Posted by
Michael Schmid on
Mar 18, 2020; 5:07pm
URL: http://imagej.273.s1.nabble.com/KeyListener-problem-tp5023044p5023061.html
Hi Kenneth,
getting KeyListeners: There is method
KeyListener[] Component.getKeyListeners().
Canvases, Containers (Windows, Panels), and gui elements (checkboxes,
text fields, ...) are java.awt.Components.
ImagePlus.show() should wait until the window appears, unless you call
it from the EventQueue (e.g. from any Listener). Then you will
experience a 2 sec delay, which is its timeout for waiting (if the image
has not appeared yet in 2 sec).
If you want to create the ImagePlus from the EventQueue, start a new
Thread that creates it.
After spawning the thread, I think you need a loop with maybe 10 msec
delay waiting until the ImagePlus is shown (e.g. check for
imp.getWindow() being non-null and win.isVisible() being true).
If it is possible that your plugin will ever run in a macro, make sure
that it also works in batchmode where no window will be displayed.
Michael
_____________________________________________________________
On 18/03/2020 5:52 pm, Kenneth Sloan wrote:
> No joy. The improved(?) version exhibits the same problem. Now on two machines (but not yet on mine). The symptoms are that no KeyPresses are registered AT ALL. Note that there is a call to IJ.log at the start of keyPressed() - so this is not an issue with wait/notify. I'm glad I cleaned that up - but it wasn't the problem.
>
> It appears as if the KeyListeners are not being registered. Is there a way to double check that a given class has been successfully registered as a KeyListener?
>
> It also occurs to me that there might be a race condition here:
>
> ipl.show();
> win = ipl.getWindow();
> canvas = win.getCanvas();
>
> Is it possible that win and canvas may not yet be set, because ipl.show() takes some time to complete? Should I add something like "wait(1000)" after the ipl.show()"? Is there a direct way to check that ipl.show() has finished all of its work before proceeding?
>
> For example...will this help?
>
> ...
> ipl.show();
> ImageWindow win = null;
> while(null == win) {win = ipl.getWindow();}
> ...
>
> --
> Kenneth Sloan
>
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> Vision is the art of seeing what is invisible to others.
>
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