TextEdit: replace monomorphization with &mut dyn TextBuffer

egui/src/widgets/text_edit.rs

@@ -118,7 +118,7 @@ impl CCursorPair {
 /// an underlying buffer.
 ///
 /// Most likely you will use a `String` which implements `TextBuffer`.
-pub trait TextBuffer: AsRef<str> + Into<String> {
+pub trait TextBuffer: AsRef<str> {
     /// Can this text be edited?
     fn is_mutable(&self) -> bool;
 
@@ -253,8 +253,8 @@ impl<'a> TextBuffer for &'a str {
 /// ```
 ///
 #[must_use = "You should put this widget in an ui with `ui.add(widget);`"]
-pub struct TextEdit<'t, S: TextBuffer = String> {
+pub struct TextEdit<'t> {
-    text: &'t mut S,
+    text: &'t mut dyn TextBuffer,
     hint_text: String,
     id: Option<Id>,
     id_source: Option<Id>,
@@ -271,18 +271,9 @@ pub struct TextEdit<'t, S: TextBuffer = String> {
     cursor_at_end: bool,
 }
 
-impl<'t, S: TextBuffer> TextEdit<'t, S> {
+impl<'t> TextEdit<'t> {
-    pub fn cursor(ui: &Ui, id: Id) -> Option<CursorPair> {
-        ui.memory()
-            .id_data
-            .get::<State>(&id)
-            .and_then(|state| state.cursorp)
-    }
-}
-
-impl<'t, S: TextBuffer> TextEdit<'t, S> {
     /// No newlines (`\n`) allowed. Pressing enter key will result in the `TextEdit` losing focus (`response.lost_focus`).
-    pub fn singleline(text: &'t mut S) -> Self {
+    pub fn singleline(text: &'t mut dyn TextBuffer) -> Self {
         Self {
             desired_height_rows: 1,
             multiline: false,
@@ -291,7 +282,7 @@ impl<'t, S: TextBuffer> TextEdit<'t, S> {
     }
 
     /// A `TextEdit` for multiple lines. Pressing enter key will create a new line.
-    pub fn multiline(text: &'t mut S) -> Self {
+    pub fn multiline(text: &'t mut dyn TextBuffer) -> Self {
         Self {
             text,
             hint_text: Default::default(),
@@ -433,7 +424,16 @@ impl<'t, S: TextBuffer> TextEdit<'t, S> {
     }
 }
 
-impl<'t, S: TextBuffer> Widget for TextEdit<'t, S> {
+impl<'t> TextEdit<'t> {
+    pub fn cursor(ui: &Ui, id: Id) -> Option<CursorPair> {
+        ui.memory()
+            .id_data
+            .get::<State>(&id)
+            .and_then(|state| state.cursorp)
+    }
+}
+
+impl<'t> Widget for TextEdit<'t> {
     fn ui(self, ui: &mut Ui) -> Response {
         let is_mutable = self.text.is_mutable();
         let frame = self.frame;
@@ -507,7 +507,7 @@ fn mask_if_password(is_password: bool, text: &str) -> String {
     }
 }
 
-impl<'t, S: TextBuffer> TextEdit<'t, S> {
+impl<'t> TextEdit<'t> {
     fn content_ui(self, ui: &mut Ui) -> Response {
         let TextEdit {
             text,
@@ -1038,18 +1038,18 @@ fn byte_index_from_char_index(s: &str, char_index: usize) -> usize {
     s.len()
 }
 
-fn insert_text<S: TextBuffer>(ccursor: &mut CCursor, text: &mut S, text_to_insert: &str) {
+fn insert_text(ccursor: &mut CCursor, text: &mut dyn TextBuffer, text_to_insert: &str) {
     ccursor.index += text.insert_text(text_to_insert, ccursor.index);
 }
 
 // ----------------------------------------------------------------------------
 
-fn delete_selected<S: TextBuffer>(text: &mut S, cursorp: &CursorPair) -> CCursor {
+fn delete_selected(text: &mut dyn TextBuffer, cursorp: &CursorPair) -> CCursor {
     let [min, max] = cursorp.sorted();
     delete_selected_ccursor_range(text, [min.ccursor, max.ccursor])
 }
 
