ReadViewSDK/Sources/RDReaderView/EPUBTextRendering/RDEPUBDTCoreTextRenderer.swift
2026-05-21 19:40:51 +08:00

80 lines
3.1 KiB
Swift

import UIKit
#if canImport(DTCoreText)
import DTCoreText
#endif
public struct RDEPUBDTCoreTextRenderer: RDEPUBTextRenderer {
public init() {}
public static var isAvailable: Bool {
#if canImport(DTCoreText)
return true
#else
return false
#endif
}
public func renderChapter(
html: String,
baseURL: URL?,
style: RDEPUBTextRenderStyle
) throws -> RDEPUBRenderedChapterContent {
#if canImport(DTCoreText)
let markedHTML = RDEPUBTextRendererSupport.injectFragmentMarkers(into: html)
guard let data = markedHTML.data(using: .utf8) else {
throw RDEPUBTextRenderingError.htmlEncodingFailed
}
guard let rendered = makeAttributedString(from: data, baseURL: baseURL, style: style) else {
return fallbackRenderedContent(for: markedHTML, style: style)
}
let attributedString = NSMutableAttributedString(attributedString: rendered)
let fragmentOffsets = RDEPUBTextRendererSupport.extractFragmentOffsets(from: attributedString)
RDEPUBTextRendererSupport.normalizeReadingAttributes(in: attributedString, style: style)
return RDEPUBRenderedChapterContent(attributedString: attributedString, fragmentOffsets: fragmentOffsets)
#else
let markedHTML = RDEPUBTextRendererSupport.injectFragmentMarkers(into: html)
return fallbackRenderedContent(for: markedHTML, style: style)
#endif
}
private func fallbackRenderedContent(for html: String, style: RDEPUBTextRenderStyle) -> RDEPUBRenderedChapterContent {
let attributedString = RDEPUBTextRendererSupport.fallbackAttributedString(for: html, style: style)
let fragmentOffsets = RDEPUBTextRendererSupport.extractFragmentOffsets(from: attributedString)
RDEPUBTextRendererSupport.normalizeReadingAttributes(in: attributedString, style: style)
return RDEPUBRenderedChapterContent(attributedString: attributedString, fragmentOffsets: fragmentOffsets)
}
#if canImport(DTCoreText)
private func makeAttributedString(from data: Data, baseURL: URL?, style: RDEPUBTextRenderStyle) -> NSAttributedString? {
let builder = DTHTMLAttributedStringBuilder(
html: data,
options: dtOptions(baseURL: baseURL, style: style),
documentAttributes: nil
)
return builder?.generatedAttributedString()
}
private func dtOptions(baseURL: URL?, style: RDEPUBTextRenderStyle) -> [AnyHashable: Any] {
var options: [AnyHashable: Any] = [
NSTextSizeMultiplierDocumentOption: 1.0,
DTDefaultFontFamily: style.font.familyName,
DTDefaultFontName: style.font.fontName,
DTDefaultFontSize: style.font.pointSize,
DTDefaultLineHeightMultiplier: max((style.font.lineHeight + style.lineSpacing) / max(style.font.lineHeight, 1), 1),
DTUseiOS6Attributes: true
]
if let baseURL {
options[NSBaseURLDocumentOption] = baseURL
}
if let textColor = style.textColor {
options[DTDefaultTextColor] = textColor
}
return options
}
#endif
}