics.setColor(c);
     }
     public void drawLast(Graphics graphics) {
        Rectangle rect = lastBounds();
        graphics.drawRect(rect.x, rect.y, rect.width, rect.height);
     }
     public void drawNext(Graphics graphics) {
        Rectangle rect = currentBounds();
        graphics.drawRect(rect.x, rect.y, rect.width, rect.height);
     }
 
     public Point getAnchor   () { return anchor;    }
     public Point getStretched() { return stretched; }
     public Point getLast     () { return last;      }
     public Point getEnd      () { return end;       }
 
     public void anchor(Point p) {
        firstStretch = true;
        stretched.x = last.x = anchor.x = p.x;
        stretched.y = last.y = anchor.y = p.y;
 
        if ( regionSelected && !region.contains(anchor.x,anchor.y) ) {
           Graphics g = this.getGraphics();
           if (g != null) clearRegion(g);
           regionSelected = false;
        }
     }
     public void stretch(Point p) {
        last.x      = stretched.x;
        last.y      = stretched.y;
        stretched.x = p.x;
        stretched.y = p.y;
 
        Graphics g = this.getGraphics();
        if ( g != null && !regionSelected ) {
           g.setXORMode(this.getBackground());
 
           if ( firstStretch ) firstStretch = false;
           else                drawLast(g);
           drawNext(g);
        }
     }
     public void end(Point p) {
        last.x = end.x = p.x;
        last.y = end.y = p.y;
 
        Graphics g = this.getGraphics();
        if ( g != null && !regionSelected ) {
           g.setXORMode(this.getBackground());
           drawLast(g);
           region.setBounds( stretched.x < anchor.x ? stretched.x : anchor.x,
                             stretched.y < anchor.y ? stretched.y : anchor.y,
                             Math.abs(stretched.x - anchor.x),
                             Math.abs(stretched.y - anchor.y));
           if ( findItems() ) {
              regionSelected = true;
              drawRegion(g);
           }
        }
     }
     public Rectangle currentBounds() {
        return new Rectangle(stretched.x < anchor.x ? stretched.x : anchor.x,
                             stretched.y < anchor.y ? stretched.y : anchor.y,
                             Math.abs(stretched.x - anchor.x),
                             Math.abs(stretched.y - anchor.y));
     }
 
     public Rectangle lastBounds() {
        return new Rectangle(last.x < anchor.x ? last.x : anchor.x,
                             last.y < anchor.y ? last.y : anchor.y,
                             Math.abs(last.x - anchor.x),
                             Math.abs(last.y - anchor.y));
     }
 
     public Vector boundedItems() {
        if ( regionSelected ) return items;
        return new Vector();
     }
 
     protected boolean findItems() {
        Component[] all_items = getComponents();
        items.removeAllElements();
 
        for( int i = 0; i < all_items.length; i++ ) {
           Rectangle r = all_items[i].getBounds();
           if ( region.contains(r.x,r.y) &&
                region.contains(r.x+r.width,r.y+r.height) )
              items.addElement(all_items[i]);
        }
        return !items.isEmpty();
     }
 }