Add One Case To Layout Invalidation, Selection Drawing Uses LayoutManager

Author: thecoolwinter

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManager+Layout.swift

@@ -55,10 +55,13 @@ extension TextLayoutManager {
 
         // Layout all lines, fetching lines lazily as they are laid out.
         for linePosition in lineStorage.linesStartingAt(minY, until: maxY).lazy {
-            guard linePosition.yPos < maxY else { break }
-            if forceLayout
-                || linePosition.data.needsLayout(maxWidth: maxLineLayoutWidth)
-                || !visibleLineIds.contains(linePosition.data.id) {
+            guard linePosition.yPos < maxY else { continue }
+            // Three ways to determine if a line needs to be re-calculated.
+            let changedWidth = linePosition.data.needsLayout(maxWidth: maxLineLayoutWidth)
+            let wasNotVisible = !visibleLineIds.contains(linePosition.data.id)
+            let lineNotEntirelyLaidOut = linePosition.height != linePosition.data.lineFragments.height
+
+            if forceLayout || changedWidth || wasNotVisible || lineNotEntirelyLaidOut {
                 let lineSize = layoutLine(
                     linePosition,
                     textStorage: textStorage,

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManager+Public.swift

@@ -137,15 +137,13 @@ extension TextLayoutManager {
         : (textStorage?.string as? NSString)?.rangeOfComposedCharacterSequence(at: offset)
         ?? NSRange(location: offset, length: 0)
 
-        let minXPos = CTLineGetOffsetForStringIndex(
-            fragmentPosition.data.ctLine,
-            realRange.location - linePosition.range.location, // CTLines have the same relative range as the line
-            nil
+        let minXPos = characterXPosition(
+            in: fragmentPosition.data,
+            for: realRange.location - linePosition.range.location
         )
-        let maxXPos = CTLineGetOffsetForStringIndex(
-            fragmentPosition.data.ctLine,
-            realRange.max - linePosition.range.location,
-            nil
+        let maxXPos = characterXPosition(
+            in: fragmentPosition.data,
+            for: realRange.max - linePosition.range.location
         )
 
         return CGRect(
@@ -187,7 +185,7 @@ extension TextLayoutManager {
         var rects: [CGRect] = []
         for fragmentPosition in line.data.lineFragments.linesInRange(relativeRange) {
             guard let intersectingRange = fragmentPosition.range.intersection(relativeRange) else { continue }
-            let fragmentRect = fragmentPosition.data.rectFor(range: intersectingRange)
+            let fragmentRect = characterRect(in: fragmentPosition.data, for: intersectingRange)
             guard fragmentRect.width > 0 else { continue }
             rects.append(
                 CGRect(
@@ -270,6 +268,28 @@ extension TextLayoutManager {
         return nil
     }
 
+    // MARK: - Line Fragment Rects
+
+    /// Finds the x position of the offset in the string the fragment represents.
+    /// - Parameters:
+    ///   - lineFragment: The line fragment to calculate for.
+    ///   - offset: The offset, relative to the start of the *line*.
+    /// - Returns: The x position of the character in the drawn line, from the left.
+    public func characterXPosition(in lineFragment: LineFragment, for offset: Int) -> CGFloat {
+        renderDelegate?.characterXPosition(in: lineFragment, for: offset) ?? lineFragment._xPos(for: offset)
+    }
+
+    public func characterRect(in lineFragment: LineFragment, for range: NSRange) -> CGRect {
+        let minXPos = characterXPosition(in: lineFragment, for: range.lowerBound)
+        let maxXPos = characterXPosition(in: lineFragment, for: range.upperBound)
+        return CGRect(
+            x: minXPos,
+            y: 0,
+            width: maxXPos - minXPos,
+            height: lineFragment.scaledHeight
+        ).pixelAligned
+    }
+
     // MARK: - Ensure Layout
 
     /// Forces layout calculation for all lines up to and including the given offset.

