We Keep Coding

Java Swing Animations

I have to do Java Project about elevator management system.
My problem is in 2 JPanel's. First is for JLabel's and Button's, one for each floor - I use layout because i want it to be responsive. Before program start I have dialog which I can set first and last floor level. Here's code:
public void setFloors() {
floorNavigation = new JPanel();
floorNavigation.setLayout(new BoxLayout(floorNavigation, BoxLayout.Y_AXIS));
floorNavigation.add(Box.createVerticalGlue());
for(JPanel p : floorPanels){
floorNavigation.add(p);
}
floorNavigation.add(Box.createVerticalGlue());
frame.add(floorNavigation, BorderLayout.LINE_START);
}
public void createFloorPanel() {
JPanel floorPanel;
for(JLabel l : floorLabels){
floorPanel = new JPanel(new FlowLayout());
floorPanel.add(l);
floorPanel.add(floorButtons.get(floorLabels.indexOf(l)));
floorPanels.add(floorPanel);
}
}
I want to make a elevator move animation to Y of each JLabel in the other JPanel. Any ideas how to do that? Things like getY() don't work.

If I understood correctly both the panel that contains the buttons and the panel that contains the animation are going to be positioned side by side, and thus going to have the same height. In this situation you can calculate the Y coordinate positions simply by knowing the current height of the panel and the number of buttons you have. Simply divide the height with number of buttons and multiply by number of floors you want to reach (note that this will give you the floors in reverse order, top down).
After you calculate those positions you can use simple linear animation to move your "elevator" (I am guessing an imported icon or image) to the corresponding positions of the buttons. Here is a simple template for the animation (the small circle represents your elevator image):
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class SimpleAnimation {
static int x;
static int y = 150;
static int floor_distance = 130;
static int animation_speed = 10; //less is faster
static MyDrawPanel panel = new MyDrawPanel();
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JButton buttonUp = new JButton("Floor Up");
final JButton buttonDown = new JButton("Floor Down");
buttonUp.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
(new AnimatorUp()).execute();
}
});
buttonDown.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
(new AnimatorDown()).execute();
}
});
frame.getContentPane().add(BorderLayout.NORTH, buttonUp);
frame.getContentPane().add(BorderLayout.SOUTH, buttonDown);
frame.getContentPane().add(panel);
frame.setSize(300,300);
frame.setVisible(true);
}
static class AnimatorUp extends SwingWorker<String, Object> {
#Override
public String doInBackground() {
try {
x = (int)(panel.getWidth() / 2);
for(int i = 0; i < floor_distance; i++) {
y--;
panel.repaint();
try{ Thread.sleep(animation_speed); } catch(Exception ex) { ex.printStackTrace(); }
}
} catch (Exception ignore) {
}
return "";
}
}
static class AnimatorDown extends SwingWorker<String, Object> {
#Override
public String doInBackground() {
try {
x = (int)(panel.getWidth() / 2);
for(int i = 0; i < floor_distance; i++) {
y++;
panel.repaint();
try{ Thread.sleep(animation_speed); } catch(Exception ex) { ex.printStackTrace(); }
}
} catch (Exception ignore) {
}
return "";
}
}
static class MyDrawPanel extends JPanel {
public void paintComponent(Graphics g) {
g.fillRect(0, 0, this.getWidth(), this.getHeight());
g.setColor(new Color(215,215,215));
x = (int)(panel.getWidth() / 2);
g.fillOval(x, y, 50, 50);
}
}
}
You can modify this code so the buttons trigger the animation which moves the "elevator" to a specific floor. By calculating the difference between current Y position of the "elevator" and the Y position of wanted floor, you can set the direction and range of animation to execute.

