93 lines
4.0 KiB
Swift
93 lines
4.0 KiB
Swift
import Foundation
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/// EPUB 阅读器位置协调器：负责阅读位置的恢复、查询和持久化。
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///
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/// 职责：
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/// - 根据保存的位置恢复阅读进度
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/// - 获取当前可见页面的阅读位置
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/// - 从持久化存储加载已保存位置
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/// - 持久化当前位置并通知委托
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final class RDEPUBReaderLocationCoordinator {
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private unowned let context: RDEPUBReaderContext
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init(context: RDEPUBReaderContext) {
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self.context = context
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}
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/// 恢复到指定阅读位置，返回是否成功跳转。
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@discardableResult
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func restoreReadingLocation(_ location: RDEPUBLocation, animated: Bool = false) -> Bool {
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guard let controller = context.controller,
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let readerView = context.readerView else { return false }
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guard let targetPageNumber = controller.pageNumber(for: location) else {
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readerView.transitionToPage(pageNum: 0)
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context.readingSession?.transition(to: .idle)
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return false
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}
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if context.bookPageMap != nil {
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guard context.runtime?.prepareOnDemandChapter(forAbsolutePageNumber: targetPageNumber) == true else {
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return false
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}
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_ = context.readingSession?.queueNavigation(
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to: location,
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relativeToSpineIndex: nil,
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bookIdentifier: context.currentBookIdentifier
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)
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} else if context.textBook == nil {
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_ = context.readingSession?.queueNavigation(
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to: location,
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relativeToSpineIndex: nil,
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bookIdentifier: context.currentBookIdentifier
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)
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} else {
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context.readingSession?.transition(to: .jumping)
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}
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readerView.transitionToPage(pageNum: max(targetPageNumber - 1, 0), animated: animated)
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return true
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}
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/// 获取当前可见页面对应的阅读位置。
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func currentVisibleLocation() -> RDEPUBLocation? {
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guard let controller = context.controller,
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let readerView = context.readerView else {
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return nil
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}
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let pageNumber = readerView.currentPage + 1
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if (context.textBook != nil || context.bookPageMap != nil), readerView.currentPage >= 0 {
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if let location = controller.resolvedTextLocation(forPageNumber: pageNumber) {
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return location
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}
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// resolvedTextLocation 可能因章节数据未加载而返回 nil，
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// 通过 readingSession 的 activePages 构建回退位置
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if let readingSession = context.readingSession,
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readingSession.activePages.indices.contains(readerView.currentPage) {
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return readingSession.fallbackLocation(
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for: readingSession.activePages[readerView.currentPage],
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bookIdentifier: context.currentBookIdentifier
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)
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}
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}
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return context.readingSession?.currentReadingLocation(bookIdentifier: context.currentBookIdentifier)
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}
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/// 从持久化存储加载上次保存的阅读位置。
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func persistenceLocation() -> RDEPUBLocation? {
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guard let controller = context.controller,
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let currentBookIdentifier = context.currentBookIdentifier else {
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return nil
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}
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return controller.persistence?.loadLocation(for: currentBookIdentifier)
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}
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/// 持久化阅读位置，并通知委托更新目录项和书签状态。
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func persist(location: RDEPUBLocation) {
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guard let controller = context.controller,
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let currentBookIdentifier = context.currentBookIdentifier else { return }
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controller.persistence?.saveLocation(location, for: currentBookIdentifier)
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controller.delegate?.epubReader(controller, didUpdateLocation: location)
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controller.delegate?.epubReader(controller, didUpdateCurrentTableOfContentsItem: controller.currentTableOfContentsItem)
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controller.updateBookmarkChrome()
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}
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}
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