Added SwiftUITimer

Added SwiftUITimer a Swift UI specific timer that can execute a tick method after a given amount of time.

Sources/SwiftUIKit/Utilities/SwiftUITimer.swift

@@ -0,0 +1,57 @@
+//
+//  SwiftUITimer.swift
+//  Escape from Mystic Manor
+//
+//  Created by Kevin Mullins on 11/16/21.
+//
+
+import Foundation
+import SwiftUI
+import SwiftletUtilities
+
+/// A swift UI specific timer that can execute a tick method after a given amount of time.
+open class SwiftUITimer {
+    // MARK: - Events
+    /// Handle a give tick expiring.
+    public typealias tickHandler = () -> Void
+
+    // MARK: - Properties
+    /// The time that does the work in the background.
+    public var timer:Timer? = nil
+
+    /// The inverval between the ticks.
+    public var interval:Double = 1.0
+
+    /// Handle a give tick expiring.
+    public var onTick:tickHandler? = nil
+
+    // MARK: - Initializers
+    /// Creates a new instance.
+    /// - Parameters:
+    ///   - interval: The inverval between the ticks.
+    ///   - onTick: Handle a give tick expiring.
+    public init(interval:Double = 1.0, onTick:@escaping tickHandler) {
+        self.interval = interval
+        self.onTick = onTick
+    }
+
+    // MARK: - Functions
+    /// Starts the timer.
+    public func start() {
+        timer = Timer.scheduledTimer(withTimeInterval: interval, repeats: true) {timer in
+            if let onTick = self.onTick {
+                Execute.onMain {
+                    onTick()
+                }
+            }
+        }
+    }
+
+    /// Stops the timer.
+    public func stop() {
+        if let timer = timer {
+            timer.invalidate()
+            self.timer = nil
+        }
+    }
+}