Merge pull request #81 from achristmascarl/expose-selection-start

Expose `selection_start`

src/textarea.rs

@@ -1430,7 +1430,7 @@ impl<'a> TextArea<'a> {
         self.select_style
     }
 
-    fn selection_range(&self) -> Option<(Pos, Pos)> {
+    fn selection_range_(&self) -> Option<(Pos, Pos)> {
         let (sr, sc) = self.selection_start?;
         let (er, ec) = self.cursor;
         let (so, eo) = (self.line_offset(sr, sc), self.line_offset(er, ec));
@@ -1444,7 +1444,7 @@ impl<'a> TextArea<'a> {
     }
 
     fn take_selection_range(&mut self) -> Option<(Pos, Pos)> {
-        let range = self.selection_range();
+        let range = self.selection_range_();
         self.cancel_selection();
         range
     }
@@ -1608,7 +1608,7 @@ impl<'a> TextArea<'a> {
             hl.search(matches, self.search.style);
         }
 
-        if let Some((start, end)) = self.selection_range() {
+        if let Some((start, end)) = self.selection_range_() {
             hl.selection(row, start.row, start.offset, end.row, end.offset);
         }
 
@@ -2040,6 +2040,34 @@ impl<'a> TextArea<'a> {
         self.cursor
     }
 
+    /// Get the current selection range. A tuple (selection_start, cursor) of 0-base character-wise (row, col)
+    /// positions. The selection start position will always come first, even when it is ahead of
+    /// the cursor.
+    /// ```
+    /// use tui_textarea::TextArea;
+    /// use tui_textarea::CursorMove;
+    ///
+    /// let mut textarea = TextArea::from(["abc"]);
+    /// assert_eq!(textarea.selection_range(), None);
+    ///
+    /// textarea.start_selection();
+    /// assert_eq!(textarea.selection_range(), Some(((0, 0), (0, 0))));
+    ///
+    /// textarea.move_cursor(CursorMove::Forward);
+    /// assert_eq!(textarea.selection_range(), Some(((0, 0), (0, 1))));
+    ///
+    /// textarea.cancel_selection();
+    /// assert_eq!(textarea.selection_range(), None);
+    ///
+    /// textarea.start_selection();
+    /// textarea.move_cursor(CursorMove::Back);
+    /// assert_eq!(textarea.selection_range(), Some(((0, 1), (0, 0))));
+    /// ```
+    pub fn selection_range(&self) -> Option<((usize, usize), (usize, usize))> {
+        self.selection_start
+            .map(|selection_start| (selection_start, self.cursor))
+    }
+
     /// Set text alignment. When [`Alignment::Center`] or [`Alignment::Right`] is set, line number is automatically
     /// disabled because those alignments don't work well with line numbers.
     /// ```