Separator styles, including menubar/toolbar borders, are missing

[rozniak]

Per title, most noticable in explorer - the borders for separators and menubar/toolbars are missing. I think this is complicated because even in Windows it's not really consistent how they appear in say notepad/wordpad vs. explorer.

Reference XPTC explorer:

Reference Windows XP explorer:

[rozniak]

Been working on this - the simple separator controls are working fine, the issue really is the toolbar/menubar styles...

Issue is that we really want to just style siblings, like menubar followed by toolbar. But that fails in cases where these controls are packed into GtkBox widgets, like in explorer above. Explorers structure is like so:

<box>
  <menubar />
  <throbber />
</box>
<box>
  <toolbar />
  <toolbar />
</box>

Due to the boxes, the toolbars are separate and sibling selectors will not work...

Adwaita commits to having borders under all menubars (via box-shadow). It's tough because this would look weird in notepad, or really any program where the next widget (outside the box) is a frame.

Perhaps it's worth taking a note from Adwaita... apply a border to the bottom of all toolbars/menus unless they're the :last-child in a vertical box? I'll investigate whether this is feasible... it's kind of bodge-y.

[rozniak]

The alternative strategy does seem better...

Only implemented in the native theme for now. notepad is the exception really in that it now has a menubar border when it usually doesn't - it's possible to just put a bodge in notepad to get around that though.

I think the result is pretty cool to be honest, quite a few GTK programs I've tried look much better with these borders.

[rozniak]

Going to merge the current work, here are the other themes: