Fix mousewheel function

[GunChleoc]

After the port to SDL2, Panel::do_mousewheel only works for focused elements. We need to fix this, so elements can be scrolled when the mouse hovers over them.

[SirVer (sirver)]

could you provide an example that works right now in trunk, but does not work with SDL2?

[GunChleoc (gunchleoc)]

Single Player-> New Map. Choose a map that has a long description, so the description's MultilineTextarea will have a scrollbar. Hover the mouse over it and try to scroll.

[kaputtnik (franku)]

While playing open "Warehelp" "Messages" and "Building statistic". All should have a scrollbar. Play around this windows (activate one after another and use the mousewheel). Sometimes the Window which has the focus before scrolls, not the current activated window. Sometimes the actvated Window do not scroll anymore, even if all other windows are closed. This happens with two windows too.

Scrolling for the new "Build help" window do not work at all.

I have build 7278.

[kaputtnik (franku)]

May the SDL_GetMouseFocus do the trick: http://wiki.libsdl.org/SDL_GetMouseFocus

[Notabilis (notabilis27)]

I linked a branch that tries to fix the mouse wheel. It always scrolls the list/text/... under the cursor, independent of the window which has the keyboard focus or which window is in the foreground.

[GunChleoc (gunchleoc)]

I can't test right now, but the code looks promising. Could you please make a merge request?

[Notabilis (notabilis27)]

No problem, is done.

[kaputtnik (franku)]

This is really great !!!

I have tested a bit and found only one little thing: During gameplay i opened the messages menu and another menu. Placing the second menu above the messages menu so that it covers some area of the messages list. Scrolling then with mouse wheel the messages are scrolled.

But in general all is working and this is a great progress. Please make a merge request :-)

[Notabilis (notabilis27)]

Thanks for testing, should be fixed now. The mouse wheel will now only affect the topmost window at the current mouse position. I also found another bug with modal dialogs (e.g. in the campaign) which is fixed, too.

[GunChleoc (gunchleoc)]

Brilliant, thanks for the fix!

[GunChleoc (gunchleoc)]

Fixed in build19-rc1.