From 9bf09194cc2def3922a44f55be97603630e42e1b Mon Sep 17 00:00:00 2001
From: Michael Alexsander <michaelalexsander@protonmail.com>
Date: Tue, 26 Sep 2023 14:12:08 -0300
Subject: [PATCH] Make hovered tabs be drawn with the unselected's width at
 minimum

(cherry picked from commit decae848a8fb6399a596418168a1cd0bd4305f9c)
---
 doc/classes/TabBar.xml       |  1 +
 doc/classes/TabContainer.xml |  1 +
 scene/gui/tab_bar.cpp        | 15 ++++++++++-----
 scene/gui/tab_bar.h          |  2 +-
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/doc/classes/TabBar.xml b/doc/classes/TabBar.xml
index cdbe9d933a6..a57a2f292f5 100644
--- a/doc/classes/TabBar.xml
+++ b/doc/classes/TabBar.xml
@@ -398,6 +398,7 @@
 		</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.
+			[b]Note:[/b] This style will be drawn with the same width as [theme_item tab_unselected] at minimum.
 		</theme_item>
 		<theme_item name="tab_selected" data_type="style" type="StyleBox">
 			The style of the currently selected tab.
diff --git a/doc/classes/TabContainer.xml b/doc/classes/TabContainer.xml
index ebf9bb25841..3f324ffb46f 100644
--- a/doc/classes/TabContainer.xml
+++ b/doc/classes/TabContainer.xml
@@ -293,6 +293,7 @@
 		</theme_item>
 		<theme_item name="tab_hovered" data_type="style" type="StyleBox">
 			The style of the currently hovered tab.
+			[b]Note:[/b] This style will be drawn with the same width as [theme_item tab_unselected] at minimum.
 		</theme_item>
 		<theme_item name="tab_selected" data_type="style" type="StyleBox">
 			The style of the currently selected tab.
diff --git a/scene/gui/tab_bar.cpp b/scene/gui/tab_bar.cpp
index 959a51eff91..0224416d79f 100644
--- a/scene/gui/tab_bar.cpp
+++ b/scene/gui/tab_bar.cpp
@@ -899,7 +899,7 @@ void TabBar::_update_hover() {
 	}
 }
 
-void TabBar::_update_cache() {
+void TabBar::_update_cache(bool p_update_hover) {
 	if (tabs.is_empty()) {
 		buttons_visible = false;
 		return;
@@ -962,7 +962,9 @@ void TabBar::_update_cache() {
 	buttons_visible = offset > 0 || missing_right;
 
 	if (tab_alignment == ALIGNMENT_LEFT) {
-		_update_hover();
+		if (p_update_hover) {
+			_update_hover();
+		}
 		return;
 	}
 
@@ -980,7 +982,9 @@ void TabBar::_update_cache() {
 		}
 	}
 
-	_update_hover();
+	if (p_update_hover) {
+		_update_hover();
+	}
 }
 
 void TabBar::_on_mouse_exited() {
@@ -990,7 +994,7 @@ void TabBar::_on_mouse_exited() {
 	highlight_arrow = -1;
 	dragging_valid_tab = false;
 
-	_update_cache();
+	_update_cache(false);
 	queue_redraw();
 }
 
@@ -1324,7 +1328,8 @@ 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) {
+		// Use the unselected style's width if the hovered one is shorter, to avoid an infinite loop when switching tabs with the mouse.
+	} else if (hover == p_idx && theme_cache.tab_hovered_style->get_minimum_size().width >= theme_cache.tab_unselected_style->get_minimum_size().width) {
 		style = theme_cache.tab_hovered_style;
 	} else {
 		style = theme_cache.tab_unselected_style;
diff --git a/scene/gui/tab_bar.h b/scene/gui/tab_bar.h
index 438b6c60b5c..33eefcd90b4 100644
--- a/scene/gui/tab_bar.h
+++ b/scene/gui/tab_bar.h
@@ -143,7 +143,7 @@ private:
 	void _ensure_no_over_offset();
 
 	void _update_hover();
-	void _update_cache();
+	void _update_cache(bool p_update_hover = true);
 
 	void _on_mouse_exited();