rework line higlight from drawing to layer

Sources/STTextViewAppKit/Overlays/STLineHighlightView.swift

@@ -0,0 +1,27 @@
+//  Created by Marcin Krzyzanowski
+//  https://github.com/krzyzanowskim/STTextView/blob/main/LICENSE.md
+
+import AppKit
+
+final class STLineHighlightView: NSView {
+
+    override init(frame frameRect: NSRect) {
+        super.init(frame: frameRect)
+        wantsLayer = true
+        clipsToBounds = true
+    }
+
+    required init?(coder: NSCoder) {
+        super.init(coder: coder)
+        wantsLayer = true
+        clipsToBounds = true
+    }
+
+    override var isFlipped: Bool {
+#if os(macOS)
+        true
+#else
+        false
+#endif
+    }
+}

Sources/STTextViewAppKit/Overlays/SelectionHighlightView.swift → Sources/STTextViewAppKit/Overlays/STSelectionHighlightView.swift

@@ -3,7 +3,7 @@
 
 import AppKit
 
-final class SelectionHighlightView: NSView {
+final class STSelectionHighlightView: NSView {
     override var isFlipped: Bool {
 #if os(macOS)
         true

Sources/STTextViewAppKit/STTextFinderClient.swift

@@ -85,7 +85,8 @@ final class STTextFinderClient: NSObject, NSTextFinderClient {
             }
 
             textLayoutManager.textSelections = [NSTextSelection(textRanges, affinity: .downstream, granularity: .character)]
-            textView?.updateSelectionHighlights()
+            textView?.updateSelectedRangeHighlight()
+            textView?.updateSelectedLineHighlight()
             textView?.updateTypingAttributes()
         }
 

Sources/STTextViewAppKit/STTextView+Mouse.swift

@@ -28,7 +28,8 @@ extension STTextView {
             if !handled, holdsShift && holdsControl {
                 textLayoutManager.appendInsertionPointSelection(interactingAt: eventPoint)
                 updateTypingAttributes()
-                updateSelectionHighlights()
+                updateSelectedRangeHighlight()
+                updateSelectedLineHighlight()
                 needsDisplay = true
                 handled = true
             }

Sources/STTextViewAppKit/STTextView+NSTextViewportLayoutControllerDelegate.swift

@@ -70,7 +70,8 @@ extension STTextView: NSTextViewportLayoutControllerDelegate {
 
     public func textViewportLayoutControllerDidLayout(_ textViewportLayoutController: NSTextViewportLayoutController) {
         sizeToFit()
-        updateSelectionHighlights()
+        updateSelectedRangeHighlight()
+        updateSelectedLineHighlight()
         adjustViewportOffsetIfNeeded()
 
         if let viewportRange = textViewportLayoutController.viewportRange {

Sources/STTextViewAppKit/STTextView+Select.swift

@@ -44,7 +44,8 @@ extension STTextView {
         ]
 
         updateTypingAttributes()
-        updateSelectionHighlights()
+        updateSelectedRangeHighlight()
+        updateSelectedLineHighlight()
     }
 
     open override func selectLine(_ sender: Any?) {
@@ -496,7 +497,8 @@ extension STTextView {
         }
 
         updateTypingAttributes()
-        updateSelectionHighlights()
+        updateSelectedRangeHighlight()
+        updateSelectedLineHighlight()
         needsDisplay = true
     }
 

Sources/STTextViewAppKit/STTextView.swift

@@ -4,6 +4,7 @@
 //
 //  STTextView
 //      |---selectionView
+//              |---(STLineHighlightView | SelectionHighlightView)
 //      |---contentView
 //              |---(STInsertionPointView | STTextLayoutFragmentView)
 //      |---decorationView
@@ -315,7 +316,7 @@ import AVFoundation
     }
 
     /// A Boolean that controls whether the text view highlights the currently selected line.
-    @Invalidating(.display)
+    @Invalidating(.layout)
     @objc dynamic open var highlightSelectedLine: Bool = false
 
     /// Enable to show line numbers in the gutter.
@@ -587,6 +588,7 @@ import AVFoundation
         allowsUndo = true
         _undoManager = CoalescingUndoManager()
 
+
         textFinder = NSTextFinder()
         textFinderClient = STTextFinderClient()
 
@@ -708,7 +710,8 @@ import AVFoundation
 
     open override func viewDidChangeEffectiveAppearance() {
         super.viewDidChangeEffectiveAppearance()
-        self.updateSelectionHighlights()
+        self.updateSelectedRangeHighlight()
+        self.updateSelectedLineHighlight()
     }
 
     open override func viewDidMoveToSuperview() {
@@ -828,126 +831,6 @@ import AVFoundation
         }
     }
 
