LibGUI: Allow double clicking on tabwidgets

Author: https://github.com/ebiederstadt
Commit: https://github.com/SerenityOS/serenity/commit/0cfe446d3f5
Pull-request: https://github.com/SerenityOS/serenity/pull/11139
Reviewed-by: https://github.com/alimpfard

Userland/Libraries/LibGUI/TabWidget.cpp

@@ -635,6 +635,18 @@ void TabWidget::context_menu_event(ContextMenuEvent& context_menu_event)
     }
 }
 
+void TabWidget::doubleclick_event(MouseEvent&)
+{
+    for (auto& tab : m_tabs) {
+        if (auto* widget = tab.widget) {
+            deferred_invoke([this, widget] {
+                if (on_double_click)
+                    on_double_click(*widget);
+            });
+        }
+    }
+}
+
 void TabWidget::set_container_margins(GUI::Margins const& margins)
 {
     m_container_margins = margins;

Userland/Libraries/LibGUI/TabWidget.h

@@ -86,6 +86,7 @@ public:
     Function<void(Widget&)> on_middle_click;
     Function<void(Widget&)> on_tab_close_click;
     Function<void(Widget&, const ContextMenuEvent&)> on_context_menu_request;
+    Function<void(Widget&)> on_double_click;
 
 protected:
     TabWidget();
@@ -99,6 +100,7 @@ protected:
     virtual void leave_event(Core::Event&) override;
     virtual void keydown_event(KeyEvent&) override;
     virtual void context_menu_event(ContextMenuEvent&) override;
+    virtual void doubleclick_event(MouseEvent&) override;
 
 private:
     Gfx::IntRect child_rect_for_size(const Gfx::IntSize&) const;