repository·main·Indexed 20 days ago
https://github.com/kyle-n/highlightedtexteditorA SwiftUI-based text editor for iOS 13.0+ and macOS 10.15+ that provides live syntax highlighting using regular expressions. It allows developers to apply complex text styles to specific patterns via HighlightRule and TextFormattingRule, and includes built-in presets for Markdown and URLs. The library provides modifiers for text and selection changes, as well as an .introspect modifier to access the underlying UITextView or NSTextView.
HighlightedTextEditor supports iOS 13.0+ and macOS 10.15+.
Use the following URL to add the package dependency:
https://github.com/kyle-n/HighlightedTextEditor
Add the following line to your Podfile and run pod install:
pod 'HighlightedTextEditor'pod 'HighlightedTextEditor'The library provides several built-in presets for common syntax highlighting tasks. These are available as static properties on [HighlightRule].
Available presets:
.markdown.urlExample usage:
HighlightedTextEditor(text: $text, highlightRules: .markdown)You can use NSRegularExpression.all to easily select and apply formatting to the entire string content.
HighlightedTextEditor(text: $text, highlightRules: [
HighlightRule(pattern: .all, formattingRule: TextFormattingRule(key: .underlineStyle, value: NSUnderlineStyle.single.rawValue))
])To use HighlightedTextEditor, provide a Binding<String> for the text content and an array of HighlightRule objects to define how text should be styled based on regex patterns.
Performance Tip: Always instantiate NSRegularExpression objects once (e.g., as a constant or static property) rather than recreating them inside a view's body to avoid performance degradation during redraws.
import HighlightedTextEditor
// matches text between underscores
let betweenUnderscores = try! NSRegularExpression(pattern: "_[^_]+_", options: [])
struct ContentView: View {
@State private var text: String = ""
private let rules: [HighlightRule] = [
HighlightRule(pattern: betweenUnderscores, formattingRules: [
TextFormattingRule(fontTraits: [.traitItalic, .traitBold]),
TextFormattingRule(key: .foregroundColor, value: UIColor.red),
TextFormattingRule(key: .underlineStyle) { content, range in
if content.count > 10 { return NSUnderlineStyle.double.rawValue }
else { return NSUnderlineStyle.single.rawValue }
}
])
]
var body: some View {
VStack {
HighlightedTextEditor(text: $text, highlightRules: rules)
.onCommit { print("commited") }
.onEditingChanged { print("editing changed") }
.onTextChange { print("latest text value", $0) }
.onSelectionChange { (range: NSRange) in
print(range)
}
.introspect { editor in
// access underlying UITextView or NSTextView
editor.textView.backgroundColor = .green
}
}
}
}The HighlightedTextEditor view supports several modifiers for handling user interaction and accessing underlying components:
.onCommit(_ callback: @escaping () -> Void): Triggered when the user stops editing..onEditingChanged(_ callback: @escaping () -> Void): Triggered when the user begins or ends editing..onTextChange(_ callback: @escaping (_ editorContent: String) -> Void): Triggered whenever the text content changes..onSelectionChange(_ callback: @escaping (_ selectedRange: NSRange) -> Void): Triggered when the selection changes (NSRange)..onSelectionChange(_ callback: @escaping (_ selectedRanges: [NSRange]) -> Void): (AppKit only) Triggered when multiple selection ranges change..introspect(callback: (_ editor: HighlightedTextEditorInternals) -> Void): Provides access to the underlying UITextView (iOS) or NSTextView (macOS) via the HighlightedTextEditorInternals object.The .introspect modifier passes a HighlightedTextEditorInternals object to your callback, allowing you to customize the underlying UIKit or AppKit components.
HighlightedTextEditorInternals Properties:
textView: The underlying UITextView (UIKit) or NSTextView (AppKit).scrollView: The NSScrollView wrapper (AppKit only; returns nil in UIKit)..introspect { editor in
// access underlying UITextView or NSTextView
editor.textView.backgroundColor = .green
}A HighlightRule maps a regex pattern to specific text formatting styles.
Parameters:
pattern: An NSRegularExpression defining the content to highlight. (Instantiate once for performance).formattingRule: A single TextFormattingRule to apply to all text matching the pattern.formattingRules: An array of [TextFormattingRule] to apply multiple styles to the matched text.A TextFormattingRule defines how text matching a pattern should be styled using NSAttributedString.Keys. There are three ways to initialize a rule:
Static Value: Set a specific style for a key.
key: NSAttributedString.Key (e.g., .foregroundColor, .underlineStyle).value: The style value (e.g., UIColor.red, NSUnderlineStyle.single.rawValue).Dynamic Value (Callback): Calculate the style based on the matched content.
key: NSAttributedString.Key.calculateValue: A closure (String, Range<String.Index>) -> Any where the first parameter is the matched text and the second is the match's range in the overall string.Font Traits: Set symbolic font traits.
fontTraits: UIFontDescriptor.SymbolicTraits (iOS) or NSFontDescriptor.SymbolicTraits (macOS) (e.g., [.traitBold]).SwiftUI Color (iOS 14+ / macOS 11+):
foregroundColor: A SwiftUI Color.fontTraits: Symbolic font traits.
Note: If using Xcode beta, you may need to add the -DBETA flag to your Build Settings to enable this initializer.