Add … when chars are truncated in picker

helix-term/src/ui/picker.rs

@@ -289,7 +289,7 @@ impl<T: 'static> Component for Picker<T> {
                 surface.set_string(inner.x + 1, inner.y + 2 + i as u16, ">", selected);
             }
 
-            surface.set_stringn(
+            surface.set_string_truncated(
                 inner.x + 3,
                 inner.y + 2 + i as u16,
                 (self.format_fn)(option),
@@ -299,6 +299,7 @@ impl<T: 'static> Component for Picker<T> {
                 } else {
                     style
                 },
+                true,
             );
         }
     }

helix-tui/src/buffer.rs

@@ -266,11 +266,30 @@ impl Buffer {
         width: usize,
         style: Style,
     ) -> (u16, u16)
+    where
+        S: AsRef<str>,
+    {
+        self.set_string_truncated(x, y, string, width, style, false)
+    }
+
+    /// Print at most the first `width` characters of a string if enough space is available
+    /// until the end of the line. If `markend` is true appends a `…` at the end of
+    /// truncated lines.
+    pub fn set_string_truncated<S>(
+        &mut self,
+        x: u16,
+        y: u16,
+        string: S,
+        width: usize,
+        style: Style,
+        ellipsis: bool,
+    ) -> (u16, u16)
     where
         S: AsRef<str>,
     {
         let mut index = self.index_of(x, y);
         let mut x_offset = x as usize;
+        let width = if ellipsis { width - 1 } else { width };
         let graphemes = UnicodeSegmentation::graphemes(string.as_ref(), true);
         let max_offset = min(self.area.right() as usize, width.saturating_add(x as usize));
         for s in graphemes {
@@ -293,6 +312,9 @@ impl Buffer {
             index += width;
             x_offset += width;
         }
+        if ellipsis && x_offset - (x as usize) < string.as_ref().chars().count() {
+            self.content[index].set_symbol("…");
+        }
         (x_offset as u16, y)
     }