findaccessory.java

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package com.btsendfile;
/**
A threaded file search accessory for JFileChooser.
<P>
Presents JFileChooser users with a tabbed panel interface for
specifying file search criteria including (1) search by name,
(2) search by date of modification, and (3) search by file content.
Finded are performed "in the background" with found files displayed
dynamically as they are found. Only one search can be active at
a time. FindResults are displayed in a scrolling list within a results
tab panel.
<P>
Findes are performed asynchronously so the user can continue
browsing the file system. The user may stop the search at any time.
Accepting or cancelling the file chooser or closing the dialog window
will automatically stop a search in progress.
<P>
The starting folder of the search (the search base) is displayed
at the top of the accessory panel. The search base dsiplay will
not change while a search is running. Thes search base display
will change to reflect the current directory of JFileChooser
when a search is not running.
<P>
Changing the search options does not affect a search in progress.

@version	1.0, 2000/01/19
@author		Ken Klinner, [e-mail]
 */

import java.io.*;
import java.util.*;
import java.text.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.filechooser.*;
import javax.swing.border.*;
import java.beans.*;


public class FindAccessory	extends		JPanel
							implements	Runnable,
										PropertyChangeListener,
										ActionListener,
										FindProgressCallback
{
	/**
	Label for this accessory.
	*/
	static public final String	ACCESSORY_NAME = " Find ";

	/**
	Default max number of found items. Prevents overloading results list.
	*/
	static public final int		DEFAULT_MAX_SEARCH_HITS = 500;

	/**
	Find start action name
	*/
	static public final String	ACTION_START = "Start";

	/**
	Find stop action name
	*/
	static public final String	ACTION_STOP = "Stop";

	/**
	Parent JFileChooser component
	*/
	protected JFileChooser		chooser = null;

	protected FindAction		actionStart = null;
	protected FindAction		actionStop = null;

	/**
	This version of FindAccesory supports only one active search thread
	*/
	protected Thread			searchThread = null;

	/**
	Set to true to stop current search
	*/
	protected boolean			killFind = false;

	/**
	Displays full path of search base
	*/
	protected FindFolder		pathPanel = null;

	/**
	Find options with results list
	*/
	protected FindTabs		searchTabs = null;

	/**
	Find controls with progress display
	*/
	protected FindControls	controlPanel = null;

	/**
	Number of items inspected by current/last search
	*/
	protected int				total = 0;

	/**
	Number of items found by current/last search
	*/
	protected int				matches = 0;

	/**
	Max number of found items to prevent overloading
	the results list.
	*/
	protected int				maxMatches = DEFAULT_MAX_SEARCH_HITS;



    /**
     Construct a search panel with start and stop actions, option panes and a
	 results list pane that can display up to DEFAULT_MAX_SEARCH_HITS items.
     */
	public FindAccessory ()
	{
		super();

		setBorder(new TitledBorder(ACCESSORY_NAME));
		setLayout(new BorderLayout());

		actionStart = new FindAction(ACTION_START,null);
		actionStop = new FindAction(ACTION_STOP,null);

		add(pathPanel = new FindFolder(),BorderLayout.NORTH);
		add(searchTabs = new FindTabs(),BorderLayout.CENTER);
		add(controlPanel = new FindControls(actionStart,actionStop,true),
							BorderLayout.SOUTH);

		updateFindDirectory();
	}

    /**
		Construct a search panel with start and stop actions and "attach" it to
		the specified JFileChooser component. Calls register() to establish
		FindAccessory as a PropertyChangeListener of JFileChooser.

		@param parent JFileChooser containing this accessory
     */
	public FindAccessory (JFileChooser parent)
	{
		this();
		chooser = parent;
		register(chooser);
	}

    /**
		Construct a search panel with start and stop actions and "attach" it to
		the specified JFileChooser component. Calls register() to establish
		FindAccessory as a PropertyChangeListener of JFileChooser. Sets maximum
		number of found items to limit the load in the results list.

		@param parent JFileChooser containing this accessory
		@param max Max number of items for results list. Find stops when max
		number of items found.
     */
	public FindAccessory (JFileChooser c, int max)
	{
		this(c);
		setMaxFindHits(max);
	}

    /**
		Sets maximum capacity of the results list.
		Find stops when max number of items found.

