54798ba578
- 给全部 78 个 Swift 源文件添加详细的中文注释（文件级、类级、方法级） - 删除 LegacyRDReaderController/ 死代码目录（16 文件 4592 行） - 根目录翻页容器文件移入 ReaderView/ 目录 - Resources/ 移入 EPUBCore/Resources/（与使用者归属一致） - RDEPUBTextIndexTable.swift 移入 EPUBTextRendering/（消除反向依赖） - RDURLReaderController.swift 移入 EPUBUI/（入口控制器归入 UI 层） - 更新 podspec 资源路径
384 lines
15 KiB
Swift
384 lines
15 KiB
Swift
// RDEPUBPaginator.swift
|
||
// EPUB 离屏分页计算器
|
||
// 使用隐藏的 WKWebView 加载每个 spine 项，通过 JS 测量 scrollWidth
|
||
// 计算每章的页数。采用多轮延迟测量（0ms/80ms/180ms）确保布局稳定。
|
||
// 固定版式（Fixed Layout）直接返回 1 页。
|
||
|
||
import UIKit
|
||
import WebKit
|
||
|
||
/// EPUB 分页计算器，通过离屏 WebView 测量每个 spine 项的分页数
|
||
public final class RDEPUBPaginator: NSObject {
|
||
/// 当前解析器引用
|
||
private var parser: RDEPUBParser?
|
||
/// 承载 WebView 的父视图（弱引用）
|
||
private weak var hostingView: UIView?
|
||
/// 当前展示样式（视口尺寸、内边距、字号、行高）
|
||
private var presentation = RDEPUBPresentationStyle(
|
||
viewportSize: .zero,
|
||
contentInsets: .zero,
|
||
fontSize: 16,
|
||
lineHeightMultiple: 1.5
|
||
)
|
||
/// 全量分页完成回调（返回每个 spine 项的页数数组）
|
||
private var completion: (([Int]) -> Void)?
|
||
/// 单个 spine 项分页完成回调
|
||
private var singlePageCountCompletion: ((Int) -> Void)?
|
||
/// 各 spine 项的页数结果
|
||
private var pageCounts: [Int] = []
|
||
/// 待测量的 spine 项索引列表
|
||
private var measurementIndices: [Int] = []
|
||
/// 当前测量偏移量（在 measurementIndices 中的位置）
|
||
private var currentMeasurementOffset = 0
|
||
/// 当前 spine 项的待定页数（多轮测量取最大值）
|
||
private var pendingMeasurementValue = 1
|
||
/// 当前测量轮次（0/1/2 对应延迟 0ms/80ms/180ms）
|
||
private var measurementPass = 0
|
||
/// 当前测量会话 ID，用于防并发和取消过期任务
|
||
private var activeSessionID = UUID()
|
||
/// 调试日志作用域标识
|
||
private let debugScope = "PaginatorWebView"
|
||
|
||
/// 用于分页测量的隐藏 WebView（非持久化数据存储，禁止用户交互）
|
||
private lazy var webView: WKWebView = {
|
||
let configuration = WKWebViewConfiguration()
|
||
configuration.websiteDataStore = .nonPersistent()
|
||
let webView = WKWebView(frame: .zero, configuration: configuration)
|
||
webView.navigationDelegate = self
|
||
webView.isOpaque = false
|
||
webView.backgroundColor = .clear
|
||
webView.scrollView.isScrollEnabled = false
|
||
webView.scrollView.bounces = false
|
||
webView.scrollView.showsHorizontalScrollIndicator = false
|
||
webView.scrollView.showsVerticalScrollIndicator = false
|
||
webView.isUserInteractionEnabled = false
|
||
if #available(iOS 16.4, *) {
|
||
webView.isInspectable = true
|
||
} else {
|
||
// Fallback on earlier versions
|
||
}
|
||
RDEPUBWebViewDebug.log("PaginatorWebView", message: "configured webView=\(RDEPUBWebViewDebug.webViewID(webView))")
|
||
return webView
|
||
}()
|
||
|
||
public override init() {
|
||
super.init()
|
||
}
|
||
|
||
deinit {
|
||
cleanupMeasurementState()
|
||
webView.navigationDelegate = nil
|
||
webView.stopLoading()
|
||
webView.removeFromSuperview()
|
||
}
|
||
|
||
/// 计算所有 spine 项的分页数
|
||
/// - Parameters:
|
||
/// - parser: EPUB 解析器
|
||
/// - hostingView: 承载 WebView 的父视图
|
||
/// - presentation: 展示样式（视口、内边距、字号、行高）
|
||
/// - completion: 完成回调，返回每个 spine 项的页数数组
|
||
public func calculate(
|
||
parser: RDEPUBParser,
|
||
hostingView: UIView,
|
||
presentation: RDEPUBPresentationStyle,
|
||
completion: @escaping ([Int]) -> Void
|
||
) {
|
||
self.parser = parser
|
||
self.hostingView = hostingView
|
||
self.presentation = presentation
|
||
self.completion = completion
