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From: Eric Sosman <esosman@comcast-dot-net.invalid>
Newsgroups: comp.lang.java.programmer
Subject: Re: What do you think of my CropImage class
Date: Thu, 21 Jul 2016 11:13:16 -0400
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On 7/21/2016 10:58 AM, Knute Johnson wrote:
> On 7/21/2016 03:05, Cecil Westerhof wrote:
>>
>>> Runnable r = new Runnable() {
>>> public void run() {
>>> try {
>>> ImageIO.write(subImage,"JPEG",new
>>> File("crop.jpg"));
>>> } catch (IOException ioe) {
>>> ioe.printStackTrace();
>>> }
>>> }
>>> };
>>> new Thread(r).start();
>>
>> Why are you doing this in a separate thread?
>>
>
> So if you have a large image that takes a second or two to write it
> won't block the Event Dispatch Thread and mess up the mouse movement.

     A slightly slicker way to do this is with a SwingWorker, the
advantage being that it can inform the GUI when the save completes.
You could then display a JDialog if there was a problem, or arrange
to display a busy cursor while the save runs and restore the original
cursor afterward, or ...

     SwingWorker is, however, a bit more complex than a "fire and forget"
Thread, so CW might choose to stick with the simpler alternative for
now and revisit the fancier one later on.

http://docs.oracle.com/javase/tutorial/uiswing/concurrency/worker.html

-- 
esosman@comcast-dot-net.invalid
"Don't be afraid of work. Make work afraid of you." -- TLM