Extract HTML to attributed string converter to separate helper

This commit is contained in:
Shadowfacts 2022-12-03 18:58:19 -05:00
parent cde3109203
commit 7e5d8675c2
3 changed files with 146 additions and 101 deletions

View File

@ -64,6 +64,7 @@
D61F75B1293BD85300C0B37F /* CreateFilterService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61F75B0293BD85300C0B37F /* CreateFilterService.swift */; };
D61F75B3293BD89C00C0B37F /* UpdateFilterService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61F75B2293BD89C00C0B37F /* UpdateFilterService.swift */; };
D61F75B5293BD97400C0B37F /* DeleteFilterService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61F75B4293BD97400C0B37F /* DeleteFilterService.swift */; };
D61F75BB293C183100C0B37F /* HTMLConverter.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61F75BA293C183100C0B37F /* HTMLConverter.swift */; };
D620483423D3801D008A63EF /* LinkTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D620483323D3801D008A63EF /* LinkTextView.swift */; };
D620483623D38075008A63EF /* ContentTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D620483523D38075008A63EF /* ContentTextView.swift */; };
D620483823D38190008A63EF /* StatusContentTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D620483723D38190008A63EF /* StatusContentTextView.swift */; };
@ -444,6 +445,7 @@
D61F75B0293BD85300C0B37F /* CreateFilterService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CreateFilterService.swift; sourceTree = "<group>"; };
D61F75B2293BD89C00C0B37F /* UpdateFilterService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UpdateFilterService.swift; sourceTree = "<group>"; };
D61F75B4293BD97400C0B37F /* DeleteFilterService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DeleteFilterService.swift; sourceTree = "<group>"; };
D61F75BA293C183100C0B37F /* HTMLConverter.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HTMLConverter.swift; sourceTree = "<group>"; };
D620483323D3801D008A63EF /* LinkTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LinkTextView.swift; sourceTree = "<group>"; };
D620483523D38075008A63EF /* ContentTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentTextView.swift; sourceTree = "<group>"; };
D620483723D38190008A63EF /* StatusContentTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusContentTextView.swift; sourceTree = "<group>"; };
@ -1453,6 +1455,7 @@
D6D4DDCF212518A000E1C4BB /* AppDelegate.swift */,
D6CA6A91249FAD8900AD45C1 /* AudioSessionHelper.swift */,
D6E4269C2532A3E100C02E1C /* FuzzyMatcher.swift */,
D61F75BA293C183100C0B37F /* HTMLConverter.swift */,
D6B30E08254BAF63009CAEE5 /* ImageGrayscalifier.swift */,
D60E2F2B24423EAD005F8713 /* LazilyDecoding.swift */,
D64D0AAC2128D88B005A6F37 /* LocalData.swift */,
@ -1856,6 +1859,7 @@
D61F759229365C6C00C0B37F /* CollectionViewController.swift in Sources */,
04DACE8C212CB14B009840C4 /* MainTabBarViewController.swift in Sources */,
D68E525D24A3E8F00054355A /* SearchViewController.swift in Sources */,
D61F75BB293C183100C0B37F /* HTMLConverter.swift in Sources */,
D61F75A5293ABD6F00C0B37F /* EditFilterView.swift in Sources */,
D6AEBB412321642700E5038B /* SendMesasgeActivity.swift in Sources */,
D6BC9DB1232C61BC002CA326 /* NotificationsPageViewController.swift in Sources */,

