Allow quick reload of gui2 themes (#9117)

* New "Apply" button in preferences dialog that is used to quickly apply the GUI2 theme, no restart needed.
* gui initialization reorganized a bit. gui2::init() now responsible for reading themes from file only. Actual theme switching and activation done by gui2::switch_theme(). preferences dependency removed from gui and moved to caller of gui2::init(). gui2 tests updated accordingly.

data/gui/themes/default/window/preferences.cfg

@@ -419,16 +419,33 @@
 						tooltip = _ "Display the game version and build information"
 					[/button]
 				[/column]
-
+				
 				[column]
 					horizontal_alignment = "right"
-					border = "all"
-					border_size = 5
-					[button]
-						id = "ok"
-						definition = "default"
-						label = _ "Close"
-					[/button]
+					
+					[grid]
+						[row]
+							[column]
+								border = "all"
+								border_size = 5
+								[button]
+									id = "apply"
+									definition = "default"
+									label = _ "Apply"
+								[/button]
+							[/column]
+
+							[column]
+								border = "all"
+								border_size = 5
+								[button]
+									id = "ok"
+									definition = "default"
+									label = _ "Close"
+								[/button]
+							[/column]
+						[/row]
+					[/grid]
 				[/column]
 
 			[/row]

data/gui/themes/default/window/preferences/03_display.cfg

@@ -196,7 +196,7 @@
 				[/row]
 				[row]
 					[column]
-						border = "top,left,right"
+						border = "all"
 						border_size = 5
 						horizontal_alignment = "left"
 
@@ -206,20 +206,6 @@
 						[/menu_button]
 					[/column]
 				[/row]
-				[row]
-					[column]
-						border = "bottom,left,right"
-						border_size = 5
-						horizontal_alignment = "left"
-
-						[label]
-							id = restart_msg
-							label = _ "<span color='red'>*restart required</span>"
-							definition = "default_small"
-							use_markup = true
-						[/label]
-					[/column]
-				[/row]
 			[/grid]
 		[/column]
 

src/gui/dialogs/preferences_dialog.cpp

@@ -38,6 +38,7 @@
 #include "gui/dialogs/log_settings.hpp"
 #include "gui/dialogs/multiplayer/mp_alerts_options.hpp"
 #include "gui/dialogs/select_orb_colors.hpp"
+#include "gui/dialogs/title_screen.hpp"
 
 #include "gui/auxiliary/find_widget.hpp"
 #include "gui/dialogs/game_version_dialog.hpp"
@@ -110,6 +111,7 @@ preferences_dialog::preferences_dialog(const pref_constants::PREFERENCE_VIEW ini
 	, themes_() // populated by set_theme_list
 	, gui2_themes_() // populated by set_gui2_theme_list
 	, last_selected_item_(0)
+	, current_gui_theme_(0)
 	, accl_speeds_({0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 3, 4, 8, 16})
 	, visible_hotkeys_()
 	, visible_categories_()
@@ -163,17 +165,16 @@ void preferences_dialog::set_theme_list(menu_button& theme_list)
 
 void preferences_dialog::set_gui2_theme_list(menu_button& theme_list)
 {
-	std::string current_theme_name = prefs::get().gui_theme();
+	std::string current_gui_theme_name = prefs::get().gui_theme();
 
 	std::vector<config> options;
-	std::size_t current_theme = 0;
 	bool theme_found = false;
 	unsigned i = 0;
 	for(auto& gui : guis) {
 		gui2_themes_.emplace_back(gui.first);
 		options.emplace_back("label", gui.second.description());
-		if (current_theme_name == gui.first) {
-			current_theme = i;
+		if (current_gui_theme_name == gui.first) {
+			current_gui_theme_ = i;
 			theme_found = true;
 		}
 		if (!theme_found) {
@@ -182,7 +183,7 @@ void preferences_dialog::set_gui2_theme_list(menu_button& theme_list)
 	}
 
 	theme_list.set_values(options);
-	theme_list.set_selected(current_theme);
+	theme_list.set_selected(current_gui_theme_);
 }
 
 widget_data preferences_dialog::get_friends_list_row_data(const preferences::acquaintance& entry)
@@ -590,7 +591,7 @@ void preferences_dialog::initialize_callbacks()
 	/* SELECT GUI2 THEME */
 	menu_button& gui2_theme_list = find_widget<menu_button>(this, "choose_gui2_theme", false);
 	set_gui2_theme_list(gui2_theme_list);
-	connect_signal_notify_modified(gui2_theme_list,
+	connect_signal_mouse_left_click(find_widget<button>(this, "apply", false),
 		std::bind(&preferences_dialog::handle_gui2_theme_select, this));
 
