Make sure bigmap isn't overdrawn by in-game UI

The storyscreen would trigger a full redraw-cycle partially through
displaying bigmap. Due to the implementation of the storyscreen, this
would cause it to have the background overdrawn and never updated. The
fix implemented here is to remove layered-drawing functionality from
the storyscreen and trigger a full redraw manually at the end of the
story screen functionality.

src/storyscreen/controller.cpp

@@ -147,8 +147,6 @@ void controller::resolve_wml(const vconfig& cfg)
 STORY_RESULT controller::show(START_POSITION startpos)
 {
 
-	events::event_context story_context;
-
 	if(parts_.empty()) {
 		LOG_NG << "no storyscreen parts to show\n";
 		return NEXT;

src/storyscreen/interface.cpp

@@ -37,6 +37,8 @@ static lg::log_domain log_engine("engine");
 void show_story(display &disp, const std::string &scenario_name,
 	const config::const_child_itors &story)
 {
+	events::event_context story_context;
+
 	int segment_count = 0;
 	config::const_child_iterator itor = story.first;
 	storyscreen::START_POSITION startpos = storyscreen::START_BEGINNING;
@@ -62,8 +64,9 @@ void show_story(display &disp, const std::string &scenario_name,
 			}
 			break;
 		case storyscreen::QUIT:
-			return;
+			break;
 		}
 	}
+	video2::trigger_full_redraw();
 	return;
 }

src/storyscreen/render.cpp

@@ -88,7 +88,7 @@ namespace storyscreen {
 
 part_ui::part_ui(part &p, display &disp, gui::button &next_button,
 	gui::button &back_button, gui::button&play_button)
-	: video2::draw_layering(false)
+	: events::sdl_handler(false)
 	, p_(p)
 	, disp_(disp)
 	, video_(disp.video())
@@ -382,6 +382,7 @@ bool part_ui::render_floating_images()
 		const floating_image& fi = p_.get_floating_images()[fi_n];
 
 		if(!ri.image.null()) {
+			render_background();
 			sdl_blit(ri.image, NULL, video_.getSurface(), &ri.rect);
 			update_rect(ri.rect);
 		}

src/storyscreen/render.hpp

@@ -41,7 +41,7 @@ namespace storyscreen {
  * assumed that the screen dimensions remain constant between the
  * constructor call, and the destruction of the objects.
  */
-class part_ui : public video2::draw_layering
+class part_ui : public events::sdl_handler
 {
 public:
 	/** Storyscreen result. */

src/video.cpp

@@ -263,6 +263,10 @@ draw_layering::~draw_layering()
 {
 	draw_layers.remove(this);
 
+	video2::trigger_full_redraw();
+}
+
+void trigger_full_redraw() {
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 	SDL_Event event;
 	event.type = SDL_WINDOWEVENT;

src/video.hpp

@@ -324,6 +324,6 @@ protected:
 	draw_layering(const bool auto_join=true);
 	virtual ~draw_layering();
 };
-
+void trigger_full_redraw();
 }
 #endif

src/widgets/widget.cpp

@@ -33,7 +33,7 @@ namespace gui {
 bool widget::mouse_lock_ = false;
 
 widget::widget(const widget &o)
-	: video2::draw_layering(), focus_(o.focus_), video_(o.video_), restorer_(o.restorer_), rect_(o.rect_),
+	: events::sdl_handler(), focus_(o.focus_), video_(o.video_), restorer_(o.restorer_), rect_(o.rect_),
 	   needs_restore_(o.needs_restore_), state_(o.state_), hidden_override_(o.hidden_override_),
 	  enabled_(o.enabled_), clip_(o.clip_), clip_rect_(o.clip_rect_), volatile_(o.volatile_),
 	  help_text_(o.help_text_), tooltip_text_(o.tooltip_text_), help_string_(o.help_string_), id_(o.id_), mouse_lock_local_(o.mouse_lock_local_)
@@ -41,7 +41,7 @@ widget::widget(const widget &o)
 }
 
 widget::widget(CVideo& video, const bool auto_join)
-	: video2::draw_layering(auto_join), focus_(true), video_(&video), rect_(EmptyRect), needs_restore_(false),
+	: events::sdl_handler(auto_join), focus_(true), video_(&video), rect_(EmptyRect), needs_restore_(false),
 	  state_(UNINIT), hidden_override_(false), enabled_(true), clip_(false),
 	  clip_rect_(EmptyRect), volatile_(false), help_string_(0), mouse_lock_local_(false)
 {

src/widgets/widget.hpp

@@ -23,7 +23,7 @@ class CVideo;
 
 namespace gui {
 
-class widget : public video2::draw_layering
+class widget : public events::sdl_handler
 {
 public:
 	SDL_Rect const &location() const;