128
Tusker/HTMLConverter.swift Normal file
View File

@ -0,0 +1,128 @@
//
// HTMLConverter.swift
// Tusker
//
// Created by Shadowfacts on 12/3/22.
// Copyright © 2022 Shadowfacts. All rights reserved.
//
import UIKit
import SwiftSoup
import WebURL
import WebURLFoundationExtras
struct HTMLConverter {
static let defaultFont = UIFont.systemFont(ofSize: 17)
static let defaultColor = UIColor.label
static let defaultParagraphStyle: NSParagraphStyle = {
let style = NSMutableParagraphStyle()
// 2 points is enough that it doesn't make things look weirdly spaced out, but leaves a slight gap when there are multiple lines of emojis
style.lineSpacing = 2
return style
}()
var font: UIFont = defaultFont
var color: UIColor = defaultColor
var paragraphStyle: NSParagraphStyle = defaultParagraphStyle
func convert(_ html: String) -> NSAttributedString {
let doc = try! SwiftSoup.parseBodyFragment(html)
let body = doc.body()!
let attributedText = attributedTextForHTMLNode(body)
let mutAttrString = NSMutableAttributedString(attributedString: attributedText)
mutAttrString.trimTrailingCharactersInSet(.whitespacesAndNewlines)
mutAttrString.collapseWhitespace()
mutAttrString.addAttribute(.paragraphStyle, value: paragraphStyle, range: mutAttrString.fullRange)
return mutAttrString
}
private func attributedTextForHTMLNode(_ node: Node, usePreformattedText: Bool = false) -> NSAttributedString {
switch node {
case let node as TextNode:
let text: String
if usePreformattedText {
text = node.getWholeText()
} else {
text = node.text()
}
return NSAttributedString(string: text, attributes: [.font: font, .foregroundColor: color])
case let node as Element:
let attributed = NSMutableAttributedString(string: "", attributes: [.font: font, .foregroundColor: color])
for child in node.getChildNodes() {
attributed.append(attributedTextForHTMLNode(child, usePreformattedText: usePreformattedText || node.tagName() == "pre"))
}
switch node.tagName() {
case "br":
// need to specify defaultFont here b/c otherwise it uses the default 12pt Helvetica which
// screws up its determination of the line height making multiple lines of emojis squash together
attributed.append(NSAttributedString(string: "\n", attributes: [.font: font]))
case "a":
let href = try! node.attr("href")
if let webURL = WebURL(href),
let url = URL(webURL) {
attributed.addAttribute(.link, value: url, range: attributed.fullRange)
} else if let url = URL(string: href) {
attributed.addAttribute(.link, value: url, range: attributed.fullRange)
}
case "p":
attributed.append(NSAttributedString(string: "\n\n", attributes: [.font: font]))
case "em", "i":
let currentFont: UIFont
if attributed.length == 0 {
currentFont = font
} else {
currentFont = attributed.attribute(.font, at: 0, effectiveRange: nil) as? UIFont ?? font
}
attributed.addAttribute(.font, value: currentFont.withTraits(.traitItalic)!, range: attributed.fullRange)
case "strong", "b":
let currentFont: UIFont
if attributed.length == 0 {
currentFont = font
} else {
currentFont = attributed.attribute(.font, at: 0, effectiveRange: nil) as? UIFont ?? font
}
attributed.addAttribute(.font, value: currentFont.withTraits(.traitBold)!, range: attributed.fullRange)
case "del":
attributed.addAttribute(.strikethroughStyle, value: NSUnderlineStyle.single.rawValue, range: attributed.fullRange)
case "code":
// TODO: this probably breaks with dynamic type
attributed.addAttribute(.font, value: UIFont.monospacedSystemFont(ofSize: font.pointSize, weight: .regular), range: attributed.fullRange)
case "pre":
attributed.append(NSAttributedString(string: "\n\n"))
attributed.addAttribute(.font, value: UIFont.monospacedSystemFont(ofSize: font.pointSize, weight: .regular), range: attributed.fullRange)
case "ol", "ul":
attributed.append(NSAttributedString(string: "\n\n"))
attributed.trimLeadingCharactersInSet(.whitespacesAndNewlines)
case "li":
let parentEl = node.parent()!
let parentTag = parentEl.tagName()
let bullet: NSAttributedString
if parentTag == "ol" {
let index = (try? node.elementSiblingIndex()) ?? 0
// we use the monospace digit font so that the periods of all the list items line up
// TODO: this probably breaks with dynamic type
bullet = NSAttributedString(string: "\(index + 1).\t", attributes: [.font: UIFont.monospacedDigitSystemFont(ofSize: font.pointSize, weight: .regular)])
} else if parentTag == "ul" {
bullet = NSAttributedString(string: "\u{2022}\t", attributes: [.font: font])
} else {
bullet = NSAttributedString()
}
attributed.insert(bullet, at: 0)
attributed.append(NSAttributedString(string: "\n", attributes: [.font: font]))
default:
break
}
return attributed
default:
fatalError("Unexpected node type \(type(of: node))")
}
}
}