 	//
@@ -1137,9 +1138,6 @@ void preferences_dialog::pre_show(window& window)
 	VALIDATE(selector.get_item_count() == pager.get_layer_count(),
 		"The preferences pager and its selector listbox do not have the same number of items.");
 
-	// don't show the "*restart required" message for UI theme at start
-	find_widget<label>(&window, "restart_msg", false).set_visible(widget::visibility::invisible);
-
 	const int main_index = index_in_pager_range(initial_index_.first, pager);
 
 	// Loops through each pager layer and checks if it has both a tab bar
@@ -1213,9 +1211,13 @@ void preferences_dialog::handle_theme_select()
 
 void preferences_dialog::handle_gui2_theme_select()
 {
-	find_widget<label>(get_window(), "restart_msg", false).set_visible(widget::visibility::visible);
 	menu_button& gui2_theme_list = find_widget<menu_button>(this, "choose_gui2_theme", false);
-	prefs::get().set_gui_theme(gui2_themes_.at(gui2_theme_list.get_value()));
+	unsigned selected_theme = gui2_theme_list.get_value();
+	if (selected_theme != current_gui_theme_) {
+		current_gui_theme_ = selected_theme;
+		prefs::get().set_gui_theme(gui2_themes_.at(selected_theme));
+		set_retval(gui2::dialogs::title_screen::RELOAD_UI);
+	}
 }
 
 void preferences_dialog::on_page_select()

src/gui/dialogs/preferences_dialog.hpp

@@ -110,6 +110,7 @@ private:
 	std::vector<std::string> gui2_themes_;
 
 	int last_selected_item_;
+	unsigned current_gui_theme_;
 
 	std::vector<double> accl_speeds_;
 

src/gui/dialogs/title_screen.cpp

@@ -329,7 +329,11 @@ void title_screen::init_callbacks()
 	// Preferences
 	//
 	register_button(*this, "preferences", hotkey::HOTKEY_PREFERENCES, [this]() {
-		gui2::dialogs::preferences_dialog::display();
+		gui2::dialogs::preferences_dialog pref_dlg;
+		pref_dlg.show();
+		if (pref_dlg.get_retval() == RELOAD_UI) {
+			set_retval(RELOAD_UI);
+		}
 
 		// Currently blurred windows don't capture well if there is something
 		// on top of them at the time of blur. Resizing the game window in

src/gui/dialogs/title_screen.hpp

@@ -61,6 +61,9 @@ public:
 		QUIT_GAME,
 		// Used to reload all game data
 		RELOAD_GAME_DATA,
+		// Used to reshow the titlescreen, for example,
+		// in the case of a gui2 theme change
+		RELOAD_UI,
 	};
 
 private:

src/gui/gui.cpp

@@ -23,7 +23,6 @@
 #include "gui/core/log.hpp"
 #include "gui/core/gui_definition.hpp"
 #include "gui/widgets/settings.hpp"
-#include "preferences/preferences.hpp"
 #include "serialization/parser.hpp"
 #include "serialization/preprocessor.hpp"
 #include "serialization/schema_validator.hpp"
@@ -31,14 +30,9 @@
 
 namespace gui2
 {
-static bool initialized = false;
 
 void init()
 {
-	if(initialized) {
-		return;
-	}
-
 	LOG_GUI_G << "Initializing UI subststem.";
 
 	// Save current screen size.
@@ -47,14 +41,13 @@ void init()
 	//
 	// Read and validate the WML files.
 	//
-	config cfg;
+	config guis_cfg;
 	try {
 		schema_validation::schema_validator validator(filesystem::get_wml_location("schema/gui.cfg").value());
 
 		preproc_map preproc(game_config::config_cache::instance().get_preproc_map());
 		filesystem::scoped_istream stream = preprocess_file(filesystem::get_wml_location("gui/_main.cfg").value(), &preproc);
-
-		read(cfg, *stream, &validator);
+		read(guis_cfg, *stream, &validator);
 	} catch(const config::error& e) {
 		ERR_GUI_P << e.what();
 		ERR_GUI_P << "Setting: could not read file 'data/gui/_main.cfg'.";
@@ -66,9 +59,7 @@ void init()
 	//
 	// Parse GUI definitions.
 	//
-	const std::string& current_theme = prefs::get().gui_theme();
-
-	for(const config& g : cfg.child_range("gui")) {
+	for(const config& g : guis_cfg.child_range("gui")) {
 		const std::string id = g["id"];
 
 		auto iter = guis.emplace(id, gui_definition(g)).first;
@@ -76,24 +67,34 @@ void init()
 		if(id == "default") {
 			default_gui = iter;
 		}
-
-		if(!current_theme.empty() && id == current_theme) {
-			current_gui = iter;
-		}
 	}
 
