Java example source code file (gui.js)

This example Java source code file (gui.js) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

color, gui, jfilechooser, joptionpane, messagebox, swingutilities

The gui.js Java example source code

/*
 * Copyright (c) 2006, 2013, 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.
 */

/*
 * This source code is provided to illustrate the usage of a given feature
 * or technique and has been deliberately simplified. Additional steps
 * required for a production-quality application, such as security checks,
 * input validation and proper error handling, might not be present in
 * this sample code.
 */

/*
 * Few user interface utilities.
 */

if (this.window === undefined) {
    this.window = null;
}

/**
 * Swing invokeLater - invokes given function in AWT event thread
 */
Function.prototype.invokeLater = function() {
    var SwingUtilities = javax.swing.SwingUtilities;
    var func = this;
    var args = arguments;
    SwingUtilities.invokeLater(new java.lang.Runnable() {
                       run: function() {
                           func.apply(func, args);
                       }
                  });
};

/**
 * Swing invokeAndWait - invokes given function in AWT event thread
 * and waits for it's completion
 */
Function.prototype.invokeAndWait = function() {
    var SwingUtilities = javax.swing.SwingUtilities;
    var func = this;
    var args = arguments;
    SwingUtilities.invokeAndWait(new java.lang.Runnable() {
                       run: function() {
                           func.apply(func, args);
                       }
                  });
};

/**
 * Am I running in AWT event dispatcher thread?
 */
function isEventThread() {
    var SwingUtilities = javax.swing.SwingUtilities;
    return SwingUtilities.isEventDispatchThread();
}
isEventThread.docString = "returns whether the current thread is GUI thread";

/**
 * Opens a file dialog box
 *
 * @param curDir current directory [optional]
 * @param save flag tells whether this is a save dialog or not
 * @return selected file or else null
 */
function fileDialog(curDir, save) {
    var result;
    function _fileDialog() {
        if (curDir == undefined) {
            curDir = new java.io.File(".");
        }

        var JFileChooser = javax.swing.JFileChooser;
        var dialog = new JFileChooser(curDir);
        var res = save ? dialog.showSaveDialog(window):
            dialog.showOpenDialog(window);

        if (res == JFileChooser.APPROVE_OPTION) {
           result = dialog.getSelectedFile();
        } else {
           result = null;
        }
    }

    if (isEventThread()) {
        _fileDialog();
    } else {
        _fileDialog.invokeAndWait();
    }

    return result;
}
fileDialog.docString = "show a file dialog box";

/**
 * Opens a color chooser dialog box
 *
 * @param title of the dialog box [optional]
 * @param color default color [optional]
 * @return chosen color or default color
 */
function colorDialog(title, color) {
    var result;

    function _colorDialog() {
        if (title == undefined) {
            title = "Choose Color";
        }

        if (color == undefined) {
            color = java.awt.Color.BLACK;
        }

        var chooser = new javax.swing.JColorChooser();
        var res = chooser.showDialog(window, title, color);
        result = res ? res : color;
    }

    if (isEventThread()) {
        _colorDialog();
    } else {
        _colorDialog.invokeAndWait();
    }

    return result;
}
colorDialog.docString = "shows a color chooser dialog box";

/**
 * Shows a message box
 *
 * @param msg message to be shown
 * @param title title of message box [optional]
 * @param msgType type of message box [constants in JOptionPane]
 */
function msgBox(msg, title, msgType) {
    function _msgBox() {
        var JOptionPane = javax.swing.JOptionPane;
        if (msg === undefined) msg = "undefined";
        if (msg === null) msg = "null";
        if (title == undefined) title = msg;
        if (msgType == undefined) msgType = JOptionPane.INFORMATION_MESSAGE;
        JOptionPane.showMessageDialog(window, msg, title, msgType);
    }

    if (isEventThread()) {
        _msgBox();
    } else {
        _msgBox.invokeAndWait();
    }
}
msgBox.docString = "shows MessageBox to the user";

/**
 * Shows an information alert box
 *
 * @param msg message to be shown
 * @param title title of message box [optional]
 */
function alert(msg, title) {
    var JOptionPane = javax.swing.JOptionPane;
    msgBox(msg, title, JOptionPane.INFORMATION_MESSAGE);
}
alert.docString = "shows an alert message box to the user";

/**
 * Shows an error alert box
 *
 * @param msg message to be shown
 * @param title title of message box [optional]
 */
function error(msg, title) {
    var JOptionPane = javax.swing.JOptionPane;
    msgBox(msg, title, JOptionPane.ERROR_MESSAGE);
}
error.docString = "shows an error message box to the user";

/**
 * Shows a warning alert box
 *
 * @param msg message to be shown
 * @param title title of message box [optional]
 */
function warn(msg, title) {
    var JOptionPane = javax.swing.JOptionPane;
    msgBox(msg, title, JOptionPane.WARNING_MESSAGE);
}
warn.docString = "shows a warning message box to the user";

/**
 * Shows a prompt dialog box
 *
 * @param question question to be asked
 * @param answer default answer suggested [optional]
 * @return answer given by user
 */
function prompt(question, answer) {
    var result;
    function _prompt() {
        var JOptionPane = javax.swing.JOptionPane;
        if (answer == undefined) answer = "";
        result = JOptionPane.showInputDialog(window, question, answer);
    }

    if (isEventThread()) {
        _prompt();
    } else {
        _prompt.invokeAndWait();
    }

    return result;
}
prompt.docString = "shows a prompt box to the user and returns the answer";

/**
 * Shows a confirmation dialog box
 *
 * @param msg message to be shown
 * @param title title of message box [optional]
 * @return boolean (yes->true, no->false)
 */
function confirm(msg, title) {
    var result;
    var JOptionPane = javax.swing.JOptionPane;

    function _confirm() {
        if (title == undefined) title = msg;
        var optionType = JOptionPane.YES_NO_OPTION;
        result = JOptionPane.showConfirmDialog(window, msg, title, optionType);
    }

    if (isEventThread()) {
        _confirm();
    } else {
        _confirm.invokeAndWait();
    }

    return result == JOptionPane.YES_OPTION;
}
confirm.docString = "shows a confirmation message box to the user";

/**
 * Exit the process after confirmation from user
 *
 * @param exitCode return code to OS [optional]
 */
function exit(exitCode) {
    if (exitCode == undefined) exitCode = 0;
    if (confirm("Do you really want to exit?")) {
        java.lang.System.exit(exitCode);
    }
}
exit.docString = "exits jconsole";

// synonym to exit
var quit = exit;

// if echo function is not defined, define it as synonym
// for println function
if (this.echo == undefined) {
    function echo(str) {
        println(str);
    }
}