Add a theme usability setting which updates the touch area of UI elements (e.g: scrollbar) for the editor on touchscreen devices

doc/classes/EditorSettings.xml

@@ -607,6 +607,10 @@
 		<member name="interface/theme/draw_extra_borders" type="bool" setter="" getter="">
 			If [code]true[/code], draws additional borders around interactive UI elements in the editor. This is automatically enabled when using the [b]Black (OLED)[/b] theme preset, as this theme preset uses a fully black background.
 		</member>
+		<member name="interface/theme/enable_touchscreen_touch_area" type="bool" setter="" getter="">
+			If [code]true[/code], increases the touch area for the UI elements to improve usability on touchscreen devices.
+			[b]Note:[/b] Defaults to [code]true[/code] on touchscreen devices.
+		</member>
 		<member name="interface/theme/icon_and_font_color" type="int" setter="" getter="">
 			The icon and font color scheme to use in the editor.
 			- [b]Auto[/b] determines the color scheme to use automatically based on [member interface/theme/base_color].

editor/editor_settings.cpp

@@ -453,6 +453,7 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 
 	// Theme
 	EDITOR_SETTING(Variant::STRING, PROPERTY_HINT_ENUM, "interface/theme/preset", "Default", "Default,Breeze Dark,Godot 2,Gray,Light,Solarized (Dark),Solarized (Light),Black (OLED),Custom")
+	EDITOR_SETTING(Variant::BOOL, PROPERTY_HINT_NONE, "interface/theme/enable_touchscreen_touch_area", DisplayServer::get_singleton()->is_touchscreen_available(), "")
 	EDITOR_SETTING(Variant::INT, PROPERTY_HINT_ENUM, "interface/theme/icon_and_font_color", 0, "Auto,Dark,Light")
 	EDITOR_SETTING(Variant::COLOR, PROPERTY_HINT_NONE, "interface/theme/base_color", Color(0.2, 0.23, 0.31), "")
 	EDITOR_SETTING(Variant::COLOR, PROPERTY_HINT_NONE, "interface/theme/accent_color", Color(0.41, 0.61, 0.91), "")

editor/editor_themes.cpp

@@ -394,6 +394,7 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	Color accent_color = EDITOR_GET("interface/theme/accent_color");
 	Color base_color = EDITOR_GET("interface/theme/base_color");
 	float contrast = EDITOR_GET("interface/theme/contrast");
+	bool enable_touchscreen_touch_area = EDITOR_GET("interface/theme/enable_touchscreen_touch_area");
 	bool draw_extra_borders = EDITOR_GET("interface/theme/draw_extra_borders");
 	float icon_saturation = EDITOR_GET("interface/theme/icon_saturation");
 	float relationship_line_opacity = EDITOR_GET("interface/theme/relationship_line_opacity");
@@ -1492,7 +1493,11 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	// HScrollBar
 	Ref<Texture2D> empty_icon = memnew(ImageTexture);
 
-	theme->set_stylebox("scroll", "HScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollBg"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));
+	if (enable_touchscreen_touch_area) {
+		theme->set_stylebox("scroll", "HScrollBar", make_line_stylebox(separator_color, 50));
+	} else {
+		theme->set_stylebox("scroll", "HScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollBg"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));
+	}
 	theme->set_stylebox("scroll_focus", "HScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollBg"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));
 	theme->set_stylebox("grabber", "HScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollGrabber"), SNAME("EditorIcons")), 6, 6, 6, 6, 1, 1, 1, 1));
 	theme->set_stylebox("grabber_highlight", "HScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollGrabberHl"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));
@@ -1506,7 +1511,11 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	theme->set_icon("decrement_pressed", "HScrollBar", empty_icon);
 
 	// VScrollBar
-	theme->set_stylebox("scroll", "VScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollBg"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));
+	if (enable_touchscreen_touch_area) {
+		theme->set_stylebox("scroll", "VScrollBar", make_line_stylebox(separator_color, 50, 1, 1, true));
+	} else {
+		theme->set_stylebox("scroll", "VScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollBg"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));
+	}
 	theme->set_stylebox("scroll_focus", "VScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollBg"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));
 	theme->set_stylebox("grabber", "VScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollGrabber"), SNAME("EditorIcons")), 6, 6, 6, 6, 1, 1, 1, 1));
 	theme->set_stylebox("grabber_highlight", "VScrollBar", make_stylebox(theme->get_icon(SNAME("GuiScrollGrabberHl"), SNAME("EditorIcons")), 5, 5, 5, 5, 1, 1, 1, 1));

scene/resources/style_box.cpp

@@ -1007,7 +1007,7 @@ void StyleBoxLine::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::COLOR, "color"), "set_color", "get_color");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "grow_begin", PROPERTY_HINT_RANGE, "-300,300,1,suffix:px"), "set_grow_begin", "get_grow_begin");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "grow_end", PROPERTY_HINT_RANGE, "-300,300,1,suffix:px"), "set_grow_end", "get_grow_end");
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "thickness", PROPERTY_HINT_RANGE, "0,10,suffix:px"), "set_thickness", "get_thickness");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "thickness", PROPERTY_HINT_RANGE, "0,100,suffix:px"), "set_thickness", "get_thickness");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "vertical"), "set_vertical", "is_vertical");
 }