/*

 * Copyright (c) 1997, 2016, 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 javax.swing;

import javax.swing.event.*;

import javax.swing.filechooser.*;

import javax.swing.filechooser.FileFilter;

import javax.swing.plaf.FileChooserUI;

import javax.accessibility.*;

import java.io.*;

import java.util.Vector;

import java.awt.AWTEvent;

import java.awt.Component;

import java.awt.Container;

import java.awt.BorderLayout;

import java.awt.Window;

import java.awt.Dialog;

import java.awt.Frame;

import java.awt.GraphicsEnvironment;

import java.awt.HeadlessException;

import java.awt.EventQueue;

import java.awt.Toolkit;

import java.awt.event.*;

import java.beans.JavaBean;

import java.beans.BeanProperty;

import java.beans.PropertyChangeListener;

import java.beans.PropertyChangeEvent;

import java.lang.ref.WeakReference;

/**

 * <code>JFileChooser</code> provides a simple mechanism for the user to

 * choose a file.

 * For information about using <code>JFileChooser</code>, see

 * <a

 href="http://docs.oracle.com/javase/tutorial/uiswing/components/filechooser.html">How to Use File Choosers</a>,

 * a section in <em>The Java Tutorial</em>.

 *

 * <p>

 *

 * The following code pops up a file chooser for the user's home directory that

 * sees only .jpg and .gif images:

 * <pre>

 *    JFileChooser chooser = new JFileChooser();

 *    FileNameExtensionFilter filter = new FileNameExtensionFilter(

 *        "JPG & GIF Images", "jpg", "gif");

 *    chooser.setFileFilter(filter);

 *    int returnVal = chooser.showOpenDialog(parent);

 *    if(returnVal == JFileChooser.APPROVE_OPTION) {

 *       System.out.println("You chose to open this file: " +

 *            chooser.getSelectedFile().getName());

 *    }

 * </pre>

 * <p>

 * <strong>Warning:</strong> Swing is not thread safe. For more

 * information see <a

 * href="package-summary.html#threading">Swing's Threading

 * Policy</a>.

 *

 * @author Jeff Dinkins

 * @since 1.2

 */

@JavaBean(defaultProperty = "UI", description = "A component which allows for the interactive selection of a file.")

@SwingContainer(false)

@SuppressWarnings("serial") // Superclass is not serializable across versions

public class JFileChooser extends JComponent implements Accessible {

    /**

     * @see #getUIClassID

     * @see #readObject

     */

    private static final String uiClassID = "FileChooserUI";

    // ************************

    // ***** Dialog Types *****

    // ************************

    /**

     * Type value indicating that the <code>JFileChooser</code> supports an

     * "Open" file operation.

     */

    public static final int OPEN_DIALOG = 0;

    /**

     * Type value indicating that the <code>JFileChooser</code> supports a

     * "Save" file operation.

     */

    public static final int SAVE_DIALOG = 1;

    /**

     * Type value indicating that the <code>JFileChooser</code> supports a

     * developer-specified file operation.

     */

    public static final int CUSTOM_DIALOG = 2;

    // ********************************

    // ***** Dialog Return Values *****

    // ********************************

    /**

     * Return value if cancel is chosen.

     */

    public static final int CANCEL_OPTION = 1;

    /**

     * Return value if approve (yes, ok) is chosen.

     */

    public static final int APPROVE_OPTION = 0;

    /**

     * Return value if an error occurred.

     */

    public static final int ERROR_OPTION = -1;

    // **********************************

    // ***** JFileChooser properties *****

    // **********************************

    /** Instruction to display only files. */

    public static final int FILES_ONLY = 0;

    /** Instruction to display only directories. */

    public static final int DIRECTORIES_ONLY = 1;

    /** Instruction to display both files and directories. */

    public static final int FILES_AND_DIRECTORIES = 2;

    /** Instruction to cancel the current selection. */

    public static final String CANCEL_SELECTION = "CancelSelection";

    /**

     * Instruction to approve the current selection

     * (same as pressing yes or ok).

