Cancel button does not halt extensions

[Windell Oskay]

The "Cancel" button does not properly halt execution of Inkscape extensions.

This is not normally noticeable because extensions execute quickly. But for extensions that take a while-- i.e., those that you'd want to cancel --it turns out not to work. It appears to wait (possibly a very long time) for the extension to finish executing before stopping the operation.

To replicate, select Extensions>Render>L-system. Set Order to 4. Click Apply, try to cancel the operation. If your computer is fast and that didn't take very long, set Order to 5, 6, or 7 to make the extension take longer to run.

Discovered on Mac OS 10.4/ Inkscape 0.47
Verified on Windows XP/ Inkscape 0.47
Verified on Mac OS 10.6/ Inkscape pre-0.48 snapshot from last week

[Windell Oskay (windell)]

Note added:

Another way to describe the issue is that Inkscape *appears to freeze* when you try to cancel an extension operating. However, it is a temporary freeze in the cases that I have tested.

[jazzynico (jazzynico)]

Confirmed on Windows XP, Inkscape r9451.

Tested with L-system and Voronoi.
Canceled or not, the extension take about the same time to finish.

[TimeWaster (sebi-k-deactivatedaccount)]

what would be the alternative? to "kill" the python script on click?

maybe the button should just be removed, the only effect of this button seems to be that it reverts the changes.

[Windell Oskay (windell)]

It has been more than five years since this issue has been reported. The presence of this non-working button continues to cause user frustration, occasionally manifested as additional bug reports and/or requests for technical support.

I would ask that the developers consider simply hiding (or removing) the button until such a time that a mechanism for halting extensions can be determined and implemented.

The text that is presently displayed above the button ("EXTENSION_NAME" working, please wait...) is clear enough. Simply removing the button is a simple solution that will likely save user confusion and frustration.

[jazzynico (jazzynico)]

Yes, hiding the button could be a temporary workaround.

On the other hand, I wonder how hard it would be to just kill the extension process from the main code.

[Windell Oskay (windell)]

Killing the process sounds (to me) like a real and acceptable solution to the issue.

[Jonathan Hofinger (jhofinger)]

Hi, I'm closing this issue - a duplicate of it has been opened on GitLab: https://gitlab.com/inkscape/inkscape/-/issues/1553

Closed by https://gitlab.com/jhofinger