Add theming support for hovered tabs

Tabs can now be styled differently when hovered by the mouse pointer.

doc/classes/TabBar.xml

@@ -326,6 +326,9 @@
 		<theme_item name="font_disabled_color" data_type="color" type="Color" default="Color(0.875, 0.875, 0.875, 0.5)">
 			Font color of disabled tabs.
 		</theme_item>
+		<theme_item name="font_hovered_color" data_type="color" type="Color" default="Color(0.95, 0.95, 0.95, 1)">
+			Font color of the currently hovered tab. Does not apply to the selected tab.
+		</theme_item>
 		<theme_item name="font_outline_color" data_type="color" type="Color" default="Color(1, 1, 1, 1)">
 			The tint of text outline of the tab name.
 		</theme_item>
@@ -378,6 +381,9 @@
 		<theme_item name="tab_disabled" data_type="style" type="StyleBox">
 			The style of disabled tabs.
 		</theme_item>
+		<theme_item name="tab_hovered" data_type="style" type="StyleBox">
+			The style of the currently hovered tab. Does not apply to the selected tab.
+		</theme_item>
 		<theme_item name="tab_selected" data_type="style" type="StyleBox">
 			The style of the currently selected tab.
 		</theme_item>

doc/classes/TabContainer.xml

@@ -200,6 +200,9 @@
 		<theme_item name="font_disabled_color" data_type="color" type="Color" default="Color(0.875, 0.875, 0.875, 0.5)">
 			Font color of disabled tabs.
 		</theme_item>
+		<theme_item name="font_hovered_color" data_type="color" type="Color" default="Color(0.95, 0.95, 0.95, 1)">
+			Font color of the currently hovered tab.
+		</theme_item>
 		<theme_item name="font_outline_color" data_type="color" type="Color" default="Color(1, 1, 1, 1)">
 			The tint of text outline of the tab name.
 		</theme_item>
@@ -256,6 +259,9 @@
 		<theme_item name="tab_disabled" data_type="style" type="StyleBox">
 			The style of disabled tabs.
 		</theme_item>
+		<theme_item name="tab_hovered" data_type="style" type="StyleBox">
+			The style of the currently hovered tab.
+		</theme_item>
 		<theme_item name="tab_selected" data_type="style" type="StyleBox">
 			The style of the currently selected tab.
 		</theme_item>

editor/editor_themes.cpp

@@ -747,6 +747,12 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	style_tab_selected->set_border_color(tab_highlight);
 	style_tab_selected->set_corner_radius_all(0);
 
+	Ref<StyleBoxFlat> style_tab_hovered = style_tab_base->duplicate();
+
+	style_tab_hovered->set_bg_color(dark_color_1.lerp(base_color, 0.4));
+	// Hovered tab has a subtle highlight between normal and selected states.
+	style_tab_hovered->set_corner_radius_all(0);
+
 	Ref<StyleBoxFlat> style_tab_unselected = style_tab_base->duplicate();
 	style_tab_unselected->set_expand_margin(SIDE_BOTTOM, 0);
 	style_tab_unselected->set_bg_color(dark_color_1);
@@ -1319,17 +1325,21 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	theme->set_stylebox("tabbar_background", "TabContainer", style_tabbar_background);
 
 	theme->set_stylebox("tab_selected", "TabContainer", style_tab_selected);
+	theme->set_stylebox("tab_hovered", "TabContainer", style_tab_hovered);
 	theme->set_stylebox("tab_unselected", "TabContainer", style_tab_unselected);
 	theme->set_stylebox("tab_disabled", "TabContainer", style_tab_disabled);
 	theme->set_stylebox("tab_selected", "TabBar", style_tab_selected);
+	theme->set_stylebox("tab_hovered", "TabBar", style_tab_hovered);
 	theme->set_stylebox("tab_unselected", "TabBar", style_tab_unselected);
 	theme->set_stylebox("tab_disabled", "TabBar", style_tab_disabled);
 	theme->set_stylebox("button_pressed", "TabBar", style_menu);
 	theme->set_stylebox("button_highlight", "TabBar", style_menu);
 	theme->set_color("font_selected_color", "TabContainer", font_color);
+	theme->set_color("font_hovered_color", "TabContainer", font_color);
 	theme->set_color("font_unselected_color", "TabContainer", font_disabled_color);
 	theme->set_color("font_outline_color", "TabContainer", font_outline_color);
 	theme->set_color("font_selected_color", "TabBar", font_color);
+	theme->set_color("font_hovered_color", "TabBar", font_color);
 	theme->set_color("font_unselected_color", "TabBar", font_disabled_color);
 	theme->set_color("font_outline_color", "TabBar", font_outline_color);
 	theme->set_color("drop_mark_color", "TabContainer", tab_highlight);

