Add support for platform's customization of the editor theme

Adds a new theme for the Android and XR editor based off https://github.com/passivestar/godot-minimal-theme

core/os/os.h

@@ -359,6 +359,10 @@ class OS {
 	// This is invoked by the GDExtensionManager after loading GDExtensions specified by the project.
 	virtual void load_platform_gdextensions() const {}
 
+	// Allows the platform to customize the editor theme.
+	// Should return a path to a theme resource that will be merged with the current editor theme.
+	virtual String get_editor_theme_override(const String &p_editor_theme_preset) { return String(); }
+
 	OS();
 	virtual ~OS();
 };

doc/classes/EditorSettings.xml

@@ -1024,12 +1024,20 @@
 			The saturation to use for editor icons. Higher values result in more vibrant colors.
 			[b]Note:[/b] The default editor icon saturation was increased by 30% in Godot 4.0 and later. To get Godot 3.x's icon saturation back, set [member interface/theme/icon_saturation] to [code]0.77[/code].
 		</member>
+		<member name="interface/theme/increase_scrollbar_touch_area" type="bool" setter="" getter="">
+			If [code]true[/code], increases the scrollbar touch area to improve usability on touchscreen devices.
+			[b]Note:[/b] Defaults to [code]true[/code] on touchscreen devices.
+		</member>
 		<member name="interface/theme/preset" type="String" setter="" getter="">
 			The editor theme preset to use.
 		</member>
 		<member name="interface/theme/relationship_line_opacity" type="float" setter="" getter="">
 			The opacity to use when drawing relationship lines in the editor's [Tree]-based GUIs (such as the Scene tree dock).
 		</member>
+		<member name="interface/theme/scale_gizmo_handles" type="float" setter="" getter="">
+			Specify the multiplier to apply to the scale for the editor gizmo handles to improve usability on touchscreen devices.
+			[b]Note:[/b] Defaults to [code]1[/code] on non-touchscreen devices.
+		</member>
 		<member name="interface/theme/spacing_preset" type="String" setter="" getter="">
 			The editor theme spacing preset to use. See also [member interface/theme/base_spacing] and [member interface/theme/additional_spacing].
 		</member>
@@ -1045,14 +1053,6 @@
 			If [code]true[/code], enable two finger pan and scale gestures on touchscreen devices.
 			[b]Note:[/b] Defaults to [code]true[/code] on touchscreen devices.
 		</member>
-		<member name="interface/touchscreen/increase_scrollbar_touch_area" type="bool" setter="" getter="">
-			If [code]true[/code], increases the scrollbar touch area to improve usability on touchscreen devices.
-			[b]Note:[/b] Defaults to [code]true[/code] on touchscreen devices.
-		</member>
-		<member name="interface/touchscreen/scale_gizmo_handles" type="float" setter="" getter="">
-			Specify the multiplier to apply to the scale for the editor gizmo handles to improve usability on touchscreen devices.
-			[b]Note:[/b] Defaults to [code]1[/code] on non-touchscreen devices.
-		</member>
 		<member name="network/connection/engine_version_update_mode" type="int" setter="" getter="">
 			Specifies how the engine should check for updates.
 			- [b]Disable Update Checks[/b] will block the engine from checking updates (see also [member network/connection/network_mode]).

editor/editor_settings.cpp

@@ -537,8 +537,16 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 	EDITOR_SETTING_BASIC(Variant::INT, PROPERTY_HINT_ENUM, "interface/inspector/default_color_picker_shape", (int32_t)ColorPicker::SHAPE_OKHSL_CIRCLE, "HSV Rectangle,HSV Rectangle Wheel,VHS Circle,OKHSL Circle")
 