I am trying to display a JPEG image in java

I have an assignment that I am doing where I am supposed to implement and design an application that plays a game called catch the creature. Have the creature appear at a random location then disappear and reappear somewhere else. The goal is to "catch" the creature by clicking the creature with a mouse button. Record the number of times the creature is caught.
I need help just displaying the creature which is an JPEG of a pikachu, I have tried a few things but none of them work. Any help is appreciated thank you!
Main Code:
import javax.swing.*;
public class Catch_The_Creature
{
public static void main(String[] args)
{
JFrame frame = new JFrame("Catch the Creature");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Creature panel = new Creature();
JOptionPane.showMessageDialog(frame, "Catch Pikachu!");
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);
}
}
Creature Code:
import java.awt.*;
import java.util.Random;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
public class Creature extends JPanel
{
private final int WIDTH = 400, HEIGHT = 300;
private final int DELAY=20, IMAGE_SIZE = 60;
private ImageIcon image;
private int pikachuX, pikachuY;
private int x, y;
private int catchCount=0;
private static Random generator = new Random();
private Timer time;
private ActionListener updater;
private JLabel countLabel;
public Creature()
{
image = new ImageIcon("image/pikachu.jpg");
time = new Timer(DELAY, updater);
addMouseListener ((MouseListener) new MouseClickedListener());
setBackground (Color.green);
setPreferredSize(new Dimension(1900,1000));
time.start();
}
public boolean point(int x, int y)
{
if (x == pikachuX && y == pikachuY)
{
catchCount++;
return true;
}
return false;
}
public int getCatchCount()
{
return catchCount;
}
private class MouseClickedListener extends MouseAdapter
{
public void mouseClicked(MouseEvent event)
{
point(event.getX(), event.getY());
}
}
public void paintComponent(Graphics page)
{
super.paintComponent(page);
page.drawImage(image.getImage(),WIDTH, HEIGHT, null);
page.drawString("Pikachus Captured: " + catchCount, 10, 35);
setFont(new Font("Arial", Font.BOLD,35));
}
public void actionPerformed(ActionEvent event)
{
time.setDelay(1000);
x += pikachuX;
y += pikachuY;
if (x <= 0 || x >= WIDTH-IMAGE_SIZE)
pikachuX = pikachuX * -1;
if (y <= 0 || y >= HEIGHT-IMAGE_SIZE)
pikachuY = pikachuY * -1;
repaint();
}
public void mouseEntered(MouseEvent arg0) {}
public void mouseExited(MouseEvent arg0) {}
public void mousePressed(MouseEvent arg0) {}
public void mouseReleased(MouseEvent arg0){}
}

It doesn't look like you ever add the ImageIcon to the panel or tell it to paint in the paintComponent() method.
First solution [Preferred]: Add ImageIcon to the panel. In the constructor
super.add(image);
Make sure you use the correct layout (probably a null or absolute layout) and that you update the coordinates of the ImageIcon itself, not just some member variables.
Second solution: Paint the ImageIcon in the paintComponent() method. This is probably discouraged because it goes against the general Swing principles.

Make sure your Image file is in the right directory. If you're running from netbeans or eclipse your file structure should look like this
ProjectRoot
src
bin
image
pikachu.jpeg
Since you are using "image/pikachu.png", you image filder should be a child of the project root folder as that's where the IDE will first search fore your file path
Edit: To draw image. Instead of using ImageIcon, use BufferedImage
try {
BufferedImage image = ImageIO.read("image/pikachu.jpeg");
} catch (Exception ex){
ex.printStackTrace();
}
public void paintComponent(Graphics page)
{
super.paintComponent(page);
page.drawImage(image, x, y, heightYouWant, widthYouWant, this);
page.drawString("Pikachus Captured: " + catchCount, 10, 35);
setFont(new Font("Arial", Font.BOLD,35));
}

All i needed to do was put values on where I wanted the picture to start at in the constructor.
public Creature()
{
image = new ImageIcon ("pikachu.png");
time = new Timer(DELAY, updater);
x = 0;
y = 50;
addMouseListener ((MouseListener) new MouseClickedListener());
setBackground (Color.green);
setPreferredSize(new Dimension(1900,1000));
time.start();
}
While still using an Image Icon and still paint the image in the paint component.
public void paintComponent(Graphics page)
{
super.paintComponent(page);
image.paintIcon (this, page, x, y);
page.drawString("Pikachus Captured: " + catchCount, 10, 35);
setFont(new Font("Arial", Font.BOLD,35));
}

java swing: in paintComponent method how to know what to repaint?

My component is bigger than the screen and parts of it are not shown (I will use scrollbars).
When I receive a call in paintComponent(g) how do I know what area should I paint?

