ToolBar.java

import java.awt.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;

/**
   A tool bar that contains node and edge prototype icons.
   Exactly one icon is selected at any time.
*/
public class ToolBar extends JPanel
{
   /**
      Constructs a tool bar with no icons.
   */
   public ToolBar(Graph graph)
   {
      group = new ButtonGroup();
      tools = new ArrayList<Object>();

      JToggleButton grabberButton = new JToggleButton(new
         Icon()
         {
            public int getIconHeight() { return BUTTON_SIZE; }
            public int getIconWidth() { return BUTTON_SIZE; }
            public void paintIcon(Component c, Graphics g,
               int x, int y)
            {
               Graphics2D g2 = (Graphics2D) g;
               GraphPanel.drawGrabber(g2, x + OFFSET, y + OFFSET);
               GraphPanel.drawGrabber(g2, x + OFFSET, y + BUTTON_SIZE - OFFSET);
               GraphPanel.drawGrabber(g2, x + BUTTON_SIZE - OFFSET, y + OFFSET);
               GraphPanel.drawGrabber(g2, x + BUTTON_SIZE - OFFSET, y + BUTTON_SIZE - OFFSET);
            }
         });
      group.add(grabberButton);
      add(grabberButton);
      grabberButton.setSelected(true);
      tools.add(null);

      Node[] nodeTypes = graph.getNodePrototypes();
      for (Node n : nodeTypes)
         add(n);

      Edge[] edgeTypes = graph.getEdgePrototypes();
      for (Edge e : edgeTypes)
         add(e);
   }

   /**
      Gets the node or edge prototype that is associated with
      the currently selected button
      @return a Node or Edge prototype
   */
   public Object getSelectedTool()
   {
      int i=0;
      for (Object o : tools)
      {
         JToggleButton button = (JToggleButton) getComponent(i++);
         if (button.isSelected()) return o;
      }
      return null;
   }

   /**
      Adds a node to the tool bar.
      @param n the node to add
   */
   public void add(final Node n)
   {
      JToggleButton button = new JToggleButton(new
         Icon()
         {
            public int getIconHeight() { return BUTTON_SIZE; }
            public int getIconWidth() { return BUTTON_SIZE; }
            public void paintIcon(Component c, Graphics g,
               int x, int y)
            {
               double width = n.getBounds().getWidth();
               double height = n.getBounds().getHeight();
               Graphics2D g2 = (Graphics2D) g;
               double scaleX = (BUTTON_SIZE - OFFSET)/ width;
               double scaleY = (BUTTON_SIZE - OFFSET)/ height;
               double scale = Math.min(scaleX, scaleY);

               AffineTransform oldTransform = g2.getTransform();
               g2.translate(x, y);
               g2.scale(scale, scale);
               g2.translate(Math.max((height - width) / 2, 0), Math.max((width - height) / 2, 0));
               g2.setColor(Color.black);
               n.draw(g2);
               g2.setTransform(oldTransform);
            }
         });
      group.add(button);
      add(button);
      tools.add(n);
   }

   /**
      Adds an edge to the tool bar.
      @param n the edge to add
   */
   public void add(final Edge e)
   {
      JToggleButton button = new JToggleButton(new
         Icon()
         {
            public int getIconHeight() { return BUTTON_SIZE; }
            public int getIconWidth() { return BUTTON_SIZE; }
            public void paintIcon(Component c, Graphics g,
               int x, int y)
            {
               Graphics2D g2 = (Graphics2D) g;
               PointNode p = new PointNode();
               p.translate(OFFSET, OFFSET);
               PointNode q = new PointNode();
               q.translate(BUTTON_SIZE - OFFSET, BUTTON_SIZE - OFFSET);
               e.connect(p, q);
               g2.translate(x, y);
               g2.setColor(Color.black);
               e.draw(g2);
               g2.translate(-x, -y);
            }
         });
      group.add(button);
      add(button);
      tools.add(e);
   }

   private ButtonGroup group;
   private ArrayList<Object> tools;

   private static final int BUTTON_SIZE = 25;
   private static final int OFFSET = 4;
}