scene/gui/tab_bar.cpp

@@ -44,7 +44,7 @@ Size2 TabBar::get_minimum_size() const {
 		return ms;
 	}
 
-	int y_margin = MAX(MAX(theme_cache.tab_unselected_style->get_minimum_size().height, theme_cache.tab_selected_style->get_minimum_size().height), theme_cache.tab_disabled_style->get_minimum_size().height);
+	int y_margin = MAX(MAX(MAX(theme_cache.tab_unselected_style->get_minimum_size().height, theme_cache.tab_hovered_style->get_minimum_size().height), theme_cache.tab_selected_style->get_minimum_size().height), theme_cache.tab_disabled_style->get_minimum_size().height);
 
 	for (int i = 0; i < tabs.size(); i++) {
 		if (tabs[i].hidden) {
@@ -58,6 +58,8 @@ Size2 TabBar::get_minimum_size() const {
 			style = theme_cache.tab_disabled_style;
 		} else if (current == i) {
 			style = theme_cache.tab_selected_style;
+		} else if (hover == i) {
+			style = theme_cache.tab_hovered_style;
 		} else {
 			style = theme_cache.tab_unselected_style;
 		}
@@ -307,6 +309,7 @@ void TabBar::_update_theme_item_cache() {
 	theme_cache.icon_max_width = get_theme_constant(SNAME("icon_max_width"));
 
 	theme_cache.tab_unselected_style = get_theme_stylebox(SNAME("tab_unselected"));
+	theme_cache.tab_hovered_style = get_theme_stylebox(SNAME("tab_hovered"));
 	theme_cache.tab_selected_style = get_theme_stylebox(SNAME("tab_selected"));
 	theme_cache.tab_disabled_style = get_theme_stylebox(SNAME("tab_disabled"));
 
@@ -322,6 +325,7 @@ void TabBar::_update_theme_item_cache() {
 	theme_cache.outline_size = get_theme_constant(SNAME("outline_size"));
 
 	theme_cache.font_selected_color = get_theme_color(SNAME("font_selected_color"));
+	theme_cache.font_hovered_color = get_theme_color(SNAME("font_hovered_color"));
 	theme_cache.font_unselected_color = get_theme_color(SNAME("font_unselected_color"));
 	theme_cache.font_disabled_color = get_theme_color(SNAME("font_disabled_color"));
 	theme_cache.font_outline_color = get_theme_color(SNAME("font_outline_color"));
@@ -397,6 +401,9 @@ void TabBar::_notification(int p_what) {
 					if (tabs[i].disabled) {
 						sb = theme_cache.tab_disabled_style;
 						col = theme_cache.font_disabled_color;
+					} else if (i == hover) {
+						sb = theme_cache.tab_hovered_style;
+						col = theme_cache.font_hovered_color;
 					} else {
 						sb = theme_cache.tab_unselected_style;
 						col = theme_cache.font_unselected_color;
@@ -857,6 +864,7 @@ void TabBar::_update_hover() {
 		if (hover != -1) {
 			emit_signal(SNAME("tab_hovered"), hover);
 		}
+		queue_redraw();
 	}
 
 	if (hover_buttons == -1) { // No hover.
@@ -1296,6 +1304,8 @@ int TabBar::get_tab_width(int p_idx) const {
 		style = theme_cache.tab_disabled_style;
 	} else if (current == p_idx) {
 		style = theme_cache.tab_selected_style;
+	} else if (hover == p_idx) {
+		style = theme_cache.tab_hovered_style;
 	} else {
 		style = theme_cache.tab_unselected_style;
 	}

scene/gui/tab_bar.h

@@ -111,6 +111,7 @@ private:
 		int icon_max_width = 0;
 
 		Ref<StyleBox> tab_unselected_style;
+		Ref<StyleBox> tab_hovered_style;
 		Ref<StyleBox> tab_selected_style;
 		Ref<StyleBox> tab_disabled_style;
 
