Easy to Learn Java: Programming Articles, Examples and Tips

Start with Java in a few days with Java Lessons or Lectures


Code Examples

Java Tools

More Java Tools!

Java Forum

All Java Tips


Submit News
Search the site here...

Swing Chapter 5. (The basics) Labels and Buttons. Easy for reading, Click here!

Custom Search
Swing Chapter 5. (The basics) Labels and Buttons. Easy for reading, Click here!

[ Return to Swing (Book) ]

Page: 4/4 

Previous Page Previous Page (3/4)
Subpages: 1. Labels and buttons overview
2. Custom buttons: part I - Transparent buttons
3. Custom buttons: part II - Polygonal buttons
4. Custom buttons: part III - Tooltip management

5.4    Custom buttons: part III - Tooltip management

In this section we'll discuss how to implement custom management of tooltips in a Swing application. If you're completely satisfied with the default ToolTipManager provided with Swing, you can skip this section. But there may be situations when this default implementation is not satisfactory, as in our example above using non-rectangular components.

We will construct our own version of a tooltip manager to display a tooltip window if the mouse cursor rests over some point inside the button's area longer than a specified time interval. It will be displayed for a speecified amount of time and, to avoid annoying the user, we will then hide the tooltip window until the mouse cursor moves to a new position. In designing our tooltip manager we will take a different approach than that taken by Swing's default ToolTipManager (see section 5.4). Instead of using three different Timers, we will use just one. This involves tracking more information, but is slightly more efficient by avoiding the handling of multiple ActionEvents.

Figure 5.11 Polygonal buttons with custom tooltip manager.

<<file figure5-11.gif>>

The Code: ButtonApplet3.java

see \Chapter5\6

import java.applet.*;

import java.awt.*;

import java.awt.event.*;

import java.net.*;

import java.util.*;

import javax.swing.*;

import javax.swing.border.*;

import javax.swing.event.*;

public class ButtonApplet3 extends JApplet


  protected ToolTipManager m_manager;

  public ButtonApplet3() {}

  public synchronized void init() {

    // unchanged code from section 5.3

    m_manager = new ToolTipManager(this);

    PolygonButton.m_toolTip = m_manager.m_toolTip;



    bigLabel.setBounds(0, 0, bigImage.getIconWidth(),



  // unchanged code from section 5.3


class PolygonButton extends JComponent

 implements MouseListener, MouseMotionListener


  // unchanged code from section 5.3

  public static JToolTip m_toolTip;

  protected void setState(boolean active) {

    m_active = active;


    if (active) {

      if (m_currentButton != null)





      if (m_toolTip != null)



    else {

      m_currentButton = null;




      if (m_toolTip != null)





class MyToolTipManager extends MouseMotionAdapter

 implements ActionListener


  protected Timer m_timer;

  protected int m_lastX = -1;

  protected int m_lastY = -1;

  protected boolean m_moved = false;

  protected int m_counter = 0;

  public JToolTip m_toolTip = new JToolTip();

  ToolTipManager(JApplet parent) {





    m_timer = new Timer(1000, this);



  public void mouseMoved(MouseEvent e) {

    m_moved = true;

    m_counter = -1;

    m_lastX = e.getX();

    m_lastY = e.getY();

    if (m_toolTip.isVisible()) {





  public void actionPerformed(ActionEvent e) {

    if (m_moved || m_counter==0 || m_toolTip.getTipText()==null) {

      if (m_toolTip.isVisible())


      m_moved = false;



    if (m_counter < 0) {

      m_counter = 4;


      Dimension d = m_toolTip.getPreferredSize();

      m_toolTip.setBounds(m_lastX, m_lastY+20,

      d.width, d.height);





Understanding the Code

Class ButtonApplet3

This class requires very few modifications from ButtonApplet2 in the last section. It declares and creates MyToolTipManager m_manager and passes a this reference to it:

        m_manager = new MyToolTipManager(this);

As you will see below, our MyToolTipManager class manages a publically accessible JToolTip, m_toolTip. MyToolTipManager itself is not intended to provide any meaningful content to this tooltip. Rather, this is to be done by other components, in our case, by the PolygonButtons. Thus, our PolygonButton class declares a static reference to a JToolTip component. Whenever a button becomes active, this JToolTip's text will be assigned to that of the active button. So, when we create our instance of MyToolTipManager, we assign its publically accessible JToolTip as our Polygon class's static JToolTip (which is also publically accessible):

        PolygonButton.m_toolTip = m_manager.m_toolTip;

Thus, there will only be one JToolTip instance in existance for the lifetime of this applet, and both MyToolTipManager and our PolygonButtons have control over it.

