LibGUI+WindowServer: Add "visible" state to GUI actions

This patch adds a visibility state to GUI::Action. All actions default
to being visible. When invisible, they do not show up in toolbars on
menus (and importantly, they don't occupy any space).

This can be used to hide/show context-sensitive actions dynamically
without rebuilding menus and toolbars.

Thanks to Tim Slater for assuming that action visibility was a thing,
which gave me a reason to implement it! :^)

1 files changed, 4 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGUI/MenuItem.h b/Userland/Libraries/LibGUI/MenuItem.h
index c98cb94abb..574f8a3b2f 100644
--- a/Userland/Libraries/LibGUI/MenuItem.h
+++ b/Userland/Libraries/LibGUI/MenuItem.h
@@ -45,6 +45,9 @@ public:
     bool is_enabled() const { return m_enabled; }
     void set_enabled(bool);
 
+    bool is_visible() const { return m_visible; }
+    void set_visible(bool);
+
     bool is_default() const { return m_default; }
     void set_default(bool);
 
@@ -61,6 +64,7 @@ private:
     int m_menu_id { -1 };
     unsigned m_identifier { 0 };
     bool m_enabled { true };
+    bool m_visible { true };
     bool m_checkable { false };
     bool m_checked { false };
     bool m_default { false };