Is there any way to see from the ComponentEvent whether the user
resized the window or I did through setSize()?
yes it is, use boolean flag reseted by Swing Timer
in the case that user resized window then ComponentListener firing a new event per every pixel, bunch of events
by determine the contianer set(Xxx)Size is this event fired only once time
example about events from ComponentListner
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Vector;
public class ComponentEventDemo extends JPanel
implements ComponentListener, HierarchyListener,
ItemListener {
private JFrame frame;
private static final long serialVersionUID = 1L;
private JTextArea display;
private JLabel label;
private JButton button = new JButton("Change Size");
private String newline = "\n";
public ComponentEventDemo() {
display = new JTextArea();
display.setEditable(false);
JScrollPane scrollPane = new JScrollPane(display);
scrollPane.setPreferredSize(new Dimension(350, 200));
label = new JLabel("This is a label", JLabel.CENTER);
label.addComponentListener(this);
JCheckBox checkbox = new JCheckBox("Label visible", true);
checkbox.addItemListener(this);
checkbox.addComponentListener(this);
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Dimension dim = frame.getPreferredSize();
if (!dim.equals(new Dimension(800, 600))) {
frame.setPreferredSize(new Dimension(800, 600));
frame.pack();
} else {
frame.setPreferredSize(new Dimension(400, 300));
frame.pack();
}
}
});
JPanel panel = new JPanel(new GridLayout(1, 3));
panel.add(label);
panel.add(checkbox);
panel.add(button);
panel.addComponentListener(this);
frame = new JFrame("ComponentEventDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scrollPane, BorderLayout.CENTER);
frame.add(panel, BorderLayout.PAGE_END);
frame.pack();
frame.setVisible(true);
}
@Override
public void itemStateChanged(ItemEvent e) {
if (e.getStateChange() == ItemEvent.SELECTED) {
label.setVisible(true);
label.revalidate();
label.repaint();
} else {
label.setVisible(false);
}
}
protected void displayMessage(String message) {
//If the text area is not yet realized, and
//we tell it to draw text, it could cause
//a text/AWT tree deadlock. Our solution is
//to ensure that the text area is realized
//before attempting to draw text.
// if (display.isShowing()) {
display.append(message + newline);
display.setCaretPosition(display.getDocument().getLength());
//}
}
@Override
public void componentHidden(ComponentEvent e) {
//displayMessage(e.getComponent().getClass().getName() + " --- Hidden");
}
@Override
public void componentMoved(ComponentEvent e) {
//displayMessage(e.getComponent().getClass().getName() + " --- Moved");
}
@Override
public void componentResized(ComponentEvent e) {
displayMessage(e.getComponent().getClass().getName() + " --- Resized ");
}
@Override
public void componentShown(ComponentEvent e) {
//displayMessage(e.getComponent().getClass().getName() + " --- Shown");
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
ComponentEventDemo componentEventDemo = new ComponentEventDemo();
}
});
}
@Override
public void hierarchyChanged(HierarchyEvent e) {
displayMessage(e.getComponent().getClass().getName() + " --- Hierarchy changed");
}
}