I'm not sure if this is what you mean, but the problem is you will have to call repaint() on the JScrollPane each time you get a call in paintComponent(Graphics g) of the JPanel or else updates on the JPanel will not be visible in the JScrollPane.
Also I see you want to use JScrollBar (or maybe you confused the terminology)? I'd recommend a JScrollPane
I made a small example which is a JPanel with a grid that will change its colour every 2 seconds (Red to black and vice versa). The JPanel/Grid is larger then the JScrollPane; regardless we have to call repaint() on the JScrollPane instance or else the grid wont change colour:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class Test {
public static void main(String[] args) throws Exception {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test().createAndShowUI();
}
});
}
private void createAndShowUI() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initComponents(frame);
frame.setPreferredSize(new Dimension(400, 400));
frame.pack();
frame.setVisible(true);
}
private void initComponents(JFrame frame) {
JScrollPane jsp = new JScrollPane();
jsp.setViewportView(new Panel(800, 800, jsp));
frame.getContentPane().add(jsp);
}
}
class Panel extends JPanel {
private int across, down;
private Panel.Tile[][] tiles;
private Color color = Color.black;
private final JScrollPane jScrollPane;
public Panel(int width, int height, JScrollPane jScrollPane) {
this.setPreferredSize(new Dimension(width, height));
this.jScrollPane = jScrollPane;
createTiles();
changePanelColorTimer();//just something to do to check if its repaints fine
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (int i = 0; i < across; i++) {
for (int j = 0; j < down; j++) {
g.setColor(color);
for (int k = 0; k < 5; k++) {
g.drawRect(tiles[i][j].x + k, tiles[i][j].y + k, tiles[i][j].side - k * 2, tiles[i][j].side - 2 * k);
}
}
}
updateScrollPane();//refresh the pane after every paint
}
//calls repaint on the scrollPane instance
private void updateScrollPane() {
jScrollPane.repaint();
}
private void createTiles() {
across = 13;
down = 9;
tiles = new Panel.Tile[across][down];
for (int i = 0; i < across; i++) {
for (int j = 0; j < down; j++) {
tiles[i][j] = new Panel.Tile((i * 50), (j * 50), 50);
}
}
}
//change the color of the grid lines from black to red and vice versa every 2s
private void changePanelColorTimer() {
Timer timer = new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (color == Color.black) {
color = Color.red;
} else {
color = Color.black;
}
}
});
timer.setInitialDelay(2000);
timer.start();
}
private class Tile {
int x, y, side;
public Tile(int inX, int inY, int inSide) {
x = inX;
y = inY;
side = inSide;
}
}
}
In the Panel class if we comment the line updateScrollPane(); in paintComponent(Graphics g) we wont see the grid change colour.

