jfilechooser.java

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/* class JFileChooser
 *
 * Copyright (C) 2003  R M Pitman
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*
 * Modified Jul 14, 2003 by Tadpole Computer, Inc.
 * Modifications Copyright 2003 by Tadpole Computer, Inc.
 *
 * Modifications are hereby licensed to all parties at no charge under
 * the same terms as the original.
 *
 * Fixed bug to allow save dialog to work when files do not exist.
 * Added setSelectedFile method.  Fixed fileSelectionMode to mean
 * that when FILES_ONLY, entry of a directory name in the textfield now
 * causes the appropriate setCurrentDirectory() call.
 */

package charvax.swing;

import java.io.File;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.TreeSet;
import java.util.Vector;

import charva.awt.BorderLayout;
import charva.awt.Component;
import charva.awt.Dialog;
import charva.awt.Dimension;
import charva.awt.FlowLayout;
import charva.awt.Insets;
import charva.awt.Point;
import charva.awt.Toolkit;
import charva.awt.event.ActionEvent;
import charva.awt.event.ActionListener;
import charva.awt.event.EventListener;
import charva.awt.event.KeyEvent;
import charva.awt.event.KeyListener;
import charvax.swing.border.EmptyBorder;
import charvax.swing.border.TitledBorder;
import charvax.swing.event.ListSelectionEvent;
import charvax.swing.event.ListSelectionListener;
import charvax.swing.filechooser.FileFilter;

/**
 * <p>The JFileChooser class displays a dialog from which the user can choose
 * a file.  The dialog is always modal (i.e. the user cannot interact
 * with any other windows until he closes the dialog).</p>
 *
 * <p>The dialog is displayed by calling its showDialog() method, which blocks 
 * until the dialog is closed (by the user pressing the Approve or Cancel 
 * buttons, or by pressing ENTER while the focus is in the "Filename" field).
 * After the dialog has been closed, the program can find out what 
 * File was selected by calling the getSelectedFile() method.</p>
 *
 * The labels of the buttons that are displayed in the JFileChooser
 * can be customized by changing the following static variables:
 * <ul>
 * <li> <code>PARENT_DIRECTORY_LABEL</code>
 * <li> <code>NEW_DIRECTORY_LABEL</code>
 * <li> <code>APPROVE_LABEL</code>
 * <li> <code>CANCEL_LABEL</code>
 * </ul>
 * <p>"Accelerator keys" can also be set for the buttons. For example,
 * to set the F1 key to have the same effect as pressing the CANCEL
 * button, call the following code before using the JFileChooser:</p>
 * <pre>
 *	JFileChooser.CANCEL_LABEL = "Cancel (F1)";
 *	JFileChooser.CANCEL_ACCELERATOR = KeyEvent.VK_F1;
 * </pre>
 * Note that after the buttons have been customized, they stay customized
 * for all future invocations of JFileChooser (until they are re-customized
 * to some other value).
 */
public class JFileChooser
    extends JComponent
{
    /**
     * Constructs a JFileChooser pointing to the user's home directory.
     */
    public JFileChooser()
    {
	this((File) null);
    }

    /**
     * Constructs a JFileChooser pointing to the specified directory.
     * Passing in a null parameter causes the JFileChooser to point to 
     * the user's home directory.
     */
    public JFileChooser(File currentDirectory_) 
    {
	setCurrentDirectory(currentDirectory_);
    }

    /**
     * Constructs a JFileChooser with the specified pathname. Passing a value
     * of <code>null</code> causes the file chooser to point to the user's
     * home directory.
     */
    public JFileChooser(String currentDirectoryPath_)
    {
	if (currentDirectoryPath_ == null)
	    setCurrentDirectory(null);
	else
	    setCurrentDirectory(new File(currentDirectoryPath_));
    }


    /** Set the current directory. Passing a parameter of <code>null</code>
     * cause the JFileChooser to point to the user's home directory.
     */
    public void setCurrentDirectory(File dir_) {
	if (dir_ == null) {
	    String home = System.getProperty("user.home");
	    dir_ = new File(home);
	}

	if (dir_.isDirectory() == false) {
	    throw new IllegalArgumentException("not a directory");
	}
	_currentDirectory = dir_;
	_location = dir_.getAbsolutePath();
    }

    /**
     * Returns the currently displayed directory.
     */
    public File getCurrentDirectory() { 
	return _currentDirectory; 
    }

    /**
     * Get the File selected by the user.  If the user pressed Cancel, 
     * the return value is null.
     */
    public File getSelectedFile() {
	if (_cancelWasPressed)
	    return null;

	return new File(_location);
    }

    public void setSelectedFile(File file_) {
	if (!file_.isAbsolute()) {
	    file_ = new File(_currentDirectory, file_.getPath());
	}

