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Fix Cursor Lagging - Update Cursors in TextView.layout #109

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Merged
thecoolwinter merged 1 commit into from
Jun 19, 2025
Merged

Fix Cursor Lagging - Update Cursors in TextView.layout #109

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108 changes: 58 additions & 50 deletions Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -136,72 +136,80 @@ public class TextSelectionManager: NSObject {

// MARK: - Selection Views

/// Update all selection cursors. Placing them in the correct position for each text selection and reseting the
/// blink timer.
func updateSelectionViews(force: Bool = false) {
/// Update all selection cursors. Placing them in the correct position for each text selection and
/// optionally reseting the blink timer.
func updateSelectionViews(force: Bool = false, skipTimerReset: Bool = false) {
guard textView?.isFirstResponder ?? false else { return }
var didUpdate: Bool = false

for textSelection in textSelections {
if textSelection.range.isEmpty {
guard let cursorRect = layoutManager?.rectForOffset(textSelection.range.location) else {
continue
}

var doesViewNeedReposition: Bool

// If using the system cursor, macOS will change the origin and height by about 0.5, so we do an
// approximate equals in that case to avoid extra updates.
if useSystemCursor, #available(macOS 14.0, *) {
doesViewNeedReposition = !textSelection.boundingRect.origin.approxEqual(cursorRect.origin)
|| !textSelection.boundingRect.height.approxEqual(layoutManager?.estimateLineHeight() ?? 0)
} else {
doesViewNeedReposition = textSelection.boundingRect.origin != cursorRect.origin
|| textSelection.boundingRect.height != layoutManager?.estimateLineHeight() ?? 0
}

if textSelection.view == nil || doesViewNeedReposition {
let cursorView: NSView
didUpdate = didUpdate || repositionCursorSelection(textSelection: textSelection)
} else if !textSelection.range.isEmpty && textSelection.view != nil {
textSelection.view?.removeFromSuperview()
textSelection.view = nil
didUpdate = true
}
}

if let existingCursorView = textSelection.view {
cursorView = existingCursorView
} else {
textSelection.view?.removeFromSuperview()
textSelection.view = nil
if didUpdate || force {
delegate?.setNeedsDisplay()
if !skipTimerReset {
cursorTimer.resetTimer()
resetSystemCursorTimers()
}
}
}

if useSystemCursor, #available(macOS 14.0, *) {
let systemCursorView = NSTextInsertionIndicator(frame: .zero)
cursorView = systemCursorView
systemCursorView.displayMode = .automatic
} else {
let internalCursorView = CursorView(color: insertionPointColor)
cursorView = internalCursorView
cursorTimer.register(internalCursorView)
}
private func repositionCursorSelection(textSelection: TextSelection) -> Bool {
guard let cursorRect = layoutManager?.rectForOffset(textSelection.range.location) else {
return false
}

textView?.addSubview(cursorView, positioned: .above, relativeTo: nil)
}
var doesViewNeedReposition: Bool

cursorView.frame.origin = cursorRect.origin
cursorView.frame.size.height = cursorRect.height
// If using the system cursor, macOS will change the origin and height by about 0.5, so we do an
// approximate equals in that case to avoid extra updates.
if useSystemCursor, #available(macOS 14.0, *) {
doesViewNeedReposition = !textSelection.boundingRect.origin.approxEqual(cursorRect.origin)
|| !textSelection.boundingRect.height.approxEqual(layoutManager?.estimateLineHeight() ?? 0)
} else {
doesViewNeedReposition = textSelection.boundingRect.origin != cursorRect.origin
|| textSelection.boundingRect.height != layoutManager?.estimateLineHeight() ?? 0
}

textSelection.view = cursorView
textSelection.boundingRect = cursorView.frame
if textSelection.view == nil || doesViewNeedReposition {
let cursorView: NSView

didUpdate = true
}
} else if !textSelection.range.isEmpty && textSelection.view != nil {
if let existingCursorView = textSelection.view {
cursorView = existingCursorView
} else {
textSelection.view?.removeFromSuperview()
textSelection.view = nil
didUpdate = true

if useSystemCursor, #available(macOS 14.0, *) {
let systemCursorView = NSTextInsertionIndicator(frame: .zero)
cursorView = systemCursorView
systemCursorView.displayMode = .automatic
} else {
let internalCursorView = CursorView(color: insertionPointColor)
cursorView = internalCursorView
cursorTimer.register(internalCursorView)
}

textView?.addSubview(cursorView, positioned: .above, relativeTo: nil)
}
}

if didUpdate || force {
delegate?.setNeedsDisplay()
cursorTimer.resetTimer()
resetSystemCursorTimers()
cursorView.frame.origin = cursorRect.origin
cursorView.frame.size.height = cursorRect.height

textSelection.view = cursorView
textSelection.boundingRect = cursorView.frame

return true
}

return false
}

private func resetSystemCursorTimers() {
Expand Down
1 change: 1 addition & 0 deletions Sources/CodeEditTextView/TextView/TextView+Layout.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@ extension TextView {
override public func layout() {
super.layout()
layoutManager.layoutLines()
selectionManager.updateSelectionViews(skipTimerReset: true)
}

open override class var isCompatibleWithResponsiveScrolling: Bool {
Expand Down