/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2001 Intersect Software Corporation

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.ui.swing;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.border.EmptyBorder;
import javax.swing.table.TableColumn;

import net.wotonomy.foundation.NSArray;
import net.wotonomy.ui.EOAssociation;
import net.wotonomy.ui.EODisplayGroup;
import net.wotonomy.ui.swing.components.ButtonPanel;
import net.wotonomy.ui.swing.util.WindowUtilities;

/**
 * ReferenceInspector tracks objects until they are garbage collected. Use it to
 * track objects that you suspect are not being GCed. ReferenceInspector retains
 * only weak references to the objects that it tracks, so when those weak
 * references cannot be resolved, the object has been garbage collected. Note
 * that under some GC implementations, adding a weak reference to an object will
 * delay garbage collection for that object.
 *
 * @author michael@mpowers.net
 * @version $Revision: 904 $
 */

public class ReferenceInspector implements MouseListener, ActionListener {
	protected JTable table;
	protected JLabel memoryLabel;

	static protected EODisplayGroup displayGroup;
	static protected JFrame window;

	/* Reference queue for cleared WeakKeys */
	private static ReferenceQueue queue = new ReferenceQueue();

	// key command to copy contents to clipboard
	static public final String COPY = "COPY";

	/**
	 * Launches a new ReferenceInspector if one does not already exist.
	 */
	public ReferenceInspector() {
		if (window == null) {
			table = new JTable();
			memoryLabel = new JLabel();

			displayGroup = new EODisplayGroup();

			TableColumn column;
			TableColumnAssociation assoc;

			column = new TableColumn();
			column.setHeaderValue("Object");

			assoc = new TableColumnAssociation(column);
			assoc.bindAspect(EOAssociation.ValueAspect, displayGroup, "");
			assoc.setTable(table);
			assoc.establishConnection();

			column = new TableColumn();
			column.setHeaderValue("Address");
			column.setMaxWidth(100);

			assoc = new TableColumnAssociation(column);
			assoc.bindAspect(EOAssociation.ValueAspect, displayGroup, "identityHashCode");
			assoc.setTable(table);
			assoc.establishConnection();

			initLayout();
		}
		window.show();
	}

	/**
	 * Adds the specified object to the ReferenceInspector, launching a new
	 * ReferenceInspector if one does not already exist.
	 */
	public ReferenceInspector(Object anObject) {
		this();
		displayGroup.insertObjectAtIndex(new ExtendedWeakReference(anObject, queue), 0);
		window.show();
	}

	protected void initLayout() {
		table.addMouseListener(this); // listen for double-clicks

		JPanel panel = new JPanel();
		panel.setBorder(new EmptyBorder(new Insets(10, 10, 10, 10)));
		panel.setLayout(new BorderLayout(10, 10));

		JScrollPane scrollPane = new JScrollPane(table);
		scrollPane.setPreferredSize(new Dimension(500, 250));
		panel.add(scrollPane, BorderLayout.CENTER);

		ButtonPanel buttonPanel = new ButtonPanel(new String[] { "Update" });
		buttonPanel.addActionListener(this);

		JPanel bottomPanel = new JPanel();
		bottomPanel.setLayout(new BorderLayout());
		bottomPanel.add(buttonPanel, BorderLayout.EAST);
		bottomPanel.add(memoryLabel, BorderLayout.CENTER);
		panel.add(bottomPanel, BorderLayout.SOUTH);

		window = new JFrame();
		window.setTitle("Reference Inspector");
		window.getContentPane().add(panel);

//        javax.swing.Timer timer = new javax.swing.Timer( 10000, this );
//        timer.restart();

		window.pack();
		WindowUtilities.cascade(window);
		window.show();
	}

	/*
	 * Remove all invalidated entries from the map, that is, remove all entries
	 * whose keys have been discarded. This method should be invoked once by each
	 * public mutator in this class. We don't invoke this method in public accessors
	 * because that can lead to surprising ConcurrentModificationExceptions.
	 */
	private static void processQueue() {
//        System.out.println( "ReferenceInspector.processQueue:");
		synchronized (displayGroup) {
			int idx;
			WeakReference rk;
			while ((rk = (WeakReference) queue.poll()) != null) {
//                System.out.println( "ReferenceInspector.processQueue: removing object: " + rk );
				if (rk != null) {
					idx = displayGroup.displayedObjects().indexOfIdenticalObject(rk);
					if (idx != NSArray.NotFound) {
						displayGroup.deleteObjectAtIndex(idx);
					}
				}
			}
			displayGroup.updateDisplayedObjects();
		}
	}

	// interface ActionListener

	public void actionPerformed(ActionEvent evt) {
		Runtime runtime = Runtime.getRuntime();
		runtime.gc();
		processQueue();

		long totalMemory = runtime.totalMemory() / 1024;
		long freeMemory = runtime.freeMemory() / 1024;
		memoryLabel.setText(Long.toString(totalMemory - freeMemory) + "K / " + Long.toString(totalMemory) + "K");
	}

	// interface MouseListener

	/**
	 * Double click to launch object inspector.
	 */

	public void mouseClicked(MouseEvent e) {
		if (e.getSource() == table) {
			if (e.getClickCount() > 1) {
				int row = table.rowAtPoint(e.getPoint());
				int col = table.columnAtPoint(e.getPoint());
				col = table.convertColumnIndexToModel(col);

				if (row == -1)
					return;

				if (col == 0) // time
				{
				} else {
				}
			}
		}
	}

	public void mouseReleased(MouseEvent e) {
	}

	public void mousePressed(MouseEvent e) {
	}

	public void mouseEntered(MouseEvent e) {
	}

	public void mouseExited(MouseEvent e) {
	}

	public class ExtendedWeakReference extends WeakReference {
		public ExtendedWeakReference(Object referent, ReferenceQueue q) {
			super(referent, q);
		}

		public String toString() {
			if (get() != null) {
				return get().toString();
			}
			return null;
		}

		public String identityHashCode() {
			if (get() != null) {
				return Integer.toHexString(System.identityHashCode(get()));
			}
			return null;
		}

	}
}

/*
 * $Log$ Revision 1.2 2006/02/18 23:19:05 cgruber Update imports and maven
 * dependencies.
 *
 * Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.5 2003/08/06 23:07:52 chochos general code cleanup (mostly,
 * removing unused imports)
 *
 * Revision 1.4 2002/03/22 22:39:59 mpowers Now shows the window even if
 * previously hidden.
 *
 * Revision 1.3 2001/10/02 14:22:39 mpowers Now shows used and heap memory
 * usage.
 *
 * Revision 1.2 2001/07/10 16:39:32 mpowers Removed printlns.
 *
 * Revision 1.1 2001/07/10 16:32:50 mpowers Adding the reference inspector.
 *
 *
 */