Class PolygonButton

As we've mentioned above, this class now declares the static variable: JToolTip m_toolTip. Class PolygonButton does not initialize this reference. However, this reference is checked during PolygonButton activation in the setState() method. If m_toolTip is not null (set to point to a valid tooltip window by some outer class--which, in our example, is done in the ButtonApplet3 init() method shown above), the setTipText() method is invoked to set the proper text while the mouse cursor hovers over the button.

Class MyToolTipManager

This class represents a custom tooltip manager which is free from assumption of the rectangularity of its child components. It extends the MouseMotionAdapter class and implements the ActionListener interface to work as both a MouseMotionListener and ActionListener. Six instance variables are declared:

Timer m_timer: our managing timer.

int m_lastX, m_lastY: the last coordinates of the mouse cursor--reassigned each time the mouse is moved.

boolean m_moved: flag indicating that the mouse cursor has moved.

int m_counter: time ticks counter managing the tooltip's time to live (see below).

JToolTip m_toolTip: the tooltip component to be displayed.

The constructor of the MyToolTipManager class takes a reference to the parenting JApplet as a parameter and registers itself as a MouseMotionListener on this component. Then it creates the JToolTip m_toolTip component and adds it to the applet's content pane. m_tooltip is set invisible, using setVisible(false), and can then be used by any interested class by repositioning it and calling setVisible(true). Finally a Timer with a 1000 ms delay time is created and started.

The mouseMoved() method will be invoked when the mouse cursor moves over the applet's pane. It sets the m_moved flag to true, m_counter to -1, and stores the coordinates of the mouse cursor. Then this method hides the tooltip component if is visible.

The actionPerformed() method is called when the Timer fires events (see 2.6 for details). It implements the logic of displaying/hiding the tooltip window based on two instance variables: m_moved and m_counter:

    if (m_moved || m_counter==0 || m_toolTip.getTipText()==null) {

      if (m_toolTip.isVisible())


      m_moved = false;



The above block of code is invoked when any one of the following statements are true:

1. Mouse cursor has been moved since the last time tick.

2. Counter has reached zero.

3. No tooltip text is set.

In any of these cases, the tooltip component is hidden (if previously visible), and the m_moved flag is set to false. Note that the m_counter variable remains unchanged.

    if (m_counter < 0) {

      m_counter = 4;


      Dimension d = m_toolTip.getPreferredSize();

      m_toolTip.setBounds(m_lastX, m_lastY+20,

      d.width, d.height);


This block of code is responsible for displaying the tooltip component. It will be executed only when m_counter is equal to -1 (set by mouseMoved()), and the m_moved flag is false (cleared by the previous code fragment). m_counter is set to four which determines the amount of time the tooltip will be displayed (4000ms in this example). Then we make the tooltip component visible and place it at the current mouse location with a vertical offset approximately equal to the mouse cursor's height. Note that this construction provides an arbitrary time delay between when mouse motion stops and the tooltip is displayed.

The last line of code in the actionPerformed() method is m_counter--, which decrements the counter each time tick until it reaches 0. As we saw above, once it reaches 0 the tooltip will be hidden.

Note: The actual delay time may vary from 1000ms to 2000 ms since the mouse movements and time ticks are not synchronized. A more accurate and complex implementation could start a new timer after each mouse movement, as is done in Swing's ToolTipManager.

The following table illustrates how the m_counter and m_moved variables control this behavior.

Timer   m_moved         m_counter        m_counter        Comment

tick      flag                  before              after

0          false                  0                      0

1          true                   -1                     -1                     Mouse moved between 0-th and 1-st ticks

2          false                  -1                     4                      Tool tip is displayed

3          false                  4                      3

4          false                  3                      2

5          false                  2                      1

6          false                  1                      0

7          false                  0                      0                      Tool tip is hidden

8          false                  0                      0                      Waiting for the next mouse move

Running the Code

Figure 5.11 shows ButtonApplet3 running in Netscape Navigator 4.05 with the Java Plug-in. You can use the same HTML file as presented in the previous section. Move the mouse cursor over some non-rectangular component and note how it displays the proper tooltip message. This tooltip disappears after a certain amount of time or when the mouse is moved to a new location.

[ Return to Swing (Book) ]

Top 10 read Java Articles
 Get free "1000 Java Tips eBook"

 Java Calendar and Date: good to know facts and code examples

 Array vs ArrayList vs LinkedList vs Vector: an excellent overview and examples

 How can I convert any Java Object into byte array? And byte array to file object

 The Java Lesson 1: What is Java?

 How do I compare two dates and times, date between dates, time between times and

 Maven vs Ant or Ant vs Maven?