-    open override func draw(_ dirtyRect: NSRect) {
-        drawBackground(in: dirtyRect)
-        super.draw(dirtyRect)
-    }
-
-    /// Draws the background of the text view.
-    open func drawBackground(in rect: NSRect) {
-        guard highlightSelectedLine,
-              textLayoutManager.textSelectionsRanges(.withoutInsertionPoints).isEmpty,
-              !textLayoutManager.insertionPointSelections.isEmpty
-        else {
-            // don't highlight when there's selection
-            return
-        }
-
-        drawHighlightedLine(in: rect)
-    }
-
-    private func drawHighlightedLine(in rect: NSRect) {
-
-        func drawHighlight(in fillRect: CGRect) {
-            guard let context = NSGraphicsContext.current?.cgContext else {
-                return
-            }
-
-            context.saveGState()
-            context.setFillColor(selectedLineHighlightColor.cgColor)
-            context.fill(fillRect)
-            context.restoreGState()
-        }
-
-        if textLayoutManager.documentRange.isEmpty {
-            // - empty document has no layout fragments, nothing, it's empty and has to be handled explicitly.
-            // - there's no layout fragment at the document endLocation (technically it's out of bounds), has to be handled explicitly.
-            if let selectionFrame = textLayoutManager.textSegmentFrame(at: textLayoutManager.documentRange.location, type: .standard) {
-                drawHighlight(
-                    in: CGRect(
-                        origin: CGPoint(
-                            x: convert(contentView.bounds, from: contentView).minX,
-                            y: selectionFrame.origin.y
-                        ),
-                        size: CGSize(
-                            width: max(scrollView?.contentSize.width ?? 0, contentView.bounds.width),
-                            height: typingLineHeight
-                        )
-                    )
-                )
-            }
-            return
-        }
-
-        guard let viewportRange = textLayoutManager.textViewportLayoutController.viewportRange else {
-            return
-        }
-
-        // build the rectangle out of fragments rectangles
-        var combinedFragmentsRect: CGRect?
-
-        // TODO some beutiful day:
-        // Don't rely on NSTextParagraph.paragraphContentRange, but that
-        // makes tricky to get all the conditions right (especially for last line)
-        // Problem is that NSTextParagraph.rangeInElement span across two lines (eg. "abc\n" are two lines) while
-        // paragraphContentRange is just one ("abc")
-        //
-        // Another idea here is to use `textLayoutManager.textLayoutFragment(for: selectionTextRange.location)`
-        // to find the layout fragment and us its frame as highlight area. It has its issue when it comes to the
-        // extra line fragment area (sic).
-        textLayoutManager.enumerateTextLayoutFragments(in: viewportRange) { layoutFragment in
-            let contentRangeInElement = (layoutFragment.textElement as? NSTextParagraph)?.paragraphContentRange ?? layoutFragment.rangeInElement
-            for lineFragment in layoutFragment.textLineFragments {
-
-                func isLineSelected() -> Bool {
-                    textLayoutManager.textSelections.flatMap(\.textRanges).reduce(true) { partialResult, selectionTextRange in
-                        var result = true
-                        if lineFragment.isExtraLineFragment {
-                            let c1 = layoutFragment.rangeInElement.endLocation == selectionTextRange.location
-                            result = result && c1
-                        } else {
-                            let c1 = contentRangeInElement.contains(selectionTextRange)
-                            let c2 = contentRangeInElement.intersects(selectionTextRange)
-                            let c3 = selectionTextRange.contains(contentRangeInElement)
-                            let c4 = selectionTextRange.intersects(contentRangeInElement)
-                            let c5 = contentRangeInElement.endLocation == selectionTextRange.location
-                            result = result && (c1 || c2 || c3 || c4 || c5)
-                        }
-                        return partialResult && result
-                    }
-                }
-
-                if isLineSelected() {
-                    var lineFragmentFrame = layoutFragment.layoutFragmentFrame
-                    lineFragmentFrame.size.height = lineFragment.typographicBounds.height
-
-
-                    let r = CGRect(
-                        origin: CGPoint(
-                            x: convert(contentView.bounds, from: contentView).minX,
-                            y: lineFragmentFrame.origin.y + lineFragment.typographicBounds.minY
-                        ),
-                        size: CGSize(
-                            width: max(scrollView?.contentSize.width ?? 0, contentView.bounds.width),
-                            height: lineFragmentFrame.height
-                        )
-                    )
-
-                    if let rect = combinedFragmentsRect {
-                        combinedFragmentsRect = rect.union(r)
-                    } else {
-                        combinedFragmentsRect = r
-                    }
-                }
-            }
-            return true
-        }
-
-        if let combinedFragmentsRect {
-            drawHighlight(in: combinedFragmentsRect.pixelAligned)
-        }
-    }
-
     internal func setString(_ string: Any?) {
         undoManager?.disableUndoRegistration()
         defer {
@@ -1047,11 +930,118 @@ import AVFoundation
         }
     }
 
