Editor/Palette: mark get_help_string const override

Note that location_palette::get_help_string is not virtual as it does not inherit from editor_palette (where the pure virtual get_help_string is defined) but rather common_palette.

src/editor/palette/editor_palettes.hpp

@@ -90,7 +90,7 @@ public:
 
 	void swap() override;
 
-	virtual std::string get_help_string() = 0;
+	virtual std::string get_help_string() const = 0;
 
 	/** Return the currently selected foreground/background item. */
 	const Item& selected_fg_item() const { return item_map_.find(selected_fg_item_)->second; }

src/editor/palette/item_palette.cpp

@@ -28,7 +28,7 @@
 
 namespace editor {
 
-std::string item_palette::get_help_string()
+std::string item_palette::get_help_string() const
 {
 	return VGETTEXT("Left-click: Place item $item | Right-click to remove", {{ "item", selected_fg_item().name }});
 }

src/editor/palette/item_palette.hpp

@@ -39,7 +39,7 @@ public:
 
 	virtual void setup(const game_config_view& cfg);
 
-	virtual std::string get_help_string();
+	virtual std::string get_help_string() const override;
 
 private:
 

src/editor/palette/location_palette.hpp

@@ -74,7 +74,7 @@ public:
 	void swap() override {}
 	bool can_swap() { return false; }
 
-	virtual std::string get_help_string() { return ""; }
+	std::string get_help_string() const { return ""; }
 
 	/** Return the currently selected item. */
 	const std::string& selected_item() const { return selected_item_; }

src/editor/palette/terrain_palettes.cpp

@@ -218,7 +218,7 @@ const std::string& terrain_palette::get_id(const t_translation::terrain_code& te
 	return t_info.id();
 }
 
-std::string terrain_palette::get_help_string()
+std::string terrain_palette::get_help_string() const
 {
 	std::ostringstream msg;
 	msg << _("Left-click: ") << map().get_terrain_editor_string(selected_fg_item())	<< " | "

src/editor/palette/terrain_palettes.hpp

@@ -47,7 +47,7 @@ public:
 	const t_translation::terrain_code& selected_fg_item() const;
 	const t_translation::terrain_code& selected_bg_item() const;
 
-	virtual std::string get_help_string();
+	virtual std::string get_help_string() const override;
 
 private:
 

src/editor/palette/unit_palette.cpp

@@ -28,7 +28,7 @@
 
 namespace editor {
 
-std::string unit_palette::get_help_string() {
+std::string unit_palette::get_help_string() const {
 	return selected_fg_item().type_name();
 }
 

src/editor/palette/unit_palette.hpp

@@ -39,7 +39,7 @@ public:
 
 	virtual void setup(const game_config_view& cfg);
 
-	virtual std::string get_help_string();
+	virtual std::string get_help_string() const override;
 
 	bool supports_swap() { return false; }