From dce014c6ee2564c44e38c222a3fdc6eef76892d6 Mon Sep 17 00:00:00 2001
From: Matt <85322+mattmassicotte@users.noreply.github.com>
Date: Mon, 16 Dec 2024 09:46:59 -0500
Subject: [PATCH] Last position line fragment for TK2 fix

---
 Sources/Glyph/NSTextContainer+Additions.swift |  6 ++--
 .../Glyph/NSTextLayoutManager+Additions.swift | 28 +++++++++++++++++++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/Sources/Glyph/NSTextContainer+Additions.swift b/Sources/Glyph/NSTextContainer+Additions.swift
index 7a1b416..2dc1980 100644
--- a/Sources/Glyph/NSTextContainer+Additions.swift
+++ b/Sources/Glyph/NSTextContainer+Additions.swift
@@ -85,16 +85,16 @@ extension NSTextContainer {
 	public func lineFragment(for index: Int, offset: Int) -> (CGRect, NSRange)? {
 		var fragment: (CGRect, NSRange)?
 		let forward = offset >= 0
-		var targetCount = abs(offset)
+		var count = abs(offset)
 
 		enumerateLineFragments(from: index, forward: forward) { rect, range, stop in
-			if targetCount == 0 {
+			if count <= 0 {
 				fragment = (rect, range)
 				stop = true
 				return
 			}
 
-			targetCount -= 1
+			count -= 1
 		}
 
 		return fragment
diff --git a/Sources/Glyph/NSTextLayoutManager+Additions.swift b/Sources/Glyph/NSTextLayoutManager+Additions.swift
index 2e58d79..f540f92 100644
--- a/Sources/Glyph/NSTextLayoutManager+Additions.swift
+++ b/Sources/Glyph/NSTextLayoutManager+Additions.swift
@@ -69,6 +69,22 @@ extension NSTextLayoutManager {
 		})
 	}
 
+	// the last index in the storage might not return a fragment, and the logic required
+	// to figure out which one should be in effect is atually quite complex
+	private func lastTextLayoutFragment() -> NSTextLayoutFragment? {
+		guard let textContentManager else { return nil }
+
+		if let fragment = textLayoutFragment(for: documentRange.endLocation) {
+			return fragment
+		}
+
+		guard let locBefore = textContentManager.location(documentRange.endLocation, offsetBy: -1) else {
+			return nil
+		}
+
+		return textLayoutFragment(for: locBefore)
+	}
+
 	private func enumerateTextLineFragments(
 		in range: NSRange,
 		options: NSTextLayoutFragment.EnumerationOptions = [],
@@ -84,6 +100,18 @@ extension NSTextLayoutManager {
 			return
 		}
 
+		if textContentManager.offset(from: start, to: documentRange.endLocation) == 0 {
+			guard let fragment = lastTextLayoutFragment() else { return }
+
+			var stop = false
+
+			fragment.enumerateLineFragments(with: textContentManager) { lineFragment, frame, elementRange in
+				block(fragment, lineFragment, frame, elementRange, &stop)
+			}
+
+			return
+		}
+
 		enumerateTextLayoutFragments(from: start, options: options) { fragment in
 			let fragmentRange = fragment.rangeInElement