scrollingsimple.java

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/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  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 Sun Microsystems 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.
 */ 

/*
 * Java(TM) SE 6 version.
 */

import javax.swing.JApplet;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

//Since we're adding a Swing component, we now need to
//extend JApplet. We need to be careful to access
//components only on the event-dispatching thread.
public class ScrollingSimple extends JApplet {

    JTextField field;

    public void init() {
        //Execute a job on the event-dispatching thread:
        //creating this applet's GUI.
        try {
            SwingUtilities.invokeAndWait(new Runnable() {
                public void run() {
                    createGUI();
                }
            });
        } catch (Exception e) {
            System.err.println("createGUI didn't successfully complete");
        }

        addItem(false, "initializing... ");
    }

    private void createGUI() {        
        //Create the text field and make it uneditable.
        field = new JTextField();
        field.setEditable(false);

        //Set the layout manager so that the text field will be
        //as wide as possible.
        setLayout(new java.awt.GridLayout(1,0));

        //Add the text field to the applet.
        add(field);
    }

    public void start() {
        addItem(false, "starting... ");
    }

    public void stop() {
        addItem(false, "stopping... ");
    }

    public void destroy() {
        addItem(false, "preparing for unloading...");
        cleanUp();
    }
    
    private void cleanUp() {
        //Execute a job on the event-dispatching thread:
        //taking the text field out of this applet.
        try {
            SwingUtilities.invokeAndWait(new Runnable() {
                public void run() {
                    remove(field);
                }
            });
        } catch (Exception e) {
            System.err.println("cleanUp didn't successfully complete");
        }
        field = null;
    }

    private void addItem(boolean alreadyInEDT, String newWord) {
        if (alreadyInEDT) {
            addItem(newWord);
        } else {
            final String word = newWord;
            //Execute a job on the event-dispatching thread:
            //invoking addItem(newWord).
            try {
                SwingUtilities.invokeAndWait(new Runnable() {
                    public void run() {
                        addItem(word);
                    }
                });
            } catch (Exception e) {
                System.err.println("addItem didn't successfully complete");
            }
        }
    }
        
    //Invoke this method ONLY from the event-dispatching thread.
    private void addItem(String newWord) {
        String t = field.getText();
        System.out.println(newWord);
        field.setText(t + newWord);
    }
}