Back to index...

	/*
	* Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package java.awt;

	import java.awt.peer.FileDialogPeer;
	import java.io.FilenameFilter;
	import java.io.IOException;
	import java.io.ObjectInputStream;
	import java.io.File;
	import sun.awt.AWTAccessor;

	/**
	* The <code>FileDialog</code> class displays a dialog window
	* from which the user can select a file.
	* <p>
	* Since it is a modal dialog, when the application calls
	* its <code>show</code> method to display the dialog,
	* it blocks the rest of the application until the user has
	* chosen a file.
	*
	* @see Window#show
	*
	* @author Sami Shaio
	* @author Arthur van Hoff
	* @since JDK1.0
	*/
	public class FileDialog extends Dialog {

	/**
	* This constant value indicates that the purpose of the file
	* dialog window is to locate a file from which to read.
	*/
	public static final int LOAD = 0;

	/**
	* This constant value indicates that the purpose of the file
	* dialog window is to locate a file to which to write.
	*/
	public static final int SAVE = 1;

	/*
	* There are two <code>FileDialog</code> modes: <code>LOAD</code> and
	* <code>SAVE</code>.
	* This integer will represent one or the other.
	* If the mode is not specified it will default to <code>LOAD</code>.
	*
	* @serial
	* @see getMode()
	* @see setMode()
	* @see java.awt.FileDialog#LOAD
	* @see java.awt.FileDialog#SAVE
	*/
	int mode;

	/*
	* The string specifying the directory to display
	* in the file dialog. This variable may be <code>null</code>.
	*
	* @serial
	* @see getDirectory()
	* @see setDirectory()
	*/
	String dir;

	/*
	* The string specifying the initial value of the
	* filename text field in the file dialog.
	* This variable may be <code>null</code>.
	*
	* @serial
	* @see getFile()
	* @see setFile()
	*/
	String file;

	/**
	* Contains the File instances for all the files that the user selects.
	*
	* @serial
	* @see #getFiles
	* @since 1.7
	*/
	private File[] files;

	/**
	* Represents whether the file dialog allows the multiple file selection.
	*
	* @serial
	* @see #setMultipleMode
	* @see #isMultipleMode
	* @since 1.7
	*/
	private boolean multipleMode = false;

	/*
	* The filter used as the file dialog's filename filter.
	* The file dialog will only be displaying files whose
	* names are accepted by this filter.
	* This variable may be <code>null</code>.
	*
	* @serial
	* @see #getFilenameFilter()
	* @see #setFilenameFilter()
	* @see FileNameFilter
	*/
	FilenameFilter filter;

	private static final String base = "filedlg";
	private static int nameCounter = 0;

	/*
	* JDK 1.1 serialVersionUID
	*/
	private static final long serialVersionUID = 5035145889651310422L;


	static {
	/* ensure that the necessary native libraries are loaded */
	Toolkit.loadLibraries();
	if (!GraphicsEnvironment.isHeadless()) {
	initIDs();
	}
	}

	static {
	AWTAccessor.setFileDialogAccessor(
	new AWTAccessor.FileDialogAccessor() {
	public void setFiles(FileDialog fileDialog, File files[]) {
	fileDialog.setFiles(files);
	}
	public void setFile(FileDialog fileDialog, String file) {
	fileDialog.file = ("".equals(file)) ? null : file;
	}
	public void setDirectory(FileDialog fileDialog, String directory) {
	fileDialog.dir = ("".equals(directory)) ? null : directory;
	}
	public boolean isMultipleMode(FileDialog fileDialog) {
	synchronized (fileDialog.getObjectLock()) {
	return fileDialog.multipleMode;
	}
	}
	});
	}

	/**
	* Initialize JNI field and method IDs for fields that may be
	accessed from C.
	*/
	private static native void initIDs();