View File

@ -22,14 +22,19 @@ class ContentTextView: LinkTextView, BaseEmojiLabel {
weak var overrideMastodonController: MastodonController?
var mastodonController: MastodonController? { overrideMastodonController ?? navigationDelegate?.apiController }
var defaultFont: UIFont = .systemFont(ofSize: 17)
var defaultColor: UIColor = .label
var paragraphStyle: NSParagraphStyle = {
let style = NSMutableParagraphStyle()
// 2 points is enough that it doesn't make things look weirdly spaced out, but leaves a slight gap when there are multiple lines of emojis
style.lineSpacing = 2
return style
}()
private var htmlConverter = HTMLConverter()
var defaultFont: UIFont {
_read { yield htmlConverter.font }
_modify { yield &htmlConverter.font }
}
var defaultColor: UIColor {
_read { yield htmlConverter.color }
_modify { yield &htmlConverter.color }
}
var paragraphStyle: NSParagraphStyle {
_read { yield htmlConverter.paragraphStyle }
_modify { yield &htmlConverter.paragraphStyle }
}
private(set) var hasEmojis = false
@ -85,99 +90,7 @@ class ContentTextView: LinkTextView, BaseEmojiLabel {
// MARK: - HTML Parsing
func setTextFromHtml(_ html: String) {
let doc = try! SwiftSoup.parse(html)
let body = doc.body()!
let attributedText = attributedTextForHTMLNode(body)
let mutAttrString = NSMutableAttributedString(attributedString: attributedText)
mutAttrString.trimTrailingCharactersInSet(.whitespacesAndNewlines)
mutAttrString.collapseWhitespace()
mutAttrString.addAttribute(.paragraphStyle, value: paragraphStyle, range: mutAttrString.fullRange)
self.attributedText = mutAttrString
}
private func attributedTextForHTMLNode(_ node: Node, usePreformattedText: Bool = false) -> NSAttributedString {
switch node {
case let node as TextNode:
let text: String
if usePreformattedText {
text = node.getWholeText()
} else {
text = node.text()
}
return NSAttributedString(string: text, attributes: [.font: defaultFont, .foregroundColor: defaultColor])
case let node as Element:
let attributed = NSMutableAttributedString(string: "", attributes: [.font: defaultFont, .foregroundColor: defaultColor])
for child in node.getChildNodes() {
attributed.append(attributedTextForHTMLNode(child, usePreformattedText: usePreformattedText || node.tagName() == "pre"))
}
switch node.tagName() {
case "br":
// need to specify defaultFont here b/c otherwise it uses the default 12pt Helvetica which
// screws up its determination of the line height making multiple lines of emojis squash together
attributed.append(NSAttributedString(string: "\n", attributes: [.font: defaultFont]))
case "a":
let href = try! node.attr("href")
if let webURL = WebURL(href),
let url = URL(webURL) {
attributed.addAttribute(.link, value: url, range: attributed.fullRange)
} else if let url = URL(string: href) {
attributed.addAttribute(.link, value: url, range: attributed.fullRange)
}
case "p":
attributed.append(NSAttributedString(string: "\n\n", attributes: [.font: defaultFont]))
case "em", "i":
let currentFont: UIFont
if attributed.length == 0 {
currentFont = defaultFont
} else {
currentFont = attributed.attribute(.font, at: 0, effectiveRange: nil) as? UIFont ?? defaultFont
}
attributed.addAttribute(.font, value: currentFont.withTraits(.traitItalic)!, range: attributed.fullRange)
case "strong", "b":
let currentFont: UIFont
if attributed.length == 0 {
currentFont = defaultFont
} else {
currentFont = attributed.attribute(.font, at: 0, effectiveRange: nil) as? UIFont ?? defaultFont
}
attributed.addAttribute(.font, value: currentFont.withTraits(.traitBold)!, range: attributed.fullRange)
case "del":
attributed.addAttribute(.strikethroughStyle, value: NSUnderlineStyle.single.rawValue, range: attributed.fullRange)
case "code":
attributed.addAttribute(.font, value: UIFont.monospacedSystemFont(ofSize: defaultFont.pointSize, weight: .regular), range: attributed.fullRange)
case "pre":
attributed.append(NSAttributedString(string: "\n\n"))
attributed.addAttribute(.font, value: UIFont.monospacedSystemFont(ofSize: defaultFont.pointSize, weight: .regular), range: attributed.fullRange)
case "ol", "ul":
attributed.append(NSAttributedString(string: "\n\n"))
attributed.trimLeadingCharactersInSet(.whitespacesAndNewlines)
case "li":
let parentEl = node.parent()!
let parentTag = parentEl.tagName()
let bullet: NSAttributedString
if parentTag == "ol" {
let index = (try? node.elementSiblingIndex()) ?? 0
// we use the monospace digit font so that the periods of all the list items line up
bullet = NSAttributedString(string: "\(index + 1).\t", attributes: [.font: UIFont.monospacedDigitSystemFont(ofSize: defaultFont.pointSize, weight: .regular)])
} else if parentTag == "ul" {
bullet = NSAttributedString(string: "\u{2022}\t", attributes: [.font: defaultFont])
} else {
bullet = NSAttributedString()
}
attributed.insert(bullet, at: 0)
attributed.append(NSAttributedString(string: "\n", attributes: [.font: defaultFont]))
default:
break
}
return attributed
default:
fatalError("Unexpected node type \(type(of: node))")
}
self.attributedText = htmlConverter.convert(html)
}
// MARK: - Interaction