Non-expanded expander should not let <tab> go through its content
We are having issues with the shortcut on non-expanded expanders. I have attached a testcase:
- test.glade contains a glade interface,
- and gtkbuilder.c contains a program that loads it (one needs to pass it the path to test.glade as argument)
When running this testcase, with both gtk3 and gtk4 the expanders are initially non-expanded.
With gtk3, when the focus is on the first (non-expanded) expander, pressing focuses the entry which is within that expander, which is surprising since the expander is not expanded, we do not even see where the focus is. The focus should rather go to the next expander.
With gtk4, the behavior is different but problematic too (worse, actually): pressing does not move the focus at all unless the expander is expanded, in which cases it focuses the entry within the expander (as expected then since it's expanded). This means that one can't move from one expander to the other at all unless opening them, which is precisely not the goal of expanders.
In both gtk3 and gtk4 when expanders are not expanded the shortcut should just move focus to the item after the content of the expander.
This is for instance an issue when going through the interface navigator of accerciser with only the keyboard.