|
||
self.singlePageCountCompletion = nil
|
||
self.pageCounts = Array(repeating: 1, count: parser.spine.count)
|
||
self.measurementIndices = Array(parser.spine.indices)
|
||
self.currentMeasurementOffset = 0
|
||
self.activeSessionID = UUID()
|
||
RDEPUBWebViewDebug.log(debugScope, message: "calculate session=\(activeSessionID) spineCount=\(parser.spine.count)")
|
||
|
||
guard parser.metadata.layout != .fixed else {
|
||
completion(self.pageCounts)
|
||
return
|
||
}
|
||
|
||
webView.navigationDelegate = self
|
||
if webView.superview == nil {
|
||
hostingView.addSubview(webView)
|
||
}
|
||
webView.frame = CGRect(origin: .zero, size: presentation.viewportSize)
|
||
measureNextSpineItem()
|
||
}
|
||
|
||
/// 便捷方法：使用独立参数计算所有 spine 项的分页数
|
||
public func calculate(
|
||
parser: RDEPUBParser,
|
||
hostingView: UIView,
|
||
viewportSize: CGSize,
|
||
padding: UIEdgeInsets,
|
||
fontSize: CGFloat,
|
||
lineHeightMultiple: CGFloat,
|
||
completion: @escaping ([Int]) -> Void
|
||
) {
|
||
calculate(
|
||
parser: parser,
|
||
hostingView: hostingView,
|
||
presentation: RDEPUBPresentationStyle(
|
||
viewportSize: viewportSize,
|
||
contentInsets: padding,
|
||
fontSize: fontSize,
|
||
lineHeightMultiple: lineHeightMultiple
|
||
),
|
||
completion: completion
|
||
)
|
||
}
|
||
|
||
/// 仅计算单个 spine 项的分页数
|
||
/// - Parameters:
|
||
/// - parser: EPUB 解析器
|
||
/// - spineIndex: 要测量的 spine 项索引
|
||
/// - hostingView: 承载 WebView 的父视图
|
||
/// - presentation: 展示样式
|
||
/// - completion: 完成回调，返回该 spine 项的页数
|
||
public func calculateSingleSpinePageCount(
|
||
parser: RDEPUBParser,
|
||
spineIndex: Int,
|
||
hostingView: UIView,
|
||
presentation: RDEPUBPresentationStyle,
|
||
completion: @escaping (Int) -> Void
|
||
) {
|
||
self.parser = parser
|
||
self.hostingView = hostingView
|
||
self.presentation = presentation
|
||
self.completion = nil
|
||
self.singlePageCountCompletion = completion
|
||
self.pageCounts = Array(repeating: 1, count: parser.spine.count)
|
||
self.measurementIndices = parser.spine.indices.contains(spineIndex) ? [spineIndex] : []
|
||
self.currentMeasurementOffset = 0
|
||
self.activeSessionID = UUID()
|
||
RDEPUBWebViewDebug.log(debugScope, message: "calculateSingle session=\(activeSessionID) spineIndex=\(spineIndex)")
|
||
|
||
guard parser.metadata.layout != .fixed, !measurementIndices.isEmpty else {
|
||
completion(1)
|
||
return
|
||
}
|
||
|
||
webView.navigationDelegate = self
|
||
if webView.superview == nil {
|
||
hostingView.addSubview(webView)
|
||
}
|
||
webView.frame = CGRect(origin: .zero, size: presentation.viewportSize)
|
||
measureNextSpineItem()
|
||
}
|
||
|
||
/// 便捷方法：使用独立参数计算单个 spine 项的分页数
|
||
public func calculateSingleSpinePageCount(
|
||
parser: RDEPUBParser,
|
||
spineIndex: Int,
|
||
hostingView: UIView,
|
||
viewportSize: CGSize,
|
||
padding: UIEdgeInsets,
|
||
fontSize: CGFloat,
|
||
lineHeightMultiple: CGFloat,
|
||
completion: @escaping (Int) -> Void
|
||
) {
|
||
calculateSingleSpinePageCount(
|
||
parser: parser,
|
||
spineIndex: spineIndex,
|
||
hostingView: hostingView,
|
||
presentation: RDEPUBPresentationStyle(
|
||
viewportSize: viewportSize,
|
||
contentInsets: padding,
|
||
fontSize: fontSize,
|
||
lineHeightMultiple: lineHeightMultiple
|
||
),
|
||
completion: completion
|
||
)
|
||
}
|
||
|
||
/// 静态方法：将分页 CSS 注入到 HTML 字符串中（用于预渲染场景）
|
||
