fix(#13): Separate Cursor Updates, Fix Focus Issues (#14)

* Separate Cursor Updates, Fix Focus Issues

* Linter

* Update TextSelectionManagerTests.swift

Author: thecoolwinter

Sources/CodeEditTextView/Cursors/CursorTimer.swift

@@ -0,0 +1,77 @@
+//
+//  CursorTimer.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 1/16/24.
+//
+
+import Foundation
+import AppKit
+
+class CursorTimer {
+    /// # Properties
+
+    /// The timer that publishes the cursor toggle timer.
+    private var timer: Timer?
+    /// Maps to all cursor views, uses weak memory to not cause a strong reference cycle.
+    private var cursors: NSHashTable<CursorView> = .init(options: .weakMemory)
+    /// Tracks whether cursors are hidden or not.
+    var shouldHide: Bool = false
+
+    // MARK: - Methods
+
+    /// Resets the cursor blink timer.
+    /// - Parameter newBlinkDuration: The duration to blink, leave as nil to never blink.
+    func resetTimer(newBlinkDuration: TimeInterval? = 0.5) {
+        timer?.invalidate()
+
+        guard let newBlinkDuration else {
+            notifyCursors(shouldHide: true)
+            return
+        }
+
+        shouldHide = false
+        notifyCursors(shouldHide: shouldHide)
+
+        timer = Timer.scheduledTimer(withTimeInterval: newBlinkDuration, repeats: true) { [weak self] _ in
+            self?.assertMain()
+            self?.shouldHide.toggle()
+            guard let shouldHide = self?.shouldHide else { return }
+            self?.notifyCursors(shouldHide: shouldHide)
+        }
+    }
+
+    func stopTimer() {
+        shouldHide = true
+        notifyCursors(shouldHide: true)
+        cursors.removeAllObjects()
+        timer?.invalidate()
+        timer = nil
+    }
+
+    /// Notify all cursors of a new blink state.
+    /// - Parameter shouldHide: Whether or not the cursors should be hidden or not.
+    private func notifyCursors(shouldHide: Bool) {
+        for cursor in cursors.allObjects {
+            cursor.blinkTimer(shouldHide)
+        }
+    }
+
+    /// Register a new cursor view with the timer.
+    /// - Parameter newCursor: The cursor to blink.
+    func register(_ newCursor: CursorView) {
+        cursors.add(newCursor)
+    }
+
+    deinit {
+        timer?.invalidate()
+        timer = nil
+        cursors.removeAllObjects()
+    }
+
+    private func assertMain() {
+#if DEBUG
+        assert(Thread.isMainThread, "CursorTimer used from non-main thread")
+#endif
+    }
+}

Sources/CodeEditTextView/Cursors/CursorView.swift

@@ -0,0 +1,54 @@
+//
+//  CursorView.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 8/15/23.
+//
+
+import AppKit
+
+/// Animates a cursor. Will sync animation with any other cursor views.
+open class CursorView: NSView {
+    /// The color of the cursor.
+    public var color: NSColor {
+        didSet {
+            layer?.backgroundColor = color.cgColor
+        }
+    }
+
+    /// The width of the cursor.
+    private let width: CGFloat
+    /// The timer observer.
+    private var observer: NSObjectProtocol?
+
+    open override var isFlipped: Bool {
+        true
+    }
+
+    /// Create a cursor view.
+    /// - Parameters:
+    ///   - blinkDuration: The duration to blink, leave as nil to never blink.
+    ///   - color: The color of the cursor.
+    ///   - width: How wide the cursor should be.
+    init(
+        color: NSColor = NSColor.labelColor,
+        width: CGFloat = 1.0
+    ) {
+        self.color = color
+        self.width = width
+
+        super.init(frame: .zero)
+
+        frame.size.width = width
+        wantsLayer = true
+        layer?.backgroundColor = color.cgColor
+    }
+
+    func blinkTimer(_ shouldHideCursor: Bool) {
+        self.isHidden = shouldHideCursor
+    }
+
+    public required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+}

Sources/CodeEditTextView/TextSelectionManager/CursorView.swift

@@ -384,10 +384,10 @@ public extension TextSelectionManager {
     ///   - delta: The direction the selection should be extended. `1` for forwards, `-1` for backwards.
     /// - Returns: The range of the extended selection.
     private func extendSelectionContainer(from offset: Int, delta: Int) -> NSRange {
-        guard let layoutView, let endOffset = layoutManager?.textOffsetAtPoint(
+        guard let textView, let endOffset = layoutManager?.textOffsetAtPoint(
             CGPoint(
-                x: delta > 0 ? layoutView.frame.maxX : layoutView.frame.minX,
-                y: delta > 0 ? layoutView.frame.maxY : layoutView.frame.minY
+                x: delta > 0 ? textView.frame.maxX : textView.frame.minX,
+                y: delta > 0 ? textView.frame.maxY : textView.frame.minY
             )
         ) else {
             return NSRange(location: offset, length: 0)

Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager+SelectionManipulation.swift

