input: Grouping input history to avoid IME placeholder. (#1375)

crates/ui/src/history.rs

@@ -27,6 +27,7 @@ pub struct History<I: HistoryItem> {
     pub(crate) ignore: bool,
     max_undo: usize,
     group_interval: Option<Duration>,
+    grouping: bool,
     unique: bool,
 }
 
@@ -43,6 +44,7 @@ where
             version: 0,
             max_undo: 1000,
             group_interval: None,
+            grouping: false,
             unique: false,
         }
     }
@@ -66,10 +68,20 @@ where
         self
     }
 
+    /// Start grouping changes, this will prevent the version from being incremented until `end_grouping` is called.
+    pub fn start_grouping(&mut self) {
+        self.grouping = true;
+    }
+
+    /// End grouping changes, this will allow the version to be incremented again.
+    pub fn end_grouping(&mut self) {
+        self.grouping = false;
+    }
+
     /// Increment the version number if the last change was made more than `GROUP_INTERVAL` milliseconds ago.
     fn inc_version(&mut self) -> usize {
         let t = Instant::now();
-        if Some(self.last_changed_at.elapsed()) > self.group_interval {
+        if !self.grouping && Some(self.last_changed_at.elapsed()) > self.group_interval {
             self.version += 1;
         }
 

crates/ui/src/input/state.rs

@@ -1579,7 +1579,6 @@ impl InputState {
         }
 
         let old_text = text.slice(range.clone()).to_string();
-
         let new_range = range.start..range.start + new_text.len();
 
         self.history
@@ -2150,6 +2149,7 @@ impl EntityInputHandler for InputState {
         }
 
         self.push_history(&old_text, &range, &new_text);
+        self.history.end_grouping();
         if let Some(diagnostics) = self.mode.diagnostics_mut() {
             diagnostics.reset(&self.text)
         }
@@ -2205,7 +2205,6 @@ impl EntityInputHandler for InputState {
             }
         }
 
-        self.push_history(&old_text, &range, new_text);
         if let Some(diagnostics) = self.mode.diagnostics_mut() {
             diagnostics.reset(&self.text)
         }
@@ -2228,7 +2227,8 @@ impl EntityInputHandler for InputState {
                 .into();
         }
         self.mode.update_auto_grow(&self.text_wrapper);
-        cx.emit(InputEvent::Change);
+        self.history.start_grouping();
+        self.push_history(&old_text, &range, new_text);
         cx.notify();
     }