	/**
	* Creates a file dialog for loading a file. The title of the
	* file dialog is initially empty. This is a convenience method for
	* <code>FileDialog(parent, "", LOAD)</code>.
	*
	* @param parent the owner of the dialog
	* @since JDK1.1
	*/
	public FileDialog(Frame parent) {
	this(parent, "", LOAD);
	}

	/**
	* 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
	* <code>FileDialog(parent, title, LOAD)</code>.
	*
	* @param parent the owner of the dialog
	* @param title the title of the dialog
	*/
	public FileDialog(Frame parent, String title) {
	this(parent, title, LOAD);
	}

	/**
	* Creates a file dialog window with the specified title for loading
	* or saving a file.
	* <p>
	* If the value of <code>mode</code> is <code>LOAD</code>, then the
	* file dialog is finding a file to read, and the files shown are those
	* in the current directory. If the value of
	* <code>mode</code> is <code>SAVE</code>, the file dialog is finding
	* a place to write a file.
	*
	* @param parent the owner of the dialog
	* @param title the title of the dialog
	* @param mode the mode of the dialog; either
	* <code>FileDialog.LOAD</code> or <code>FileDialog.SAVE</code>
	* @exception IllegalArgumentException if an illegal file
	* dialog mode is supplied
	* @see java.awt.FileDialog#LOAD
	* @see java.awt.FileDialog#SAVE
	*/
	public FileDialog(Frame parent, String title, int mode) {
	super(parent, title, true);
	this.setMode(mode);
	setLayout(null);
	}

	/**
	* Creates a file dialog for loading a file. The title of the
	* file dialog is initially empty. This is a convenience method for
	* <code>FileDialog(parent, "", LOAD)</code>.
	*
	* @param parent the owner of the dialog
	* @exception java.lang.IllegalArgumentException if the <code>parent</code>'s
	* <code>GraphicsConfiguration</code>
	* is not from a screen device;
	* @exception java.lang.IllegalArgumentException if <code>parent</code>
	* is <code>null</code>; this exception is always thrown when
	* <code>GraphicsEnvironment.isHeadless</code>
	* returns <code>true</code>
	* @see java.awt.GraphicsEnvironment#isHeadless
	* @since 1.5
	*/
	public FileDialog(Dialog parent) {
	this(parent, "", LOAD);
	}

	/**
	* 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
	* <code>FileDialog(parent, title, LOAD)</code>.
	*
	* @param parent the owner of the dialog
	* @param title the title of the dialog; a <code>null</code> value
	* will be accepted without causing a
	* <code>NullPointerException</code> to be thrown
	* @exception java.lang.IllegalArgumentException if the <code>parent</code>'s
	* <code>GraphicsConfiguration</code>
	* is not from a screen device;
	* @exception java.lang.IllegalArgumentException if <code>parent</code>
	* is <code>null</code>; this exception is always thrown when
	* <code>GraphicsEnvironment.isHeadless</code>
	* returns <code>true</code>
	* @see java.awt.GraphicsEnvironment#isHeadless
	* @since 1.5
	*/
	public FileDialog(Dialog parent, String title) {
	this(parent, title, LOAD);
	}

	/**
	* Creates a file dialog window with the specified title for loading
	* or saving a file.
	* <p>
	* If the value of <code>mode</code> is <code>LOAD</code>, then the
	* file dialog is finding a file to read, and the files shown are those
	* in the current directory. If the value of
	* <code>mode</code> is <code>SAVE</code>, the file dialog is finding
	* a place to write a file.
	*
	* @param parent the owner of the dialog
	* @param title the title of the dialog; a <code>null</code> value
	* will be accepted without causing a
	* <code>NullPointerException</code> to be thrown
	* @param mode the mode of the dialog; either
	* <code>FileDialog.LOAD</code> or <code>FileDialog.SAVE</code>
	* @exception java.lang.IllegalArgumentException if an illegal
	* file dialog mode is supplied;
	* @exception java.lang.IllegalArgumentException if the <code>parent</code>'s
	* <code>GraphicsConfiguration</code>
	* is not from a screen device;
	* @exception java.lang.IllegalArgumentException if <code>parent</code>
	* is <code>null</code>; this exception is always thrown when
	* <code>GraphicsEnvironment.isHeadless</code>
	* returns <code>true</code>
	* @see java.awt.GraphicsEnvironment#isHeadless
	* @see java.awt.FileDialog#LOAD
	* @see java.awt.FileDialog#SAVE
	* @since 1.5
	*/
	public FileDialog(Dialog parent, String title, int mode) {
	super(parent, title, true);
	this.setMode(mode);
	setLayout(null);
	}

