LibGUI: Implement case inversion in Vim emulation

When in visual mode with text selected, on Key_Tilde press, uppercase
characters convert to lowercase and lowercase ones to uppercase.

1 files changed, 2 insertions, 1 deletions

diff --git a/Userland/Libraries/LibGUI/VimEditingEngine.h b/Userland/Libraries/LibGUI/VimEditingEngine.h
index d9e956524a..f3b372890f 100644
--- a/Userland/Libraries/LibGUI/VimEditingEngine.h
+++ b/Userland/Libraries/LibGUI/VimEditingEngine.h
@@ -162,7 +162,8 @@ private:
 
     enum class Casing {
         Uppercase,
-        Lowercase
+        Lowercase,
+        Invertcase
     };
 
     VimMode m_vim_mode { VimMode::Normal };