Initial commit

2026-07-14 11:11:36 +08:00
commit 656499cf94
604 changed files with 119518 additions and 0 deletions
@@ -0,0 +1,209 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+
+mixin BannerCarouselMixin<T extends StatefulWidget>
+    on State<T>, WidgetsBindingObserver {
+  final PageController pageController = PageController();
+  Timer? _autoPlayTimer;
+  Timer? _resumeTimer;
+  int currentIndex = 0;
+  bool hovering = false;
+  bool _manualPaused = false;
+  bool _appPaused = false;
+  bool _autoPageChangeInProgress = false;
+  double? lastBannerWidth;
+  bool _tickerVisible = true;
+
+  static const autoInterval = Duration(seconds: 5);
+  static const _manualPauseDuration = Duration(seconds: 8);
+  static const slideDuration = Duration(milliseconds: 450);
+  static const slideCurve = Curves.easeInOutCubic;
+
+  int get itemCount;
+  bool get isActive;
+  void emitActiveItem();
+  void precacheAdjacentSlides();
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addObserver(this);
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted) return;
+      emitActiveItem();
+      syncAutoPlay();
+    });
+  }
+
+  @override
+  void dispose() {
+    _autoPlayTimer?.cancel();
+    _resumeTimer?.cancel();
+    pageController.dispose();
+    WidgetsBinding.instance.removeObserver(this);
+    super.dispose();
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final visible = TickerMode.of(context);
+    if (visible == _tickerVisible) return;
+    _tickerVisible = visible;
+    if (visible) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (!mounted || !_tickerVisible) return;
+        emitActiveItem();
+        precacheAdjacentSlides();
+      });
+      syncAutoPlay();
+    } else {
+      stopAutoPlay();
+      _resumeTimer?.cancel();
+      _manualPaused = false;
+    }
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    final paused =
+        state == AppLifecycleState.paused ||
+        state == AppLifecycleState.inactive ||
+        state == AppLifecycleState.hidden;
+    if (paused == _appPaused) return;
+    _appPaused = paused;
+    paused ? stopAutoPlay() : syncAutoPlay();
+  }
+
+  bool get shouldAutoPlay =>
+      mounted &&
+      isActive &&
+      _tickerVisible &&
+      !_appPaused &&
+      !hovering &&
+      !_manualPaused &&
+      itemCount > 1;
+
+  void syncAutoPlay() {
+    if (!shouldAutoPlay) {
+      stopAutoPlay();
+      return;
+    }
+    _autoPlayTimer ??= Timer.periodic(
+      autoInterval,
+      (_) => nextPage(manual: false),
+    );
+  }
+
+  void stopAutoPlay() {
+    _autoPlayTimer?.cancel();
+    _autoPlayTimer = null;
+  }
+
+
+  void setHovering(bool value) {
+    hovering = value;
+    value ? stopAutoPlay() : syncAutoPlay();
+    if (mounted) setState(() {});
+  }
+
+  void pauseForManual() {
+    if (!_manualPaused) setState(() => _manualPaused = true);
+    stopAutoPlay();
+    _resumeTimer?.cancel();
+    _resumeTimer = Timer(_manualPauseDuration, () {
+      if (!mounted) return;
+      setState(() => _manualPaused = false);
+      syncAutoPlay();
+    });
+  }
+
+  void onPageChanged(int index) {
+    setState(() => currentIndex = index);
+    emitActiveItem();
+    precacheAdjacentSlides();
+    if (_autoPageChangeInProgress) {
+      _autoPageChangeInProgress = false;
+      return;
+    }
+    pauseForManual();
+  }
+
+  void goToPage(int index) {
+    if (index < 0 || index >= itemCount) return;
+    if (!pageController.hasClients) return;
+    pageController.animateToPage(
+      index,
+      duration: slideDuration,
+      curve: slideCurve,
+    );
+    pauseForManual();
+  }
+
+  void nextPage({bool manual = true}) {
+    if (itemCount <= 1) return;
+    if (!pageController.hasClients) return;
+    final nextIndex = (currentIndex + 1) % itemCount;
+    if (!manual) _autoPageChangeInProgress = true;
+    pageController.animateToPage(
+      nextIndex,
+      duration: slideDuration,
+      curve: slideCurve,
+    );
+    if (manual) pauseForManual();
+  }
+
+  void prevPage() {
+    if (itemCount <= 1) return;
+    if (!pageController.hasClients) return;
+    final previousIndex = (currentIndex - 1 + itemCount) % itemCount;
+    pageController.animateToPage(
+      previousIndex,
+      duration: slideDuration,
+      curve: slideCurve,
+    );
+    pauseForManual();
+  }
+
+  int? bannerCacheWidth() {
+    final width = lastBannerWidth;
+    if (width == null || !width.isFinite || width <= 0) return null;
+    return (width * MediaQuery.devicePixelRatioOf(context)).ceil();
+  }
+
+
+  void resetCarouselItems() {
+    stopAutoPlay();
+    _resumeTimer?.cancel();
+    _manualPaused = false;
+    if (itemCount > 0 && pageController.hasClients) {
+      pageController.jumpToPage(0);
+    }
+    currentIndex = 0;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted) return;
+      emitActiveItem();
+      precacheAdjacentSlides();
+      syncAutoPlay();
+    });
+  }
+
+
+  void activateCarousel() {
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted) return;
+      emitActiveItem();
+      precacheAdjacentSlides();
+      syncAutoPlay();
+    });
+  }
+
+
+  void deactivateCarousel() {
+    stopAutoPlay();
+    _resumeTimer?.cancel();
+    _manualPaused = false;
+  }
+}