public static func injectPaginationCSS(
|
||
into html: String,
|
||
viewportSize: CGSize,
|
||
padding: UIEdgeInsets,
|
||
fontSize: CGFloat,
|
||
lineHeightMultiple: CGFloat,
|
||
themeBackgroundColor: String? = nil,
|
||
themeTextColor: String? = nil
|
||
) -> String {
|
||
RDEPUBStyleSheetBuilder.injectPaginationCSS(
|
||
into: html,
|
||
presentation: RDEPUBPresentationStyle(
|
||
viewportSize: viewportSize,
|
||
contentInsets: padding,
|
||
fontSize: fontSize,
|
||
lineHeightMultiple: lineHeightMultiple,
|
||
themeBackgroundColor: themeBackgroundColor,
|
||
themeTextColor: themeTextColor
|
||
)
|
||
)
|
||
}
|
||
|
||
/// 测量下一个 spine 项：加载文件到 WebView，跳过不可渲染或文件缺失的项
|
||
private func measureNextSpineItem() {
|
||
guard let parser else {
|
||
finishIfNeeded()
|
||
return
|
||
}
|
||
|
||
guard currentMeasurementOffset < measurementIndices.count else {
|
||
finishIfNeeded()
|
||
return
|
||
}
|
||
|
||
let currentSpineIndex = measurementIndices[currentMeasurementOffset]
|
||
|
||
let item = parser.spine[currentSpineIndex]
|
||
guard isRenderablePage(item: item),
|
||
let opfDirectoryURL = parser.opfDirectoryURL else {
|
||
pageCounts[currentSpineIndex] = 1
|
||
currentMeasurementOffset += 1
|
||
measureNextSpineItem()
|
||
return
|
||
}
|
||
|
||
let fileURL = opfDirectoryURL.appendingPathComponent(item.href)
|
||
guard FileManager.default.fileExists(atPath: fileURL.path) else {
|
||
pageCounts[currentSpineIndex] = 1
|
||
currentMeasurementOffset += 1
|
||
measureNextSpineItem()
|
||
return
|
||
}
|
||
|
||
pendingMeasurementValue = 1
|
||
measurementPass = 0
|
||
let readAccessURL = parser.extractionRootURL ?? opfDirectoryURL
|
||
RDEPUBWebViewDebug.logNavigationEvent(debugScope, webView: webView, event: "measure-load", url: fileURL)
|
||
webView.loadFileURL(fileURL, allowingReadAccessTo: readAccessURL)
|
||
}
|
||
|
||
/// 获取当前正在测量的 spine 项索引
|
||
private func currentSpineIndexForMeasurement() -> Int? {
|
||
measurementIndices[safe: currentMeasurementOffset]
|
||
}
|
||
|
||
/// 检查是否所有 spine 项都已测量完毕，触发对应的完成回调
|
||
private func finishIfNeeded() {
|
||
if let singlePageCountCompletion {
|
||
let measuredSpineIndex = measurementIndices.first ?? 0
|
||
singlePageCountCompletion(max(1, pageCounts[safe: measuredSpineIndex] ?? 1))
|
||
self.singlePageCountCompletion = nil
|
||
cleanupMeasurementState()
|
||
return
|
||
}
|
||
guard let completion else { return }
|
||
completion(pageCounts)
|
||
self.completion = nil
|
||
cleanupMeasurementState()
|
||
}
|
||
|
||
/// 清理测量状态，释放 WebView 和所有引用
|
||
private func cleanupMeasurementState() {
|
||
parser = nil
|
||
hostingView = nil
|
||
completion = nil
|
||
singlePageCountCompletion = nil
|
||
measurementIndices = []
|
||
currentMeasurementOffset = 0
|
||
pendingMeasurementValue = 1
|
||
measurementPass = 0
|
||
activeSessionID = UUID()
|
||
webView.stopLoading()
|
||
webView.navigationDelegate = nil
|
||
webView.removeFromSuperview()
|
||
}
|
||
|
||
/// 判断 spine 项是否可渲染（仅 HTML/XHTML/XML 类型可分页）
|
||
private func isRenderablePage(item: RDEPUBSpineItem) -> Bool {
|
||
let mediaType = item.mediaType.lowercased()
|
||
return mediaType.contains("html") || mediaType.contains("xhtml") || mediaType.contains("xml")
|
||
}
|
||
|
||
/// 调度多轮测量：0ms/80ms/180ms 三轮延迟，取最大值以应对布局抖动
|
||
private func scheduleMeasurementPass() {
|
||
let sessionID = activeSessionID
|
||
let delays: [TimeInterval] = [0.0, 0.08, 0.18]
