fix rendering of the cursor position in the line editor

src/ssh.rs

@@ -44,13 +44,18 @@ fn password_prompt(
 
         // Rewrite the input so that we can obscure the password
         // characters when output to the terminal widget
-        fn highlight_line(&self, line: &str, _cursor_position: usize) -> Vec<OutputElement> {
+        fn highlight_line(
+            &self,
+            line: &str,
+            cursor_position: usize,
+        ) -> (Vec<OutputElement>, usize) {
+            let placeholder = "🔑";
             let grapheme_count = unicode_column_width(line);
             let mut output = vec![];
             for _ in 0..grapheme_count {
-                output.push(OutputElement::Text("🔑".to_string()));
+                output.push(OutputElement::Text(placeholder.to_string()));
             }
-            output
+            (output, unicode_column_width(placeholder) * cursor_position)
         }
     }
     match termwiztermtab::run(60, 10, move |mut term| {

termwiz/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 authors = ["Wez Furlong"]
 name = "termwiz"
-version = "0.4.0"
+version = "0.5.0"
 edition = "2018"
 repository = "https://github.com/wez/wezterm"
 description = "Terminal Wizardry for Unix and Windows"

termwiz/src/lineedit/host.rs

@@ -57,8 +57,9 @@ pub trait LineEditorHost {
     /// The `OutputElement` type allows returning graphic attribute changes
     /// as well as textual output.
     /// The default implementation returns the line as-is with no coloring.
-    fn highlight_line(&self, line: &str, _cursor_position: usize) -> Vec<OutputElement> {
-        vec![OutputElement::Text(line.to_owned())]
+    fn highlight_line(&self, line: &str, cursor_position: usize) -> (Vec<OutputElement>, usize) {
+        let cursor_x_pos = crate::cell::unicode_column_width(&line[0..cursor_position]);
+        (vec![OutputElement::Text(line.to_owned())], cursor_x_pos)
     }
 
     /// Returns the history implementation

termwiz/src/lineedit/mod.rs

@@ -163,16 +163,12 @@ impl<T: Terminal> LineEditor<T> {
         }
         changes.push(Change::AllAttributes(Default::default()));
 
-        let mut grapheme_count = 0;
-        for ele in host.highlight_line(&self.line, self.cursor) {
-            if let OutputElement::Text(ref t) = ele {
-                grapheme_count += unicode_column_width(t);
-            }
+        let (elements, cursor_x_pos) = host.highlight_line(&self.line, self.cursor);
+        for ele in elements {
             changes.push(ele.into());
         }
-
         changes.push(Change::CursorPosition {
-            x: Position::Absolute(prompt_width + grapheme_count),
+            x: Position::Absolute(prompt_width + cursor_x_pos),
             y: Position::NoChange,
         });