[Feature] Improve snapping functionalities

[mind84]

A bunch of changes on the snapping functionality:

• make the snap layer transparent, so that it does not overlap with the map layer symbology.
• disable snap on the hidden layers. If a layer is turned off, then users can refresh the snap to disable snapping on that layer.
• add a panel to select which layers to snap to.
  Below the snap button I added a panel with the list of snap layers configured for the layer being edited.

Hidden layers are placed at the bottom of this list and users cannot act on them. When a layer is turned off from layertree, then this list is updated accordingly.
Users can turn on/off the snap on visible layers. Then, as for previous point, users can refresh the snap to see the changes.

I'm not sure about this last point, I think it could be useful if there are a lot of snap layers configured. If you think so, I can go ahead with e2e tests, otherwise I'll roll back this last feature and only keep the first two.

You can check this functionality on the test project attached to this PR (form_edition_multilayer_snap.qgs).

Thanks

Funded by Faunalia

[rldhont]

Thanks, only docstrings.

[mdouchin]

Thanks for this feature. I requested to add some text to help the user

[rldhont]

Cypress failing tests : Feature Toolbar in popup - should display working custom action for the popup feature

[Gustry]

I didn't check carefully your PR yet, sorry, I have noticed you have included a Playwright test with some snapping. Simulating mouse drag etc ?

I'm asking for curiosity this because some manual test before each release, one is snapping, because with Cypress, we couldn't integrate it in E2E at that time. CF the current manual test CC @nboisteault

[mind84]

because with Cypress, we couldn't integrate it in E2E at that time

Hi!
I'm curious too because I hit the same problem and I didn't reach that UI interaction level. I'm testing the new panel behavior and the application XHR activities when user disable/enable layer on the layer tree or toggle the snap directly from the new panel (and refresh the snap, of course).

I assume that if the geometry requests to the server are consistent with the user's interactions then the snap works as expected. Maybe not a strong assumption, but not so weak and IHMO acceptable.

So basically yes, it's a manual testing :)

I think I could spend some time to investigate if this can be done with playwright, but not sure about timing.

[Gustry]

So basically yes, it's a manual testing :)

Ok, thanks for the explanations.

I'm going to test the PR.

[Gustry]

On my screen, new options are quite on the right side, and I have an horizontal scroll bar which is not very good for UX, given the lot of space on the left side :

I was also visiting the other snapping project : http://lizmap.local:8130/index.php/view/map?repository=testsrepository&project=form_edition_snap

I guess it's linked to the request from @mdouchin above ?

[mind84]

On my screen, new options are quite on the right side, and I have an horizontal scroll bar which is not very good for UX, given the lot of space on the left side :

Yes, I've placed the new panel in the same control group of the buttons. Initially the center position looks good to me, but in the end I think I will place it left aligned

Thanks

[mind84]

@Gustry

now you should see the list in the right place

Thanks

[Gustry]

Thanks, it's a better UX without any horizontal scrollbar like before :

[Gustry]

From the UX