[Commits] [wesnoth/wesnoth] a5f8d6: Add initial support for GUI layering

[GitHub]

  Branch: refs/heads/guifixes
  Home:   https://github.com/wesnoth/wesnoth
  Commit: a5f8d62a75d979ed897b4e5a3271016827f68bd0
      https://github.com/wesnoth/wesnoth/commit/a5f8d62a75d979ed897b4e5a3271016827f68bd0
  Author: Andreas Löf <andreas at alternating.net>
  Date:   2016-01-30 (Sat, 30 Jan 2016)

  Changed paths:
    M src/controller_base.hpp
    M src/gui/auxiliary/event/handler.cpp
    M src/show_dialog.hpp
    M src/storyscreen/render.cpp
    M src/storyscreen/render.hpp
    M src/video.cpp
    M src/video.hpp
    M src/widgets/widget.cpp
    M src/widgets/widget.hpp

  Log Message:
  -----------
  Add initial support for GUI layering

This introduces a subclass of events::sdl_handler that keeps track of
all instantiated classes. When a new instance is created it's pushed
onto a list of all tracked instances. When an instance is destroyed,
all known instances are sent a resize event (under SDL2) to mark them
as dirty. After that there's a DRAW_ALL event pushed onto the event
queue to cause a redraw. There's currently no logic in place to ensure
that there's only one DRAW_ALL event in the event queue at any given
time, but it should be harmless as long as no components are marked as
dirty.