 	VALIDATE(default_gui != guis.end(), _("No default gui defined."));
+}
 
-	if(current_theme.empty()) {
-		current_gui = default_gui;
-	} else if(current_gui == guis.end()) {
-		ERR_GUI_P << "Missing [gui] definition for '" << current_theme << "'";
+void switch_theme(const std::string& current_theme)
+{
+	if (current_theme.empty() || current_theme == "default") {
 		current_gui = default_gui;
+	} else {
+		gui_theme_map_t::iterator gui_itor = guis.begin();
+		for (const auto& gui : guis) {
+			if (gui.first == current_theme) {
+				current_gui = gui_itor;
+			}
+
+			if (gui_itor != guis.end()) {
+				gui_itor++;
+			}
+		}
+
+		if(current_gui == guis.end()) {
+			ERR_GUI_P << "Missing [gui] definition for '" << current_theme << "'";
+			current_gui = default_gui;
+		}
 	}
 
 	current_gui->second.activate();
-
-	initialized = true;
 }
 
 } // namespace gui2

src/gui/gui.hpp

@@ -15,14 +15,24 @@
 
 #pragma once
 
+#include <string>
+
 namespace gui2
 {
 /**
  * Initializes the GUI subsystems.
  *
  * @note This function must be called before other parts of the UI engine
- * are used.
+ * are used. Use @ref switch_theme below to actually activate the theme.
  */
 void init();
 
+/**
+ * Set and activate the given gui2 theme
+ *
+ * @param current_theme    the name of the gui2 theme to switch to
+ */
+void switch_theme(const std::string& current_theme);
+
+
 } // namespace gui2

src/tests/main.cpp

@@ -87,6 +87,7 @@ struct wesnoth_global_fixture {
 		test_utils::get_fake_display(1024, 768);
 
 		gui2::init();
+		gui2::switch_theme("default");
 		static const gui2::event::manager gui_event_manager;
 
 		// TODO: For some reason this fails on MacOS and prevents any tests from running

src/tests/utils/game_config_manager_tests.cpp

@@ -76,6 +76,7 @@ namespace test_utils {
 
 			font::load_font_config();
 			gui2::init();
+			gui2::switch_theme("default");
 			load_language_list();
 			game_config::config_cache::instance().add_define("TEST");
 			game_config::config_cache::instance().get_config(game_config::path + "/data/test/", cfg_);

src/wesnoth.cpp

@@ -36,6 +36,7 @@
 #include "gui/dialogs/title_screen.hpp" // for title_screen, etc
 #include "gui/gui.hpp"                  // for init
 #include "log.hpp"                      // for LOG_STREAM, general, logger, etc
+#include "preferences/preferences.hpp"
 #include "scripting/application_lua_kernel.hpp"
 #include "scripting/plugins/context.hpp"
 #include "scripting/plugins/manager.hpp"
@@ -716,6 +717,7 @@ static int do_gameloop(commandline_options& cmdline_opts)
 #endif
 
 	gui2::init();
+	gui2::switch_theme(prefs::get().gui_theme());
 	const gui2::event::manager gui_event_manager;
 
 	// if the log directory is not writable, then this is the error condition so show the error message.
@@ -856,7 +858,9 @@ static int do_gameloop(commandline_options& cmdline_opts)
 		{ // scope to not keep the title screen alive all game
 			gui2::dialogs::title_screen dlg(*game);
 
-			// Allows re-layout on resize
+			// Allows re-layout on resize.
+			// Since RELOAD_UI is not checked here, it causes
+			// the dialog to be closed and reshown with changes.
 			while(dlg.get_retval() == gui2::dialogs::title_screen::REDRAW_BACKGROUND) {
 				dlg.show();
 			}
@@ -892,6 +896,9 @@ static int do_gameloop(commandline_options& cmdline_opts)
 			break;
 		case gui2::dialogs::title_screen::REDRAW_BACKGROUND:
 			break;
+		case gui2::dialogs::title_screen::RELOAD_UI:
+			gui2::switch_theme(prefs::get().gui_theme());
+			break;
 		}
 	}
 }