How to set the scrollbar to bottom after JTextPane finish loading image?

Question

I'm making a chat room with a JTextPane with html function. Users are able to input html tag to show image on the screen. But I'm having a problem to keep the scrollbar at bottom. I already try to do

SwingUtilities.invokeLater(new Runnable() {
    public void run() {
        vertical.setValue(vertical.getMaximum());
    }
});

but the scrollbar scroll down then scroll up again. It seems like the picture finish loading after the function been called. I also tried:

ClientScreen._chatMsgPane.setCaretPosition(_chatMsgPane.getDocument().getLength());

but the result are the same. Is there's any event will trigger after all image finish loading? Or is there any other way to fix this?

btw I also tried to call Thread.sleep(450); after setText(); but it work strangely. The screen will become messy if I type quickly and every time when I send message the scrollbar will scroll up and scroll down. I mean it work but not well. — Ashley Shen, Jun 09 '13 at 20:41
Please edit your question to include an [sscce](http://sscce.org/) that exhibits the problem you describe; you can access posted images via `URL`, as shown [here](http://stackoverflow.com/a/10862262/230513), to reproduce latency. — trashgod, Jun 09 '13 at 21:04

score 0 · Answer 1 · answered Jun 10 '13 at 02:15

0

I've never tried this on a JTextPane that is loading an image but Smart Scrolling might work for you.

answered Jun 10 '13 at 02:15

camickr

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VGR · Answer 2 · 2013-06-10T18:11:10.633

JComponent has a method named scrollRectToVisible which is designed to do this:

SwingUtilities.invokeLater(new Runnable() {
    public void run() {
        int end = chatMsgPane.getDocument().getLength();
        try {
            chatMsgPane.scrollRectToVisible(chatMsgPane.modelToView(end));
        } catch (BadLocationException e) {
            throw new RuntimeException(e); // Should never get here.
        }
    }
});

I'm not entirely sure how you are addng the image to the JTextPane, but if you are loading it yourself, you can load it in a different thread with ImageIO.read and then scroll to bottom when the read is finished; or, if you want to show the image progressively, you can obtain an ImageReader from ImageIO, and pass your own listener to its addIIOReadProgressListener method.

How to set the scrollbar to bottom after JTextPane finish loading image?

2 Answers2