/*

 * 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.filechooser;

import java.awt.Image;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.lang.ref.WeakReference;

import java.security.AccessController;

import java.security.PrivilegedAction;

/**

 * FileSystemView is JFileChooser's gateway to the

 * file system. Since the JDK1.1 File API doesn't allow

 * access to such information as root partitions, file type

 * information, or hidden file bits, this class is designed

 * to intuit as much OS-specific file system information as

 * possible.

 *

 * <p>

 *

 * Java Licensees may want to provide a different implementation of

 * FileSystemView to better handle a given operating system.

 *

 * @author Jeff Dinkins

 */

// PENDING(jeff) - need to provide a specification for

// how Mac/OS2/BeOS/etc file systems can modify FileSystemView

// to handle their particular type of file system.

public abstract class FileSystemView {

    static FileSystemView windowsFileSystemView = null;

    static FileSystemView unixFileSystemView = null;

    //static FileSystemView macFileSystemView = null;

    static FileSystemView genericFileSystemView = null;

    private boolean useSystemExtensionHiding =

            UIManager.getDefaults().getBoolean("FileChooser.useSystemExtensionHiding");

    /**

     * Returns the file system view.

     * @return the file system view

     */

    public static FileSystemView getFileSystemView() {

        if(File.separatorChar == '\\') {

            if(windowsFileSystemView == null) {

                windowsFileSystemView = new WindowsFileSystemView();

            }

            return windowsFileSystemView;

        }

        if(File.separatorChar == '/') {

            if(unixFileSystemView == null) {

                unixFileSystemView = new UnixFileSystemView();

            }

            return unixFileSystemView;

        }

        // if(File.separatorChar == ':') {

        //    if(macFileSystemView == null) {

        //      macFileSystemView = new MacFileSystemView();

        //    }

        //    return macFileSystemView;

        //}

        if(genericFileSystemView == null) {

            genericFileSystemView = new GenericFileSystemView();

        }

        return genericFileSystemView;

    }

    /**

     * Constructs a FileSystemView.

     */

    public FileSystemView() {

        });

    }

    /**

     * Determines if the given file is a root in the navigable tree(s).

     * Examples: Windows 98 has one root, the Desktop folder. DOS has one root

     * per drive letter, <code>C:\</code>, <code>D:\</code>, etc. Unix has one root,

     * the <code>"/"</code> directory.

     *

     * The default implementation gets information from the <code>ShellFolder</code> class.

     *

     * @param f a <code>File</code> object representing a directory

     * @return <code>true</code> if <code>f</code> is a root in the navigable tree.

     * @see #isFileSystemRoot

     */

    public boolean isRoot(File f) {

        if (f == null || !f.isAbsolute()) {

            return false;

        }

        File[] roots = getRoots();

        for (File root : roots) {

            if (root.equals(f)) {

                return true;

            }

        }

        return false;

    }

    /**

     * Returns true if the file (directory) can be visited.

     * Returns false if the directory cannot be traversed.

     *

     * @param f the <code>File</code>

     * @return <code>true</code> if the file/directory can be traversed, otherwise <code>false</code>

     * @see JFileChooser#isTraversable

     * @see FileView#isTraversable

     * @since 1.4

     */

    public Boolean isTraversable(File f) {

        return Boolean.valueOf(f.isDirectory());

    }

    /**

     * Name of a file, directory, or folder as it would be displayed in

     * a system file browser. Example from Windows: the "M:\" directory

     * displays as "CD-ROM (M:)"

     *

     * The default implementation gets information from the ShellFolder class.

     *

     * @param f a <code>File</code> object

     * @return the file name as it would be displayed by a native file chooser

     * @see JFileChooser#getName

     * @since 1.4

     */

    public String getSystemDisplayName(File f) {

        if (f == null) {

            return null;

        }

        String name = f.getName();

        if (!name.equals("..") && !name.equals(".") &&

                (useSystemExtensionHiding || !isFileSystem(f) || isFileSystemRoot(f)) &&

                (f instanceof ShellFolder || f.exists())) {

            try {

                name = getShellFolder(f).getDisplayName();

            } catch (FileNotFoundException e) {

                return null;

            }

            if (name == null || name.length() == 0) {

                name = f.getPath(); // e.g. "/"

            }

        }

        return name;

    }

    /**

     * Type description for a file, directory, or folder as it would be displayed in

     * a system file browser. Example from Windows: the "Desktop" folder

     * is described as "Desktop".

