原生epub阅读

lib/pages/epub_reader/mixins/progress_mixin.dart

@@ -0,0 +1,45 @@
+part of '../reader_screen.dart';
+
+mixin _ProgressMixin on State<ReaderScreen> {
+  // === Borrowed state (provided by _ReaderScreenState fields) ===
+  int get totalPagesInChapter;
+
+  int get currentPageInChapter;
+
+  int get currentSpineItemIndex;
+
+  BookSession get bookSession;
+
+  bool get isWebViewLoading;
+
+  String get displayProgress;
+  set displayProgress(String v);
+
+  Timer? get progressDebouncer;
+  set progressDebouncer(Timer? v);
+
+  void updateProgressDebounced() {
+    progressDebouncer?.cancel();
+    progressDebouncer = Timer(const Duration(milliseconds: 150), () {
+      if (!mounted) return;
+      if (isWebViewLoading) return;
+
+      final pageInChapterStr =
+          '${currentPageInChapter + 1}/$totalPagesInChapter';
+
+      if (displayProgress != pageInChapterStr) {
+        setState(() {
+          displayProgress = pageInChapterStr;
+        });
+      }
+    });
+  }
+
+  void saveProgress() {
+    bookSession.saveProgress(
+      currentChapterIndex: currentSpineItemIndex,
+      currentPageInChapter: currentPageInChapter,
+      totalPagesInChapter: totalPagesInChapter,
+    );
+  }
+}