		@param max Max capacity of results list.
     */
	public void setMaxFindHits (int max)
	{
		maxMatches = max;
	}

    /**
		Returns maximum capacity of results list.

		@return Max capacity of results list.
     */
	public int getMaxFindHits ()
	{
		return maxMatches;
	}

    /**
		Called by JFileChooser when a property changes. FindAccessory listens
		for DIRECTORY_CHANGED_PROPERTY and updates the path component to display
		the full path of the current JFileChooser directory. When a search is
		in progress the path component is <b>not</b> updated - the path component
		will display the starting point of the current search.

		@param e PropertyChangeEvent from parent JFileChooser.
     */
	public void propertyChange (PropertyChangeEvent e)
	{
		String prop = e.getPropertyName();
		if (prop.equals(JFileChooser.DIRECTORY_CHANGED_PROPERTY))
		{
			updateFindDirectory();
		}
	}

    /**
		Called by JFileChooser when the user provokes an action like "cancel"
		or "open". Listens for APPROVE_SELECTION and CANCEL_SELECTION action
		and stops the current search, if there is one.

		@param e ActionEvent from parent JFileChooser.
     */
	public void actionPerformed (ActionEvent e)
	{
		String command = e.getActionCommand();
		if (command == null) return; // Can this happen? Probably not. Call me paranoid.
		if (command.equals(JFileChooser.APPROVE_SELECTION))
			quit();
		else if (command.equals(JFileChooser.CANCEL_SELECTION))
			quit();
	}


    /**
		Displays the absolute path to the parent's current directory if and only
		if there is no active search.
     */
	public void updateFindDirectory ()
	{
		if (isRunning()) return;
		if (chooser == null) return;
		if (pathPanel == null) return;
		File f = chooser.getCurrentDirectory();
		pathPanel.setFindDirectory(f);
	}

    /**
		Set parent's current directory to the parent folder of the specified
		file and select the specified file. This method is invoked when the
		user double clicks on an item in the results list.

		@param f File to select in parent JFileChooser
     */
	public void goTo (File f)
	{
		if (f == null) return;
		if (!f.exists()) return;
		if (chooser == null) return;

		// Make sure that files and directories can be displayed
		chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);

		// Make sure that parent file chooser will show the type of file
		// specified
		javax.swing.filechooser.FileFilter filter = chooser.getFileFilter();
		if (filter != null)
		{
			if (!filter.accept(f))
			{
				// The current filter will not display the specified file.
				// Set the file filter to the built-in accept-all filter (*.*)
				javax.swing.filechooser.FileFilter all = 
					chooser.getAcceptAllFileFilter();
				chooser.setFileFilter(all);
			}
		}

		// Tell parent file chooser to display contents of parentFolder.
		// Prior to Java 1.2.2 setSelectedFile() did not set the current
		// directory the folder containing the file to be selected.
		File parentFolder = f.getParentFile();
		if (parentFolder != null) chooser.setCurrentDirectory(parentFolder);

		// Nullify the current selection, if any.
		// Why is this necessary?
		// Emperical evidence suggests that JFileChooser gets "sticky" (i.e. it
		// does not always relinquish the current selection). Nullifying the
		// current selection seems to yield better results.
		chooser.setSelectedFile(null);

		// Select the file
		chooser.setSelectedFile(f);

		// Refresh file chooser display.
		// Is this really necessary? Testing on a variety of systems with
		// Java 1.2.2 suggests that this helps. Sometimes it doesn't work,
		// but it doesn't do any harm.
		chooser.invalidate();
		chooser.repaint();
	}

    /**
		Start a search. The path display will show the starting folder of the
		search.
		Finds are recursive and will span the entire folder hierarchy below the
		base folder. The user may continue to browse with JFileChooser.
     */
	public synchronized void start ()
	{
		if (searchTabs != null) searchTabs.showFindResults();
		updateFindDirectory();
		killFind = false;
		if (searchThread == null)
		{
			searchThread = new Thread(this);
		}
		if (searchThread != null) searchThread.start();
	}

    /**
		Stop the active search.
     */
	public synchronized void stop ()
	{
		killFind = true;
	}

    /**
		@return true if a search is currently running
     */
	public boolean isRunning ()
	{
		if (searchThread == null) return false;
		return searchThread.isAlive();
	}