You can find out the area that actually has to be painted by querying the clip bounds of the Graphics object.
The JavaDoc seems to be a bit out-dated for this method: It says, that it may return a null clip. However, this is obviously never the case (and other Swing classes also rely on the clip never being null!).
The follwing MCVE illustrates the difference between using a the clip or painting the whole component:
It contains a JPanel with a size of 800x800 in a scroll pane. The panel paints a set of rectangles, and prints how many rectangles have been painted.
One can use the "Use clip bounds" checkbox to enable and disable using the clip. When the clip is used, only the visible area of the panel is repainted, and the number of rectangles is much lower. (Note that the test whether a rectangle has to be painted or not is rather simple here: It only performs an intersection test of the rectangle with the visible region. For a real application, one would directly use the clip bounds to find out which rectangles have to be painted).
This example also shows some of the tricky internals of scroll panes: When the blinking is switched off, and the scroll bars are moved, one can see that - although the whole visible area changes - only a tiny area actually has to be repainted (namely the area that has become visible due to the scrolling). The other part is simply moved as-it-is, by blitting the previous contents. This behavior can be modified with JViewport.html#setScrollMode.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class PaintRegionTest
{
public static void main(String[] args) throws Exception
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final PaintRegionPanel paintRegionPanel = new PaintRegionPanel();
paintRegionPanel.setPreferredSize(new Dimension(800, 800));
final Timer timer = new Timer(1000, new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
paintRegionPanel.changeColor();
}
});
timer.setInitialDelay(1000);
timer.start();
JScrollPane scrollPane = new JScrollPane(paintRegionPanel);
frame.getContentPane().setLayout(new BorderLayout());
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
JPanel controlPanel = new JPanel(new FlowLayout());
final JCheckBox blinkCheckbox = new JCheckBox("Blink", true);
blinkCheckbox.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
if (blinkCheckbox.isSelected())
{
timer.start();
}
else
{
timer.stop();
}
}
});
controlPanel.add(blinkCheckbox);
final JCheckBox useClipCheckbox = new JCheckBox("Use clip bounds");
useClipCheckbox.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
paintRegionPanel.setUseClipBounds(
useClipCheckbox.isSelected());
}
});
controlPanel.add(useClipCheckbox);
frame.getContentPane().add(controlPanel, BorderLayout.SOUTH);
frame.setPreferredSize(new Dimension(400, 400));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
class PaintRegionPanel extends JPanel
{
private Color color = Color.BLACK;
private boolean useClipBounds = false;
void setUseClipBounds(boolean useClipBounds)
{
this.useClipBounds = useClipBounds;
}
void changeColor()
{
if (color == Color.BLACK)
{
color = Color.RED;
}
else
{
color = Color.BLACK;
}
repaint();
}
#Override
protected void paintComponent(Graphics gr)
{
super.paintComponent(gr);
Graphics2D g = (Graphics2D)gr;
g.setColor(color);
Rectangle clipBounds = g.getClipBounds();
Rectangle ownBounds = new Rectangle(0,0,getWidth(),getHeight());
System.out.println("clipBounds: " + clipBounds);
System.out.println(" ownBounds: " + ownBounds);
Rectangle paintedRegion = null;
if (useClipBounds)
{
System.out.println("Using clipBounds");
paintedRegion = clipBounds;
}
else
{
System.out.println("Using ownBounds");
paintedRegion = ownBounds;
}
int counter = 0;
// This loop performs a a simple test see whether the objects
// have to be painted. In a real application, one would
// probably use the clip information to ONLY create the
// rectangles that actually have to be painted:
for (int x = 0; x < getWidth(); x += 20)
{
for (int y = 0; y < getHeight(); y += 20)
{
Rectangle r = new Rectangle(x + 5, y + 5, 10, 10);
if (r.intersects(paintedRegion))
{
g.fill(r);
counter++;
}
}
}
System.out.println("Painted "+counter+" rectangles ");
}
}
An aside: For many application cases, such an "optimization" should hardly be necessary. The painted elements are intersected against the clip anyhow, so one will probably not gain much performance. When "preparing" the elements to be painted is computationally expensive, one can consider this as one option. (In the example, "preparing" refers to creating the Rectangle instance, but there may be more complicated patterns). But in these cases, there may also be more elegant and easier solutions than manually checking the clip bounds.

All answers are wrong. So I decided to answer the question despide the fact that the question is two years old.
I believe that the correct answer is calling g.getClipBounds() inside of paintComponent(Graphics g) method. It will return the rectangle in the control's coordinate system of the area which is invalidated and must be redrawn.

JTabbedPane: show task progress in a tab

I have a simple Swing Java application that performs searches, and the results are shown in a new tab. While the search is running, I want to show a progress icon or animation in the title of the tab. I tried adding a gif icon, but it doesn't animate. Is there a reason why this isn't working?

