1 files changed, 25 insertions, 0 deletions
diff --git a/src/selection.rs b/src/selection.rs
index b98a113..2c1e43d 100644
--- a/src/selection.rs
+++ b/src/selection.rs
@@ -208,6 +208,31 @@ impl Selection {
         self.select_range(start, end);
     }
 
+    /// Updates the current selection by setting a new end point, either to the end of a following
+    /// line, or the beginning of a previous one.
+    pub fn change_selection_by_line(
+        &mut self,
+        new_line: usize,
+        paragraph: &Paragraph,
+    ) {
+        if new_line < self.start.line {
+            self.direction = Direction::Left;
+        } else if new_line > self.end.line {
+            self.direction = Direction::Right;
+        }
+
+        let (start, end) = if self.direction == Direction::Right {
+            let value = Value::new(paragraph.buffer().lines[new_line].text());
+
+            (self.start, SelectionEnd::new(new_line, value.len()))
+        } else {
+            (SelectionEnd::new(new_line, 0), self.end)
+        };
+
+        self.moving_line_index = None;
+        self.select_range(start, end);
+    }
+
     /// Selects the word around the given grapheme position.
     pub fn select_word(
         &mut self,