can drag the cat

touchbar_nyancat/NyanCatCanvas.swift

@@ -10,16 +10,39 @@ import Cocoa
 
 class NyanCatCanvas: NSImageView {
 
+    var xPosition: CGFloat = 0 {
+        didSet {
+            self.frame = CGRect(x: xPosition, y: 0, width: 685, height: 30)
+        }
+    }
+    
     override func draw(_ dirtyRect: NSRect) {
         super.draw(dirtyRect)
 
         // Drawing code here.
       
-        self.frame = CGRect(x: 0, y: 0, width: 685, height: 30)
-      
         self.animates = true
         self.image = NSImage(named: "nyan_long@2x.gif")!
         self.canDrawSubviewsIntoLayer = true
+        self.frame = CGRect(x: xPosition, y: 0, width: 685, height: 30)
+    }
+    
+    override func touchesBegan(with event: NSEvent) {
+        // Calling super causes the cat to jump back to its original position 🤔
+        //super.touchesBegan(with: event)
+    }
+    
+    override func touchesMoved(with event: NSEvent) {
+        if #available(OSX 10.12.1, *) {
+            let current = event.allTouches().first?.location(in: self).x ?? 0
+            let previous = event.allTouches().first?.previousLocation(in: self).x ?? 0
+        
+            let dX = (current - previous)
+            
+            xPosition += dX
+        } else {
+            // Fallback on earlier versions
+        }
     }
     
 }