mayoff · February 27, 2024 11:21 · Mar 6, 2017 · Jan 17, 2016
diff --git a/FloatiengViewController.swift → FloatingViewController.swift b/FloatiengViewController.swift → FloatingViewController.swift
diff --git a/FloatiengViewController.swift b/FloatiengViewController.swift
@@ -0,0 +1,118 @@
+import UIKit
+
+class FloatingButtonController: UIViewController {
+
+    private(set) var button: UIButton!
+
+    required init?(coder aDecoder: NSCoder) {
+        fatalError()
+    }
+
+    init() {
+        super.init(nibName: nil, bundle: nil)
+        window.windowLevel = CGFloat.max
+        window.hidden = false
+        window.rootViewController = self
+
+        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardDidShow:", name: UIKeyboardDidShowNotification, object: nil)
+    }
+
+    private let window = FloatingButtonWindow()
+
+    override func loadView() {
+        let view = UIView()
+        let button = UIButton(type: .Custom)
+        button.setTitle("Floating", forState: .Normal)
+        button.setTitleColor(UIColor.greenColor(), forState: .Normal)
+        button.backgroundColor = UIColor.whiteColor()
+        button.layer.shadowColor = UIColor.blackColor().CGColor
+        button.layer.shadowRadius = 3
+        button.layer.shadowOpacity = 0.8
+        button.layer.shadowOffset = CGSize.zero
+        button.sizeToFit()
+        button.frame = CGRect(origin: CGPointMake(10, 10), size: button.bounds.size)
+        button.autoresizingMask = []
+        view.addSubview(button)
+        self.view = view
+        self.button = button
+        window.button = button
+
+        let panner = UIPanGestureRecognizer(target: self, action: "panDidFire:")
+        button.addGestureRecognizer(panner)
+    }
+
+    override func viewDidLayoutSubviews() {
+        super.viewDidLayoutSubviews()
+        snapButtonToSocket()
+    }
+
+    func panDidFire(panner: UIPanGestureRecognizer) {
+        let offset = panner.translationInView(view)
+        panner.setTranslation(CGPoint.zero, inView: view)
+        var center = button.center
+        center.x += offset.x
+        center.y += offset.y
+        button.center = center
+
+        if panner.state == .Ended || panner.state == .Cancelled {
+            UIView.animateWithDuration(0.3) {
+                self.snapButtonToSocket()
+            }
+        }
+    }
+
+    func keyboardDidShow(note: NSNotification) {
+        window.windowLevel = 0
+        window.windowLevel = CGFloat.max
+    }
+
+    private func snapButtonToSocket() {
+        var bestSocket = CGPoint.zero
+        var distanceToBestSocket = CGFloat.infinity
+        let center = button.center
+        for socket in sockets {
+            let distance = hypot(center.x - socket.x, center.y - socket.y)
+            if distance < distanceToBestSocket {
+                distanceToBestSocket = distance
+                bestSocket = socket
+            }
+        }
+        button.center = bestSocket
+    }
+
+    private var sockets: [CGPoint] {
+        let buttonSize = button.bounds.size
+        let rect = view.bounds.insetBy(dx: 4 + buttonSize.width / 2, dy: 4 + buttonSize.height / 2)
+        let sockets: [CGPoint] = [
+            CGPointMake(rect.minX, rect.minY),
+            CGPointMake(rect.minX, rect.maxY),
+            CGPointMake(rect.maxX, rect.minY),
+            CGPointMake(rect.maxX, rect.maxY),
+            CGPointMake(rect.midX, rect.midY)
+        ]
+        return sockets
+    }
+
+}
+
+private class FloatingButtonWindow: UIWindow {
+
+    var button: UIButton?
+
+    init() {
+        super.init(frame: UIScreen.mainScreen().bounds)
+        backgroundColor = nil
+    }
+
+    required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+
+    private override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
+        guard let button = button else { return false }
+        let buttonPoint = convertPoint(point, toView: button)
+        return button.pointInside(buttonPoint, withEvent: event)
+    }
+
+}