Puranjay Savar Mattas
6e1ffb96fd
Convert from git submodule to plain vendored copy. No push access to upstream nodes-app/swift-markdown-engine meant our local fix commit (05c1720) was stranded and unreachable from any remote on fresh clones/CI. Vendoring as plain files folds it into normal repo history instead.
51 lines
2.1 KiB
Swift
51 lines
2.1 KiB
Swift
//
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// HeadingHelpers.swift
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// MarkdownEngine
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//
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// Created by Luca Chen on 18.02.26.
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//
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// Small helper values for heading size/spacing, plus shared text measurements.
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import AppKit
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enum HeadingHelpers {
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/// Use heading context to scale LaTeX font size consistently with surrounding text.
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/// `headings` is the document's heading tokens, built once per styling pass —
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/// scanning all tokens per LaTeX token here was O(#latex × #tokens).
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static func latexFontSize(
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for token: MarkdownToken,
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headings: [MarkdownToken],
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baseFont: NSFont,
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configuration: HeadingStyle = .default
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) -> CGFloat {
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if let headingToken = headings.first(where: { NSLocationInRange(token.contentRange.location, $0.contentRange) }) {
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let level = headingToken.markerRanges.first?.length ?? 1
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return baseFont.pointSize * configuration.fontMultiplier(for: level)
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}
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return baseFont.pointSize
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}
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/// Memoized string-width measurement. `size(withAttributes:)` is a full CoreText
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/// measure (~31µs); the styler calls this thousands of times per open on a small set
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/// of repeated strings — list markers (`- `, `1. `), the `$`/`$$` latex markers, per
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/// formula/char slices. Only 2 distinct inline formulas × 4 calls each, 372 list
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/// items with ~5 distinct markers, etc. Same (text, font) → same width, so the cache
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/// is byte-identical to the direct call. `NSCache` bounds memory and is thread-safe.
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private static let widthCache: NSCache<NSString, NSNumber> = {
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let c = NSCache<NSString, NSNumber>()
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c.countLimit = 4096
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return c
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}()
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static func textWidth(_ text: String, font: NSFont) -> CGFloat {
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let key = "\(font.fontName)|\(font.pointSize)|\(text)" as NSString
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if let cached = widthCache.object(forKey: key) {
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return CGFloat(cached.doubleValue)
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}
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let width = (text as NSString).size(withAttributes: [.font: font]).width
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widthCache.setObject(NSNumber(value: Double(width)), forKey: key)
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return width
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}
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}
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