top_level_drawable: Implement copy and move constructors

src/draw_manager.cpp

@@ -290,9 +290,10 @@ void raise_drawable(top_level_drawable* tld)
 static void tidy_drawables()
 {
 	// Remove all invalidated TLDs from the list.
-	DBG_DM << "tidying drawables";
+	DBG_DM << "tidying " << top_level_drawables_.size() << " drawables";
 	auto& vec = top_level_drawables_;
 	vec.erase(std::remove(vec.begin(), vec.end(), nullptr), vec.end());
+	DBG_DM << top_level_drawables_.size() << " after tidying";
 }
 
 } // namespace draw_manager

src/gui/core/top_level_drawable.cpp

@@ -29,4 +29,26 @@ top_level_drawable::~top_level_drawable()
 	draw_manager::deregister_drawable(this);
 }
 
+top_level_drawable::top_level_drawable(const top_level_drawable&)
+{
+	draw_manager::register_drawable(this);
+}
+
+top_level_drawable& top_level_drawable::operator=(const top_level_drawable&)
+{
+	draw_manager::register_drawable(this);
+	return *this;
+}
+
+top_level_drawable::top_level_drawable(top_level_drawable&&)
+{
+	draw_manager::register_drawable(this);
+}
+
+top_level_drawable& top_level_drawable::operator=(top_level_drawable&&)
+{
+	draw_manager::register_drawable(this);
+	return *this;
+}
+
 } // namespace gui2

src/gui/core/top_level_drawable.hpp

@@ -53,6 +53,13 @@ class top_level_drawable
 protected:
 	top_level_drawable();
 	virtual ~top_level_drawable();
+
+	// These make sure the TLD is registered.
+	top_level_drawable(const top_level_drawable&);
+	top_level_drawable& operator=(const top_level_drawable&);
+	top_level_drawable(top_level_drawable&&);
+	top_level_drawable& operator=(top_level_drawable&&);
+
 public:
 	/**
 	 * Update state and any parameters that may effect layout, or any of