Get location of a swing component

Question

I have put some JPanels into another JPanel which its\' layout is Box Layout and Y-Axis. After I have put all the panels I need to get the Y position of each added JPanel in

Answer 1

The problem is often that the layout or the drawing is done only after the whole method returned. In that case, getX and getY return 0.

It may help to call pack() on the frame window, or doLayout() or validate() on the JPanel you are working on. But often it doesn't help, because you have little influence on the internal scheduling: http://www.oracle.com/technetwork/java/painting-140037.html

What does help me in this case is to put the part where I need the X and Y location into a worker thread:

JPanel panelHolder = new JPanel(new BoxLayout(this, BoxLayout.Y_AXIS));
for(int i = 0; i< 10; i++){
    JPanel p = new JPanel(); 
    panelHolder.add(p);
}

int componentCount = panelHolder.getComponentCount();

SwingUtilities.invokeLater(new Runnable() {         
    @Override
    public void run() {
        for (int j = 0; i < componentCount; j++) {    
            Component c = pnlRowHolder.getComponent(i);
            JPanel p = (JPanel) c;
            System.out.println(p.getY());
        }
    }
});

This way getting the X and Y will be postponed until the layout is done.