FileDialog

java.awt
Class FileDialog

java.lang.Object
  java.awt.Component
      java.awt.Container
          java.awt.Window
              java.awt.Dialog
                  java.awt.FileDialog

All Implemented Interfaces:: Accessible, ImageObserver, MenuContainer, Serializable

public class FileDialog
extends Dialog

The FileDialog class displays a dialog window from which the user can select a file.

Since it is a modal dialog, when the application calls its show method to display the dialog, it blocks the rest of the application until the user has chosen a file.

Since:: JDK1.0
See Also:: Window.show(), Serialized Form

Field Summary
`static int`	`LOAD` This constant value indicates that the purpose of the file dialog window is to locate a file from which to read.
`static int`	`SAVE` This constant value indicates that the purpose of the file dialog window is to locate a file to which to write.

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT,


      CENTER_ALIGNMENT,


      LEFT_ALIGNMENT,


      RIGHT_ALIGNMENT,


      TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT,


      ALLBITS,


      ERROR,


      FRAMEBITS,


      HEIGHT,


      PROPERTIES,


      SOMEBITS,


      WIDTH

Constructor Summary
`FileDialog(Frame parent)` Creates a file dialog for loading a file.
`FileDialog(Frame parent, String title)` Creates a file dialog window with the specified title for loading a file.
`FileDialog(Frame parent, String title, int mode)` Creates a file dialog window with the specified title for loading or saving a file.

Method Summary
`void`	`addNotify()` Creates the file dialog's peer.
`String`	`getDirectory()` Gets the directory of this file dialog.
`String`	`getFile()` Gets the selected file of this file dialog.
`FilenameFilter`	`getFilenameFilter()` Determines this file dialog's filename filter.
`int`	`getMode()` Indicates whether this file dialog box is for loading from a file or for saving to a file.
`protected String`	`paramString()` Returns a string representing the state of this `FileDialog` window.
`void`	`setDirectory(String dir)` Sets the directory of this file dialog window to be the specified directory.
`void`	`setFile(String file)` Sets the selected file for this file dialog window to be the specified file.
`void`	`setFilenameFilter(FilenameFilter filter)` Sets the filename filter for this file dialog window to the specified filter.
`void`	`setMode(int mode)` Sets the mode of the file dialog.

Methods inherited from class java.awt.Dialog

dispose,


      getAccessibleContext,


      getTitle,


      hide,


      isModal,


      isResizable,


      isUndecorated,


      setModal,


      setResizable,


      setTitle,


      setUndecorated,


      show

Methods inherited from class java.awt.Window

addPropertyChangeListener,


      addPropertyChangeListener,


      addWindowFocusListener,


      addWindowListener,


      addWindowStateListener,


      applyResourceBundle,


      applyResourceBundle,


      createBufferStrategy,


      createBufferStrategy,


      finalize,


      getBufferStrategy,


      getFocusableWindowState,


      getFocusCycleRootAncestor,


      getFocusOwner,


      getFocusTraversalKeys,


      getGraphicsConfiguration,


      getInputContext,


      getListeners,


      getLocale,


      getMostRecentFocusOwner,


      getOwnedWindows,


      getOwner,


      getToolkit,


      getWarningString,


      getWindowFocusListeners,


      getWindowListeners,


      getWindowStateListeners,


      isActive,


      isFocusableWindow,


      isFocusCycleRoot,


      isFocused,


      isShowing,


      pack,


      postEvent,


      processEvent,


      processWindowEvent,


      processWindowFocusEvent,


      processWindowStateEvent,


      removeWindowFocusListener,


      removeWindowListener,


      removeWindowStateListener,


      setCursor,


      setFocusableWindowState,


      setFocusCycleRoot,


      setLocationRelativeTo,


      toBack,


      toFront

Field Detail

LOAD

public static final int LOAD

This constant value indicates that the purpose of the file dialog window is to locate a file from which to read.

See Also:: Constant Field Values

SAVE

public static final int SAVE

This constant value indicates that the purpose of the file dialog window is to locate a file to which to write.

