perf: merged theming optimizations from simonbs#380

Author: mach-port-t

Sources/Runestone/StringSyntaxHighlighter.swift

@@ -27,7 +27,7 @@ public final class StringSyntaxHighlighter {
     ///   - language: The language to use when parsing the text
     ///   - languageProvider: Object that can provide embedded languages on demand. A strong reference will be stored to the language provider..
     public init(
-        theme: Theme = DefaultTheme(),
+        theme: Theme = DefaultTheme.share,
         language: TreeSitterLanguage,
         languageProvider: TreeSitterLanguageProvider? = nil
     ) {

Sources/Runestone/TextView/Appearance/DefaultTheme.swift

@@ -18,6 +18,8 @@ public final class DefaultTheme: Runestone.Theme {
     public let selectionColor = UIColor(themeColorNamed: "selection")
 
     public init() {}
+    
+    public static let share = DefaultTheme()
 
     // swiftlint:disable:next cyclomatic_complexity
     public func textColor(for highlightName: String) -> UIColor? {

Sources/Runestone/TextView/Core/LayoutManager.swift

@@ -35,7 +35,7 @@ public class LayoutManager {
             }
         }
     }
-    var theme: Theme = DefaultTheme() {
+    var theme: Theme = DefaultTheme.share {
         didSet {
             if theme !== oldValue {
                 gutterBackgroundView.backgroundColor = theme.gutterBackgroundColor

Sources/Runestone/TextView/Core/TextInputView.swift

@@ -914,7 +914,11 @@ public class TextInputView: UIView, UITextInput {
         super.pressesEnded(presses, with: event)
         if let keyCode = presses.first?.key?.keyCode, presses.count == 1 {
             if markedRange != nil {
-                handleKeyPressDuringMultistageTextInput(keyCode: keyCode)
+                if #available(iOS 13.4, *) {
+                    handleKeyPressDuringMultistageTextInput(keyCode: keyCode)
+                } else {
+                    // Fallback on earlier versions
+                }
             }
         }
     }
@@ -936,6 +940,7 @@ private extension TextInputView {
 
 // MARK: - Navigation
 private extension TextInputView {
+    @available(iOS 13.4, *)
     private func handleKeyPressDuringMultistageTextInput(keyCode: UIKeyboardHIDUsage) {
         // When editing multistage text input (that is, we have a marked text) we let the user unmark the text
         // by pressing the arrow keys or Escape. This isn't common in iOS apps but it's the default behavior

Sources/Runestone/TextView/Core/TextView.swift

@@ -655,7 +655,7 @@ open class TextView: UIScrollView {
     /// Create a new text view.
     /// - Parameter frame: The frame rectangle of the text view.
     override public init(frame: CGRect) {
-        textInputView = TextInputView(theme: DefaultTheme())
+        textInputView = TextInputView(theme: DefaultTheme.share)
         super.init(frame: frame)
         backgroundColor = .white
         textInputView.delegate = self

Sources/Runestone/TextView/LineController/LineController.swift

@@ -25,7 +25,7 @@ final class LineController {
             }
         }
     }
-    var theme: Theme = DefaultTheme() {
+    var theme: Theme = DefaultTheme.share {
         didSet {
             syntaxHighlighter?.theme = theme
             applyThemeToAllLineFragmentControllers()

Sources/Runestone/TextView/SyntaxHighlighting/Internal/PlainText/PlainTextSyntaxHighlighter.swift

@@ -2,7 +2,7 @@ import CoreGraphics
 import Foundation
 
 final class PlainTextSyntaxHighlighter: LineSyntaxHighlighter {
-    var theme: Theme = DefaultTheme()
+    var theme: Theme = DefaultTheme.share
     var kern: CGFloat = 0
     var canHighlight: Bool {
         false

Sources/Runestone/TextView/SyntaxHighlighting/Internal/TreeSitter/TreeSitterSyntaxHighlighter.swift

@@ -15,7 +15,7 @@ enum TreeSitterSyntaxHighlighterError: LocalizedError {
 }
 
 final class TreeSitterSyntaxHighlighter: LineSyntaxHighlighter {
-    var theme: Theme = DefaultTheme()
+    var theme: Theme = DefaultTheme.share
     var kern: CGFloat = 0
     var canHighlight: Bool {
         languageMode.canHighlight