Question

By input elements I mean things like JSpinners and JComboxBoxes. My glasspane is passed a JPanel containing JSpinners, JComboBoxes and for the most part, JLabels. The glasspane has a MouseListener attached. The surprising thing is that mouseEntered is called upon the mouse cursor leaving the input elements and hovering over the other parts or empty space of the JPanel! Is this normal behaviour? How can I get the input elements to be considered part of the JPanel for Glasspane purposes?

Here is a screenshot of my UI with its input elements and jLabels.

Here is an example piece of Code:

import javax.swing.*;

public class DialogTest {
    public DialogTest() {
        JPanel dialogPanel = new JPanel();
        SpinnerModel edgeModel = new SpinnerNumberModel(1, 1, 9, 1);
        JSpinner edgeSpn = new JSpinner(edgeModel);
        dialogPanel.add(edgeSpn);

        JDialog initialDialog = new JDialog(new JFrame(), "Test", true);
        initialDialog.setContentPane(dialogPanel);
        initialDialog.pack();
        glass = new GlassComponent(dialogPanel);
        initialDialog.setGlassPane(glass);
        glass.setOpaque(false);
        glass.setVisible(true);
    initialDialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
    initialDialog.setVisible(true);
    }
}

public class GlassComponent implements MouseListener {
   JPanel c;
   public GlassComponent(JPanel c) {
       this.c = c;
       this.c.addMouseListener(this);
   }

   ...
   public mouseEntered(MouseEvent e) {
       System.out.println("Entered JPanel");
   }    
}

By way of explanation, my goal is to eventually use the GlassPane to block input for those elements marked with the prohibition sign. However, given that the mouseListener assigned to the dialogPanel is seemingly generating new events upon leaving the input elements, I may have some difficulties achieving this.

Answer 1

You can forward mouse events to the underlying components, as shown in The Glass Pane demo’s method, redispatchMouseEvent().