@@ -126,6 +127,7 @@ private:
 		int outline_size = 0;
 
 		Color font_selected_color;
+		Color font_hovered_color;
 		Color font_unselected_color;
 		Color font_disabled_color;
 		Color font_outline_color;

scene/gui/tab_container.cpp

@@ -150,6 +150,7 @@ void TabContainer::_update_theme_item_cache() {
 	theme_cache.outline_size = get_theme_constant(SNAME("outline_size"));
 
 	theme_cache.tab_unselected_style = get_theme_stylebox(SNAME("tab_unselected"));
+	theme_cache.tab_hovered_style = get_theme_stylebox(SNAME("tab_hovered"));
 	theme_cache.tab_selected_style = get_theme_stylebox(SNAME("tab_selected"));
 	theme_cache.tab_disabled_style = get_theme_stylebox(SNAME("tab_disabled"));
 
@@ -227,6 +228,7 @@ void TabContainer::_on_theme_changed() {
 	}
 
 	tab_bar->add_theme_style_override(SNAME("tab_unselected"), theme_cache.tab_unselected_style);
+	tab_bar->add_theme_style_override(SNAME("tab_hovered"), theme_cache.tab_hovered_style);
 	tab_bar->add_theme_style_override(SNAME("tab_selected"), theme_cache.tab_selected_style);
 	tab_bar->add_theme_style_override(SNAME("tab_disabled"), theme_cache.tab_disabled_style);
 

scene/gui/tab_container.h

@@ -63,6 +63,7 @@ class TabContainer : public Container {
 		int outline_size = 0;
 
 		Ref<StyleBox> tab_unselected_style;
+		Ref<StyleBox> tab_hovered_style;
 		Ref<StyleBox> tab_selected_style;
 		Ref<StyleBox> tab_disabled_style;
 

scene/resources/default_theme/default_theme.cpp

@@ -825,8 +825,11 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	style_tab_unselected->set_border_color(style_popup_border_color);
 	Ref<StyleBoxFlat> style_tab_disabled = style_tab_unselected->duplicate();
 	style_tab_disabled->set_bg_color(style_disabled_color);
+	Ref<StyleBoxFlat> style_tab_hovered = style_tab_unselected->duplicate();
+	style_tab_hovered->set_bg_color(Color(0.1, 0.1, 0.1, 0.3));
 
 	theme->set_stylebox("tab_selected", "TabContainer", style_tab_selected);
+	theme->set_stylebox("tab_hovered", "TabContainer", style_tab_hovered);
 	theme->set_stylebox("tab_unselected", "TabContainer", style_tab_unselected);
 	theme->set_stylebox("tab_disabled", "TabContainer", style_tab_disabled);
 	theme->set_stylebox("panel", "TabContainer", make_flat_stylebox(style_normal_color, 0, 0, 0, 0));
@@ -844,6 +847,7 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	theme->set_font_size("font_size", "TabContainer", -1);
 
 	theme->set_color("font_selected_color", "TabContainer", control_font_hover_color);
+	theme->set_color("font_hovered_color", "TabContainer", control_font_hover_color);
 	theme->set_color("font_unselected_color", "TabContainer", control_font_low_color);
 	theme->set_color("font_disabled_color", "TabContainer", control_font_disabled_color);
 	theme->set_color("font_outline_color", "TabContainer", Color(1, 1, 1));
@@ -857,6 +861,7 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	// TabBar
 
 	theme->set_stylebox("tab_selected", "TabBar", style_tab_selected);
+	theme->set_stylebox("tab_hovered", "TabBar", style_tab_hovered);
 	theme->set_stylebox("tab_unselected", "TabBar", style_tab_unselected);
 	theme->set_stylebox("tab_disabled", "TabBar", style_tab_disabled);
 	theme->set_stylebox("button_pressed", "TabBar", button_pressed);
@@ -873,6 +878,7 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	theme->set_font_size("font_size", "TabBar", -1);
 
 	theme->set_color("font_selected_color", "TabBar", control_font_hover_color);
+	theme->set_color("font_hovered_color", "TabBar", control_font_hover_color);
 	theme->set_color("font_unselected_color", "TabBar", control_font_low_color);
 	theme->set_color("font_disabled_color", "TabBar", control_font_disabled_color);
 	theme->set_color("font_outline_color", "TabBar", Color(1, 1, 1));