	/**
	* Constructs a name for this component. Called by <code>getName()</code>
	* when the name is <code>null</code>.
	*/
	String constructComponentName() {
	synchronized (FileDialog.class) {
	return base + nameCounter++;
	}
	}

	/**
	* Creates the file dialog's peer. The peer allows us to change the look
	* of the file dialog without changing its functionality.
	*/
	public void addNotify() {
	synchronized(getTreeLock()) {
	if (parent != null && parent.getPeer() == null) {
	parent.addNotify();
	}
	if (peer == null)
	peer = getToolkit().createFileDialog(this);
	super.addNotify();
	}
	}

	/**
	* Indicates whether this file dialog box is for loading from a file
	* or for saving to a file.
	*
	* @return the mode of this file dialog window, either
	* <code>FileDialog.LOAD</code> or
	* <code>FileDialog.SAVE</code>
	* @see java.awt.FileDialog#LOAD
	* @see java.awt.FileDialog#SAVE
	* @see java.awt.FileDialog#setMode
	*/
	public int getMode() {
	return mode;
	}

	/**
	* Sets the mode of the file dialog. If <code>mode</code> is not
	* a legal value, an exception will be thrown and <code>mode</code>
	* will not be set.
	*
	* @param mode the mode for this file dialog, either
	* <code>FileDialog.LOAD</code> or
	* <code>FileDialog.SAVE</code>
	* @see java.awt.FileDialog#LOAD
	* @see java.awt.FileDialog#SAVE
	* @see java.awt.FileDialog#getMode
	* @exception IllegalArgumentException if an illegal file
	* dialog mode is supplied
	* @since JDK1.1
	*/
	public void setMode(int mode) {
	switch (mode) {
	case LOAD:
	case SAVE:
	this.mode = mode;
	break;
	default:
	throw new IllegalArgumentException("illegal file dialog mode");
	}
	}

	/**
	* Gets the directory of this file dialog.
	*
	* @return the (potentially <code>null</code> or invalid)
	* directory of this <code>FileDialog</code>
	* @see java.awt.FileDialog#setDirectory
	*/
	public String getDirectory() {
	return dir;
	}

	/**
	* Sets the directory of this file dialog window to be the
	* specified directory. Specifying a <code>null</code> 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, <code>getDirectory()</code>
	* will return the value passed into this method.
	* <p>
	* Specifying "" as the directory is exactly equivalent to
	* specifying <code>null</code> as the directory.
	*
	* @param dir the specified directory
	* @see java.awt.FileDialog#getDirectory
	*/
	public void setDirectory(String dir) {
	this.dir = (dir != null && dir.equals("")) ? null : dir;
	FileDialogPeer peer = (FileDialogPeer)this.peer;
	if (peer != null) {
	peer.setDirectory(this.dir);
	}
	}

	/**
	* Gets the selected file of this file dialog. If the user
	* selected <code>CANCEL</code>, the returned file is <code>null</code>.
	*
	* @return the currently selected file of this file dialog window,
	* or <code>null</code> if none is selected
	* @see java.awt.FileDialog#setFile
	*/
	public String getFile() {
	return file;
	}

	/**
	* Returns files that the user selects.
	* <p>
	* If the user cancels the file dialog,
	* then the method returns an empty array.
	*
	* @return files that the user selects or an empty array
	* if the user cancels the file dialog.
	* @see #setFile(String)
	* @see #getFile
	* @since 1.7
	*/
	public File[] getFiles() {
	synchronized (getObjectLock()) {
	if (files != null) {
	return files.clone();
	} else {
	return new File[0];
	}
	}
	}