     *

     * Override for platforms with native ShellFolder implementations.

     *

     * @param f a <code>File</code> object

     * @return the file type description as it would be displayed by a native file chooser

     * or null if no native information is available.

     * @see JFileChooser#getTypeDescription

     * @since 1.4

     */

    public String getSystemTypeDescription(File f) {

        return null;

    }

    /**

     * Icon for a file, directory, or folder as it would be displayed in

     * a system file browser. Example from Windows: the "M:\" directory

     * displays a CD-ROM icon.

     *

     * The default implementation gets information from the ShellFolder class.

     *

     * @param f a <code>File</code> object

     * @return an icon as it would be displayed by a native file chooser

     * @see JFileChooser#getIcon

     * @since 1.4

     */

    public Icon getSystemIcon(File f) {

        if (f == null) {

            return null;

        }

        ShellFolder sf;

        try {

            sf = getShellFolder(f);

        } catch (FileNotFoundException e) {

            return null;

        }

        Image img = sf.getIcon(false);

        if (img != null) {

            return new ImageIcon(img, sf.getFolderType());

        } else {

            return UIManager.getIcon(f.isDirectory() ? "FileView.directoryIcon" : "FileView.fileIcon");

        }

    }

    /**

     * On Windows, a file can appear in multiple folders, other than its

     * parent directory in the filesystem. Folder could for example be the

     * "Desktop" folder which is not the same as file.getParentFile().

     *

     * @param folder a <code>File</code> object representing a directory or special folder

     * @param file a <code>File</code> object

     * @return <code>true</code> if <code>folder</code> is a directory or special folder and contains <code>file</code>.

     * @since 1.4

     */

    public boolean isParent(File folder, File file) {

        if (folder == null || file == null) {

            return false;

        } else if (folder instanceof ShellFolder) {

                File parent = file.getParentFile();

                if (parent != null && parent.equals(folder)) {

                    return true;

                }

            File[] children = getFiles(folder, false);

            for (File child : children) {

                if (file.equals(child)) {

                    return true;

                }

            }

            return false;

        } else {

            return folder.equals(file.getParentFile());

        }

    }

    /**

     *

     * @param parent a <code>File</code> object representing a directory or special folder

     * @param fileName a name of a file or folder which exists in <code>parent</code>

     * @return a File object. This is normally constructed with <code>new

     * File(parent, fileName)</code> except when parent and child are both

     * special folders, in which case the <code>File</code> is a wrapper containing

     * a <code>ShellFolder</code> object.

     * @since 1.4

     */

    public File getChild(File parent, String fileName) {

        if (parent instanceof ShellFolder) {

            File[] children = getFiles(parent, false);

            for (File child : children) {

                if (child.getName().equals(fileName)) {

                    return child;

                }

            }

        }

        return createFileObject(parent, fileName);

    }

    /**

     * Checks if <code>f</code> represents a real directory or file as opposed to a

     * special folder such as <code>"Desktop"</code>. Used by UI classes to decide if

     * a folder is selectable when doing directory choosing.

     *

     * @param f a <code>File</code> object

     * @return <code>true</code> if <code>f</code> is a real file or directory.

     * @since 1.4

     */

    public boolean isFileSystem(File f) {

        if (f instanceof ShellFolder) {

            ShellFolder sf = (ShellFolder)f;

            // Shortcuts to directories are treated as not being file system objects,

            // so that they are never returned by JFileChooser.

            return sf.isFileSystem() && !(sf.isLink() && sf.isDirectory());

        } else {

            return true;

        }

    }

    /**

     * Creates a new folder with a default folder name.

     *

     * @param containingDir a {@code File} object denoting directory to contain the new folder

     * @return a {@code File} object denoting the newly created folder

     * @throws IOException if new folder could not be created

     */

    public abstract File createNewFolder(File containingDir) throws IOException;

    /**

     * Returns whether a file is hidden or not.

     *

     * @param f a {@code File} object

     * @return true if the given {@code File} denotes a hidden file

     */

    public boolean isHiddenFile(File f) {

        return f.isHidden();

    }

    /**

     * Is dir the root of a tree in the file system, such as a drive

     * or partition. Example: Returns true for "C:\" on Windows 98.

