LibGUI: Convert mouse events from a visual to a physical position

When clicking a position within a TextEditor, we should interpret that
position as a visual location. That location should be converted to a
"physical" location before using it to set the physical cursor position.

For example, consider a document with 2 emoji, each consisting of 3 code
points. Visually, these will occupy 2 columns. When a mouse click occurs
between these columns, we need to convert the visual column number 1 to
the physical column number 3 when storing the new cursor location.

1 files changed, 1 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGUI/TextEditor.h b/Userland/Libraries/LibGUI/TextEditor.h
index 903dbd9046..4892794f29 100644
--- a/Userland/Libraries/LibGUI/TextEditor.h
+++ b/Userland/Libraries/LibGUI/TextEditor.h
@@ -190,6 +190,7 @@ public:
     void set_cursor_and_focus_line(size_t line, size_t column);
     void set_cursor(size_t line, size_t column);
     virtual void set_cursor(TextPosition const&);
+    void set_cursor_to_text_position(Gfx::IntPoint);
 
     Syntax::Highlighter* syntax_highlighter();
     Syntax::Highlighter const* syntax_highlighter() const;