Add support for a grid in a window definition.

This allows to add scrollbars to a window which in turn could avoid
resize failures. (Support for the latter hasn't been added yet.)

src/gui/auxiliary/window_builder.cpp

@@ -149,7 +149,17 @@ twindow* build(CVideo& video, const std::string& type)
 
 	window->set_easy_close(definition->easy_close);
 
-	window->init_grid(definition->grid);
+	boost::intrusive_ptr<const twindow_definition::tresolution> conf =
+			boost::dynamic_pointer_cast<
+				const twindow_definition::tresolution>(window->config());
+	assert(conf);
+
+	if(conf->grid) {
+		window->init_grid(conf->grid);
+		window->finalize(definition->grid);
+	} else {
+		window->init_grid(definition->grid);
+	}
 
 	window->add_to_keyboard_chain(window);
 

src/gui/widgets/settings.cpp

@@ -1366,7 +1366,7 @@ tvertical_scrollbar_definition::tresolution::tresolution(const config& cfg) :
 }
 
 twindow_definition::twindow_definition(const config& cfg) :
-	tpanel_definition(cfg)
+	tcontrol_definition(cfg)
 {
 /*WIKI
  * @page = GUIWidgetDefinitionWML
@@ -1380,6 +1380,21 @@ twindow_definition::twindow_definition(const config& cfg) :
  */
 
 	DBG_GUI_P << "Parsing window " << id << '\n';
+
+	load_resolutions<tresolution>(cfg);
+}
+
+twindow_definition::tresolution::tresolution(const config& cfg)
+	: tpanel_definition::tresolution(cfg)
+	, grid(NULL)
+{
+	const config &child = cfg.child("grid");
+//	VALIDATE(child, _("No grid defined."));
+
+	/** @todo Evaluate whether the grid should become mandatory. */
+	if(child) {
+		grid = new tbuilder_grid(child);
+	}
 }
 
 tresolution_definition_ptr get_control(

src/gui/widgets/settings.hpp

@@ -421,9 +421,18 @@ struct tvertical_scrollbar_definition : public tcontrol_definition
 	};
 };
 
-struct twindow_definition : public tpanel_definition
+struct twindow_definition
+	: public tcontrol_definition
 {
 	twindow_definition(const config& cfg);
+
+	struct tresolution
+		: public tpanel_definition::tresolution
+	{
+		tresolution(const config& cfg);
+
+		tbuilder_grid_ptr grid;
+	};
 };
 
 struct tgui_definition

src/gui/widgets/window.cpp

@@ -925,6 +925,44 @@ void twindow::draw(surface& /*surf*/, const bool /*force*/,
 	assert(false);
 }
 
+namespace {
+
+/**
+ * Swaps an item in a grid for another one.*/
+void swap_grid(tgrid* grid,
+		tgrid* content_grid, twidget* widget, const std::string& id)
+{
+	assert(content_grid);
+	assert(widget);
+
+	// Make sure the new child has same id.
+	widget->set_id(id);
+
+	// Get the container containing the wanted widget.
+	tgrid* parent_grid = NULL;
+	if(grid) {
+		parent_grid = NEW_find_widget<tgrid>(grid, id, false, false);
+	}
+	if(!parent_grid) {
+		parent_grid = NEW_find_widget<tgrid>(content_grid, id, true, false);
+	}
+	parent_grid = dynamic_cast<tgrid*>(parent_grid->parent());
+	assert(parent_grid);
+
+	// Replace the child.
+	widget = parent_grid->swap_child(id, widget, false);
+	assert(widget);
+
+	delete widget;
+}
+
+} // namespace
+
+void twindow::finalize(const boost::intrusive_ptr<tbuilder_grid>& content_grid)
+{
+	swap_grid(NULL, &grid(), content_grid->build(), "_content_grid");
+}
+
 #ifdef DEBUG_WINDOW_LAYOUT_GRAPHS
 
 void twindow::generate_dot_file(const std::string& generator,

src/gui/widgets/window.hpp

@@ -52,6 +52,7 @@ class twindow
 	, public cursor::setter
 {
 	friend class tdebug_layout_graph;
+	friend twindow* build(CVideo&, const std::string&);
 	friend struct twindow_implementation;
 
 	// Wants to use layout().
@@ -557,6 +558,13 @@ private:
 	 */
 	boost::function<void ()> event_loop_pre_cb_;
 
+	/**
+	 * Finishes the initialization of the grid.
+	 *
+	 * @param content_grid        The new contents for the content grid.
+	 */
+	void finalize(const boost::intrusive_ptr<tbuilder_grid>& content_grid);
+
 #ifdef DEBUG_WINDOW_LAYOUT_GRAPHS
 	tdebug_layout_graph* debug_layout_;