|
||
guard measurementPass < delays.count else {
|
||
guard sessionID == activeSessionID,
|
||
let currentSpineIndex = currentSpineIndexForMeasurement() else {
|
||
return
|
||
}
|
||
pageCounts[currentSpineIndex] = max(1, pendingMeasurementValue)
|
||
currentMeasurementOffset += 1
|
||
measureNextSpineItem()
|
||
return
|
||
}
|
||
|
||
let delay = delays[measurementPass]
|
||
measurementPass += 1
|
||
DispatchQueue.main.asyncAfter(deadline: .now() + delay) { [weak self] in
|
||
guard let self, self.activeSessionID == sessionID else { return }
|
||
self.measureCurrentDocument(sessionID: sessionID)
|
||
}
|
||
}
|
||
|
||
/// 执行当前文档的测量：通过 JS 获取 scrollWidth 并计算页数
|
||
private func measureCurrentDocument(sessionID: UUID) {
|
||
let script = RDEPUBStyleSheetBuilder.measurementScript(for: presentation)
|
||
RDEPUBWebViewDebug.logJavaScript(debugScope, webView: webView, action: "measure", details: "session=\(sessionID) pass=\(measurementPass)")
|
||
|
||
webView.evaluateJavaScript(script) { [weak self] value, _ in
|
||
guard let self else { return }
|
||
guard self.activeSessionID == sessionID,
|
||
self.currentSpineIndexForMeasurement() != nil else {
|
||
return
|
||
}
|
||
if let number = value as? NSNumber {
|
||
self.pendingMeasurementValue = max(self.pendingMeasurementValue, number.intValue)
|
||
} else if let intValue = value as? Int {
|
||
self.pendingMeasurementValue = max(self.pendingMeasurementValue, intValue)
|
||
}
|
||
RDEPUBWebViewDebug.log(self.debugScope, message: "measurement value=\(self.pendingMeasurementValue) session=\(sessionID)")
|
||
self.scheduleMeasurementPass()
|
||
}
|
||
}
|
||
|
||
}
|
||
|
||
extension RDEPUBPaginator: WKNavigationDelegate {
|
||
public func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
|
||
RDEPUBWebViewDebug.logNavigationEvent(debugScope, webView: webView, event: "didStart", url: webView.url)
|
||
}
|
||
|
||
public func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
|
||
RDEPUBWebViewDebug.logNavigationEvent(debugScope, webView: webView, event: "didFinish", url: webView.url)
|
||
guard currentSpineIndexForMeasurement() != nil else { return }
|
||
scheduleMeasurementPass()
|
||
}
|
||
|
||
public func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
|
||
RDEPUBWebViewDebug.logNavigationEvent(debugScope, webView: webView, event: "didFail", url: webView.url, error: error)
|
||
let currentSpineIndex = measurementIndices[safe: currentMeasurementOffset] ?? 0
|
||
pageCounts[currentSpineIndex] = 1
|
||
currentMeasurementOffset += 1
|
||
measureNextSpineItem()
|
||
}
|
||
|
||
public func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
|
||
RDEPUBWebViewDebug.logNavigationEvent(debugScope, webView: webView, event: "didFailProvisional", url: webView.url, error: error)
|
||
let currentSpineIndex = measurementIndices[safe: currentMeasurementOffset] ?? 0
|
||
pageCounts[currentSpineIndex] = 1
|
||
currentMeasurementOffset += 1
|
||
measureNextSpineItem()
|
||
}
|
||
|
||
public func webViewWebContentProcessDidTerminate(_ webView: WKWebView) {
|
||
RDEPUBWebViewDebug.logNavigationEvent(debugScope, webView: webView, event: "processTerminated", url: webView.url)
|
||
}
|
||
}
|
||
|
||
/// Array 安全下标扩展，越界时返回 nil 而非崩溃
|
||
private extension Array {
|
||
subscript(safe index: Int) -> Element? {
|
||
indices.contains(index) ? self[index] : nil
|
||
}
|
||
}
|