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Wrong size with JScrollPane containing updated image

I am coding a GUI containing a JScrollPane that displays an image that gets updated (with potential modification of its dimensions). The image is in an ImageIcon in a JLabel. The image size is retrieved using ImageIcon.getIconWith() and getIconHeight(). And the JLabel preferred size is updated with those dimensions.
When the application is started for the first time, the JScrollPane and its scrollbars have the right dimensions to view the whole image (potentially using scrolling). But when the image gets updated the JScrollPane and the scrollbars assume the image has the dimensions of the previous image. How do I get the JScrollPane to update correctly ?
Here is a curated version of my GUI. Visualizer.java uses the GUI VisualizerGUI.java. When the "Run" button is pushed, a new image is randomly generated using ImageDrawer.drawImage() (simulates the behavior of the real application) and the content of the JScrollPane is updated using the function VisualizerGUI.setTransitionsImage(String imgPath).
Visualizer.java:
import java.util.*;
import java.io.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class Visualizer implements ActionListener {
private VisualizerGUI gui = null;
public Visualizer() {
gui = VisualizerGUI.createAndStart(this);
}
public static void main(String[] args) {
Visualizer viz = new Visualizer();
}
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("Run command")) {
run();
}
}
public void run() {
updateGUIwithSolution();
}
public void updateGUIwithSolution() {
gui.initGUIupdate();
try {
ImageDrawer.drawImage();
gui.setTransitionsImage("image.png");
} catch (Exception e) {
System.out.println("Error while generating image");
e.printStackTrace();
}
gui.finalizeGUIupdate();
}
}
VisualizerGUI.java:
import java.util.*;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.event.ActionListener;
import javax.swing.*;
import java.lang.reflect.InvocationTargetException;
public final class VisualizerGUI {
private JFrame frame;
private JButton runButton;
private JButton nextButton;
private JScrollPane transitionsDisplay;
private JTabbedPane executionsDisplay;
private JTabbedPane tracesDisplay;
private JTextArea textInfoArea;
public VisualizerGUI() {}
private void initGUI(ActionListener actionsHandler) {
//Create and set up the window.
frame = new JFrame("Visualizer");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel controlPanel = new JPanel(new FlowLayout());
runButton = new JButton("Run");
runButton.addActionListener(actionsHandler);
runButton.setActionCommand("Run command");
controlPanel.add(runButton);
nextButton = new JButton("Next");
nextButton.addActionListener(actionsHandler);
nextButton.setActionCommand("Find next solution");
controlPanel.add(nextButton);
transitionsDisplay = new JScrollPane();
executionsDisplay = new JTabbedPane();
tracesDisplay = new JTabbedPane();
JSplitPane ETspliter = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, executionsDisplay, tracesDisplay);
JSplitPane graphsSpliter = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, transitionsDisplay, ETspliter);
textInfoArea = new JTextArea();
textInfoArea.setLineWrap(true);
textInfoArea.setWrapStyleWord(true);
textInfoArea.setEditable(false);
JScrollPane textInfoAreaSP = new JScrollPane(textInfoArea);
JSplitPane topSpliter = new JSplitPane(JSplitPane.VERTICAL_SPLIT, graphsSpliter, textInfoAreaSP);
transitionsDisplay.setPreferredSize(new Dimension(200,200));
executionsDisplay.setPreferredSize(new Dimension(200,200));
tracesDisplay.setPreferredSize(new Dimension(200,200));
textInfoAreaSP.setPreferredSize(new Dimension(200,100));
frame.getContentPane().setLayout(new BorderLayout());
frame.getContentPane().add(controlPanel, BorderLayout.NORTH);
frame.getContentPane().add(topSpliter, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
public static VisualizerGUI createAndStart(ActionListener actionsHandler) {
VisualizerGUI gui = new VisualizerGUI();
final Runnable guiRunner =
new Runnable() {
public void run() {
gui.initGUI(actionsHandler);
// gui.pack();
}
};
try {
javax.swing.SwingUtilities.invokeAndWait(guiRunner);
} catch (InterruptedException e) {
System.out.println(">>> WARNING <<< InterruptedException while creating the GUI");
} catch (InvocationTargetException e) {
System.out.println(">>> WARNING <<< InvocationTargetException while creating the GUI");
}
return gui;
}
public void clear() {
initGUIupdate();
finalizeGUIupdate();
}
public void initGUIupdate() {
// frame.setVisible(false);
transitionsDisplay.setViewportView(null);
executionsDisplay.removeAll();
tracesDisplay.removeAll();
textInfoArea.setText(null);
}
public void pack() {
frame.pack();
}
public void finalizeGUIupdate() {
// frame.validate();
// frame.repaint();
// frame.setVisible(true);
}
public void setTransitionsImage(String imgPath) {
ImageIcon icon = new ImageIcon(imgPath);
icon.getImage().flush();
int width = icon.getIconWidth();
int height = icon.getIconHeight();
JLabel label = new JLabel();
label.setVerticalAlignment(SwingConstants.CENTER);
label.setHorizontalAlignment(SwingConstants.CENTER);
label.setIcon(icon);
label.setPreferredSize(new Dimension(width,height));
//label.setPreferredSize(null);
transitionsDisplay.setViewportView(label);
label.revalidate();
label.repaint();
transitionsDisplay.getViewport().revalidate();
transitionsDisplay.getViewport().repaint();
transitionsDisplay.revalidate();
// transitionsDisplay.validate();
transitionsDisplay.repaint();
frame.revalidate();
// frame.validate();
frame.repaint();
}
public void setTransitionsImageInED(String imgPath) {
final Runnable guiRunner =
new Runnable() {
public void run() { setTransitionsImage(imgPath); }
};
// javax.swing.SwingUtilities.invokeLater(guiRunner);
try {
javax.swing.SwingUtilities.invokeAndWait(guiRunner);
} catch (InterruptedException e) {
System.out.println(">>> WARNING <<< InterruptedException while creating the GUI");
} catch (InvocationTargetException e) {
System.out.println(">>> WARNING <<< InvocationTargetException while creating the GUI");
}
}
}
ImageDrawer.java:
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class ImageDrawer {
public static void drawImage() throws Exception {
try {
int width = 20 + (int)(Math.random() * 1000);
int height = 20 + (int)(Math.random() * 1000);
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D ig2 = bi.createGraphics();
ig2.setPaint(Color.blue);
ig2.fillRect(0, 0, width, height);
ig2.setPaint(Color.red);
ig2.fillRect(5, 5, width - 10, height - 10);
ig2.setPaint(Color.blue);
ig2.drawLine(0, 0, width, height);
ig2.drawLine(0, height, width, 0);
ImageIO.write(bi, "PNG", new File("image.png"));
} catch (IOException ie) {
ie.printStackTrace();
}
}
}
Can someone explain why I have this problem? Thanks!

