[Bug] GUI: layer list behaviour unstable when list longer than view

[dhdeangelis]

Describe the bug

When working on a project with many layers so that the panel cannot fit all of them in the same view, choosing, checking, unchecking, or dragging a layer causes the panel view to jump, sometimes unpredictably, leaving the previous position out of view. This is impractical and not expected UI behaviour.

To reproduce

1. create or open a project with many layers, more than can be fit within a single view
2. pick any layer and try to drag it (up or down), check or uncheck
3. See error: layer list jumps and the previous position of the layer in question is probably out of view

Expected behavior

When choosing, checking, unchecking a layer, the view should remain stable in its current position and only move when dragging a layer upwards or downwards towards positions above or below the current stack view.

System description

System Info                                                                     
GRASS version: 8.6.0dev                                                         
Code revision: fe51d3824f                                                       
Build date: 2026-02-10                                                          
Build platform: x86_64-pc-linux-gnu                                             
GDAL: 3.13.0dev-2acbd45c8f-dirty                                                
PROJ: 9.8.0                                                                     
GEOS: 3.15.0dev                                                                 
SQLite: 3.51.1                                                                  
Python: 3.13.11                                                                 
wxPython: 4.2.3                                                                 
Platform: Linux-6.18.9-1-default-x86_64-with-glibc2.42    

• details about further software components
  • run g.version -rge in a GRASS terminal session or check in
    the GUI menu "Help > About"

g.version -rge                                                                  
version=8.6.0dev
date=2026
revision=fe51d3824f
build_date=2026-02-10
build_platform=x86_64-pc-linux-gnu
build_off_t_size=8
libgis_revision=83603cfd5b
libgis_date=2026-02-05T20:04:56+00:00
proj=9.8.0
gdal=3.13.0dev-2acbd45c8f-dirty
geos=3.15.0dev
sqlite=3.51.1

- run `python3 -c "import sys, wx; print(sys.version); print(wx.version())"`
  to print the Python and wxPython version numbers

> python3 -c "import sys, wx; print(sys.version); print(wx.version())"
3.13.11 (main, Dec 19 2025, 18:38:03) [GCC]
4.2.3 gtk3 (phoenix) wxWidgets 3.2.8

-->

Additional context

This behaviour is not only limited to current main. IIRC it has been present for a while.

[petrasovaa]

Some of it may be limitation of the wxpython framework, but we would need to investigate more.

[dhdeangelis]

Yes. I did not mention it but I also think it is not necessarily a GRASS problem. But would be nice to look at it anyway.

[Dasux]

I'll try and reproduce the issue...