Implement an editor to customize the touchscreen controls (luanti-org…

…#14933)

- The editor is accessible via the pause menu and the settings menu.
- Buttons can be moved via drag & drop.
- Buttons can be added/removed. The grid menu added by luanti-org#14918 is used to show
  all buttons not included in the layout.
- Custom layouts are responsive and adapt to changed screen size / DPI /
  hud_scaling.
- The layout is saved as JSON in the "touch_layout" setting.

builtin/mainmenu/settings/dlg_settings.lua

@@ -123,6 +123,22 @@ local function load()
 		end,
 	}
 
+	local touchscreen_layout = {
+		query_text = "Touchscreen layout",
+		requires = {
+			touchscreen = true,
+		},
+		get_formspec = function(self, avail_w)
+			local btn_w = math.min(avail_w, 6)
+			return ("button[0,0;%f,0.8;btn_touch_layout;%s]"):format(btn_w, fgettext("Touchscreen layout")), 0.8
+		end,
+		on_submit = function(self, fields)
+			if fields.btn_touch_layout then
+				core.show_touchscreen_layout()
+			end
+		end,
+	}
+
 	add_page({
 		id = "accessibility",
 		title = fgettext_ne("Accessibility"),
@@ -151,6 +167,8 @@ local function load()
 	load_settingtypes()
 
 	table.insert(page_by_id.controls_keyboard_and_mouse.content, 1, change_keys)
+	-- insert after "touch_controls"
+	table.insert(page_by_id.controls_touchscreen.content, 2, touchscreen_layout)
 	do
 		local content = page_by_id.graphics_and_audio_effects.content
 		local idx = table.indexof(content, "enable_dynamic_shadows")

doc/menu_lua_api.md

@@ -223,6 +223,7 @@ GUI
 * `core.set_clouds(<true/false>)`
 * `core.set_topleft_text(text)`
 * `core.show_keys_menu()`
+* `core.show_touchscreen_layout()`
 * `core.show_path_select_dialog(formname, caption, is_file_select)`
   * shows a path select dialog
   * `formname` is base name of dialog response returned in fields

src/client/game.cpp

@@ -26,6 +26,7 @@
 #include "client/event_manager.h"
 #include "fontengine.h"
 #include "gui/touchcontrols.h"
+#include "gui/touchscreeneditor.h"
 #include "itemdef.h"
 #include "log.h"
 #include "log_internal.h"
@@ -144,6 +145,11 @@ struct LocalFormspecHandler : public TextDest
 				return;
 			}
 
+			if (fields.find("btn_touchscreen_layout") != fields.end()) {
+				g_gamecallback->touchscreenLayout();
+				return;
+			}
+
 			if (fields.find("btn_exit_menu") != fields.end()) {
 				g_gamecallback->disconnect();
 				return;
@@ -1844,6 +1850,12 @@ inline bool Game::handleCallbacks()
 		g_gamecallback->keyconfig_requested = false;
 	}
 
+	if (g_gamecallback->touchscreenlayout_requested) {
+		(new GUITouchscreenLayout(guienv, guiroot, -1,
+				     &g_menumgr, texture_src))->drop();
+		g_gamecallback->touchscreenlayout_requested = false;
+	}
+
 	if (!g_gamecallback->show_open_url_dialog.empty()) {
 		(void)make_irr<GUIOpenURLMenu>(guienv, guiroot, -1,
 				 &g_menumgr, texture_src, g_gamecallback->show_open_url_dialog);
@@ -4510,9 +4522,14 @@ void Game::showPauseMenu()
 			<< strgettext("Sound Volume") << "]";
 	}
 #endif
-	os		<< "button_exit[4," << (ypos++) << ";3,0.5;btn_key_config;"
-		<< strgettext("Controls")  << "]";
 #endif
+	if (g_touchcontrols) {
+		os << "button_exit[4," << (ypos++) << ";3,0.5;btn_touchscreen_layout;"
+			<< strgettext("Touchscreen Layout")  << "]";
+	} else {
+		os << "button_exit[4," << (ypos++) << ";3,0.5;btn_key_config;"
+			<< strgettext("Controls")  << "]";
+	}
 	os		<< "button_exit[4," << (ypos++) << ";3,0.5;btn_exit_menu;"
 		<< strgettext("Exit to Menu") << "]";
 	os		<< "button_exit[4," << (ypos++) << ";3,0.5;btn_exit_os;"

src/client/hud.cpp

@@ -24,6 +24,7 @@
 #include "wieldmesh.h"
 #include "client/renderingengine.h"
 #include "client/minimap.h"
+#include "client/texturesource.h"
 #include "gui/touchcontrols.h"
 #include "util/enriched_string.h"
 #include "irrlicht_changes/CGUITTFont.h"

src/defaultsettings.cpp

@@ -542,6 +542,7 @@ void set_default_settings()
 	settings->setDefault("keymap_sneak", "KEY_SHIFT");
 #endif
 
+	settings->setDefault("touch_layout", "");
 	settings->setDefault("touchscreen_sensitivity", "0.2");
 	settings->setDefault("touchscreen_threshold", "20");
 	settings->setDefault("touch_long_tap_delay", "400");

src/gui/CMakeLists.txt

@@ -25,5 +25,7 @@ set(gui_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/modalMenu.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/profilergraph.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/touchcontrols.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/touchscreenlayout.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/touchscreeneditor.cpp
 	PARENT_SCOPE
 )

src/gui/mainmenumanager.h

@@ -21,6 +21,7 @@ class IGameCallback
 	virtual void changeVolume() = 0;
 	virtual void showOpenURLDialog(const std::string &url) = 0;
 	virtual void signalKeyConfigChange() = 0;
+	virtual void touchscreenLayout() = 0;
 };
 
 extern gui::IGUIEnvironment *guienv;
@@ -133,6 +134,11 @@ class MainGameCallback : public IGameCallback
 		keyconfig_changed = true;
 	}
 
+	void touchscreenLayout() override
+	{
+		touchscreenlayout_requested = true;
+	}
+
 	void showOpenURLDialog(const std::string &url) override
 	{
 		show_open_url_dialog = url;
@@ -142,6 +148,7 @@ class MainGameCallback : public IGameCallback
 	bool changepassword_requested = false;
 	bool changevolume_requested = false;
 	bool keyconfig_requested = false;
+	bool touchscreenlayout_requested = false;
 	bool shutdown_requested = false;
 	bool keyconfig_changed = false;
 	std::string show_open_url_dialog = "";