edu.northwestern.at.utils.swing
Class FileDialogs

java.lang.Object
  edu.northwestern.at.utils.swing.FileDialogs

public class FileDialogs
extends java.lang.Object

File Dialogs.

Provides a static encapsulation of the Swing and AWT file dialogs for "open" and "save as" so that they use the same interface. Typically the AWT FileDialog is used on MAC OS X while the Swing JFileChooser is used on Windows.

To select a file for input ("open"):

String[] fileToOpen = FileDialogs.open( "Open file" ); if ( fileName != null ) { File f = new File( fileToOpen[ 0 ] , fileToOpen[ 1 ] ); if ( f.exists() ) { // Open the file. ... } }

To select a file for output ("save" or "save as"):

String[] fileToSave = FileDialogs.open( "Save file" ); if ( fileName != null ) { File f = new File( fileToOpen[ 0 ] , fileToOpen[ 1 ] ); if ( f.exists() ) { // Save the file. ... } }

FileDialogs remembers the last used open (input) and save (output) directories. You may retrieve these using the getOpenDirectory and getSaveDirectory methods, and set them using the setOpenDirectory and setSaveDirectory methods.

You may create file filter dialogs based upon file extension using FileExtensionFilter and set the open and save dialogs to use them using addFileFilter. For example, to add a filter to allow only files with the jpg, png, and svg extensions to appear in the file dialogs, use the following:

FileExtensionFilter filter = new FileExtensionFilter( new String[]{ "jpg" , "png", "svg" }, new String[]{ "jpeg files" , "png files" , "svg file" } ); FileDialogs.addFileFilter( filter );

File filters persist between class to the open or save methods. To clear the current list of file filters, use:

FileDialogs.clearFileFilters();

This will reset the file dialogs to display all files.

File filters DO NOT WORK with the AWT dialogs under any MS Windows operating system. File filters work fine with the Swing dialogs under Windows. If you want to use filters with Windows, make sure you use the Swing dialogs. The default under Windows is to use the Swing dialogs.

Nested Class Summary

protected static class

FileDialogs.FilterWrapper Class to wrap a file filter.

Field Summary

protected static FileExtensionFilter	allFilesFilter Filter allowed all files through.
protected static java.lang.String	defaultOpenTitle Default open file dialog title.
protected static java.lang.String	defaultSaveTitle Default save file dialog title.
protected static javax.swing.JFileChooser	fileChooser Swing file chooser dialog.
protected static java.awt.FileDialog	fileDialog AWT file dialog.
protected static int	OPEN Open file dialog type.
protected static java.lang.String	openDirectory Last directory used for opening a file.
protected static int	SAVE Save file dialog type.
protected static java.lang.String	saveDirectory Last directory used for saving a file.
protected static boolean	useSwing True to use Swing JFileChooser dialogs, false to use AWT.

Constructor Summary

protected

FileDialogs() Don't allow instantiation but do allow overrides.

Method Summary

static void	addFileFilter(FileExtensionFilter fileExtensionFilter) Add a file filter.
static void	clearFileFilters() Clear any existing file name filters.
protected static void	createFileChooser() Create Swing file chooser dialog.
protected static void	createFileDialog() Create AWT file dialog.
protected static java.lang.String[]	doAWTFileDialog(java.lang.String title, java.lang.String startDirectory, int dialogType) Display AWT file dialog.
protected static java.lang.String[]	doFileDialog(java.lang.String title, java.lang.String startDirectory, int dialogType) Display file dialog.
protected static java.lang.String[]	doFileDialog(java.awt.Window parentWindow, java.lang.String title, java.lang.String startDirectory, int dialogType) Display file dialog.
protected static java.lang.String[]	doSwingFileDialog(java.awt.Window parentWindow, java.lang.String title, java.lang.String startDirectory, int dialogType) Display Swing file dialog.
static java.lang.String	getOpenDirectory() Get last open directory.
static java.lang.String	getSaveDirectory() Get last save directory.
static java.lang.String[]	open() Display open file dialog.
static java.lang.String[]	open(java.lang.String title) Display open file dialog.
static java.lang.String[]	open(java.awt.Window parentWindow) Display open file dialog.
static java.lang.String[]	open(java.awt.Window parentWindow, java.lang.String title) Display open file dialog.
static java.lang.String[]	save() Display save file dialog.
static java.lang.String[]	save(java.lang.String title) Display save file dialog.
static java.lang.String[]	save(java.awt.Window parentWindow) Display save file dialog.
static java.lang.String[]	save(java.awt.Window parentWindow, java.lang.String title) Display save file dialog.
static void	setOpenDirectory(java.lang.String directory) Set last open directory.
static void	setSaveDirectory(java.lang.String directory) Set last save directory.
protected static javax.swing.filechooser.FileFilter	wrapFilter(ExtendedFileNameFilter filter) Wraps an ExtendedFileNameFilter in a FileFilter.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

useSwing

protected static boolean useSwing

True to use Swing JFileChooser dialogs, false to use AWT.

