package com.melloware.jukes.gui.view.dialogs;
   
   import java.awt.BorderLayout;
   import java.awt.Frame;
   
   import javax.swing.JButton;
   import javax.swing.JComponent;
   import javax.swing.JLabel;
   import javax.swing.JPanel;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import com.jgoodies.forms.builder.PanelBuilder;
  import com.jgoodies.forms.factories.Borders;
  import com.jgoodies.forms.layout.CellConstraints;
  import com.jgoodies.forms.layout.FormLayout;
  import com.jgoodies.forms.layout.Sizes;
  import com.jgoodies.uif.AbstractDialog;
  import com.jgoodies.uif.util.Resizer;
  import com.jgoodies.uifextras.panel.HeaderPanel;
  import com.jgoodies.uifextras.util.UIFactory;
  import com.melloware.jukes.gui.tool.Resources;
  
  /**
   * Provides JVM Memory usage and garbage collection option.
   * <p>
   * Copyright (c) 1999-2007 Melloware, Inc. <http://www.melloware.com>
   * @author Emil A. Lefkof III <info@melloware.com>
   * @version 4.0
   */
  public final class MemoryDialog
      extends AbstractDialog {
  
      private static final Log LOG = LogFactory.getLog(MemoryDialog.class);
      private JLabel totalMemory;
      private JLabel maxMemory;
      private JLabel freeMemory;
      private JPanel panel;
      /**
       * Constructs a default about dialog using the given owner.
       *
       * @param owner   the dialog's owner
       */
      public MemoryDialog(Frame owner) {
          super(owner);
          LOG.debug("Memory Dialog created.");
      }
  
      /**
       * Builds and answers the dialog's content.
       *
       * @return the dialog's content with tabbed pane and button bar
       */
      protected JComponent buildContent() {
          JPanel content = new JPanel(new BorderLayout());
          content.add(buildMainPanel(), BorderLayout.CENTER);
          content.add(buildButtonBarWithClose(), BorderLayout.SOUTH);
          return content;
      }
  
      /**
       * Builds and returns the dialog's header.
       *
       * @return the dialog's header component
       */
      protected JComponent buildHeader() {
          return new HeaderPanel("Memory ",
                                 "You can see the memory usage of this application.\n"
                                 + "Please press garbage collection button to reclaim resources.",
                                 Resources.MEMORY_LARGE_ICON);
      }
  
      /**
       * Builds and returns the dialog's pane.
       *
       * @return the dialog's  pane component
       */
      protected JComponent buildMainPanel() {
          totalMemory = UIFactory.createBoldLabel(convertMemoryNumber(Runtime.getRuntime().totalMemory()));
          maxMemory = UIFactory.createBoldLabel(convertMemoryNumber(Runtime.getRuntime().maxMemory()));
          freeMemory = UIFactory.createBoldLabel(convertMemoryNumber(Runtime.getRuntime().maxMemory() - Runtime.getRuntime().totalMemory()));
          
          JButton buttonGC = new JButton("Garbage Collection"); 
          buttonGC.addActionListener(new java.awt.event.ActionListener() {
              public void actionPerformed(java.awt.event.ActionEvent evt) {
                  garbageCollect();
              }
          });
          
  
          FormLayout layout = new FormLayout(
                  "7dlu, left:pref, right:pref, left:0:grow", 
                  "pref, 2dlu, pref, 14dlu, " +
                  "pref, 2dlu, pref, pref, pref," +
                  "pref, 2dlu, pref, 14dlu, pref" );
                  
          PanelBuilder builder = new PanelBuilder(layout);
         builder.setDefaultDialogBorder();
         CellConstraints cc = new CellConstraints();
         int row = 1;
         builder.addSeparator("Memory Usage",      cc.xyw(1, row++, 4));
         row++;
         builder.addLabel("Max Memory: ",           cc.xy(2, row));
         builder.add(maxMemory, cc.xy(3, row++));
         builder.addLabel("Used Memory: ",           cc.xy(2, row));
         builder.add(totalMemory, cc.xy(3, row++));
         builder.addLabel("Free Memory: ",           cc.xy(2, row));
         builder.add(freeMemory, cc.xy(3, row++));
         row++;
         row++;
         builder.add(buttonGC,           cc.xy(2, row));
         panel = builder.getPanel();
         int width = Sizes.dialogUnitXAsPixel(220, panel);
         panel.setPreferredSize(Resizer.DEFAULT.fromWidth(width));
         panel.setBorder(Borders.DIALOG_BORDER);
         return panel;
     }
     
     /**
      * Updates the labels with new memory settings.
      */
     private void updateMemoryStats() {
         totalMemory.setText(convertMemoryNumber(Runtime.getRuntime().totalMemory()));
         maxMemory.setText(convertMemoryNumber(Runtime.getRuntime().maxMemory()));
         freeMemory.setText(convertMemoryNumber(Runtime.getRuntime().maxMemory() - Runtime.getRuntime().totalMemory()));
     }
    
     
     /**
      * Converts a number like 134217728  to 128 MB.
      * <p>
      * @param aMemoryNumber the number to convert
      * @return the String representation
      */
     private String convertMemoryNumber(long aMemoryNumber) {
         return FileUtils.byteCountToDisplaySize(aMemoryNumber);
     }
     
     /**
      * Runs the garbage collector.
      */
     private void garbageCollect() {
         LOG.debug("Running garbage collection.");
         System.gc();
         updateMemoryStats();
         panel.updateUI();
     }
 
     /**
      * Resizes the given component to give it a quadratic aspect ratio.
      *
      * @param component   the component to be resized
      */
     protected void resizeHook(JComponent component) {
         Resizer.ONE2ONE.resizeDialogContent(component);
     }
 
 }