	File parent = file_.getParentFile();

	if (!file_.isDirectory() && (parent != null)) {
	    _currentDirectory = parent;
	    _location = file_.getAbsolutePath();
	} else if (file_.isDirectory()) {
	    _currentDirectory = file_;
	    _location = file_.getAbsolutePath();
	}
	fireFileChooserEvent();
    }

    /**
     * Pops up a custom file chooser dialog with a custom approve button.
     * @param parent_ the parent component of the dialog; can be
     * <code>null</code>. 
     * @param approveButtonText_ the custom text string to display in the 
     * Approve button.
     * @return the return state of the file chooser on popdown:
     * <ul><li>JFileChooser.CANCEL_OPTION
     * <li>JFileChooser.APPROVE_OPTION
     * <li>JFileChooser.ERROR_OPTION</ul>
     */
    public int showDialog(Component parent_, String approveButtonText_)
    {
	_approveButtonText = approveButtonText_;
	JDialog chooserDialog = new ChooserDialog(parent_);
	chooserDialog.setLocationRelativeTo(parent_);
	chooserDialog.show();
	if (_cancelWasPressed)
	    return CANCEL_OPTION;
	else
	    return APPROVE_OPTION;
    }

    /**
     * Pops up a "Save File" file chooser dialog; this is a convenience 
     * method and is equivalent to showDialog(Component, "Save").
     * @return the return state of the file chooser on popdown:
     * <ul><li>JFileChooser.CANCEL_OPTION
     * <li>JFileChooser.APPROVE_OPTION
     * <li>JFileChooser.ERROR_OPTION</ul>
     */
    public int showSaveDialog(Component parent_)
    {
	return showDialog(parent_, "Save");
    }

    /**
     * Pops up a "Open File" file chooser dialog; this is a convenience 
     * method and is equivalent to showDialog(Component, "Open").
     * @return the return state of the file chooser on popdown:
     * <ul>
     * <li>JFileChooser.CANCEL_OPTION
     * <li>JFileChooser.APPROVE_OPTION
     * <li>JFileChooser.ERROR_OPTION
     * </ul>
     */
    public int showOpenDialog(Component parent_)
    {
	return showDialog(parent_, "Open");
    }

    /**
     * Sets the <code>JFileChooser</code> to allow the user to select
     * files only directories only, or files and directories. The default
     * is JFileChooser.FILES_ONLY.
     */
    public void setFileSelectionMode(int mode_)
    {
	if (mode_ < FILES_ONLY || mode_ > FILES_AND_DIRECTORIES)
	    throw new IllegalArgumentException("invalid file selection mode");

	_fileSelectionMode = mode_;
    }

    /** Returns the current file-selection mode.
     * @return the file-selection mode, one of the following:<p>
     * <ul>
     * <li><code>JFileChooser.FILES_ONLY</code>
     * <li><code>JFileChooser.DIRECTORIES_ONLY</code>
     * <li><code>JFileChooser.FILES_AND_DIRECTORIES</code>
     * </ul>
     */
    public int getFileSelectionMode() { 
	return _fileSelectionMode; 
    }

    public void setDialogTitle(String title_) {
	_title = title_;
    }

    /**
     * Sets the current file filter. The file filter is used by the
     * file chooser to filter out files from the user's view.
     */
    public void setFileFilter(FileFilter filter_)
    {
	_fileFilter = filter_;
    }

    /**
     * Returns the currently selected file filter.
     */
    public FileFilter getFileFilter()
    {
	return _fileFilter;
    }

    public void debug(int level_) {
	System.err.println("JFileChooser origin=" + _origin + 
		" title=" + _title );
    }

    /** Required to implement abstract method of JComponent (never used).
     */
    public Dimension minimumSize() {
	return null;
    }

    /** Required to implement abstract method of JComponent (never used).
     */
    public Dimension getSize() {
	return null;
    }

    /** Required to implement abstract method of JComponent (never used).
     */
    public int getHeight() {
	return 0;
    }

    /** Required to implement abstract method of JComponent (never used).
     */
    public int getWidth() {
	return 0;
    }

    protected void addFileChooserListener(FileChooserListener l)
    {
	_filelisteners.addElement(l);
    }

    protected void fireFileChooserEvent()
    {
	Enumeration e = _filelisteners.elements();
	while (e.hasMoreElements()) {
	    FileChooserListener l = (FileChooserListener) e.nextElement();
	    l.fileChanged(new FileChooserEvent(this));
	}
    }

    //====================================================================
    // INSTANCE VARIABLES
    protected String _title;
    protected String _approveButtonText = "Open File";