transitionsDisplay.setPreferredSize(new Dimension(200,200));
executionsDisplay.setPreferredSize(new Dimension(200,200));
tracesDisplay.setPreferredSize(new Dimension(200,200));
textInfoAreaSP.setPreferredSize(new Dimension(200,100));
Don't use setPreferredSize(...). Each Swing component is responsible for determining its own size.
The image size is retrieved using ImageIcon.getIconWith() and getIconHeight(). And the JLabel preferred size is updated with those dimensions.
Not necessary. Again the JLabel will determine its own size based on the size of the Icon. This is done dynamically as the image/icon changes.
The scrollbars of the scrollpane will appear when the preferred size of the label is greater than the size of the scrollpane. Just let the layout managers do their job.

Java JComboBox scroll to selected item

I have a grid with data and a JComboBox with a lot of users in it, of which one is selected. I would like to scroll to the selected item to the area where user can't see the rest of the data(the bottom of the grid) so that my JScrollPane will jump to this area automatically.
How can I do that?
I think this has something to do with scrollRectToVisible() method.

A JComboBox needs no JScrollPane.
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class OneLineCombo {
private JComponent ui = null;
OneLineCombo() {
initUI();
}
public void initUI() {
if (ui!=null) return;
ui = new JPanel(new BorderLayout(4,4));
ui.setBorder(new EmptyBorder(4,20,4,20));
String[] fontFamily = GraphicsEnvironment.
getLocalGraphicsEnvironment().getAvailableFontFamilyNames();
JComboBox fontCombo = new JComboBox(fontFamily);
fontCombo.setMaximumRowCount(1);
ui.add(fontCombo, BorderLayout.PAGE_START);
ui.add(new JLabel("Type some letters of the font name to select it"),
BorderLayout.PAGE_END);
}
public JComponent getUI() {
return ui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception useDefault) {
}
OneLineCombo o = new OneLineCombo();
JFrame f = new JFrame(o.getClass().getSimpleName());
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o.getUI());
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}

why does my code not show both frame.add?