The Swing tutorial about progress bars (and showing progress in general) is a very good place to start. It shows you how to perform long-lasting operations on a worker thread by using a SwingWorker, and updating your UI at certain intervals to show progress of the long-lasting operation to the user. There is another tutorial available for more information on the SwingWorker and concurrency in Swing
And as always, this site is filled with examples. For example a previous answer of mine uses the SwingWorker class to show progress to a user
Edit
As I missed the title of tab part of your question. You could create a 'progress icon' and set that on the tab. The SwingWorker can then be used to update the icon.
An example of such an icon is , which is basically an image you rotate each time some progress is made. The tabbed pane tutorial shows you how to add icons to your tabs (or even use custom components)
Edit2
As it seems my Mac in combination with JDK1.7 makes it much easier to show an animated gif then on other systems, I created a small SSCCE as well, quite similar to that of Andrew but with a rotating icon which does not look like it has been created by, and I quote, 'demented Chimpanzee'. The rotating icon code comes from this site (I used a stripped down version and added the timer). Only thing I am not too happy about is the fact I need to pass my tabbed pane to the rotating icon to trigger. Possible solution is to pull the timer outside the RotatingIcon class, but hey, it's only an SSCCE . Images are not included but were found with Google.
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTabbedPane;
import javax.swing.Timer;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
public class ProgressTabbedPane {
public static void main( String[] args ) {
EventQueue.invokeLater( new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame( "RotatingIcon" );
JTabbedPane tabbedPane = new JTabbedPane( );
tabbedPane.addTab( "Searching", new RotatingIcon( new ImageIcon( "resources/images/progress-indeterminate.png" ), tabbedPane ),
new JLabel( new ImageIcon( "resources/images/rotatingIcon.gif" ) ) );
frame.getContentPane().add( tabbedPane );
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.pack();
frame.setVisible( true );
}
} );
}
private static class RotatingIcon implements Icon{
private final Icon delegateIcon;
private double angleInDegrees = 90;
private final Timer rotatingTimer;
private RotatingIcon( Icon icon, final JComponent component ) {
delegateIcon = icon;
rotatingTimer = new Timer( 100, new ActionListener() {
#Override
public void actionPerformed( ActionEvent e ) {
angleInDegrees = angleInDegrees + 10;
if ( angleInDegrees == 360 ){
angleInDegrees = 0;
}
component.repaint();
}
} );
rotatingTimer.setRepeats( false );
rotatingTimer.start();
}
#Override
public void paintIcon( Component c, Graphics g, int x, int y ) {
rotatingTimer.stop();
Graphics2D g2 = (Graphics2D )g.create();
int cWidth = delegateIcon.getIconWidth() / 2;
int cHeight = delegateIcon.getIconHeight() / 2;
Rectangle r = new Rectangle(x, y, delegateIcon.getIconWidth(), delegateIcon.getIconHeight());
g2.setClip(r);
AffineTransform original = g2.getTransform();
AffineTransform at = new AffineTransform();
at.concatenate(original);
at.rotate(Math.toRadians( angleInDegrees ), x + cWidth, y + cHeight);
g2.setTransform(at);
delegateIcon.paintIcon(c, g2, x, y);
g2.setTransform(original);
rotatingTimer.start();
}
#Override
public int getIconWidth() {
return delegateIcon.getIconWidth();
}
#Override
public int getIconHeight() {
return delegateIcon.getIconHeight();
}
}
}
A screenshot for reference. A shame the icons do not rotate in the screenshot.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
public class ImageOnTab {
ImageOnTab() {
final BufferedImage image = new BufferedImage(
32,32,BufferedImage.TYPE_INT_RGB);
final JTabbedPane pane = new JTabbedPane();
ImageIcon icon = new ImageIcon(image);
pane.addTab( "Progress", icon, new JTree() );
ActionListener listener = new ActionListener() {
int x = 0;
int step = 1;
public void actionPerformed(ActionEvent ae) {
Graphics g = image.createGraphics();
x+=step;
if (step>0) {
if (x>32) {
step=-step;
}
} else if (x<0) {
step=-step;
}
g.setColor(Color.ORANGE);
g.fillRect(0,0,32,32);
g.setColor(Color.RED);
g.fillRect(0,0,x,32);
g.dispose();
pane.repaint();
}
};
Timer timer = new Timer(100,listener);
timer.start();
JOptionPane.showMessageDialog(null, pane);
}
public static void main(String[] args) throws Exception {
//Create the GUI on the event dispatching thread
SwingUtilities.invokeLater(new Runnable(){
#Override
public void run() {
new ImageOnTab();
}
});
}
}

