Question

I have a question about Java and JFrame in particular. Let’s say I have a JFrame that I am using with a GridLayout. Supposing that I have added JButtons in the JFrame, how can I gain access to the one I want using it’s position (by position, I mean a x and a y, used to define the exact place on the Grid). I have tried several methods, for instance getComponentAt(int x, int y), and have seen that those methods do not work as intended when combined with GridLayout, or at least don’t work as intended in my case. So I tried using getComponent(), which seems fine.

The latest method, that seems to be on a right track for me is (assuming I have a JFrame with a GridLayout with 7 rows and 7 columns, x as columns, y as rows):

public JButton getButtonByXAndY(int x, int y) {
    return (JButton) this.getContentPane().getComponent((y-1) * 7 + x);
}

image http://www.freeimagehosting.net/newuploads/9d6hq.jpg

Using the above, say I want to get the JButton at (4, 4), meaning the 25th JButton in the JFrame, I would index through the first 21 buttons at first, and then add 4 more, finally accessing the JButton I want. Problem is this works like that in theory only. Any ideas?

P.S sorry for linking to an external website, but stack overflow won’t allow me to upload the image, because I do not have the required reputation.

Answer 1

This example compares two approaches:

1. Maintain a List<JButton> and calculate the index algebraically.

2. Extend JButton and allow each button to maintain its own grid location.