the script works fine for dragging around one image but if I try to get two of them going at once it acts as if the class can only be called once? here is the code where i am adding two imageicons , but only one is showing:
import java.awt.*;
import javax.swing.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
public class TestMouseDrag {
public static void main(String[] args) {
new TestMouseDrag();
}
public TestMouseDrag() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new DragMyIcon("C:\\Users\\anon\\Desktop\\Hobbit.png")).setLocation(100, 100);
frame.add(new DragMyIcon("C:\\Users\\anon\\Desktop\\alien.png")).setLocation(100, 100)
frame.pack();
frame.setSize(700,700);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class DragMyIcon extends JPanel {
public static final long serialVersionUID = 172L;
private JLabel label;
public DragMyIcon(String path) {
setLayout(null);
ImageIcon icon = null;
icon = new ImageIcon(path);
label = new JLabel(icon);
label.setBounds(0,0,100, 100);
label.setHorizontalAlignment(JLabel.CENTER);
label.setVerticalAlignment(JLabel.CENTER);
add(label);
MouseHandler handler = new MouseHandler();
label.addMouseListener(handler);
label.addMouseMotionListener(handler);
}
}
protected class MouseHandler extends MouseAdapter {
private boolean active = false;
private int xDisp;
private int yDisp;
#Override
public void mousePressed(MouseEvent e) {
active = true;
JLabel label = (JLabel) e.getComponent();
xDisp = e.getPoint().x - label.getLocation().x;
yDisp = e.getPoint().y - label.getLocation().y;
label.setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));
}
#Override
public void mouseReleased(MouseEvent e) {
active = false;
JLabel label = (JLabel) e.getComponent();
label.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
#Override
public void mouseDragged(MouseEvent e) {
if (active) {
JLabel label = (JLabel) e.getComponent();
Point point = e.getPoint();
label.setLocation(point.x - xDisp, point.y - yDisp);
label.invalidate();
label.repaint();
}
}
#Override
public void mouseMoved(MouseEvent e) {
}
}}

Your code does not respect the layout managers that it is using -- BorderLayout. When you add a component to a BorderLayout using container without specifying position, it is placed by default BorderLayout.CENTER and covers anything added previously.
Solution: read up on the layout managers including BorderLayout to see how to use them.
Also, you're probably better off not adding two DragMyIcon objects, but rather changing DragMyIcon so that it allows for multiple JLabels.

Remove JButton rectangle white border

Does somebody know how to remove white rectangle border on JButton ? This issue is there only for windows look & feel when the button is a little bit rounded.
Please find attached the example on the image.
Setting the border to empty or null doesn't help. The same for margin.
The white margin/border dissapear only when I set the opacity of the button to false, but unfortunately in this case also the whole button is opaque on some versions of windows.
When I set opacity to false, it looks like:
Code example:
public class TestFrame extends javax.swing.JFrame {
/**
* Auto-generated main method to display this JFrame
*/
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (UnsupportedLookAndFeelException e) {
e.printStackTrace();
}
TestFrame inst = new TestFrame();
inst.setLocationRelativeTo(null);
inst.setVisible(true);
}
});
}
public TestFrame() {
this.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
this.setLayout(null);
this.getContentPane().setBackground(Color.BLACK);
JButton button = new JButton();
button.setBounds(10, 10, 100, 50);
button.setBorder(BorderFactory.createEmptyBorder()); // not working
button.setBorder(null); // not working
button.setMargin(new Insets(0,0,0,0)); // not working
add(button);
pack();
setSize(400, 300);
}
}
Thanks,
Lubos

Seems like a painting problem. You can use:
button.setBackground( Color.BLACK );

EDIT: See comments below. This sample still shows the effect, even using a proper layout. Setting the background color seems to show the unwanted border. This effect doesn't show with Metal. It seems as if Windows L&F shows a rounded edge, but the button is still rectangular. The space between is only noticable if the BG color of the container is changed to something obvious, like black.
import java.awt.*;
import javax.swing.*;
public class TestFrame extends JFrame
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch (Exception e)
{
e.printStackTrace();
}
TestFrame inst = new TestFrame();
inst.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
inst.setLocationRelativeTo(null);
inst.setVisible(true);
}
});
}
public TestFrame()
{
JButton button = new JButton("One");
JButton button2 = new JButton("Two");
JPanel p = new JPanel();
p.setBackground(Color.BLACK);
p.setLayout(new FlowLayout());
p.add(button);
p.add(button2);
add(p);
setSize(400, 300);
}
}

