#// Usage: jjs -fx filebrowser.js -- <start_dir>

/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

// Uses -fx and javafx TreeView to visualize directories

if (!$OPTIONS._fx) {

    print("Usage: jjs -fx filebrowser.js -- <start_dir>");

    exit(1);

}

// Java classes used

var File = Java.type("java.io.File");

var Files = Java.type("java.nio.file.Files");

// check directory argument, if passed

var dir = arguments.length > 0? new File(arguments[0]) : new File(".");

if (! dir.isDirectory()) {

    print(dir + " is not a directory!");

    exit(2);

}

// JavaFX classes used

var FXCollections = Java.type("javafx.collections.FXCollections");

var Scene     = Java.type("javafx.scene.Scene");

var TreeItem  = Java.type("javafx.scene.control.TreeItem");

var TreeView  = Java.type("javafx.scene.control.TreeView");

// create a subclass of JavaFX TreeItem class

var LazyTreeItem = Java.extend(TreeItem);

// lazily filling children of a directory LazyTreeItem

function buildChildren(dir) {

    var children = FXCollections.observableArrayList();

    var stream = Files.list(dir.toPath());

    stream.forEach(function(path) {

        var file = path.toFile();

        var item = file.isDirectory()?

            makeLazyTreeItem(file) : new TreeItem(file.name);

        children.add(item);

    });

    stream.close();

    return children;

}

// create an instance LazyTreeItem with override methods

function makeLazyTreeItem(dir) {

    var item = new LazyTreeItem(dir.name) {

        expanded: false,

        isLeaf: function() false,

        getChildren: function() {

            if (! this.expanded) {

                // call super class (TreeItem) method

                Java.super(item).getChildren().setAll(buildChildren(dir));

                this.expanded = true;

            }

            // call super class (TreeItem) method

            return Java.super(item).getChildren();

        }

    }

    return item;

}

// JavaFX start method

function start(stage) {

    stage.title = dir.absolutePath;

    var rootItem = makeLazyTreeItem(dir);

    rootItem.expanded = true;

    var tree = new TreeView(rootItem);

    stage.scene = new Scene(tree, 300, 450);

    stage.show();

}