	/**
	* Stores the names of all the files that the user selects.
	*
	* Note that the method is private and it's intended to be used
	* by the peers through the AWTAccessor API.
	*
	* @param files the array that contains the short names of
	* all the files that the user selects.
	*
	* @see #getFiles
	* @since 1.7
	*/
	private void setFiles(File files[]) {
	synchronized (getObjectLock()) {
	this.files = files;
	}
	}

	/**
	* 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.
	* <p>
	* When the dialog is shown, the specified file is selected. The kind of
	* selection depends on the file existence, the dialog type, and the native
	* platform. E.g., the file could be highlighted in the file list, or a
	* file name editbox could be populated with the file name.
	* <p>
	* This method accepts either a full file path, or a file name with an
	* extension if used together with the {@code setDirectory} method.
	* <p>
	* Specifying "" as the file is exactly equivalent to specifying
	* {@code null} as the file.
	*
	* @param file the file being set
	* @see #getFile
	* @see #getFiles
	*/
	public void setFile(String file) {
	this.file = (file != null && file.equals("")) ? null : file;
	FileDialogPeer peer = (FileDialogPeer)this.peer;
	if (peer != null) {
	peer.setFile(this.file);
	}
	}

	/**
	* Enables or disables multiple file selection for the file dialog.
	*
	* @param enable if {@code true}, multiple file selection is enabled;
	* {@code false} - disabled.
	* @see #isMultipleMode
	* @since 1.7
	*/
	public void setMultipleMode(boolean enable) {
	synchronized (getObjectLock()) {
	this.multipleMode = enable;
	}
	}

	/**
	* Returns whether the file dialog allows the multiple file selection.
	*
	* @return {@code true} if the file dialog allows the multiple
	* file selection; {@code false} otherwise.
	* @see #setMultipleMode
	* @since 1.7
	*/
	public boolean isMultipleMode() {
	synchronized (getObjectLock()) {
	return multipleMode;
	}
	}

	/**
	* 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 Microsoft Windows.
	*
	* @return this file dialog's filename filter
	* @see java.io.FilenameFilter
	* @see java.awt.FileDialog#setFilenameFilter
	*/
	public FilenameFilter getFilenameFilter() {
	return 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 Microsoft Windows.
	*
	* @param filter the specified filter
	* @see java.io.FilenameFilter
	* @see java.awt.FileDialog#getFilenameFilter
	*/
	public synchronized void setFilenameFilter(FilenameFilter filter) {
	this.filter = filter;
	FileDialogPeer peer = (FileDialogPeer)this.peer;
	if (peer != null) {
	peer.setFilenameFilter(filter);
	}
	}

	/**
	* Reads the <code>ObjectInputStream</code> and performs
	* a backwards compatibility check by converting
	* either a <code>dir</code> or a <code>file</code>
	* equal to an empty string to <code>null</code>.
	*
	* @param s the <code>ObjectInputStream</code> to read
	*/
	private void readObject(ObjectInputStream s)
	throws ClassNotFoundException, IOException
	{
	s.defaultReadObject();

	// 1.1 Compatibility: "" is not converted to null in 1.1
	if (dir != null && dir.equals("")) {
	dir = null;
	}
	if (file != null && file.equals("")) {
	file = null;
	}
	}

	/**
	* Returns a string representing the state of this <code>FileDialog</code>
	* 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
	* <code>null</code>.
	*
	* @return the parameter string of this file dialog window
	*/
	protected String paramString() {
	String str = super.paramString();
	str += ",dir= " + dir;
	str += ",file= " + file;
	return str + ((mode == LOAD) ? ",load" : ",save");
	}

	boolean postsOldMouseEvents() {
	return false;
	}
	}

Back to index...