     */

    public static final String APPROVE_SELECTION = "ApproveSelection";

    /** Identifies change in the text on the approve (yes, ok) button. */

    public static final String APPROVE_BUTTON_TEXT_CHANGED_PROPERTY = "ApproveButtonTextChangedProperty";

    /**

     * Identifies change in the tooltip text for the approve (yes, ok)

     * button.

     */

    public static final String APPROVE_BUTTON_TOOL_TIP_TEXT_CHANGED_PROPERTY = "ApproveButtonToolTipTextChangedProperty";

    /** Identifies change in the mnemonic for the approve (yes, ok) button. */

    public static final String APPROVE_BUTTON_MNEMONIC_CHANGED_PROPERTY = "ApproveButtonMnemonicChangedProperty";

    /** Instruction to display the control buttons. */

    public static final String CONTROL_BUTTONS_ARE_SHOWN_CHANGED_PROPERTY = "ControlButtonsAreShownChangedProperty";

    /** Identifies user's directory change. */

    public static final String DIRECTORY_CHANGED_PROPERTY = "directoryChanged";

    /** Identifies change in user's single-file selection. */

    public static final String SELECTED_FILE_CHANGED_PROPERTY = "SelectedFileChangedProperty";

    /** Identifies change in user's multiple-file selection. */

    public static final String SELECTED_FILES_CHANGED_PROPERTY = "SelectedFilesChangedProperty";

    /** Enables multiple-file selections. */

    public static final String MULTI_SELECTION_ENABLED_CHANGED_PROPERTY = "MultiSelectionEnabledChangedProperty";

    /**

     * Says that a different object is being used to find available drives

     * on the system.

     */

    public static final String FILE_SYSTEM_VIEW_CHANGED_PROPERTY = "FileSystemViewChanged";

    /**

     * Says that a different object is being used to retrieve file

     * information.

     */

    public static final String FILE_VIEW_CHANGED_PROPERTY = "fileViewChanged";

    /** Identifies a change in the display-hidden-files property. */

    public static final String FILE_HIDING_CHANGED_PROPERTY = "FileHidingChanged";

    /** User changed the kind of files to display. */

    public static final String FILE_FILTER_CHANGED_PROPERTY = "fileFilterChanged";

    /**

     * Identifies a change in the kind of selection (single,

     * multiple, etc.).

     */

    public static final String FILE_SELECTION_MODE_CHANGED_PROPERTY = "fileSelectionChanged";

    /**

     * Says that a different accessory component is in use

     * (for example, to preview files).

     */

    public static final String ACCESSORY_CHANGED_PROPERTY = "AccessoryChangedProperty";

    /**

     * Identifies whether a the AcceptAllFileFilter is used or not.

     */

    public static final String ACCEPT_ALL_FILE_FILTER_USED_CHANGED_PROPERTY = "acceptAllFileFilterUsedChanged";

    /** Identifies a change in the dialog title. */

    public static final String DIALOG_TITLE_CHANGED_PROPERTY = "DialogTitleChangedProperty";

    /**

     * Identifies a change in the type of files displayed (files only,

     * directories only, or both files and directories).

     */

    public static final String DIALOG_TYPE_CHANGED_PROPERTY = "DialogTypeChangedProperty";

    /**

     * Identifies a change in the list of predefined file filters

     * the user can choose from.

     */

    public static final String CHOOSABLE_FILE_FILTER_CHANGED_PROPERTY = "ChoosableFileFilterChangedProperty";

    // ******************************

    // ***** instance variables *****

    // ******************************

    private String dialogTitle = null;

    private String approveButtonText = null;

    private String approveButtonToolTipText = null;

    private int approveButtonMnemonic = 0;

    private Vector<FileFilter> filters = new Vector<FileFilter>(5);

    private JDialog dialog = null;

    private int dialogType = OPEN_DIALOG;

    private int returnValue = ERROR_OPTION;

    private JComponent accessory = null;

    private FileView fileView = null;

    private boolean controlsShown = true;

    private boolean useFileHiding = true;

    private static final String SHOW_HIDDEN_PROP = "awt.file.showHiddenFiles";

    // Listens to changes in the native setting for showing hidden files.