    /** The current directory shown in the dialog.
     */
    protected File _currentDirectory = null;
    protected JFileChooser.DirList _dirList = this.new DirList();
    protected String _location = "";
    protected boolean _cancelWasPressed = true;
    protected int _fileSelectionMode = FILES_ONLY;
    protected FileFilter _fileFilter = null;
    protected Vector _filelisteners = new Vector();

    protected static final int _COLS = 50;
    protected static final int _ROWS = 20;

    public static final int FILES_ONLY = 200;
    public static final int DIRECTORIES_ONLY = 201;
    public static final int FILES_AND_DIRECTORIES = 202;

    public static final int CANCEL_OPTION = 300;
    public static final int APPROVE_OPTION = 301;
    public static final int ERROR_OPTION = 302;

    // Default button labels - can be customized.
    public static String CANCEL_LABEL = "Cancel";
    public static String APPROVE_LABEL = "Approve";
    public static String PARENT_DIRECTORY_LABEL = "Parent Directory";
    public static String NEW_DIRECTORY_LABEL = "New Directory";

    // Button accelerators (disabled by default).
    public static int CANCEL_ACCELERATOR = -1;
    public static int APPROVE_ACCELERATOR = -1;
    public static int PARENT_DIRECTORY_ACCELERATOR = -1;
    public static int NEW_DIRECTORY_ACCELERATOR = -1;

    /*====================================================================
     * This is a nonstatic inner class used by JFileChooser to display
     * a popup dialog.
     */
    private class ChooserDialog
	extends JDialog
	implements ActionListener, ListSelectionListener, KeyListener,
		   FileChooserListener
    {
	ChooserDialog(Component parent_) {
	    setTitle(_title);
	    setSize(_COLS, _ROWS);

	    // Inherit colors from the parent component unless they have
	    // been set already.
	    if (JFileChooser.this.getForeground() == null)
		setForeground(parent_.getForeground());
	    else
		setForeground(JFileChooser.this.getForeground());

	    if (JFileChooser.this.getBackground() == null)
		setBackground(parent_.getBackground());
	    else
		setBackground(JFileChooser.this.getBackground());

	    /* Insert the directory list in the west.
	     */
	    _dirList.setVisibleRowCount(12);
	    _dirList.setColumns(45);
	    _dirList.addListSelectionListener(this);
	    displayCurrentDirectory();

	    _scrollPane = new JScrollPane(_dirList);
	    _scrollPane.setViewportBorder(new TitledBorder("Files"));
	    add(_scrollPane, BorderLayout.WEST);

	    /* Insert a north panel that contains the Parent and New buttons.
	     */
	    JPanel toppanel = new JPanel();
	    toppanel.setBorder(new EmptyBorder(0,1,0,1));
	    toppanel.setLayout(new FlowLayout(FlowLayout.RIGHT, 1, 0));
	    toppanel.add(_parentButton);
	    _parentButton.setText(PARENT_DIRECTORY_LABEL);
	    _parentButton.addActionListener(this);

	    toppanel.add(_newButton);
	    _newButton.setText(NEW_DIRECTORY_LABEL);
	    _newButton.addActionListener(this);
	    add(toppanel, BorderLayout.NORTH);

	    /* Insert a panel in the south for the textfield and the
	     * Approve and Cancel buttons.
	     */
	    JPanel southpanel = new JPanel();
	    southpanel.setLayout(new BorderLayout());

	    JPanel topsouth = new JPanel();
	    topsouth.add(new JLabel("Pathname:"));
	    topsouth.add(_locationField);
	    _locationField.setText(_location);
	    _locationField.setActionCommand("locationField");
	    _locationField.addActionListener(this);
	    southpanel.add(topsouth, BorderLayout.NORTH);

	    JPanel bottomsouth = new JPanel();
	    bottomsouth.setLayout(new FlowLayout(FlowLayout.RIGHT, 1, 0));
	    bottomsouth.setBorder(new EmptyBorder(1,1,0,1));
	    bottomsouth.add(_approveButton);
	    bottomsouth.add(_cancelButton);
	    _approveButton.setText(_approveButtonText);
	    _cancelButton.setText(CANCEL_LABEL);
	    _approveButton.addActionListener(this);
	    _cancelButton.addActionListener(this);
	    southpanel.add(bottomsouth, BorderLayout.SOUTH);

	    add(southpanel, BorderLayout.SOUTH);

	    pack();
	    Insets insets = getInsets();
	    _dirList.setColumns(getWidth() - insets.left - insets.right - 2);

	    addKeyListener(this);
	    addFileChooserListener(this);
	}