Any validation in Swing can be performed using an InputVerifier. 1. First create your own input verifier: public class MyInputVerifier extends InputVerifier { @Override public boolean verify(JComponent input) { String text = ((JTextField) input).getText(); try { BigDecimal value = new BigDecimal(text); return (value.scale() <= Math.abs(4)); } catch (NumberFormatException e) { return false; } } } … Read more
Never do long running tasks in response to a button, event, etc as these are on the event thread. If you block the event thread, the ENTIRE GUI will be completely unresponsive resulting in REALLY pissed off users. This is why Swing seems slow and crusty. Use Threads, Executors, and SwingWorker to run tasks NOT … Read more
You don’t have write any C/JNI code. From Java: import sun.awt.windows.WComponentPeer; public static long getHWnd(Frame f) { return f.getPeer() != null ? ((WComponentPeer) f.getPeer()).getHWnd() : 0; } Caveats: This uses a sun.* package. Obviously this is not public API. But it is unlikely to change (and I think less likely to break than the solutions … Read more
The problem is that the height of rows in JTable is fixed, so it’s not just a matter of having a renderer that wraps; I’m not sure why it doesn’t, but if it did, the wrapped text would be cropped – or maybe that’s exactly what you’re seeing. To adjust row heights, you need to … Read more
Try this. addWindowListener(new WindowAdapter() { @Override public void windowClosing(WindowEvent e) { System.out.println(“Closed”); e.getWindow().dispose(); } });
Curses! Beaten to the punch by a Google search. Unfortunately it’s true there is no easy way to create draggable tab panes (or any other components) in Swing. So whilst the example above is complete this one I’ve just written is a bit simpler. So it will hopefully demonstrate the more advanced techniques involved a … Read more
Have you tried setting JButton.setOpaque(true)? JButton button = new JButton(“test”); button.setBackground(Color.RED); button.setOpaque(true);
I doubt that is the recommended approach for appending text. This means every time you change some text you need to reparse the entire document. The reason people may do this is because the don’t understand how to use a JEditorPane. That includes me. I much prefer using a JTextPane and then using attributes. A … Read more
It does not appear this is supported in Swing in Java 6. Currently, the simplest way I can find to open this dialog is through SWT, not Swing. SWT’s FileDialog (javadoc) brings up this dialog. The following is a modification of SWT’s FileDialog snippet to use an open instead of save dialog. I know this … Read more
What will be cleaner and easier to maintain? All things being equal, probably JavaFX – the API is much more consistent across components. However, this depends much more on how the code is written rather than what library is used to write it. And what will be faster to build from scratch? Highly dependent on … Read more