StatusBar.java

package org.freehep.application;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.LayoutManager2;
import java.util.Arrays;
import java.util.Comparator;

import javax.swing.BorderFactory;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;

/**
 * An status bar typically displayed at the bottom of the application window.
 * The status bar has an area for text messages. Additional areas can be added
 * to either the left or right sides to contain application specific status
 * areas.
 * And a progress bar which displays
 * the progress of extended operations, as well as a "stop" button that can be
 * used to abort certain prolonged actions.
 * @author tonyj
 * @version $Id: StatusBar.java 8584 2006-08-10 23:06:37Z duns $
 */
public class StatusBar extends JPanel
{
   /**
    * Create a new StatusBar
    */
   public StatusBar()
   {
      setLayout(new StatusLayout());
      // We need to leave room for the little sprinkles in the corner for MacOSX
      boolean macOSX = false;
      try
      {
         macOSX = System.getProperty("mrj.version") != null;
      }
      catch (SecurityException x)
      {}
      
      setBorder(new EmptyBorder(0,0,0,(macOSX ? 18 : 0)));
      super.add(m_label);
      m_label.setBorder(BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.LOWERED));
   }
   /**
    * Set the message to display in the status bar.
    * This message is thread safe and can be called from any thread.
    * @param message The message to display, or null to clear the message
    */
   public void setMessage(final String message)
   {
      if (!SwingUtilities.isEventDispatchThread())
      {
         Runnable run = new Runnable()
         {
            public void run()
            {
               setMessage(message);
            }
         };
         SwingUtilities.invokeLater(run);
      }
      else
      {
         if (message == null) m_label.setText(" ");
         else m_label.setText(message);
      }
   }
   private JLabel m_label = new JLabel();
   
   private class StatusLayout implements LayoutManager2, Comparator
   {
      public void addLayoutComponent(String name, Component comp)
      {
      }
      public void addLayoutComponent(Component comp, Object constraints)
      {
      }
      public void removeLayoutComponent(Component comp)
      {
      }
      public float getLayoutAlignmentX(Container target)
      {
         return 0.5f;
      }
      public float getLayoutAlignmentY(Container target)
      {
         return 0.5f;
      }
      public void invalidateLayout(Container target)
      {
      }
      public void layoutContainer(Container parent)
      {
         Insets insets = parent.getInsets();
         Dimension size = parent.getSize();
         // We need to sort the elements based on their XAlignment
         // Components with XAlignment < .5 go to the left of the label
         // Components with XAlignment >= .5 go to teh right of the label
         // The label takes all remaining space
         Component[] children = parent.getComponents();
         Arrays.sort(children,this);
         int x1 = insets.left;
         for (int i=0; i<children.length; i++)
         {
            Component c = children[i];
            if (c == m_label) continue;
            float align = c.getAlignmentX();
            if (align >= .5) break;
            Dimension s = c.getPreferredSize();
            s.height = size.height-insets.top-insets.bottom;
            c.setSize(s);
            c.setLocation(x1,insets.top);
            x1 += s.width;
         }
         int x2 = size.width - insets.right;
         for (int i=children.length; i-->0; )
         {
            Component c = children[i];
            if (c == m_label) continue;
            float align = c.getAlignmentX();
            if (align < .5) break;
            Dimension s = c.getPreferredSize();
            s.height = size.height-insets.top-insets.bottom;
            c.setSize(s);
            x2 -= s.width;
            c.setLocation(x2,insets.top);
         }
         Dimension s = new Dimension(x2-x1,size.height-insets.top-insets.bottom);
         m_label.setSize(s);
         m_label.setLocation(x1,insets.top);
      }
      public Dimension maximumLayoutSize(Container target)
      {
         Insets insets = target.getInsets();
         int width = insets.left + insets.right;
         int height = Integer.MAX_VALUE;
         int count = target.getComponentCount();
         for (int i=0; i<count; i++)
         {
            Component c = target.getComponent(i);
            if (!c.isVisible()) continue;
            Dimension size = c.getMaximumSize();
            width += size.width;
            height = Math.min(height,size.height);
         }
         height += insets.top + insets.bottom;
         return new Dimension(width, height);
      }
      public Dimension minimumLayoutSize(Container parent)
      {
         Insets insets = parent.getInsets();
         int width = insets.left + insets.right;
         int height = 0;
         int count = parent.getComponentCount();
         for (int i=0; i<count; i++)
         {
            Component c = parent.getComponent(i);
            if (!c.isVisible()) continue;
            Dimension size = c.getMinimumSize();
            width += size.width;
            height = Math.max(height,size.height);
         }
         height += insets.top + insets.bottom;
         return new Dimension(width, height);
      }
      public Dimension preferredLayoutSize(Container parent)
      {
         Insets insets = parent.getInsets();
         int width = insets.left + insets.right;
         int height = 0;
         int count = parent.getComponentCount();
         for (int i=0; i<count; i++)
         {
            Component c = parent.getComponent(i);
            if (!c.isVisible()) continue;
            Dimension size = c.getPreferredSize();
            width += size.width;
            height = Math.max(height,size.height);
         }
         height += insets.top + insets.bottom;
         return new Dimension(width, height);
      }
      public int compare(Object o1, Object o2)
      {
         float delta = ((Component) o1).getAlignmentX() - ((Component) o2).getAlignmentX();
         if      (delta == 0) return 0;
         else if (delta > 0)  return 1;
         else                 return -1;
      }
   }
}