de.schlichtherle.io.swing.FileView Maven / Gradle / Ivy

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TrueZIP is a Java based Virtual File System (VFS) to enable transparent, multi-threaded read/write access to archive files (ZIP, TAR etc.) as if they were directories. Archive files may be arbitrarily nested and the nesting level is only limited by heap and file system size.
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/*
 * Copyright (C) 2006-2010 Schlichtherle IT Services
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package de.schlichtherle.io.swing;

import de.schlichtherle.io.*;

import java.util.*;

import javax.swing.*;
import javax.swing.filechooser.*;

/**
 * An archive enabled file view.
 * This class recognizes instances of the {@link File} class and returns
 * custom icons and type descriptions if it's an archive file or an archive
 * entry.
 * Otherwise, the super class behaviour is used.
 * 
 * Note that this class accesses archive files lazily, i.e. it does not
 * eagerly check the true status with {@link File#isDirectory} or similar
 * unless really necessary. This is to prevent dead locks between the Event
 * Dispatch Thread and the Basic L&F File Loading Threads which are forked
 * by JFileChooser.
 *
 * @author Christian Schlichtherle
 * @version $Id: FileView.java,v 1.4 2010/08/20 13:09:46 christian_schlichtherle Exp $
 */
final class FileView extends FilterFileView {

    private static final String CLASS_NAME
            = "de.schlichtherle.io.swing.FileView";
    private static final ResourceBundle resources
            = ResourceBundle.getBundle(CLASS_NAME);

    /**
     * Creates a new archive enabled file view.
     *
     * @param delegate The file view to be decorated - may be {@code null}.
     */
    public FileView(javax.swing.filechooser.FileView delegate) {
        super(delegate);
    }

    public Icon getIcon(java.io.File file) {
        Icon icon = closedIcon(file);
        return icon != null
                ? icon
                : super.getIcon(file);
    }

    public String getTypeDescription(java.io.File file) {
        String typeDescription = typeDescription(file);
        return typeDescription != null
                ? typeDescription
                : super.getTypeDescription(file);
    }

    public Boolean isTraversable(java.io.File file) {
        Boolean traversable = traversable(file);
        return traversable != null
                ? traversable
                : super.isTraversable(file);
    }

    static Icon openIcon(java.io.File file) {
        return icon(file);
    }

    static Icon closedIcon(java.io.File file) {
        return icon(file);
    }

    private static Icon icon(java.io.File file) {
        if (!(file instanceof File))
            return null;
        File smartFile = (File) file;
        if (isValidArchive(smartFile)) {
                return UIManager.getIcon("FileView.directoryIcon");
        } else if (isEntryInValidArchive(smartFile)) {
            return smartFile.isDirectory()
                    ? UIManager.getIcon("FileView.directoryIcon")
                    : UIManager.getIcon("FileView.fileIcon");
        }
        return null;
    }

    static String typeDescription(java.io.File file) {
        if (!(file instanceof File))
            return null;
        File smartFile = (File) file;
        if (isValidArchive(smartFile)) {
            return resources.getString("archiveFile");
        } else if (isEntryInValidArchive(smartFile)) {
            return smartFile.isDirectory()
                    ? resources.getString("archiveDirectoryEntry")
                    : resources.getString("archiveFileEntry");
        }
        return null;
    }

    private static boolean isValidArchive(File file) {
        return file.isArchive() && file.isDirectory()
                && !createNonArchiveFile(file).isDirectory();
    }

    private static File createNonArchiveFile(File file) {
        return ArchiveDetector.NULL.createFile(
                file .getParentFile(), file.getName());
    }

    private static boolean isEntryInValidArchive(File file) {
        // An archive entry always names a parent. This parent must not be
        // a regular directory.
        if (!file.isEntry())
            return false;
        java.io.File parent = file.getParentFile();
        assert parent != null : "An archive entry must always name a parent!";
        return parent.isDirectory()
                && !ArchiveDetector.NULL.createFile(parent.getPath())
                    .isDirectory();
    }

    static Boolean traversable(java.io.File file) {
        if (!(file instanceof File))
            return null;
        File smartFile = (File) file;
        return smartFile.isDirectory() ? Boolean.TRUE : Boolean.FALSE;
    }
}