See Also:: Constant Field Values

Constructor Detail

FileDialog

public FileDialog(Frame parent)

Creates a file dialog for loading a file. The title of the file dialog is initially empty. This is a convenience method for FileDialog(parent, "", LOAD).
Parameters:: parent - the owner of the dialog
Since:: JDK1.1

FileDialog

public FileDialog(Frame parent,
                  String title)

Creates a file dialog window with the specified title for loading a file. The files shown are those in the current directory. This is a convenience method for FileDialog(parent, title, LOAD).
Parameters:: parent - the owner of the dialog; title - the title of the dialog

FileDialog

public FileDialog(Frame parent,
                  String title,
                  int mode)

Creates a file dialog window with the specified title for loading or saving a file.

If the value of mode is LOAD, then the file dialog is finding a file to read, and the files shown are those in the current directory. If the value of mode is SAVE, the file dialog is finding a place to write a file.

Parameters:

parent - the owner of the dialog

title - the title of the dialog

mode - the mode of the dialog; either FileDialog.LOAD or FileDialog.SAVE

Throws:

IllegalArgumentException - if an illegal file dialog mode is supplied

See Also:

LOAD, SAVE

Method Detail

addNotify

public void addNotify()

Creates the file dialog's peer. The peer allows us to change the look of the file dialog without changing its functionality.

Overrides:: addNotify in class Dialog

See Also:: Component.isDisplayable(), Container.removeNotify()

getMode

public int getMode()

Indicates whether this file dialog box is for loading from a file or for saving to a file.

Returns:: the mode of this file dialog window, either FileDialog.LOAD or FileDialog.SAVE
See Also:: LOAD, SAVE, setMode(int)

setMode

public void setMode(int mode)

Sets the mode of the file dialog. If mode is not a legal value, an exception will be thrown and mode will not be set.

Parameters:: mode - the mode for this file dialog, either FileDialog.LOAD or FileDialog.SAVE
Throws:: IllegalArgumentException - if an illegal file dialog mode is supplied
Since:: JDK1.1
See Also:: LOAD, SAVE, getMode()

getDirectory

public String getDirectory()

Gets the directory of this file dialog.

Returns:: the (potentially null or invalid) directory of this FileDialog
See Also:: setDirectory(java.lang.String)

setDirectory

public void setDirectory(String dir)

Sets the directory of this file dialog window to be the specified directory. Specifying a null or an invalid directory implies an implementation-defined default. This default will not be realized, however, until the user has selected a file. Until this point, getDirectory() will return the value passed into this method.

Specifying "" as the directory is exactly equivalent to specifying null as the directory.

Parameters:: dir - the specified directory
See Also:: getDirectory()

getFile

public String getFile()

Gets the selected file of this file dialog. If the user selected CANCEL, the returned file is null.

Returns:: the currently selected file of this file dialog window, or null if none is selected
See Also:: setFile(java.lang.String)

setFile

public void setFile(String file)

Sets the selected file for this file dialog window to be the specified file. This file becomes the default file if it is set before the file dialog window is first shown.

Specifying "" as the file is exactly equivalent to specifying null as the file.

Parameters:: file - the file being set
See Also:: getFile()

getFilenameFilter

public FilenameFilter getFilenameFilter()

Determines this file dialog's filename filter. A filename filter allows the user to specify which files appear in the file dialog window. Filename filters do not function in Sun's reference implementation for Windows 95, 98, or NT 4.0.

Returns:: this file dialog's filename filter
See Also:: FilenameFilter, setFilenameFilter(java.io.FilenameFilter)

setFilenameFilter

public void setFilenameFilter(FilenameFilter filter)

Sets the filename filter for this file dialog window to the specified filter. Filename filters do not function in Sun's reference implementation for Windows 95, 98, or NT 4.0.

Parameters:: filter - the specified filter
See Also:: FilenameFilter, getFilenameFilter()

paramString

protected String paramString()

Returns a string representing the state of this FileDialog window. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.

Overrides:: paramString in class Dialog

Returns:: the parameter string of this file dialog window

java.awt Class FileDialog

LOAD

SAVE

FileDialog

FileDialog

FileDialog

addNotify

getMode

setMode

getDirectory

setDirectory

getFile

setFile

getFilenameFilter

setFilenameFilter

paramString

java.awt
Class FileDialog