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManagerRenderDelegate.swift

@@ -24,6 +24,8 @@ public protocol TextLayoutManagerRenderDelegate: AnyObject {
     func estimatedLineHeight() -> CGFloat?
 
     func lineFragmentView(for lineFragment: LineFragment) -> LineFragmentView
+
+    func characterXPosition(in lineFragment: LineFragment, for offset: Int) -> CGFloat
 }
 
 public extension TextLayoutManagerRenderDelegate {
@@ -51,4 +53,8 @@ public extension TextLayoutManagerRenderDelegate {
     func lineFragmentView(for lineFragment: LineFragment) -> LineFragmentView {
         LineFragmentView()
     }
+
+    func characterXPosition(in lineFragment: LineFragment, for offset: Int) -> CGFloat {
+        lineFragment._xPos(for: offset)
+    }
 }

Sources/CodeEditTextView/TextLine/LineFragment.swift

@@ -47,7 +47,17 @@ public final class LineFragment: Identifiable, Equatable {
     /// Finds the x position of the offset in the string the fragment represents.
     /// - Parameter offset: The offset, relative to the start of the *line*.
     /// - Returns: The x position of the character in the drawn line, from the left.
-    public func xPos(for offset: Int) -> CGFloat {
+    @available(*, deprecated, renamed: "layoutManager.characterXPosition(in:)", message: "Moved to layout manager")
+    public func xPos(for offset: Int) -> CGFloat { _xPos(for: offset) }
+
+    /// Finds the x position of the offset in the string the fragment represents.
+    ///
+    /// Underscored, because although this needs to be accessible outside this class, the relevant layout manager method
+    /// should be used.
+    ///
+    /// - Parameter offset: The offset, relative to the start of the *line*.
+    /// - Returns: The x position of the character in the drawn line, from the left.
+    func _xPos(for offset: Int) -> CGFloat {
         return CTLineGetOffsetForStringIndex(ctLine, offset, nil)
     }
 
@@ -84,6 +94,7 @@ public final class LineFragment: Identifiable, Equatable {
     /// Calculates the drawing rect for a given range.
     /// - Parameter range: The range to calculate the bounds for, relative to the line.
     /// - Returns: A rect that contains the text contents in the given range.
+    @available(*, deprecated, renamed: "layoutManager.characterRect(in:)", message: "Moved to layout manager")
     public func rectFor(range: NSRange) -> CGRect {
         let minXPos = CTLineGetOffsetForStringIndex(ctLine, range.lowerBound, nil)
         let maxXPos = CTLineGetOffsetForStringIndex(ctLine, range.upperBound, nil)

Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager+Draw.swift

@@ -10,7 +10,7 @@ import AppKit
 extension TextSelectionManager {
     /// Draws line backgrounds and selection rects for each selection in the given rect.
     /// - Parameter rect: The rect to draw in.
-    func drawSelections(in rect: NSRect) {
+    public func drawSelections(in rect: NSRect) {
         guard let context = NSGraphicsContext.current?.cgContext else { return }
         context.saveGState()
         var highlightedLines: Set<UUID> = []

Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager+FillRects.swift

@@ -18,7 +18,7 @@ extension TextSelectionManager {
     /// - Returns: An array of rects that the selection overlaps.
     func getFillRects(in rect: NSRect, for textSelection: TextSelection) -> [CGRect] {
         guard let layoutManager,
-                let range = textSelection.range.intersection(textView?.visibleTextRange ?? .zero) else {
+              let range = textSelection.range.intersection(delegate?.visibleTextRange ?? .zero) else {
             return []
         }
 

Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift

@@ -52,7 +52,7 @@ public class TextSelectionManager: NSObject {
     weak var delegate: TextSelectionManagerDelegate?
     var cursorTimer: CursorTimer
 
-    init(
+    public init(
         layoutManager: TextLayoutManager,
         textStorage: NSTextStorage,
         textView: TextView?,

Sources/CodeEditTextView/TextView/DraggingTextRenderer.swift

@@ -81,7 +81,7 @@ class DraggingTextRenderer: NSView {
             // Clear text that's not selected
             if fragmentRange.contains(selectedRange.lowerBound) {
                 let relativeOffset = selectedRange.lowerBound - line.range.lowerBound
-                let selectionXPos = fragment.data.xPos(for: relativeOffset)
+                let selectionXPos = layoutManager.characterXPosition(in: fragment.data, for: relativeOffset)
                 context.clear(
                     CGRect(
                         x: 0.0,
@@ -94,7 +94,7 @@ class DraggingTextRenderer: NSView {
 
             if fragmentRange.contains(selectedRange.upperBound) {
                 let relativeOffset = selectedRange.upperBound - line.range.lowerBound
-                let selectionXPos = fragment.data.xPos(for: relativeOffset)
+                let selectionXPos = layoutManager.characterXPosition(in: fragment.data, for: relativeOffset)
                 context.clear(
                     CGRect(
                         x: selectionXPos,