Add Elevation Controller for filtering vertical data in 2d maps

[nyalldawson]

This is the equivalent of the temporal controller, but for elevation z-range slicing of data in 2d maps. It's accessed through a new "Data Filtering" submenu in the View menu (in which I've also added Temporal Controller, since that was previously not accessible via menus).

The controller shows as a range slider on the left of the map. There's a configure action for setting the project's elevation range, which dictates the range available from the widget.

This works for all map layers which respect qgis/QGIS-Enhancement-Proposals#201, which are currently point clouds and raster DEMs.

[qgis-bot]

@nyalldawson
This pull request has been tagged as requiring documentation.

A documentation ticket will be opened at https://github.com/qgis/QGIS-Documentation when this PR is merged.

Please update the description (not the comments) with helpful description and screenshot to help the work from documentors.
Also, any commit having [needs-doc] or [Needs Documentation] in will see its message pushed to the issue, so please be as verbose as you can.

Thank you!

[qgis-bot]

@nyalldawson

This pull request has been tagged for the changelog.

• The description will be harvested so please provide a "nearly-ready" text for the final changelog
• If possible, add a nice illustration of the feature. Only the first one in the description will be harvested (GIF accepted as well)
• If you can, it's better to give credits to your sponsor, see below for different formats.

You can edit the description.

Format available for credits

• Funded by NAME
• Funded by URL
• Funded by NAME URL
• Sponsored by NAME
• Sponsored by URL
• Sponsored by NAME URL

Thank you!

[github-actions]

🪟 Windows builds ready!

Windows builds of this PR are available for testing here. Debug symbols for this build are available here.

(Built from commit 051ffe9)

[uclaros]

The minimalistic UI looks great! It would be quite useful to also display (or maybe even set) the rangeslider's current upper and lower values.

[nyalldawson]

This now works (independently!) with secondary canvases too, so that you can interactively slice data in different ways for these canvases:

[nirvn]

Nice stuff -- one comment on font size that's worth addressing.

[wonder-sk]

Looking great 👏

Do you plan to have the temporal controller exposed like this at some point as well, or better to keep it in the existing dock widget?

[nyalldawson]

@wonder-sk

I wouldn't be in a hurry to change the temporal controller. That's a lot "heavier" widget (it has many more subcontrols, and the different "modes" it exposes) and the horizontal arrangement works ok as a traditional panel.

[github-actions]

Tests failed for Qt 5

One or more tests failed using the build from commit 051ffe9

WMS_GetMap_Highlight_Empty_Labels

WMS_GetMap_Highlight_Empty_Labels

Test failed at test_wms_getmap_highlight_empty_labels at tests/src/python/test_qgsserver_wms_getmap.py:1391

Rendered image did not match tests/testdata/control_images/qgis_server/WMS_GetMap_Highlight_Empty_Labels/WMS_GetMap_Highlight_Empty_Labels.png (found 271 pixels different)

The full test report (included comparison of rendered vs expected images) can be found here.

Further documentation on the QGIS test infrastructure can be found in the Developer's Guide.

[nyalldawson]

Unrelated test failure