    /**
		Find thread
     */
	public void run ()
	{
		if (searchThread == null) return;
		if (Thread.currentThread() != searchThread) return;
		try
		{
			actionStart.setEnabled(false);
			actionStop.setEnabled(true);
			runFind(chooser.getCurrentDirectory(),newFind());
		}
		catch (InterruptedException e)
		{
		}
		finally
		{
			actionStart.setEnabled(true);
			actionStop.setEnabled(false);
			searchThread = null;
		}
	}

    /**
		Recursive search beginning at folder <b>base</b> for files and folders
		matching each filter in the <b>filters</b> array. To interrupt set
		<b>killFind</b> to true. Also stops when number of search hits (matches)
		equals <b>maxMatches</b>.
		<P>
		<b>Note:</b> Convert this to a nonrecursive search algorithm on systems
		where stack space might be limited and/or the search hierarchy might be
		very deep.

		@param base starting folder of search
		@param filters matches must pass each filters in array
		@exception InterruptedException if thread is interrupted
     */
	protected void runFind (File base, FindFilter[] filters)
					throws InterruptedException
	{
		if (base == null) return;
		if (!base.exists()) return; // Not likely to happen
		if (filters == null) return;

		if (killFind) return;
		File folder = null;
		if (base.isDirectory()) folder = base;
		else folder = base.getParentFile();

		File[] files = folder.listFiles();
		for (int i=0; i<files.length; i++)
		{
			total++;
			if (accept(files[i],filters))
			{
				matches++;
				searchTabs.addFoundFile(files[i]);
			}
			updateProgress();
			if (killFind) return;
			Thread.currentThread().sleep(0);

			if (files[i].isDirectory()) runFind(files[i],filters);
			if ((maxMatches > 0) && (matches >= maxMatches))
			{
				return;// stopgap measure so that we don't overload
			}
		}
	}

    /**
		@param file file to pass to each filter's accept method
		@param filters array of selection criteria

		@return true if specified file matches each filter's selection criteria
     */
	protected boolean accept (File file, FindFilter[] filters)
	{
		if (file == null) return false;
		if (filters == null) return false;
		
		for (int i=0; i<filters.length; i++)
		{
			if (!filters[i].accept(file,this)) return false;
		}
		return true;
	}

    /**
		Called by FindFilter to report progress of a search. Purely
		a voluntary report. This really should be implemented as a
		property change listener.
		Percentage completion = (current/total)*100.

		@param filter FindFilter reporting progress
		@param file file being searched
		@param current current "location" of search
		@param total expected maximum value of current

		@return true to continue search, false to abort
     */
	public boolean reportProgress (FindFilter filter, File file,
									long current, long total)
	{
		return !killFind;
	}

    /**
		Begins a new search by resetting the <b>total</b> and <b>matches</b>
		progress variables and retrieves the search filter array from the
		options panel.
		Each tab in the options panel is responsible for generating a
		FindFilter based on its current settings.

		@return Array of search filters from the options panel.
     */
	protected FindFilter[] newFind ()
	{

		total = matches = 0;
		updateProgress();

		if (searchTabs != null) return searchTabs.newFind();
		return null;
	}

    /**
		Display progress of running search.
     */
	protected void updateProgress ()
	{
		controlPanel.showProgress(matches,total);
	}


    /**
		Add this component to the specified JFileChooser's list of property
		change listeners and action listeners.

		@param c parent JFileChooser
     */
	protected void register (JFileChooser c)
	{
		if (c == null) return;
		c.addPropertyChangeListener(this);
		c.addActionListener(this);
	}

    /**
		Remove this component from the specified JFileChooser's list of property
		change listeners and action listeners.

		@param c parent JFileChooser
     */
	protected void unregister (JFileChooser c)
	{
		if (c == null) return;
		c.removeActionListener(this);
		c.removePropertyChangeListener(this);
	}

    /**
		Stop the current search and unregister in preparation for parent
		shutdown.
     */
	public void quit ()
	{
		stop();
		unregister(chooser);
	}


    /**
		Invoked by FindAction objects to start and stop searches.
     */
	public void action (String command)
	{
		if (command == null) return;
		if (command.equals(ACTION_START))
			start();
		else if (command.equals(ACTION_STOP))
			stop();
	}

	/**
		Convenience class for adding action objects to the control panel.
	*/
	class FindAction extends AbstractAction