    // The Listener is removed and the native setting is ignored if

    // setFileHidingEnabled() is ever called.

    private transient PropertyChangeListener showFilesListener = null;

    private int fileSelectionMode = FILES_ONLY;

    private boolean multiSelectionEnabled = false;

    private boolean useAcceptAllFileFilter = true;

    private boolean dragEnabled = false;

    private FileFilter fileFilter = null;

    private FileSystemView fileSystemView = null;

    private File currentDirectory = null;

    private File selectedFile = null;

    private File[] selectedFiles;

    // *************************************

    // ***** JFileChooser Constructors *****

    // *************************************

    /**

     * Constructs a <code>JFileChooser</code> pointing to the user's

     * default directory. This default depends on the operating system.

     * It is typically the "My Documents" folder on Windows, and the

     * user's home directory on Unix.

     */

    public JFileChooser() {

        this((File) null, (FileSystemView) null);

    }

    /**

     * Constructs a <code>JFileChooser</code> using the given path.

     * Passing in a <code>null</code>

     * string causes the file chooser to point to the user's default directory.

     * This default depends on the operating system. It is

     * typically the "My Documents" folder on Windows, and the user's

     * home directory on Unix.

     *

     * @param currentDirectoryPath  a <code>String</code> giving the path

     *                          to a file or directory

     */

    public JFileChooser(String currentDirectoryPath) {

        this(currentDirectoryPath, (FileSystemView) null);

    }

    /**

     * Constructs a <code>JFileChooser</code> using the given <code>File</code>

     * as the path. Passing in a <code>null</code> file

     * causes the file chooser to point to the user's default directory.

     * This default depends on the operating system. It is

     * typically the "My Documents" folder on Windows, and the user's

     * home directory on Unix.

     *

     * @param currentDirectory  a <code>File</code> object specifying

     *                          the path to a file or directory

     */

    public JFileChooser(File currentDirectory) {

        this(currentDirectory, (FileSystemView) null);

    }

    /**

     * Constructs a <code>JFileChooser</code> using the given

     * <code>FileSystemView</code>.

     *

     * @param fsv a {@code FileSystemView}

     */

    public JFileChooser(FileSystemView fsv) {

        this((File) null, fsv);

    }

    /**

     * Constructs a <code>JFileChooser</code> using the given current directory

     * and <code>FileSystemView</code>.

     *

     * @param currentDirectory a {@code File} object specifying the path to a

     *                         file or directory

     * @param fsv a {@code FileSystemView}

     */

    public JFileChooser(File currentDirectory, FileSystemView fsv) {

        setup(fsv);

        setCurrentDirectory(currentDirectory);

    }

    /**

     * Constructs a <code>JFileChooser</code> using the given current directory

     * path and <code>FileSystemView</code>.

     *

     * @param currentDirectoryPath a {@code String} specifying the path to a file

     *                             or directory

     * @param fsv a {@code FileSystemView}

     */

    public JFileChooser(String currentDirectoryPath, FileSystemView fsv) {

        setup(fsv);

        if(currentDirectoryPath == null) {

            setCurrentDirectory(null);

        } else {

            setCurrentDirectory(fileSystemView.createFileObject(currentDirectoryPath));

        }

    }

    /**

     * Performs common constructor initialization and setup.

     *

     * @param view the {@code FileSystemView} used for setup

     */

    protected void setup(FileSystemView view) {

        installShowFilesListener();

        installHierarchyListener();

        if(view == null) {

            view = FileSystemView.getFileSystemView();

        }

        setFileSystemView(view);

        updateUI();

        if(isAcceptAllFileFilterUsed()) {

            setFileFilter(getAcceptAllFileFilter());

        }

        enableEvents(AWTEvent.MOUSE_EVENT_MASK);

    }

    private void installHierarchyListener() {

        addHierarchyListener(new FCHierarchyListener());

    }

    private void installShowFilesListener() {

        // Track native setting for showing hidden files

        Toolkit tk = Toolkit.getDefaultToolkit();

