darkroom filmstrip: selection of active image can be lost

[anoderay]

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

In the darkroom the active image is intended to be always selected unless deselected. This selection can however be lost when filtering out images and moving to the next image.

Steps to reproduce

• Set up highlighting of selected photos with e.g. this css: #thumbtable-filmstrip #thumb-main:selected #thumb-image{ border: 1px solid gold;} to be able to easily see the issue.
• Set collection filter to hide rejected photos
• open a photo in darkroom
• reject the image
• hit space to switch to next photo
• observe: Selection lost (no golden border visible + "0 images selected" reported in the top bar)
• hit space again: Next photo also will not be selected

Expected behavior

darktable is supposed to keep the active image selected when advancing

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you obtain darktable from?

GitHub nightly

darktable version

5.7.0+875

What OS are you using?

Linux

What is the version of your OS?

bazzite / KDE

Describe your system

No response

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

RTX 2060m

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

[wpferguson]

What problem does the active image not being selected cause? That would be the issue.

I've done this exact scenario countless times over the years and the only impact for me is returning to lighttable without the last image worked on selected. In my workflow that's not a problem so I've never raised an issue and AFAICT no one else has raised that issue so, IMO it wasn't worth fixing.

If it causes other issues, then it's probably worth fixing. The problem with fixing is you need to know the correct expected behavior which is why it's necessary to understand the impact of the current image not being selected.

[anoderay]

What problem does the active image not being selected cause?

It's inconsistent: the darkroom is meant to keep the active image selected unless actively deselected (that's what I took away from #22285), but in this case the selection is silently dropped, and it stays dropped for the following images, too.

This explains why selecting multiple images for pasting etc. has been confusing for me: sometimes the active image was part of the selection and sometimes it wasn't, and I couldn't tell why.

It's easy to miss because the selection isn't visibly highlighted by default. I only noticed after adding a border for selected thumbnails, and since then the inconsistency is slightly distracting.

Behavior like this makes it harder to understand how selection works, especially since it differs from what people know from file managers and from darktable's own lighttable.

Also, if we find a good solution for making the selection more visible, more people will probably notice.

[TurboGit]

I agree that this is worth fixing anyway. We cannot have an highlighted thumbs in the filmstrip that is actually not part of the selection. I'm still not clear why the thumb is selected (white background) but the selected state (golden border) is not.

[TurboGit]

BTW, I have assigned this to me, but if anyone want to take this over do so :) I won't have time to work on this soon anyway.

[anoderay]

I'm still not clear why the thumb is selected (white background) but the selected state (golden border) is not.

If I understand correctly there are three sources of bright highlighting: opened (active), selected and hovered. Active and selected share the same styling, hovered is slightly brighter. Thus a non-selected but active image is still as bright as it is when it is selected but non-active.

Which gets even more complex when considering that hovering the canvas also triggers the "hovered" styling for the active image. Which makes sense IMHO but adds to the complexity.

[wpferguson]

I'm still not clear why the thumb is selected (white background) but the selected state (golden border) is not.

The opened image has the overlay displayed (stars, etc). When you hover over an image in the filmstrip, the overlay from the opened image is turned off and the hovered image's overlay is turned on.

When you select an image, the overlay isn't turned on but the background is brightened. If the opened image is also selected you can't tell the difference because the overlay is brighter than the selected image brightness. If the opened image is deselected you also can't tell because the overlay is still active. So the overlay being on hides the selected status of the image.