From 0b798a50dc84941c9e5e55f924aea3960ad8d867 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Fri, 30 Oct 2020 16:25:52 +0100
Subject: [PATCH] LibGUI: Make StackWidget/TabWidget preserve focus in inactive
 windows

This one is a bit sketchy. While a window is inactive, none of its
widgets are considered focused (Widget::is_focused() will return false)
but this caused programmatic changes of the active widget in a tab
or stack widget to fail focus propagation from old child to new child.

Work around this by checking against Window::focused_widget() directly
instead of asking Widget::is_focused().
---
 Libraries/LibGUI/StackWidget.cpp | 3 ++-
 Libraries/LibGUI/TabWidget.cpp   | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/Libraries/LibGUI/StackWidget.cpp b/Libraries/LibGUI/StackWidget.cpp
index bde65d5151..1f06eed24e 100644
--- a/Libraries/LibGUI/StackWidget.cpp
+++ b/Libraries/LibGUI/StackWidget.cpp
@@ -26,6 +26,7 @@
 
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/StackWidget.h>
+#include <LibGUI/Window.h>
 
 namespace GUI {
 
@@ -42,7 +43,7 @@ void StackWidget::set_active_widget(Widget* widget)
     if (widget == m_active_widget)
         return;
 
-    bool active_widget_had_focus = m_active_widget && m_active_widget->is_focused();
+    bool active_widget_had_focus = m_active_widget && window() && window()->focused_widget() == m_active_widget;
 
     if (m_active_widget)
         m_active_widget->set_visible(false);
diff --git a/Libraries/LibGUI/TabWidget.cpp b/Libraries/LibGUI/TabWidget.cpp
index 39583e593e..e3a6dcdb44 100644
--- a/Libraries/LibGUI/TabWidget.cpp
+++ b/Libraries/LibGUI/TabWidget.cpp
@@ -29,6 +29,7 @@
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/Painter.h>
 #include <LibGUI/TabWidget.h>
+#include <LibGUI/Window.h>
 #include <LibGfx/Bitmap.h>
 #include <LibGfx/Font.h>
 #include <LibGfx/Palette.h>
@@ -81,7 +82,7 @@ void TabWidget::set_active_widget(Widget* widget)
     if (widget == m_active_widget)
         return;
 
-    bool active_widget_had_focus = m_active_widget && m_active_widget->is_focused();
+    bool active_widget_had_focus = m_active_widget && window() && window()->focused_widget() == m_active_widget;
 
     if (m_active_widget)
         m_active_widget->set_visible(false);