add text area intent handler hook

src/app/hooks/useTextAreaIntent.ts

@@ -0,0 +1,53 @@
+import { isKeyHotkey } from 'is-hotkey';
+import { KeyboardEventHandler, useCallback } from 'react';
+import { Cursor, Intent, Operations, TextArea } from '../plugins/text-area';
+
+export const useTextAreaIntentHandler = (
+  textArea: TextArea,
+  operations: Operations,
+  intent: Intent
+) => {
+  const handler: KeyboardEventHandler<HTMLTextAreaElement> = useCallback(
+    (evt) => {
+      const target = evt.currentTarget;
+
+      if (isKeyHotkey('tab', evt)) {
+        evt.preventDefault();
+
+        const cursor = Cursor.fromTextAreaElement(target);
+        if (textArea.selection(cursor)) {
+          operations.select(intent.moveForward(cursor));
+        } else {
+          operations.deselect(operations.insert(cursor, intent.str));
+        }
+
+        target.focus();
+      }
+      if (isKeyHotkey('shift+tab', evt)) {
+        evt.preventDefault();
+        const cursor = Cursor.fromTextAreaElement(target);
+        const intentCursor = intent.moveBackward(cursor);
+        if (textArea.selection(cursor)) {
+          operations.select(intentCursor);
+        } else {
+          operations.deselect(intentCursor);
+        }
+
+        target.focus();
+      }
+      if (isKeyHotkey('enter', evt) || isKeyHotkey('shift+enter', evt)) {
+        evt.preventDefault();
+        const cursor = Cursor.fromTextAreaElement(target);
+        operations.select(intent.addNextLine(cursor));
+      }
+      if (isKeyHotkey('mod+shift+enter', evt)) {
+        evt.preventDefault();
+        const cursor = Cursor.fromTextAreaElement(target);
+        operations.select(intent.addPreviousLine(cursor));
+      }
+    },
+    [textArea, operations, intent]
+  );
+
+  return handler;
+};