#Andrew Thompson
It would be great if the J2SE supported animated GIFs 'out of the box'
in more situations. I tried that animated GIF (nice image, BTW) as a
tab icon, and no, it remains static.
I don't want to read whole ...., but put together code by yours and #trashgod's majesty
1) use Htlm (I'm not good in plain Html)
2) use GlassPane with JLabel#(setOpaque(true))
3) use JLayer (JXLayer is better, becasue Sn'Oracle remove important methods == my view)
4) you have to force ..... for Swing JComponents by #aterai
5) Rob's Animated Icon a few times metioned support by Rob for JTabbedPane
code
import java.awt.*;
import java.awt.event.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
//https://stackoverflow.com/questions/3483485/java-jprogressbar-or-equivalent-in-a-jtabbedpane-tab-title/3484251#3484251
public class JTabbedTest {
private JFrame f = new JFrame();
private JTabbedPane jtp = new JTabbedPane();
private URL url = null;
public JTabbedTest() {
try {
url = new URL("http://pscode.org/media/starzoom-thumb.gif");
} catch (MalformedURLException ex) {
Logger.getLogger(JTabbedTest.class.getName()).log(Level.SEVERE, null, ex);
}
ImageIcon ii = new ImageIcon(url);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jtp.setPreferredSize(new Dimension(400, 200));
createTab("Reds", Color.RED);
createTab("Greens", Color.GREEN);
createTab("Blues", Color.BLUE);
f.add(jtp, BorderLayout.CENTER);
jtp.setTitleAt(2, "<html><img src=" + ii + " width=20 height=20></img></html>");
// change foreground Color for disabled tab
/*jtp.setTitleAt(2, "<html><font color=" + (jtp.isEnabledAt(2) ? "black" : "red") + ">"
+ jtp.getTitleAt(2) + "</font></html>");*/
Rectangle tabBounds = jtp.getBoundsAt(0);
Container glassPane = (Container) f.getRootPane().getGlassPane();
glassPane.setVisible(true);
glassPane.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.weightx = 1.0;
gbc.weighty = 1.0;
gbc.fill = GridBagConstraints.NONE;
gbc.insets = new Insets(tabBounds.y + 23, 0, 0, 5);
gbc.anchor = GridBagConstraints.NORTHEAST;
JButton button = new JButton("My Button Position", ii);
button.setPreferredSize(new Dimension(button.getPreferredSize().width, (int) tabBounds.getHeight() - 2));
glassPane.add(button, gbc);
f.pack();
f.setVisible(true);
}
private void createTab(String name, Color color) {
ProgressIcon icon = new ProgressIcon(color);
jtp.addTab(name, icon, new ColorPanel(jtp, icon));
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JTabbedTest jTabbedTest = new JTabbedTest();
}
});
}
private static class ColorPanel extends JPanel implements ActionListener {
private static final Random rnd = new Random();
private static final long serialVersionUID = 1L;
private final Timer timer = new Timer(1000, this);
private final JLabel label = new JLabel("Stackoverflow!");
private final JTabbedPane parent;
private final ProgressIcon icon;
private final int mask;
private int count;
public ColorPanel(JTabbedPane parent, ProgressIcon icon) {
super(true);
this.parent = parent;
this.icon = icon;
this.mask = icon.color.getRGB();
this.setBackground(icon.color);
label.setForeground(icon.color);
this.add(label);
timer.start();
}
#Override
public void actionPerformed(ActionEvent e) {
this.setBackground(new Color(rnd.nextInt() & mask));
this.icon.update(count += rnd.nextInt(8));
this.parent.repaint();
}
}
private static class ProgressIcon implements Icon {
private static final int H = 16;
private static final int W = 3 * H;
private Color color;
private int w;
public ProgressIcon(Color color) {
this.color = color;
}
public void update(int i) {
w = i % W;
}
#Override
public void paintIcon(Component c, Graphics g, int x, int y) {
g.setColor(color);
g.fillRect(x, y, w, H);
}
#Override
public int getIconWidth() {
return W;
}
#Override
public int getIconHeight() {
return H;
}
}
}

MouseMotionListener in Java Swing, using it with components inside components etc

