bug#47581: 27.1; tab-bar missed mouse clicks on MS-Windows

[Juri Linkov]

>> Indeed, this code was copied from handle_tool_bar_click,
>> but this extra logic was not removed because there are parts
>> of the tab bar that should respond to moving the mouse pointer,
>> namely the tab close buttons are activated when the mouse pointer
>> is moved over them.  But I'm not sure if this feature is related
>> to this code, or won't be affected by removing this code.
>
> OK, I've fixed handle_tab_bar_click to not pay attention to
> mouse-highlight, please see if there are any adverse side effects of
> that change.
>
> I also removed note_tab_bar_highlight and the code which called it.  I
> couldn't find any place which depended on that, and there was no
> visible effect of mouse-highlight on any part of the tab-bar buttons
> that I could see.  If I missed something, please show a recipe where
> this highlight had any effect before my changes.

Sorry, I don't understand the need to remove the highlighting code.
Before the removal, the tab-bar button images reacted to mouse pointer
movements, and highlighted the buttons under the mouse pointer
using the pressed/released state DRAW_IMAGE_SUNKEN/RAISED.

Now there is no visual feedback when the user moves the mouse pointer
over the buttons.  Doesn't seem like an improvement.

> (It _is_ possible to have the tab-bar buttons react to mouse pointer
> movements, but for that we need support in display code, which isn't
> there.  If we will ever want to add mouse sensitivity to tab-bar
> buttons, we should first add code which displays those buttons
> differently when the draw_glyphs_face value is DRAW_MOUSE_FACE or
> DRAW_IMAGE_SUNKEN/RAISED; then we'd want to resurrect
> note_tab_bar_highlight that I deleted.)

Looks like a plan to re-add the same feature, but differently.