By default, use AWT for Mac OS X, and Swing for other systems.

openDirectory

protected static java.lang.String openDirectory

Last directory used for opening a file.

saveDirectory

protected static java.lang.String saveDirectory

Last directory used for saving a file.

fileDialog

protected static java.awt.FileDialog fileDialog

AWT file dialog.

fileChooser

protected static javax.swing.JFileChooser fileChooser

Swing file chooser dialog.

defaultOpenTitle

protected static java.lang.String defaultOpenTitle

Default open file dialog title.

defaultSaveTitle

protected static java.lang.String defaultSaveTitle

Default save file dialog title.

allFilesFilter

protected static FileExtensionFilter allFilesFilter

Filter allowed all files through.

OPEN

protected static final int OPEN

Open file dialog type.

See Also:

Constant Field Values

SAVE

protected static final int SAVE

Save file dialog type.

See Also:

Constant Field Values

Constructor Detail

FileDialogs

protected FileDialogs()

Don't allow instantiation but do allow overrides.

Method Detail

createFileDialog

protected static void createFileDialog()

Create AWT file dialog.

createFileChooser

protected static void createFileChooser()

Create Swing file chooser dialog.

doAWTFileDialog

protected static java.lang.String[] doAWTFileDialog(java.lang.String title,
                                                    java.lang.String startDirectory,
                                                    int dialogType)

Display AWT file dialog.

Parameters:

title - Title for open file dialog.

startDirectory - Directory whose contents should be displayed in dialog.

dialogType - Type of dialog. OPEN for opening a file. SAVE for saving a file.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

doSwingFileDialog

protected static java.lang.String[] doSwingFileDialog(java.awt.Window parentWindow,
                                                      java.lang.String title,
                                                      java.lang.String startDirectory,
                                                      int dialogType)

Display Swing file dialog.

Parameters:

parentWindow - Parent window for file dialog.

title - Title for open file dialog.

startDirectory - Directory whose contents should be displayed in dialog.

dialogType - Type of dialog. OPEN for opening a file. SAVE for saving a file.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

doFileDialog

protected static java.lang.String[] doFileDialog(java.awt.Window parentWindow,
                                                 java.lang.String title,
                                                 java.lang.String startDirectory,
                                                 int dialogType)

Display file dialog.

Parameters:

parentWindow - Parent window for dialog. Only used for Swing JFileChooser.

title - Title for open file dialog.

startDirectory - Directory whose contents should be displayed in dialog.

dialogType - Type of dialog. OPEN for opening a file. SAVE for saving a file.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

doFileDialog

protected static java.lang.String[] doFileDialog(java.lang.String title,
                                                 java.lang.String startDirectory,
                                                 int dialogType)

Display file dialog.

Parameters:

title - Title for open file dialog.

startDirectory - Directory whose contents should be displayed in dialog.

dialogType - Type of dialog. OPEN for opening a file. SAVE for saving a file.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

open

public static java.lang.String[] open(java.awt.Window parentWindow,
                                      java.lang.String title)

Display open file dialog.

Parameters:

parentWindow - Parent window for dialog.

title - Title for open file dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

open

public static java.lang.String[] open(java.lang.String title)

Display open file dialog.

Parameters:

title - Title for open file dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

open

public static java.lang.String[] open(java.awt.Window parentWindow)

Display open file dialog.

Parameters:

parentWindow - Parent window for dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

open

public static java.lang.String[] open()

Display open file dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

save

public static java.lang.String[] save(java.awt.Window parentWindow,
                                      java.lang.String title)

Display save file dialog.

Parameters:

parentWindow - Parent window for dialog.

title - Title for open file dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

save

public static java.lang.String[] save(java.awt.Window parentWindow)

Display save file dialog.

Parameters:

parentWindow - Parent window for dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

save

public static java.lang.String[] save(java.lang.String title)

Display save file dialog.

Parameters:

title - Title for open file dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

save

public static java.lang.String[] save()

Display save file dialog.

Returns:

String array with two entries. [0] = file directory [1] = file name Null if no file chosen.

getOpenDirectory

public static java.lang.String getOpenDirectory()

Get last open directory.

Returns:

The last directory used for opening a file. Empty if no directory ever chosen.

setOpenDirectory

public static void setOpenDirectory(java.lang.String directory)

Set last open directory.

Parameters:

directory - The name for the directory to be used to select a file for opening in the next file dialog.

getSaveDirectory

public static java.lang.String getSaveDirectory()

Get last save directory.

Returns:

The last directory used for saving a file. Empty if no directory ever chosen.

setSaveDirectory

public static void setSaveDirectory(java.lang.String directory)

Set last save directory.

Parameters:

directory - The name for the directory to be used to select a file for opening in the next file dialog.

addFileFilter

public static void addFileFilter(FileExtensionFilter fileExtensionFilter)

Add a file filter.

Parameters:

fileExtensionFilter - The file filter.

Note>: File filters DO NOT WORK with the AWT dialogs under Windows!

clearFileFilters

public static void clearFileFilters()

Clear any existing file name filters.

The file dialogs will return to displaying all files.

wrapFilter

protected static javax.swing.filechooser.FileFilter wrapFilter(ExtendedFileNameFilter filter)

Wraps an ExtendedFileNameFilter in a FileFilter.

Parameters:

filter - The filter.

Returns:

The filter wrapped as a FileFilter.