Fix chat_input enter submission for Chinese and Japanse (streamlit#…

…6993)

* ignore Enter on composition for Japanese

* fix incorrect indent num

* write comment why uncapture Enter with isComposing

* case of the lack of no nativeEvent or isComposing

for test sets widget value when ⌘+enter

frontend/lib/src/components/widgets/ChatInput/ChatInput.tsx

@@ -61,7 +61,11 @@ const isEnterKeyPressed = (
   // https://bugs.chromium.org/p/chromium/issues/detail?id=79407
 
   const { keyCode, key } = event
-  return key === "Enter" || keyCode === 13 || keyCode === 10
+  return (
+    (key === "Enter" || keyCode === 13 || keyCode === 10) &&
+    // Do not send the sentence being composed when Enter is typed into the IME.
+    !(event.nativeEvent?.isComposing === true)
+  )
 }
 
 function ChatInput({ width, element, widgetMgr }: Props): React.ReactElement {

frontend/lib/src/components/widgets/TextArea/TextArea.tsx

@@ -152,7 +152,11 @@ class TextArea extends React.PureComponent<Props, State> {
 
     // Using keyCode as well due to some different behaviors on Windows
     // https://bugs.chromium.org/p/chromium/issues/detail?id=79407
-    return key === "Enter" || keyCode === 13 || keyCode === 10
+    return (
+      (key === "Enter" || keyCode === 13 || keyCode === 10) &&
+      // Do not send the sentence being composed when Enter is typed into the IME.
+      !(event.nativeEvent?.isComposing === true)
+    )
   }
 
   private onKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>): void => {