Remove Problematic CATransaction, Fix Lines Disappearing (#52)

Remove Problematic CATransaction, Assert Overlapping Layout

Author: thecoolwinter

Package.resolved

@@ -1,48 +1,39 @@
 {
   "pins" : [
-    {
-      "identity" : "mainoffender",
-      "kind" : "remoteSourceControl",
-      "location" : "https://github.com/mattmassicotte/MainOffender",
-      "state" : {
-        "revision" : "343cc3797618c29b48b037b4e2beea0664e75315",
-        "version" : "0.1.0"
-      }
-    },
     {
       "identity" : "rearrange",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/ChimeHQ/Rearrange",
       "state" : {
-        "revision" : "8f97f721d8a08c6e01ab9f7460e53819bef72dfa",
-        "version" : "1.5.3"
+        "revision" : "5ff7f3363f7a08f77e0d761e38e6add31c2136e1",
+        "version" : "1.8.1"
       }
     },
     {
       "identity" : "swift-collections",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-collections.git",
       "state" : {
-        "revision" : "937e904258d22af6e447a0b72c0bc67583ef64a2",
-        "version" : "1.0.4"
+        "revision" : "9bf03ff58ce34478e66aaee630e491823326fd06",
+        "version" : "1.1.3"
       }
     },
     {
       "identity" : "swiftlintplugin",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/lukepistrol/SwiftLintPlugin",
       "state" : {
-        "revision" : "f69b412a765396d44dc9f4788a5b79919c1ca9e3",
-        "version" : "0.2.2"
+        "revision" : "5a65f4074975f811da666dfe31a19850950b1ea4",
+        "version" : "0.56.2"
       }
     },
     {
       "identity" : "textstory",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/ChimeHQ/TextStory",
       "state" : {
-        "revision" : "8883fa739aa213e70e6cb109bfbf0a0b551e4cb5",
-        "version" : "0.8.0"
+        "revision" : "8dc9148b46fcf93b08ea9d4ef9bdb5e4f700e008",
+        "version" : "0.9.0"
       }
     }
   ],

Package.swift

@@ -17,7 +17,7 @@ let package = Package(
         // Text mutation, storage helpers
         .package(
             url: "https://github.com/ChimeHQ/TextStory",
-            from: "0.8.0"
+            from: "0.9.0"
         ),
         // Useful data structures
         .package(
@@ -27,7 +27,7 @@ let package = Package(
         // SwiftLint
         .package(
             url: "https://github.com/lukepistrol/SwiftLintPlugin",
-            from: "0.2.2"
+            from: "0.52.2"
         )
     ],
     targets: [

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManager.swift

@@ -79,6 +79,13 @@ public class TextLayoutManager: NSObject {
     public var isInTransaction: Bool {
         transactionCounter > 0
     }
+    #if DEBUG
+    /// Guard variable for an assertion check in debug builds.
+    /// Ensures that layout calls are not overlapping, potentially causing layout issues.
+    /// This is used over a lock, as locks in performant code such as this would be detrimental to performance.
+    /// Also only included in debug builds. DO NOT USE for checking if layout is active or not. That is an anti-pattern.
+    private var isInLayout: Bool = false
+    #endif
 
     weak var layoutView: NSView?
 
@@ -188,15 +195,26 @@ public class TextLayoutManager: NSObject {
 
     // MARK: - Layout
 
+    /// Asserts that the caller is not in an active layout pass.
+    /// See docs on ``isInLayout`` for more details.
+    private func assertNotInLayout() {
+        #if DEBUG // This is redundant, but it keeps the flag debug-only too which helps prevent misuse.
+        assert(!isInLayout, "layoutLines called while already in a layout pass. This is a programmer error.")
+        #endif
+    }
+
     /// Lays out all visible lines
     func layoutLines(in rect: NSRect? = nil) { // swiftlint:disable:this function_body_length
+        assertNotInLayout()
         guard layoutView?.superview != nil,
               let visibleRect = rect ?? delegate?.visibleRect,
               !isInTransaction,
               let textStorage else {
             return
         }
-        CATransaction.begin()
+        #if DEBUG
+        isInLayout = true
+        #endif
         let minY = max(visibleRect.minY - verticalLayoutPadding, 0)
         let maxY = max(visibleRect.maxY + verticalLayoutPadding, 0)
         let originalHeight = lineStorage.height
@@ -237,13 +255,11 @@ public class TextLayoutManager: NSObject {
                 }
             } else {
                 // Make sure the used fragment views aren't dequeued.
-                usedFragmentIDs.formUnion(linePosition.data.typesetter.lineFragments.map(\.data.id))
+                usedFragmentIDs.formUnion(linePosition.data.lineFragments.map(\.data.id))
             }
             newVisibleLines.insert(linePosition.data.id)
         }
 
-        CATransaction.commit()
-
         // Enqueue any lines not used in this layout pass.
         viewReuseQueue.enqueueViews(notInSet: usedFragmentIDs)
 
@@ -262,6 +278,9 @@ public class TextLayoutManager: NSObject {
             delegate?.layoutManagerYAdjustment(yContentAdjustment)
         }
 
+        #if DEBUG
+        isInLayout = false
+        #endif
         needsLayout = false
     }
 
@@ -302,7 +321,7 @@ public class TextLayoutManager: NSObject {
         let relativeMinY = max(layoutData.minY - position.yPos, 0)
         let relativeMaxY = max(layoutData.maxY - position.yPos, relativeMinY)
 
-        for lineFragmentPosition in line.typesetter.lineFragments.linesStartingAt(
+        for lineFragmentPosition in line.lineFragments.linesStartingAt(
             relativeMinY,
             until: relativeMaxY
         ) {

Sources/CodeEditTextView/TextView/TextView+ReplaceCharacters.swift

@@ -38,8 +38,8 @@ extension TextView {
             delegate?.textView(self, didReplaceContentsIn: range, with: string)
         }
 
-        layoutManager.endTransaction()
         textStorage.endEditing()
+        layoutManager.endTransaction()
         selectionManager.notifyAfterEdit()
         NotificationCenter.default.post(name: Self.textDidChangeNotification, object: self)
     }