@@ -81,19 +81,21 @@ public class TextSelectionManager: NSObject {
     internal(set) public var textSelections: [TextSelection] = []
     weak var layoutManager: TextLayoutManager?
     weak var textStorage: NSTextStorage?
-    weak var layoutView: NSView?
+    weak var textView: TextView?
     weak var delegate: TextSelectionManagerDelegate?
+    var cursorTimer: CursorTimer
 
     init(
         layoutManager: TextLayoutManager,
         textStorage: NSTextStorage,
-        layoutView: NSView?,
+        textView: TextView?,
         delegate: TextSelectionManagerDelegate?
     ) {
         self.layoutManager = layoutManager
         self.textStorage = textStorage
-        self.layoutView = layoutView
+        self.textView = textView
         self.delegate = delegate
+        self.cursorTimer = CursorTimer()
         super.init()
         textSelections = []
         updateSelectionViews()
@@ -106,8 +108,10 @@ public class TextSelectionManager: NSObject {
         let selection = TextSelection(range: range)
         selection.suggestedXPos = layoutManager?.rectForOffset(range.location)?.minX
         textSelections = [selection]
-        updateSelectionViews()
-        NotificationCenter.default.post(Notification(name: Self.selectionChangedNotification, object: self))
+        if textView?.isFirstResponder ?? false {
+            updateSelectionViews()
+            NotificationCenter.default.post(Notification(name: Self.selectionChangedNotification, object: self))
+        }
     }
 
     public func setSelectedRanges(_ ranges: [NSRange]) {
@@ -123,8 +127,10 @@ public class TextSelectionManager: NSObject {
                 selection.suggestedXPos = layoutManager?.rectForOffset($0.location)?.minX
                 return selection
             }
-        updateSelectionViews()
-        NotificationCenter.default.post(Notification(name: Self.selectionChangedNotification, object: self))
+        if textView?.isFirstResponder ?? false {
+            updateSelectionViews()
+            NotificationCenter.default.post(Notification(name: Self.selectionChangedNotification, object: self))
+        }
     }
 
     public func addSelectedRange(_ range: NSRange) {
@@ -146,12 +152,16 @@ public class TextSelectionManager: NSObject {
             textSelections.append(newTextSelection)
         }
 
-        updateSelectionViews()
-        NotificationCenter.default.post(Notification(name: Self.selectionChangedNotification, object: self))
+        if textView?.isFirstResponder ?? false {
+            updateSelectionViews()
+            NotificationCenter.default.post(Notification(name: Self.selectionChangedNotification, object: self))
+        }
     }
 
     // MARK: - Selection Views
 
+    /// Update all selection cursors. Placing them in the correct position for each text selection and reseting the
+    /// blink timer.
     func updateSelectionViews() {
         var didUpdate: Bool = false
 
@@ -163,12 +173,16 @@ public class TextSelectionManager: NSObject {
                     || textSelection.boundingRect.height != layoutManager?.estimateLineHeight() ?? 0 {
                     textSelection.view?.removeFromSuperview()
                     textSelection.view = nil
+
                     let cursorView = CursorView(color: insertionPointColor)
                     cursorView.frame.origin = cursorOrigin
                     cursorView.frame.size.height = layoutManager?.estimateLineHeight() ?? 0
-                    layoutView?.addSubview(cursorView)
+                    textView?.addSubview(cursorView)
                     textSelection.view = cursorView
                     textSelection.boundingRect = cursorView.frame
+
+                    cursorTimer.register(cursorView)
+
                     didUpdate = true
                 }
             } else if !textSelection.range.isEmpty && textSelection.view != nil {
@@ -180,10 +194,13 @@ public class TextSelectionManager: NSObject {
 
         if didUpdate {
             delegate?.setNeedsDisplay()
+            cursorTimer.resetTimer()
         }
     }
 
+    /// Removes all cursor views and stops the cursor blink timer.
     func removeCursors() {
+        cursorTimer.stopTimer()
         for textSelection in textSelections {
             textSelection.view?.removeFromSuperview()
         }

Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift

@@ -8,10 +8,13 @@
 import AppKit
 
 extension TextView {
-    open override class var defaultMenu: NSMenu? {
+    override public func menu(for event: NSEvent) -> NSMenu? {
+        guard event.type == .rightMouseDown else { return nil }
+
         let menu = NSMenu()
 
         menu.items = [
+            NSMenuItem(title: "Cut", action: #selector(cut(_:)), keyEquivalent: "x"),
             NSMenuItem(title: "Copy", action: #selector(undo(_:)), keyEquivalent: "c"),
             NSMenuItem(title: "Paste", action: #selector(undo(_:)), keyEquivalent: "v")
         ]

Sources/CodeEditTextView/TextView/TextView+Menu.swift

@@ -22,7 +22,7 @@ extension TextView {
         TextSelectionManager(
             layoutManager: layoutManager,
             textStorage: textStorage,
-            layoutView: self,
+            textView: self,
             delegate: self
         )
     }