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

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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;
    }
}