 	// Theme
+	bool has_touchscreen_ui = DisplayServer::get_singleton()->is_touchscreen_available();
+	bool is_native_touchscreen = has_touchscreen_ui && !OS::get_singleton()->has_feature("xr_editor");
+
 	EDITOR_SETTING_BASIC(Variant::BOOL, PROPERTY_HINT_ENUM, "interface/theme/follow_system_theme", false, "")
-	EDITOR_SETTING_BASIC(Variant::STRING, PROPERTY_HINT_ENUM, "interface/theme/preset", "Default", "Default,Breeze Dark,Godot 2,Gray,Light,Solarized (Dark),Solarized (Light),Black (OLED),Custom")
+
+	String default_theme_preset = "Default";
+#ifdef ANDROID_ENABLED
+	default_theme_preset = "Android";
+#endif
+	EDITOR_SETTING_BASIC(Variant::STRING, PROPERTY_HINT_ENUM, "interface/theme/preset", default_theme_preset, "Default,Breeze Dark,Godot 2,Gray,Light,Solarized (Dark),Solarized (Light),Black (OLED),Custom,Android")
 	EDITOR_SETTING_BASIC(Variant::STRING, PROPERTY_HINT_ENUM, "interface/theme/spacing_preset", "Default", "Compact,Default,Spacious,Custom")
 	EDITOR_SETTING(Variant::INT, PROPERTY_HINT_ENUM, "interface/theme/icon_and_font_color", 0, "Auto,Dark,Light")
 	EDITOR_SETTING_BASIC(Variant::COLOR, PROPERTY_HINT_NONE, "interface/theme/base_color", Color(0.2, 0.23, 0.31), "")
@@ -552,21 +560,19 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 	EDITOR_SETTING(Variant::INT, PROPERTY_HINT_RANGE, "interface/theme/corner_radius", 3, "0,6,1")
 	EDITOR_SETTING(Variant::INT, PROPERTY_HINT_RANGE, "interface/theme/base_spacing", 4, "0,8,1")
 	EDITOR_SETTING(Variant::INT, PROPERTY_HINT_RANGE, "interface/theme/additional_spacing", 0, "0,8,1")
+	EDITOR_SETTING(Variant::BOOL, PROPERTY_HINT_NONE, "interface/theme/increase_scrollbar_touch_area", is_native_touchscreen, "")
+	set_restart_if_changed("interface/theme/increase_scrollbar_touch_area", true);
+	EDITOR_SETTING(Variant::FLOAT, PROPERTY_HINT_RANGE, "interface/theme/scale_gizmo_handles", has_touchscreen_ui ? 3 : 1, "1,5,1")
+	set_restart_if_changed("interface/theme/scale_gizmo_handles", true);
 	EDITOR_SETTING_USAGE(Variant::STRING, PROPERTY_HINT_GLOBAL_FILE, "interface/theme/custom_theme", "", "*.res,*.tres,*.theme", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_RESTART_IF_CHANGED)
 
 	// Touchscreen
-	bool has_touchscreen_ui = DisplayServer::get_singleton()->is_touchscreen_available();
 	EDITOR_SETTING(Variant::BOOL, PROPERTY_HINT_NONE, "interface/touchscreen/enable_pan_and_scale_gestures", has_touchscreen_ui, "")
 	set_restart_if_changed("interface/touchscreen/enable_pan_and_scale_gestures", true);
-	EDITOR_SETTING(Variant::FLOAT, PROPERTY_HINT_RANGE, "interface/touchscreen/scale_gizmo_handles", has_touchscreen_ui ? 3 : 1, "1,5,1")
-	set_restart_if_changed("interface/touchscreen/scale_gizmo_handles", true);
 
 	// Disable some touchscreen settings by default for the XR Editor.
-	bool is_native_touchscreen = has_touchscreen_ui && !OS::get_singleton()->has_feature("xr_editor");
 	EDITOR_SETTING(Variant::BOOL, PROPERTY_HINT_NONE, "interface/touchscreen/enable_long_press_as_right_click", is_native_touchscreen, "")
 	set_restart_if_changed("interface/touchscreen/enable_long_press_as_right_click", true);
-	EDITOR_SETTING(Variant::BOOL, PROPERTY_HINT_NONE, "interface/touchscreen/increase_scrollbar_touch_area", is_native_touchscreen, "")
-	set_restart_if_changed("interface/touchscreen/increase_scrollbar_touch_area", true);
 
 	// Scene tabs
 	EDITOR_SETTING(Variant::INT, PROPERTY_HINT_ENUM, "interface/scene_tabs/display_close_button", 1, "Never,If Tab Active,Always"); // TabBar::CloseButtonDisplayPolicy

editor/plugins/curve_editor_plugin.cpp

@@ -121,7 +121,7 @@ void CurveEdit::_notification(int p_what) {
 			}
 		} break;
 		case NOTIFICATION_THEME_CHANGED: {
-			float gizmo_scale = EDITOR_GET("interface/touchscreen/scale_gizmo_handles");
+			float gizmo_scale = EDITOR_GET("interface/theme/scale_gizmo_handles");
 			point_radius = Math::round(BASE_POINT_RADIUS * get_theme_default_base_scale() * gizmo_scale);
 			hover_radius = Math::round(BASE_HOVER_RADIUS * get_theme_default_base_scale() * gizmo_scale);
 			tangent_radius = Math::round(BASE_TANGENT_RADIUS * get_theme_default_base_scale() * gizmo_scale);

