Extract HTML to attributed string converter to separate helper

Tusker.xcodeproj/project.pbxproj

@@ -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 */,

Tusker/HTMLConverter.swift

@@ -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))")
+        }
+    }
+    
+    
+}

Tusker/Views/ContentTextView.swift

@@ -22,14 +22,19 @@ class ContentTextView: LinkTextView, BaseEmojiLabel {
     weak var overrideMastodonController: MastodonController?
     var mastodonController: MastodonController? { overrideMastodonController ?? navigationDelegate?.apiController }
 
-    var defaultFont: UIFont = .systemFont(ofSize: 17)
+    private var htmlConverter = HTMLConverter()
-    var defaultColor: UIColor = .label
+    var defaultFont: UIFont {
-    var paragraphStyle: NSParagraphStyle = {
+        _read { yield htmlConverter.font }
-        let style = NSMutableParagraphStyle()
+        _modify { yield &htmlConverter.font }
-        // 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
+    var defaultColor: UIColor {
-        return style
+        _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)
+        self.attributedText = htmlConverter.convert(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))")
-        }
     }
     
     // MARK: - Interaction