Draw InvisibleCharacters From Configuration

Author: thecoolwinter

Sources/CodeEditTextView/InvisibleCharacters/InvisibleCharactersDelegate.swift

@@ -0,0 +1,19 @@
+//
+//  InvisibleCharactersConfig.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 6/9/25.
+//
+
+import Foundation
+import AppKit
+
+public enum InvisibleCharacterStyle: Hashable {
+    case replace(replacementCharacter: String, color: NSColor, font: NSFont)
+    case emphasize(color: NSColor)
+}
+
+public protocol InvisibleCharactersDelegate: AnyObject {
+    var triggerCharacters: Set<Character> { get }
+    func invisibleStyle(for character: Character, at range: NSRange, lineRange: NSRange) -> InvisibleCharacterStyle?
+}

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManager+Layout.swift

@@ -251,9 +251,9 @@ extension TextLayoutManager {
             renderDelegate?.lineFragmentView(for: lineFragment.data) ?? LineFragmentView()
         }
         view.translatesAutoresizingMaskIntoConstraints = false
-        view.setLineFragment(lineFragment.data)
+        view.setLineFragment(lineFragment.data, renderer: lineFragmentRenderer)
         view.frame.origin = CGPoint(x: edgeInsets.left, y: yPos)
-        layoutView?.addSubview(view)
+        layoutView?.addSubview(view, positioned: .below, relativeTo: nil)
         view.needsDisplay = true
     }
 }

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManager.swift

@@ -66,12 +66,21 @@ public class TextLayoutManager: NSObject {
 
     public let attachments: TextAttachmentManager = TextAttachmentManager()
 
+    public weak var invisibleCharacterDelegate: InvisibleCharactersDelegate? {
+        didSet {
+            lineFragmentRenderer.invisibleCharacterDelegate = invisibleCharacterDelegate
+            layoutView?.needsDisplay = true
+        }
+    }
+
     // MARK: - Internal
 
     weak var textStorage: NSTextStorage?
     var lineStorage: TextLineStorage<TextLine> = TextLineStorage()
     var markedTextManager: MarkedTextManager = MarkedTextManager()
     let viewReuseQueue: ViewReuseQueue<LineFragmentView, LineFragment.ID> = ViewReuseQueue()
+    let lineFragmentRenderer: LineFragmentRenderer
+
     package var visibleLineIds: Set<TextLine.ID> = []
     /// Used to force a complete re-layout using `setNeedsLayout`
     package var needsLayout: Bool = false
@@ -122,14 +131,20 @@ public class TextLayoutManager: NSObject {
         wrapLines: Bool,
         textView: NSView,
         delegate: TextLayoutManagerDelegate?,
-        renderDelegate: TextLayoutManagerRenderDelegate? = nil
+        renderDelegate: TextLayoutManagerRenderDelegate? = nil,
+        invisibleCharacterDelegate: InvisibleCharactersDelegate? = nil
     ) {
         self.textStorage = textStorage
         self.lineHeightMultiplier = lineHeightMultiplier
         self.wrapLines = wrapLines
         self.layoutView = textView
         self.delegate = delegate
         self.renderDelegate = renderDelegate
+        self.lineFragmentRenderer = LineFragmentRenderer(
+            textStorage: textStorage,
+            invisibleCharacterDelegate: invisibleCharacterDelegate
+        )
+        self.invisibleCharacterDelegate = invisibleCharacterDelegate
         super.init()
         prepareTextLines()
         attachments.layoutManager = self
@@ -166,6 +181,7 @@ public class TextLayoutManager: NSObject {
         viewReuseQueue.usedViews.removeAll()
         maxLineWidth = 0
         markedTextManager.removeAll()
+        lineFragmentRenderer.textStorage = textStorage
         prepareTextLines()
         setNeedsLayout()
     }

Sources/CodeEditTextView/TextLine/LineFragment.swift

@@ -47,6 +47,7 @@ public final class LineFragment: Identifiable, Equatable {
     }
 
     public let id = UUID()
+    public let lineRange: NSRange
     public let documentRange: NSRange
     public var contents: [FragmentContent]
     public var width: CGFloat
@@ -60,13 +61,15 @@ public final class LineFragment: Identifiable, Equatable {
     }
 
     init(
+        lineRange: NSRange,
         documentRange: NSRange,
         contents: [FragmentContent],
         width: CGFloat,
         height: CGFloat,
         descent: CGFloat,
         lineHeightMultiplier: CGFloat
     ) {
+        self.lineRange = lineRange
         self.documentRange = documentRange
         self.contents = contents
         self.width = width
@@ -102,52 +105,6 @@ public final class LineFragment: Identifiable, Equatable {
         }
     }
 
-    public func draw(in context: CGContext, yPos: CGFloat) {
-        context.saveGState()
-
-        // Removes jagged edges
-        context.setAllowsAntialiasing(true)
-        context.setShouldAntialias(true)
-
-        // Effectively increases the screen resolution by drawing text in each LED color pixel (R, G, or B), rather than
-        // the triplet of pixels (RGB) for a regular pixel. This can increase text clarity, but loses effectiveness
-        // in low-contrast settings.
-        context.setAllowsFontSubpixelPositioning(true)
-        context.setShouldSubpixelPositionFonts(true)
-
-        // Quantizes the position of each glyph, resulting in slightly less accurate positioning, and gaining higher
-        // quality bitmaps and performance.
-        context.setAllowsFontSubpixelQuantization(true)
-        context.setShouldSubpixelQuantizeFonts(true)
-
-        ContextSetHiddenSmoothingStyle(context, 16)
-
-        context.textMatrix = .init(scaleX: 1, y: -1)
-
-        var currentPosition: CGFloat = 0.0
-        var currentLocation = 0
-        for content in contents {
-            context.saveGState()
-            switch content.data {
-            case .text(let ctLine):
-                context.textPosition = CGPoint(
-                    x: currentPosition,
-                    y: yPos + height - descent + (heightDifference/2)
-                ).pixelAligned
-                CTLineDraw(ctLine, context)
-            case .attachment(let attachment):
-                attachment.attachment.draw(
-                    in: context,
-                    rect: NSRect(x: currentPosition, y: yPos, width: attachment.width, height: scaledHeight)
-                )
-            }
-            context.restoreGState()
-            currentPosition += content.width
-            currentLocation += content.length
-        }
-        context.restoreGState()
-    }
-
     package func findContent(at location: Int) -> (content: FragmentContent, position: ContentPosition)? {
         var position = ContentPosition(xPos: 0, offset: 0)