CODEWITHSUNDEEP
javaswingjbutton
user3607758
user3607758

Reputation: 123

JButton remaining focused for too long

I am having a problem with a JButton named saveChanges remaining focused for too long when pressed, and I am not sure why this is happening. Below is an excerpt from my code:

saveChanges.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        saveChanges.setFocusPainted(false);
        setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));

        // execute some code which inserts records into a database

        setCursor(Cursor.getDefaultCursor());
    }
}

The code in this method takes about 5-10 seconds to execute but for some reason the cursor returns to the default cursor state several seconds before the saveChanges button returns to its non-focused state and I can't figure out why. Any help would be greatly appreciated!

Upvotes: 2

Views: 71

Answers (2)

dramzy
dramzy

Reputation: 1429

Non-GUI processes should be executed on a separate thread from the Event Dispatch Thread (EDT). Use a SwingWorker to handle these operations.

Upvotes: 0

MadProgrammer
MadProgrammer

Reputation: 347194

Swing is a single threaded environment, anything that blocks the Event Dispatching Thread, used by Swing to process new events, including repaint requests, will cause the UI to look like it's frozen, because it is.

Have a look at Concurrency in Swing for more details.

Equally, Swing is not thread safe, this means that any updates made to the UI must be made from within the context of the EDT.

You could use a SwingWorker to do the long running process in the background (from within it's doInBackground method) and update the state of the UI by overriding it's done method, which is called from within the context of the EDT once the doInBackground method has exited.

Take a look at Worker Threads and SwingWorker for more details

Upvotes: 3

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