     *

     * @param dir a <code>File</code> object representing a directory

     * @return <code>true</code> if <code>f</code> is a root of a filesystem

     * @see #isRoot

     * @since 1.4

     */

    public boolean isFileSystemRoot(File dir) {

        return ShellFolder.isFileSystemRoot(dir);

    }

    /**

     * Used by UI classes to decide whether to display a special icon

     * for drives or partitions, e.g. a "hard disk" icon.

     *

     * The default implementation has no way of knowing, so always returns false.

     *

     * @param dir a directory

     * @return <code>false</code> always

     * @since 1.4

     */

    public boolean isDrive(File dir) {

        return false;

    }

    /**

     * Used by UI classes to decide whether to display a special icon

     * for a floppy disk. Implies isDrive(dir).

     *

     * The default implementation has no way of knowing, so always returns false.

     *

     * @param dir a directory

     * @return <code>false</code> always

     * @since 1.4

     */

    public boolean isFloppyDrive(File dir) {

        return false;

    }

    /**

     * Used by UI classes to decide whether to display a special icon

     * for a computer node, e.g. "My Computer" or a network server.

     *

     * The default implementation has no way of knowing, so always returns false.

     *

     * @param dir a directory

     * @return <code>false</code> always

     * @since 1.4

     */

    public boolean isComputerNode(File dir) {

        return ShellFolder.isComputerNode(dir);

    }

    /**

     * Returns all root partitions on this system. For example, on

     * Windows, this would be the "Desktop" folder, while on DOS this

     * would be the A: through Z: drives.

     *

     * @return an array of {@code File} objects representing all root partitions

     *         on this system

     */

    public File[] getRoots() {

        // Don't cache this array, because filesystem might change

        File[] roots = (File[])ShellFolder.get("roots");

        for (int i = 0; i < roots.length; i++) {

            if (isFileSystemRoot(roots[i])) {

                roots[i] = createFileSystemRoot(roots[i]);

            }

        }

        return roots;

    }

    // Providing default implementations for the remaining methods

    // because most OS file systems will likely be able to use this

    // code. If a given OS can't, override these methods in its

    // implementation.

    /**

     * Returns the home directory.

     * @return the home directory

     */

    public File getHomeDirectory() {

        return createFileObject(System.getProperty("user.home"));

    }

    /**

     * Return the user's default starting directory for the file chooser.

     *

     * @return a <code>File</code> object representing the default

     *         starting folder

     * @since 1.4

     */

    public File getDefaultDirectory() {

        File f = (File)ShellFolder.get("fileChooserDefaultFolder");

        if (isFileSystemRoot(f)) {

            f = createFileSystemRoot(f);

        }

        return f;

    }

    /**

     * Returns a File object constructed in dir from the given filename.

     *

     * @param dir an abstract pathname denoting a directory

     * @param filename a {@code String} representation of a pathname

     * @return a {@code File} object created from {@code dir} and {@code filename}

     */

    public File createFileObject(File dir, String filename) {

        if(dir == null) {

            return new File(filename);

        } else {

            return new File(dir, filename);

        }

    }

    /**

     * Returns a File object constructed from the given path string.

     *

     * @param path {@code String} representation of path

     * @return a {@code File} object created from the given {@code path}

     */

    public File createFileObject(String path) {

        File f = new File(path);

        if (isFileSystemRoot(f)) {

            f = createFileSystemRoot(f);

        }

        return f;

    }

    /**

     * Gets the list of shown (i.e. not hidden) files.

     *

     * @param dir the root directory of files to be returned

     * @param useFileHiding determine if hidden files are returned

     * @return an array of {@code File} objects representing files and

     *         directories in the given {@code dir}. It includes hidden

     *         files if {@code useFileHiding} is false.

     */

    public File[] getFiles(File dir, boolean useFileHiding) {

        List<File> files = new ArrayList<File>();

        // add all files in dir

        if (!(dir instanceof ShellFolder)) {

            try {

                dir = getShellFolder(dir);

            } catch (FileNotFoundException e) {

                return new File[0];

            }

        }

        File[] names = ((ShellFolder) dir).listFiles(!useFileHiding);

        if (names == null) {

            return new File[0];

        }

        for (File f : names) {

            if (Thread.currentThread().isInterrupted()) {