editor/themes/editor_theme_manager.cpp

@@ -245,8 +245,8 @@ EditorThemeManager::ThemeConfiguration EditorThemeManager::_create_theme_config(
 	config.relationship_line_opacity = EDITOR_GET("interface/theme/relationship_line_opacity");
 	config.thumb_size = EDITOR_GET("filesystem/file_dialog/thumbnail_size");
 	config.class_icon_size = 16 * EDSCALE;
-	config.increase_scrollbar_touch_area = EDITOR_GET("interface/touchscreen/increase_scrollbar_touch_area");
-	config.gizmo_handle_scale = EDITOR_GET("interface/touchscreen/scale_gizmo_handles");
+	config.increase_scrollbar_touch_area = EDITOR_GET("interface/theme/increase_scrollbar_touch_area");
+	config.gizmo_handle_scale = EDITOR_GET("interface/theme/scale_gizmo_handles");
 	config.color_picker_button_height = 28 * EDSCALE;
 	config.subresource_hue_tint = EDITOR_GET("docks/property_editor/subresource_hue_tint");
 
@@ -282,9 +282,15 @@ EditorThemeManager::ThemeConfiguration EditorThemeManager::_create_theme_config(
 			Color preset_base_color;
 			float preset_contrast = 0;
 			bool preset_draw_extra_borders = false;
+			float preset_icon_saturation = config.icon_saturation;
 
 			// Please use alphabetical order if you're adding a new theme here.
-			if (config.preset == "Breeze Dark") {
+			if (config.preset == "Android") {
+				preset_accent_color = Color(0.34, 0.62, 1.00);
+				preset_base_color = Color(0.15, 0.15, 0.15);
+				preset_contrast = 0.3;
+				preset_icon_saturation = 2;
+			} else if (config.preset == "Breeze Dark") {
 				preset_accent_color = Color(0.26, 0.76, 1.00);
 				preset_base_color = Color(0.24, 0.26, 0.28);
 				preset_contrast = config.default_contrast;
@@ -326,11 +332,13 @@ EditorThemeManager::ThemeConfiguration EditorThemeManager::_create_theme_config(
 			config.base_color = preset_base_color;
 			config.contrast = preset_contrast;
 			config.draw_extra_borders = preset_draw_extra_borders;
+			config.icon_saturation = preset_icon_saturation;
 
 			EditorSettings::get_singleton()->set_initial_value("interface/theme/accent_color", config.accent_color);
 			EditorSettings::get_singleton()->set_initial_value("interface/theme/base_color", config.base_color);
 			EditorSettings::get_singleton()->set_initial_value("interface/theme/contrast", config.contrast);
 			EditorSettings::get_singleton()->set_initial_value("interface/theme/draw_extra_borders", config.draw_extra_borders);
+			EditorSettings::get_singleton()->set_initial_value("interface/theme/icon_saturation", config.icon_saturation);
 		}
 
 		if (follow_system_theme && system_base_color != Color(0, 0, 0, 0)) {
@@ -349,6 +357,7 @@ EditorThemeManager::ThemeConfiguration EditorThemeManager::_create_theme_config(
 		EditorSettings::get_singleton()->set_manually("interface/theme/base_color", config.base_color);
 		EditorSettings::get_singleton()->set_manually("interface/theme/contrast", config.contrast);
 		EditorSettings::get_singleton()->set_manually("interface/theme/draw_extra_borders", config.draw_extra_borders);
+		EditorSettings::get_singleton()->set_manually("interface/theme/icon_saturation", config.icon_saturation);
 	}
 
 	// Handle theme spacing preset.
@@ -2770,6 +2779,14 @@ Ref<EditorTheme> EditorThemeManager::generate_theme(const Ref<EditorTheme> &p_ol
 
 	OS::get_singleton()->benchmark_begin_measure(get_benchmark_key(), "Merge Custom Theme");
 
+	const String platform_theme_override_path = OS::get_singleton()->get_editor_theme_override(EDITOR_GET("interface/theme/preset"));
+	if (!platform_theme_override_path.is_empty()) {
+		Ref<Theme> platform_theme_override = ResourceLoader::load(platform_theme_override_path);
+		if (platform_theme_override.is_valid()) {
+			theme->merge_with(platform_theme_override);
+		}
+	}
+
 	const String custom_theme_path = EDITOR_GET("interface/theme/custom_theme");
 	if (!custom_theme_path.is_empty()) {
 		Ref<Theme> custom_theme = ResourceLoader::load(custom_theme_path);

platform/android/java/editor/src/main/assets/themes/README.md

@@ -0,0 +1,3 @@
+## Godot Minimal Theme
+- Source: https://github.com/passivestar/godot-minimal-theme
+- Version: https://github.com/passivestar/godot-minimal-theme/releases/tag/2.0.1