-    internal func updateSelectionHighlights() {
+    // Update selected line highlight layer
+    internal func updateSelectedLineHighlight() {
+        guard highlightSelectedLine,
+              textLayoutManager.textSelectionsRanges(.withoutInsertionPoints).isEmpty,
+              !textLayoutManager.insertionPointSelections.isEmpty
+        else {
+            // don't highlight when there's selection
+            return
+        }
+
+        func layoutHighlightView(in frameRect: CGRect) {
+            let highlightView = STLineHighlightView(frame: frameRect)
+            highlightView.layer?.backgroundColor = selectedLineHighlightColor.cgColor
+            selectionView.addSubview(highlightView)
+        }
+
+        if textLayoutManager.documentRange.isEmpty {
+            // - empty document has no layout fragments, nothing, it's empty and has to be handled explicitly.
+            // - there's no layout fragment at the document endLocation (technically it's out of bounds), has to be handled explicitly.
+            if let selectionFrame = textLayoutManager.textSegmentFrame(at: textLayoutManager.documentRange.location, type: .standard) {
+                layoutHighlightView(
+                    in: CGRect(
+                        origin: CGPoint(
+                            x: selectionView.bounds.minX,
+                            y: selectionFrame.origin.y
+                        ),
+                        size: CGSize(
+                            width: selectionView.bounds.width,
+                            height: typingLineHeight
+                        )
+                    )
+                )
+            }
+            return
+        }
+
+        guard let viewportRange = textLayoutManager.textViewportLayoutController.viewportRange else {
+            return
+        }
+
+        // build the rectangle out of fragments rectangles
+        var combinedFragmentsRect: CGRect?
+
+        // TODO some beutiful day:
+        // Don't rely on NSTextParagraph.paragraphContentRange, but that
+        // makes tricky to get all the conditions right (especially for last line)
+        // Problem is that NSTextParagraph.rangeInElement span across two lines (eg. "abc\n" are two lines) while
+        // paragraphContentRange is just one ("abc")
+        //
+        // Another idea here is to use `textLayoutManager.textLayoutFragment(for: selectionTextRange.location)`
+        // to find the layout fragment and us its frame as highlight area. It has its issue when it comes to the
+        // extra line fragment area (sic).
+        textLayoutManager.enumerateTextLayoutFragments(in: viewportRange) { layoutFragment in
+            let contentRangeInElement = (layoutFragment.textElement as? NSTextParagraph)?.paragraphContentRange ?? layoutFragment.rangeInElement
+            for lineFragment in layoutFragment.textLineFragments {
+
+                func isLineSelected() -> Bool {
+                    textLayoutManager.textSelections.flatMap(\.textRanges).reduce(true) { partialResult, selectionTextRange in
+                        var result = true
+                        if lineFragment.isExtraLineFragment {
+                            let c1 = layoutFragment.rangeInElement.endLocation == selectionTextRange.location
+                            result = result && c1
+                        } else {
+                            let c1 = contentRangeInElement.contains(selectionTextRange)
+                            let c2 = contentRangeInElement.intersects(selectionTextRange)
+                            let c3 = selectionTextRange.contains(contentRangeInElement)
+                            let c4 = selectionTextRange.intersects(contentRangeInElement)
+                            let c5 = contentRangeInElement.endLocation == selectionTextRange.location
+                            result = result && (c1 || c2 || c3 || c4 || c5)
+                        }
+                        return partialResult && result
+                    }
+                }
+
+                if isLineSelected() {
+                    var lineFragmentFrame = layoutFragment.layoutFragmentFrame
+                    lineFragmentFrame.size.height = lineFragment.typographicBounds.height
+
+
+                    let r = CGRect(
+                        origin: CGPoint(
+                            x: selectionView.bounds.minX,
+                            y: lineFragmentFrame.origin.y + lineFragment.typographicBounds.minY
+                        ),
+                        size: CGSize(
+                            width: selectionView.bounds.width,
+                            height: lineFragmentFrame.height
+                        )
+                    )
+
+                    if let rect = combinedFragmentsRect {
+                        combinedFragmentsRect = rect.union(r)
+                    } else {
+                        combinedFragmentsRect = r
+                    }
+                }
+            }
+            return true
+        }
+
+        if let combinedFragmentsRect {
+            layoutHighlightView(in: combinedFragmentsRect.pixelAligned)
+        }
+    }
+
+    // Update selection range highlight (on selectionView)
+    internal func updateSelectedRangeHighlight() {
         guard !textLayoutManager.textSelections.isEmpty,
             let viewportRange = textLayoutManager.textViewportLayoutController.viewportRange
         else {
             selectionView.subviews.removeAll()
+            // don't highlight when there's selection
             return
         }
 
@@ -1070,7 +1060,7 @@ import AVFoundation
                 }
 
                 if !selectionFrame.size.width.isZero {
-                    let selectionHighlightView = SelectionHighlightView(frame: selectionFrame)
+                    let selectionHighlightView = STSelectionHighlightView(frame: selectionFrame)
                     selectionView.addSubview(selectionHighlightView)
 
                     // Remove insertion point when selection
@@ -1106,16 +1096,6 @@ import AVFoundation
         }
     }
 
-    open override func setFrameOrigin(_ newOrigin: NSPoint) {
-        super.setFrameOrigin(newOrigin)
-        _configureTextContainerSize()
-    }
-
-    open override func setFrameSize(_ newSize: NSSize) {
-        super.setFrameSize(newSize)
-        _configureTextContainerSize()
-    }
-
     @objc internal func enclosingClipViewBoundsDidChange(_ notification: Notification) {
         layoutGutter()
     }