Improve performance of syntax highlighting

1 files changed, 25 insertions, 1 deletions

diff --git a/Map/Presentation/Base Components/MapTextEditor.swift b/Map/Presentation/Base Components/MapTextEditor.swift
index 5c7d74c..a2070e4 100644
--- a/Map/Presentation/Base Components/MapTextEditor.swift
+++ b/Map/Presentation/Base Components/MapTextEditor.swift
@@ -79,6 +79,10 @@ class MapTextEditorController: NSViewController {
   override func viewDidAppear() {
     self.view.window?.makeFirstResponder(self.view)
     updateHighlights()
+    // Initial colorization of the entire document
+    if let textView = currentTextView, let textStorage = textView.textStorage {
+      colorizeText(textStorage: textStorage)
+    }
   }
 
   var currentTextView: NSTextView? {
@@ -150,12 +154,32 @@ extension MapTextEditorController: NSTextStorageDelegate {
 
   override func textStorageDidProcessEditing(_ obj: Notification) {
     if let textStorage = obj.object as? NSTextStorage {
-      self.colorizeText(textStorage: textStorage)
+      // Only colorize the edited range instead of the entire document
+      let editedRange = textStorage.editedRange
+      if editedRange.location != NSNotFound {
+        self.colorizeEditedText(textStorage: textStorage, editedRange: editedRange)
+      }
     }
   }
 
+  nonisolated private func colorizeEditedText(textStorage: NSTextStorage, editedRange: NSRange) {
+    // Expand range to include the entire line(s) that were edited
+    let string = textStorage.string as NSString
+    let lineRange = string.lineRange(for: editedRange)
+
+    // Clear existing attributes in the range
+    textStorage.removeAttribute(.foregroundColor, range: lineRange)
+
+    // Apply syntax highlighting only to the affected lines
+    self.applySyntaxHighlighting(textStorage: textStorage, range: lineRange)
+  }
+
   nonisolated private func colorizeText(textStorage: NSTextStorage) {
     let range = NSMakeRange(0, textStorage.length)
+    self.applySyntaxHighlighting(textStorage: textStorage, range: range)
+  }
+
+  nonisolated private func applySyntaxHighlighting(textStorage: NSTextStorage, range: NSRange) {
     var matches = vertexRegex.matches(in: textStorage.string, options: [], range: range)
 
     for match in matches {