♻️ Refactor cursor position cache

frontend/src/views/editor/basic/cursorPositionExtension.ts

@@ -0,0 +1,67 @@
+import {EditorView, ViewPlugin, ViewUpdate} from '@codemirror/view';
+import {useDocumentStore} from '@/stores/documentStore';
+import {createDebounce} from '@/common/utils/debounce';
+
+/**
+ * 光标位置持久化扩展
+ * 实时监听光标位置变化并持久化到 documentStore
+ */
+export function createCursorPositionExtension(documentId: number) {
+  return ViewPlugin.fromClass(
+    class CursorPositionPlugin {
+      private readonly documentStore = useDocumentStore();
+      private readonly debouncedSave;
+
+      constructor(private view: EditorView) {
+        const { debouncedFn, flush } = createDebounce(
+          () => this.saveCursorPosition(),
+          { delay: 400 }
+        );
+        this.debouncedSave = { fn: debouncedFn, flush };
+
+        // 初始化时保存一次光标位置
+        this.saveCursorPosition();
+      }
+
+      update(update: ViewUpdate) {
+        // 只在选择变化时触发
+        if (!update.selectionSet) {
+          return;
+        }
+
+        // 防抖保存光标位置
+        this.debouncedSave.fn();
+      }
+
+      destroy() {
+        // 销毁时立即执行待保存的操作
+        this.debouncedSave.flush();
+        // 再保存一次确保最新状态
+        this.saveCursorPosition();
+      }
+
+      private saveCursorPosition() {
+        const cursorPos = this.view.state.selection.main.head;
+        // 持久化到 documentStore
+        this.documentStore.documentStates[documentId] = {
+            cursorPos
+        };
+      }
+    }
+  );
+}
+
+/**
+ * 滚动到当前光标位置（视口中心）
+ * @param view 编辑器视图
+ */
+export function scrollToCursor(view: EditorView) {
+  const cursorPos = view.state.selection.main.head;
+  view.dispatch({
+    effects: EditorView.scrollIntoView(cursorPos, {
+      y: 'center',
+      x: 'center'
+    })
+  });
+}
+