GTextEditor: Support splitting lines at the cursor with the Return key.

2 files changed, 15 insertions, 1 deletions

diff --git a/LibGUI/GTextEditor.cpp b/LibGUI/GTextEditor.cpp
index 720277347b..5e2b2f9dcb 100644
--- a/LibGUI/GTextEditor.cpp
+++ b/LibGUI/GTextEditor.cpp
@@ -240,10 +240,17 @@ void GTextEditor::insert_at_cursor(char ch)
         if (at_tail || at_head) {
             m_lines.insert(m_cursor.line() + (at_tail ? 1 : 0), make<Line>());
             update_scrollbar_ranges();
-            set_cursor(m_cursor.line() + 1, 0);
             update();
+            set_cursor(m_cursor.line() + 1, 0);
             return;
         }
+        auto new_line = make<Line>();
+        new_line->append(current_line().characters() + m_cursor.column(), current_line().length() - m_cursor.column());
+        current_line().truncate(m_cursor.column());
+        m_lines.insert(m_cursor.line() + 1, move(new_line));
+        update_scrollbar_ranges();
+        update();
+        set_cursor(m_cursor.line() + 1, 0);
         return;
     }
     current_line().insert(m_cursor.column(), ch);
@@ -414,3 +421,9 @@ void GTextEditor::Line::remove(int index)
         m_text.remove(index);
     }
 }
+
+void GTextEditor::Line::truncate(int length)
+{
+    m_text.resize(length + 1);
+    m_text.last() = 0;
+}
diff --git a/LibGUI/GTextEditor.h b/LibGUI/GTextEditor.h
index 5964df624b..1c905512b2 100644
--- a/LibGUI/GTextEditor.h
+++ b/LibGUI/GTextEditor.h
@@ -73,6 +73,7 @@ private:
         void insert(int index, char);
         void remove(int index);
         void append(const char*, int);
+        void truncate(int length);
 
     private:
         // NOTE: This vector is null terminated.