# Opacity cell - 5.12.2

**URL:** <https://discourse.slicer.org/t/opacity-cell-5-12-2/47652>\
**Category:** Development\
**Created:** [July 17, 2026, 9:51am UTC](https://discourse.slicer.org/t/opacity-cell-5-12-2/47652 "2026-07-17T09:51:25Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![BaptisteSVD](https://avatars.discourse-cdn.com/v4/letter/b/e36b37/32.png) [@BaptisteSVD](https://discourse.slicer.org/u/BaptisteSVD)\
**Post date:** [July 17, 2026, 9:51am UTC](https://discourse.slicer.org/t/opacity-cell-5-12-2/47652/1 "2026-07-17T09:51:25Z")

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Hi,

In Slicer 5.12.2, the per-segment opacity cell in the Segmentations module is no longer editable by mouse click or double-click. Editing only works after pressing F2. Is this intentional or a regression?

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [July 17, 2026, 1:37pm UTC](https://discourse.slicer.org/t/opacity-cell-5-12-2/47652/2 "2026-07-17T13:37:29Z")

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Thanks for bringing this to our attention! It is clearly a bug.

@lassoan Could this be due to not setting the delegate anymore?

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [July 17, 2026, 3:43pm UTC](https://discourse.slicer.org/t/opacity-cell-5-12-2/47652/3 "2026-07-17T15:43:24Z")

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Yes, it is a regression due to the refactoring of the segment list. I’ll have a look, it should not be difficult to fix it.

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [July 18, 2026, 4:14pm UTC](https://discourse.slicer.org/t/opacity-cell-5-12-2/47652/4 "2026-07-18T16:14:06Z")

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I’ve submitted a pull request with the fix:

> <https://github.com/Slicer/Slicer/pull/9296>
>
> Since the visibility/color button rework (94ad4fb3e8), the DoubleClicked edit tr…igger is disabled in the segments table (double-click on the name and color columns opens the terminology selector instead), which left F2 as the only way to edit the opacity column.
> 
> Open the opacity editor explicitly from the double-click handler to restore the previous behavior.
> 
> Fixes https://discourse.slicer.org/t/opacity-cell-5-12-2/47652

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**Author:** ![BaptisteSVD](https://avatars.discourse-cdn.com/v4/letter/b/e36b37/32.png) [@BaptisteSVD](https://discourse.slicer.org/u/BaptisteSVD)\
**Post date:** [July 20, 2026, 7:00am UTC](https://discourse.slicer.org/t/opacity-cell-5-12-2/47652/5 "2026-07-20T07:00:52Z")

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Thank you for your promptness and your work !