 How to open, read, write, close file(s) in Java? Examples on move, rename and de

 Java Array

 Java: JLabel font and color

[ More in News Section ]
Java Lessons

The Java Lesson 1:
What is Java?
The Java Lesson 2:
Anatomy of a simple Java program
The Java Lesson 3:
Identifiers and primitive data types
The Java Lesson 4:
Variables, constants, and literals
The Java Lesson 5:
Arithmetic operations, conversions, and casts
The Java Lesson 6:
Boolean expressions and operations
The Java Lesson 7:
Bitwise operations
The Java Lesson 8:
Flow control with if and else
The Java Lesson 9:
switch statements
The Java Lesson 10:
for, while, and do-while statements
The Java Lesson 11:
Using break and continue
The Java Lesson 12:
Class methods and how they are called
The Java Lesson 13:
Using the Math class
The Java Lesson 14:
Creating and calling custom class methods
The Java Lesson 15:
Overloading class methods
The Java Lesson 16:
An introduction to objects and object references
The Java Lesson 17:
The String class
The Java Lesson 18:
The StringBuffer class
The Java Lesson 19:
Initializing and processing arrays of primitives
The Java Lesson 20:
Initializing and processing arrays of objects
The Java Lesson 23:
Inheritance and overriding inherited methods
The Java Lesson 24:
abstract classes and polymorphism
The Java Lesson 25:
Interfaces, instanceof, and object conversion and casting
The Java Lesson 26:
Introduction to graphical programming and the java.awt packa
The Java Lesson 27:
The Component class
The Java Lesson 28:
Containers and simple layout managers
The Java Lesson 29:
The Color and Font classes
The Java Lesson 30:
Drawing geometric shapes
The Java Lesson 31:
Choice, List, and Checkbox controls
The Java Lesson 32:
Using the Scrollbar graphical control
The Java Lesson 33:
Menus and submenus
The Java Lesson 34:
An introduction to applets and the Applet class
The Java Lesson 35:
Essential HTML to launch an applet and pass it parameters
The Java Lesson 36:
Mouse event processing
Java Lesson 37:
Menus and submenus
Java Lesson 38:
The WindowListener interface and the WindowAdapter class
Java Lesson 39:
An introduction to GridBagLayout
Java Lesson 40:
An introduction to the Java Collections API
Java Lesson 41:
Exception handling with try, catch, and finally blocks
Java Lesson 42:
Claiming and throwing exceptions
Java Lesson 43:
Multithreading, the Thread class, and the Runnable interface
Java Lesson 44:
An introduction to I/O and the File and FileDialog classes
Java Lesson 45:
Low-level and high-level stream classes
Java Lesson 46:
Using the RandomAccessFile class
Java Lessons by
Joh Huhtala: Update

Latest articles
 Java Profiler JProbe to Resolve Performance Problems Faster

 SSL with GlassFish v2, page 5

 SSL with GlassFish v2, page 4

 SSL with GlassFish v2, page 3

 SSL with GlassFish v2, page 2

 The Java Lesson 2: Anatomy of a simple Java program, page 2

 New site about Java for robots and robotics: both software and hardware.

 Exceptions -III: What's an exception and why do I care?

 Exceptions -II: What's an exception and why do I care?

 Exceptions: What's an exception and why do I care?

 Double your Java code quality in 10 minutes, here is receipt

 Murach's Java Servlets and JSP

 How to get ascii code from a char in Java?

 Can we just try without catch? Yes!

 Make Tomcat page load faster

 Make your Tomcat More secure - limit network address for certain IP addresses

 New Java book online starts now here...

 Implementing RESTful Web Services in Java

 Firefox trimming from 1 GB to 40 Mb with many tabs opened

 SSL with GlassFish v2

 My request to replublish Tech Tips

 Search JavaFAQ.nu site here

 New Advanced Installer for Java 6.0 brings XML updates and imports 3rd party MSI

 EJB programming restrictions

 Maven vs Ant or Ant vs Maven?

 Why Java does not use default value which it should?

 How to unsign signed bytes in Java - your guide is here

 The Java Lesson 3: Identifiers and primitive data types. Page 2

 The Java Lesson 7: Bitwise operations with good examples, click here! Page 4

 The Java Lesson 7: Bitwise operations with good examples, click here! Page 3

[ More in News Section ]

Home Code Examples Java Forum All Java Tips Books Submit News, Code... Search... Offshore Software Tech Doodling

RSS feed Java FAQ RSS feed Java FAQ News     

    RSS feed Java Forums RSS feed Java Forums

All logos and trademarks in this site are property of their respective owner. The comments are property of their posters, all the rest 1999-2006 by Java FAQs Daily Tips.

Interactive software released under GNU GPL, Code Credits, Privacy Policy