How to Remove JFrame Border as to Let an Image Touch The Edge

I had a friend make a background for the program I made so that it wouldn't look so plain, and I thought the best way to place the images would be to make a JLabel, fill it with an image, and set it to the size of the screen. This worked fine, except there is a small border around the JFrame and I can't get the JLabel to touch the edges of the frame. Thoughts? I have attached a picture.
public class ProgramDriver extends JFrame {
private JPanel contentPane;
private static CardLayout cardLayout;
private JTextField addGradeN;
private JTextField addGradeD;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ProgramDriver frame = new ProgramDriver();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
//Global Variables
...
manager = new StateManager(gb);
//JFrame Settings
setTitle("Grade Book");
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setBounds(100, 100, 656, 530);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
cardLayout = new CardLayout(0,0);
contentPane.setLayout(cardLayout);
setResizable(false);
//Home Panel
final JPanel Home = new JPanel();
contentPane.add(Home, "Home");
Home.setLayout(null);
JButton btnSeeGrades = new JButton("See Grades");
...
//Grades Panel
JPanel Grades = new JPanel();
contentPane.add(Grades, "Grades");
Grades.setLayout(null);'

The problem isn't with the JFrame, the problem is with your code. We can spend the rest of our natural life at guessing what's wrong or you can post some example code.
Now it's up to you, we can keep trying to throw wrong guess after wrong guess at you, frustrating us all, or you can help us help you...
Here are two examples I did. The first uses a JLabel as the primary content for a JPanel, where the child components are placed on it. Nice and simple.
The second uses a custom JPanel which paints the image onto the background of the component. I then use this to replace the frames content pane. This is a little more involved, but it has the added benefit of been easily updated (replacing the content pane won't effect the rest of the program)
Example 1: JLabel used as background
public class TestBackground {
public static final String BACKGROUND_PATH = "/Volumes/Macintosh HD2/Dropbox/MT015.jpg";
public static void main(String[] args) {
new TestBackground();
}
public TestBackground() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setLayout(new BorderLayout());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new LabelPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
protected class LabelPane extends JPanel {
public LabelPane() {
BufferedImage bg = null;
try {
bg = ImageIO.read(new File(BACKGROUND_PATH));
} catch (IOException ex) {
ex.printStackTrace();
}
JLabel label = new JLabel(new ImageIcon(bg));
setLayout(new BorderLayout());
add(label);
label.setLayout(new GridBagLayout());
JLabel lblMessage = new JLabel("Look at me!");
lblMessage.setForeground(Color.WHITE);
lblMessage.setFont(lblMessage.getFont().deriveFont(Font.BOLD, 48));
label.add(lblMessage);
}
}
}
Example 2: Image used as background, replacing content pane...
public class TestBackground {
public static final String BACKGROUND_PATH = "/Volumes/Macintosh HD2/Dropbox/MT015.jpg";
public static void main(String[] args) {
new TestBackground();
}
public TestBackground() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setLayout(new BorderLayout());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new BackgroundPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
protected class BackgroundPane extends JPanel {
private BufferedImage bg = null;
public BackgroundPane() {
try {
bg = ImageIO.read(new File(BACKGROUND_PATH));
} catch (IOException ex) {
ex.printStackTrace();
}
setLayout(new GridBagLayout());
JLabel lblMessage = new JLabel("Look at me!");
lblMessage.setForeground(Color.WHITE);
lblMessage.setFont(lblMessage.getFont().deriveFont(Font.BOLD, 48));
add(lblMessage);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(1153, 823);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (bg != null) {
g.drawImage(bg, 0, 0, this);
}
}
}
}

To expand on Eng.Fouad's answer, you'll want to use the drawImage(...) method that takes 6 parameters, image, x and y location, image width and height, and image observer, and draw it like so from within a JPanel:
g.drawImage(img, 0, 0, getWidth(), getHeight(), this);
For example, my sscce:
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class ExpandingImage extends JPanel {
public static final String GUITAR = "http://duke.kenai.com/Oracle/OracleStrat.png";
BufferedImage img;
public ExpandingImage(String imgUrlPath) throws IOException {
URL imgUrl = new URL(imgUrlPath);
img = ImageIO.read(imgUrl);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
g.drawImage(img, 0, 0, getWidth(), getHeight(), this);
}
}
private static void createAndShowGui() {
ExpandingImage mainPanel;
try {
mainPanel = new ExpandingImage(GUITAR);
JFrame frame = new JFrame("ExpandingImage");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible(true);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Edit
I see that you're using an EmptyBorder around the contentPane. Why if you don't want this border to be present?

As an alternative, you can override the method paintComponent(Graphics g) of JPanel (the contentPane) and use drawImage() on the Graphics object g as in this example.

have you tried JFrame function setUndecorated() ?

Make the frame undecorated. frame.setUndecorated(true)
If you want to make it move, you can use the ComponentMover of the Java2S.
Make sure that it is undecorated before it is visible.
Next, use setContentPane(new JLabel(new ImageIcon("myimage.jpg")));
After, that you can add contents as usual.