        Object showHiddenProperty = tk.getDesktopProperty(SHOW_HIDDEN_PROP);

        if (showHiddenProperty instanceof Boolean) {

            useFileHiding = !((Boolean)showHiddenProperty).booleanValue();

            showFilesListener = new WeakPCL(this);

            tk.addPropertyChangeListener(SHOW_HIDDEN_PROP, showFilesListener);

        }

    }

    /**

     * Sets the <code>dragEnabled</code> property,

     * which must be <code>true</code> to enable

     * automatic drag handling (the first part of drag and drop)

     * on this component.

     * The <code>transferHandler</code> property needs to be set

     * to a non-<code>null</code> value for the drag to do

     * anything.  The default value of the <code>dragEnabled</code>

     * property

     * is <code>false</code>.

     *

     * <p>

     *

     * When automatic drag handling is enabled,

     * most look and feels begin a drag-and-drop operation

     * whenever the user presses the mouse button over an item

     * and then moves the mouse a few pixels.

     * Setting this property to <code>true</code>

     * can therefore have a subtle effect on

     * how selections behave.

     *

     * <p>

     *

     * Some look and feels might not support automatic drag and drop;

     * they will ignore this property.  You can work around such

     * look and feels by modifying the component

     * to directly call the <code>exportAsDrag</code> method of a

     * <code>TransferHandler</code>.

     *

     * @param b the value to set the <code>dragEnabled</code> property to

     * @exception HeadlessException if

     *            <code>b</code> is <code>true</code> and

     *            <code>GraphicsEnvironment.isHeadless()</code>

     *            returns <code>true</code>

     * @see java.awt.GraphicsEnvironment#isHeadless

     * @see #getDragEnabled

     * @see #setTransferHandler

     * @see TransferHandler

     * @since 1.4

     */

    @BeanProperty(bound = false, description

            = "determines whether automatic drag handling is enabled")

    public void setDragEnabled(boolean b) {

        checkDragEnabled(b);

        dragEnabled = b;

    }

    private static void checkDragEnabled(boolean b) {

        if (b && GraphicsEnvironment.isHeadless()) {

            throw new HeadlessException();

        }

    }

    /**

     * Gets the value of the <code>dragEnabled</code> property.

     *

     * @return  the value of the <code>dragEnabled</code> property

     * @see #setDragEnabled

     * @since 1.4

     */

    public boolean getDragEnabled() {

        return dragEnabled;

    }

    // *****************************

    // ****** File Operations ******

    // *****************************

    /**

     * Returns the selected file. This can be set either by the

     * programmer via <code>setSelectedFile</code> or by a user action, such as

     * either typing the filename into the UI or selecting the

     * file from a list in the UI.

     *

     * @see #setSelectedFile

     * @return the selected file

     */

    public File getSelectedFile() {

        return selectedFile;

    }

    /**

     * Sets the selected file. If the file's parent directory is

     * not the current directory, changes the current directory

     * to be the file's parent directory.

     *

     * @see #getSelectedFile

     *

     * @param file the selected file

     */

    @BeanProperty(preferred = true)

    public void setSelectedFile(File file) {

        File oldValue = selectedFile;

        selectedFile = file;

        if(selectedFile != null) {

            if (file.isAbsolute() && !getFileSystemView().isParent(getCurrentDirectory(), selectedFile)) {

                setCurrentDirectory(selectedFile.getParentFile());

            }

            if (!isMultiSelectionEnabled() || selectedFiles == null || selectedFiles.length == 1) {

                ensureFileIsVisible(selectedFile);

            }

        }

        firePropertyChange(SELECTED_FILE_CHANGED_PROPERTY, oldValue, selectedFile);

    }

    /**

     * Returns a list of selected files if the file chooser is

     * set to allow multiple selection.

     *

     * @return an array of selected {@code File}s

     */

    public File[] getSelectedFiles() {

        if(selectedFiles == null) {

            return new File[0];

        } else {

            return selectedFiles.clone();

        }

    }