I am working on a Touch User interface in Swing. While I know this isn't optimal, I am on a short deadline and don't have time to Touch-screen specific GUI packages (if there are any).
I want my users to be able to 'swipe' their finger across the screen, and the view of a special JScrollPane I made moves with it.
The code is very simple -
public class PanScrollPane extends JScrollPane implements MouseMotionListener{
public PanScrollPane() {
super();
this.addMouseMotionListener(this);
}
#Override
public void mouseDragged(MouseEvent arg0) {
System.out.println("Mouse Dragged!");
}
#Override
public void mouseMoved(MouseEvent arg0) {
System.out.println("Mouse Moved!");
}
The problem I'm having is that the JScrollPane is a container for all sorts of JComponents. When I first started working on this, I figured the MouseMovedEvent and MouseDraggedEvent would propagate up the 'GUI tree', untill they encountered a Component with a listener specifically for that event. Now it seems that any component I add to the panScrollPane blocks any of these MouseMotion events, leaving me unable to pan.
panScrollPane.add(new JButton("This thing blocks any mouse motion events"));
I figured propagating the MouseEvent by hand (adding listeners to every single component and then having them send the event to their parent) would work. This, however, is a very time-intensive undertaking and as I would rather spend my time working on other things, I was wondering if any of you know any work-around for this problem.
Thanks for reading, and hopefully thanks for answering! :)
edit: To make my intentions clearer. I only want the mousemotion events to be caught by the panPanel, any other event (like MouseClick, MouseRelease) should be processed normally

This ad hoc approach leverages the existing JScrollPane actions that are usually used in key bindings. You'll have to tune N to your implementation of Scrollable.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.Action;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JViewport;
import javax.swing.Timer;
/** #see http://stackoverflow.com/questions/7201509 */
public class ScrollAction extends JPanel {
private static final int TILE = 64;
private static final int DELTA = 16;
public ScrollAction() {
this.setOpaque(false);
this.setFocusable(true);
this.setPreferredSize(new Dimension(50 * TILE, 50 * TILE));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.lightGray);
int w = this.getWidth() / TILE + 1;
int h = this.getHeight() / TILE + 1;
for (int row = 0; row < h; row++) {
for (int col = 0; col < w; col++) {
if ((row + col) % 2 == 0) {
g.fillRect(col * TILE, row * TILE, TILE, TILE);
}
}
}
}
private void display() {
JFrame f = new JFrame("ScrollAction");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JScrollPane scrollPane = new JScrollPane(this);
final ScrollTimer left = new ScrollTimer(scrollPane, "scrollLeft");
final ScrollTimer right = new ScrollTimer(scrollPane, "scrollRight");
final ScrollTimer up = new ScrollTimer(scrollPane, "scrollUp");
final ScrollTimer down = new ScrollTimer(scrollPane, "scrollDown");
final JViewport viewPort = scrollPane.getViewport();
viewPort.setPreferredSize(new Dimension(5 * TILE, 5 * TILE));
viewPort.addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
left.stop();
if (e.getX() < DELTA) {
left.start();
}
right.stop();
if (e.getX() > viewPort.getWidth() - DELTA) {
right.start();
}
up.stop();
if (e.getY() < DELTA) {
up.start();
}
down.stop();
if (e.getY() > viewPort.getHeight() - DELTA) {
down.start();
}
}
});
f.add(scrollPane);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private static final class ScrollTimer implements ActionListener {
private static int N = 10;
private static int DELAY = 100;
private String cmd;
private Timer timer;
private Action action;
private JScrollPane scrollPane;
private int count;
public ScrollTimer(JScrollPane scrollPane, String action) {
this.cmd = action;
this.timer = new Timer(DELAY, this);
this.action = scrollPane.getActionMap().get(action);
this.scrollPane = scrollPane;
}
#Override
public void actionPerformed(ActionEvent e) {
if (count++ < N) {
action.actionPerformed(new ActionEvent(scrollPane, 0, cmd));
} else {
timer.stop();
}
}
public void start() {
count = 0;
timer.start();
}
public void stop() {
timer.stop();
count = 0;
}
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new ScrollAction().display();
}
});
}
}

How about using a GlassPane? I think its meant to address exactly these types of situations.

Getting mouseEvents for a component and all its children is ... tricky to get right. You might consider to rely on stable (and extensively tested :-) code around. The jdk7 way of doing it is to use a JLayer (which internally registers an AWTEventListener as it has all priviledges). For earlier versions, you can use its predecessor JXLayer