refactor: split reader architecture and chrome handling

2026-05-31 21:47:54 +08:00
parent ea21c6a831
commit 44202357c0
80 changed files with 10635 additions and 8522 deletions
@@ -0,0 +1,138 @@
+import UIKit
+
+/// UIPageViewController 数据源和代理实现
+/// 处理仿真翻页模式下的页面数据供给和翻页事件
+extension RDReaderView: UIPageViewControllerDataSource, UIPageViewControllerDelegate {
+
+    /// 创建指定页码的子控制器
+    /// 空白页返回空视图，正常页从缓存或数据源获取内容
+    private func makeSinglePageChildVC(for pageNum: Int) -> RDReaderPageChildViewController {
+        if pageNum == RDReaderView.blankPageNum || pageNum == RDReaderView.blankEndPageNum {
+            return RDReaderPageChildViewController(contentView: UIView(), pageNum: pageNum)
+        }
+        let contentView = pageViewForDisplay(pageNum: pageNum)
+        return RDReaderPageChildViewController(contentView: contentView, pageNum: pageNum)
+    }
+
+    /// 计算某页的"下一页"页码
+    /// 考虑封面页独占和末尾空白页配对的情况
+    private func nextPageNum(after pageNum: Int, isDualPage: Bool) -> Int? {
+        let totalPages = numberOfPages()
+
+        // 末尾空白页之后没有更多页
+        if pageNum == RDReaderView.blankEndPageNum {
+            return nil
+        }
+
+        if isDualPage, let coverIndex = coverPageIndex {
+            if pageNum == coverIndex {
+                return RDReaderView.blankPageNum
+            }
+            if pageNum == RDReaderView.blankPageNum {
+                let firstContent = coverIndex + 1
+                return firstContent < totalPages ? firstContent : nil
+            }
+        }
+
+        let next = pageNum + 1
+        if next < totalPages {
+            return next
+        }
+
+        // pageNum 是最后一页，检查在双页模式下是否需要空白页配对
+        if isDualPage {
+            if let coverIndex = coverPageIndex {
+                let adjustedIndex = pageNum - (coverIndex + 1)
+                if adjustedIndex >= 0 && adjustedIndex % 2 == 0 {
+                    return RDReaderView.blankEndPageNum
+                }
+            } else {
+                if pageNum % 2 == 0 {
+                    return RDReaderView.blankEndPageNum
+                }
+            }
+        }
+        return nil
+    }
+
+    /// 计算某页的"上一页"页码
+    /// 考虑封面页独占和末尾空白页配对的情况
+    private func prevPageNum(before pageNum: Int, isDualPage: Bool) -> Int? {
+        if pageNum == RDReaderView.blankEndPageNum {
+            let totalPages = numberOfPages()
+            return totalPages > 0 ? totalPages - 1 : nil
+        }
+        if isDualPage, let coverIndex = coverPageIndex {
+            if pageNum == RDReaderView.blankPageNum {
+                return coverIndex
+            }
+            if pageNum == coverIndex + 1 {
+                return RDReaderView.blankPageNum
+            }
+        }
+        let prev = pageNum - 1
+        return prev >= 0 ? prev : nil
+    }
+
+    /// UIPageViewController 数据源：返回当前页之前（左/上）的页面控制器
+    /// RTL 模式下 before/after 语义互换：before（向右翻）= 下一页
+    public func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
+        guard let vc = viewController as? RDReaderPageChildViewController else { return nil }
+        let isDualPage = landscapeDualPageEnabled && isLandscape
+        let isRTL = pageDirection == .rightToLeft
+
+        let targetNum = isRTL
+            ? nextPageNum(after: vc.pageNum, isDualPage: isDualPage)
+            : prevPageNum(before: vc.pageNum, isDualPage: isDualPage)
+
+        guard let num = targetNum else { return nil }
+        let targetVC = makeSinglePageChildVC(for: num)
+        willPreviousTransitionToViewController = targetVC
+        return targetVC
+    }
+
+    /// UIPageViewController 数据源：返回当前页之后（右/下）的页面控制器
+    /// RTL 模式下 before/after 语义互换
+    public func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
+        guard let vc = viewController as? RDReaderPageChildViewController else { return nil }
+        let isDualPage = landscapeDualPageEnabled && isLandscape
+        let isRTL = pageDirection == .rightToLeft
+
+        let targetNum = isRTL
+            ? prevPageNum(before: vc.pageNum, isDualPage: isDualPage)
+            : nextPageNum(after: vc.pageNum, isDualPage: isDualPage)
+
+        guard let num = targetNum else { return nil }
+        let targetVC = makeSinglePageChildVC(for: num)
+        willNextTransitionToViewController = targetVC
+        return targetVC
+    }
+
+    /// UIPageViewController 代理：翻页动画完成回调
+    /// 更新当前页码，触发预加载，并检测 PageViewController 异常状态
+    public func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
+        if completed, let firstVC = pageViewController.viewControllers?.first as? RDReaderPageChildViewController {
+            let pn = firstVC.pageNum
+            if pn != RDReaderView.blankPageNum && pn != RDReaderView.blankEndPageNum {
+                currentPage = pn
+                primePageCache(around: pn, preferredForward: predictedPageDirection)
+            }
+        }
+
+        predictedPageDirection = nil
+        finishPageCurlTransition()
+    }
+
+    /// UIPageViewController 代理：即将开始转场动画
+    /// 记录预测的翻页方向，用于优化预加载策略
+    public func pageViewController(_ pageViewController: UIPageViewController, willTransitionTo pendingViewControllers: [UIViewController]) {
+        pagingController.isTransitioning = true
+        willTransitionToViewController = pendingViewControllers.first
+        if let target = pendingViewControllers.first as? RDReaderPageChildViewController,
+           target.pageNum != RDReaderView.blankPageNum,
+           target.pageNum != RDReaderView.blankEndPageNum {
+            predictedPageDirection = target.pageNum >= currentPage
+            primePageCache(around: target.pageNum, preferredForward: predictedPageDirection)
+        }
+    }
+}