GUI2/Scrollbar Container: manage content grid with a unique ptr

src/gui/widgets/scrollbar_container.cpp

@@ -417,7 +417,7 @@ void scrollbar_container::place(const point& origin, const point& size)
 		vertical_scrollbar_mode_,
 		content_grid_->get_height(),
 		content_->get_height(),
-		content_grid_
+		content_grid_.get()
 	);
 
 	// Set horizontal scrollbar
@@ -427,7 +427,7 @@ void scrollbar_container::place(const point& origin, const point& size)
 		horizontal_scrollbar_mode_,
 		content_grid_->get_width(),
 		content_->get_width(),
-		content_grid_
+		content_grid_.get()
 	);
 
 	// Update the buttons.
@@ -766,7 +766,8 @@ void scrollbar_container::finalize_setup()
 	/***** Setup the content *****/
 	content_ = build_single_widget_instance<spacer>("spacer");
 
-	content_grid_ = dynamic_cast<grid*>(get_grid().swap_child("_content_grid", content_, true).release());
+	// TODO: possibly move this unique_ptr casting functionality to a helper function.
+	content_grid_.reset(dynamic_cast<grid*>(get_grid().swap_child("_content_grid", content_, true).release()));
 	assert(content_grid_);
 
 	content_grid_->set_parent(this);

src/gui/widgets/scrollbar_container.hpp

@@ -54,7 +54,6 @@ class scrollbar_container : public container_base
 
 	~scrollbar_container()
 	{
-		delete content_grid_;
 	}
 
 	/** The way to handle the showing or hiding of the scrollbar. */
@@ -160,12 +159,12 @@ class scrollbar_container : public container_base
 
 	grid* content_grid()
 	{
-		return content_grid_;
+		return content_grid_.get();
 	}
 
 	const grid* content_grid() const
 	{
-		return content_grid_;
+		return content_grid_.get();
 	}
 
 	const SDL_Rect& content_visible_area() const
@@ -479,7 +478,7 @@ class scrollbar_container : public container_base
 	scrollbar_base *vertical_scrollbar_, *horizontal_scrollbar_;
 
 	/** The grid that holds the content. */
-	grid* content_grid_;
+	std::unique_ptr<grid> content_grid_;
 
 	/** Dummy spacer to hold the contents location. */
 	spacer* content_;