-fn delete_selected_ccursor_range<S: TextBuffer>(text: &mut S, [min, max]: [CCursor; 2]) -> CCursor {
+fn delete_selected_ccursor_range(text: &mut dyn TextBuffer, [min, max]: [CCursor; 2]) -> CCursor {
     text.delete_char_range(min.index..max.index);
     CCursor {
         index: min.index,
@@ -1057,7 +1057,7 @@ fn delete_selected_ccursor_range<S: TextBuffer>(text: &mut S, [min, max]: [CCurs
     }
 }
 
-fn delete_previous_char<S: TextBuffer>(text: &mut S, ccursor: CCursor) -> CCursor {
+fn delete_previous_char(text: &mut dyn TextBuffer, ccursor: CCursor) -> CCursor {
     if ccursor.index > 0 {
         let max_ccursor = ccursor;
         let min_ccursor = max_ccursor - 1;
@@ -1067,22 +1067,22 @@ fn delete_previous_char<S: TextBuffer>(text: &mut S, ccursor: CCursor) -> CCurso
     }
 }
 
-fn delete_next_char<S: TextBuffer>(text: &mut S, ccursor: CCursor) -> CCursor {
+fn delete_next_char(text: &mut dyn TextBuffer, ccursor: CCursor) -> CCursor {
     delete_selected_ccursor_range(text, [ccursor, ccursor + 1])
 }
 
-fn delete_previous_word<S: TextBuffer>(text: &mut S, max_ccursor: CCursor) -> CCursor {
+fn delete_previous_word(text: &mut dyn TextBuffer, max_ccursor: CCursor) -> CCursor {
     let min_ccursor = ccursor_previous_word(text.as_ref(), max_ccursor);
     delete_selected_ccursor_range(text, [min_ccursor, max_ccursor])
 }
 
-fn delete_next_word<S: TextBuffer>(text: &mut S, min_ccursor: CCursor) -> CCursor {
+fn delete_next_word(text: &mut dyn TextBuffer, min_ccursor: CCursor) -> CCursor {
     let max_ccursor = ccursor_next_word(text.as_ref(), min_ccursor);
     delete_selected_ccursor_range(text, [min_ccursor, max_ccursor])
 }
 
-fn delete_paragraph_before_cursor<S: TextBuffer>(
+fn delete_paragraph_before_cursor(
-    text: &mut S,
+    text: &mut dyn TextBuffer,
     galley: &Galley,
     cursorp: &CursorPair,
 ) -> CCursor {
@@ -1099,8 +1099,8 @@ fn delete_paragraph_before_cursor<S: TextBuffer>(
     }
 }
 
-fn delete_paragraph_after_cursor<S: TextBuffer>(
+fn delete_paragraph_after_cursor(
-    text: &mut S,
+    text: &mut dyn TextBuffer,
     galley: &Galley,
     cursorp: &CursorPair,
 ) -> CCursor {
@@ -1120,9 +1120,9 @@ fn delete_paragraph_after_cursor<S: TextBuffer>(
 // ----------------------------------------------------------------------------
 
 /// Returns `Some(new_cursor)` if we did mutate `text`.
-fn on_key_press<S: TextBuffer>(
+fn on_key_press(
     cursorp: &mut CursorPair,
-    text: &mut S,
+    text: &mut dyn TextBuffer,
     galley: &Galley,
     key: Key,
     modifiers: &Modifiers,
@@ -1365,7 +1365,7 @@ fn find_line_start(text: &str, current_index: CCursor) -> CCursor {
     }
 }
 
-fn decrease_identation<S: TextBuffer>(ccursor: &mut CCursor, text: &mut S) {
+fn decrease_identation(ccursor: &mut CCursor, text: &mut dyn TextBuffer) {
     let line_start = find_line_start(text.as_ref(), *ccursor);
 
     let remove_len = if text.as_ref()[line_start.index..].starts_with('\t') {