ig-zoom-4.swift

extension ViewController: UIGestureRecognizerDelegate {
  
    // that method make it works
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }
    
    @objc func handleZoom(_ gesture: UIPinchGestureRecognizer) {
        switch gesture.state {
        case .began, .changed:
            
            // Only zoom in, not out
            if gesture.scale >= 1 {
              
                // Get the scale from the gesture passed in the function
                let scale = gesture.scale
              
                // use CGAffineTransform to transform the imageView
                gesture.view!.transform = CGAffineTransform(scaleX: scale, y: scale)
            }
          

            // Show the overlay
            UIView.animate(withDuration: 0.2) {
                self.overlay.alpha = 0.8
            }
            break;
        default:
            // If the gesture has cancelled/terminated/failed or everything else that's not performing
            // Smoothly restore the transform to the "original"
            UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseInOut, animations: {
              gesture.view!.transform = .identity
            }) { _ in
              // Hide the overlay
              UIView.animate(withDuration: 0.2) {
                self.overlay.alpha = 0
              }
            }
        }
    }
    
    @objc func handlePan(_ gesture: UIPanGestureRecognizer) {
        switch gesture.state {
        case .began, .changed:
            // Get the touch position
            let translation = gesture.translation(in: imageView)
            
            // Edit the center of the target by adding the gesture position
            gesture.view!.center = CGPoint(x: imageView.center.x + translation.x, y: imageView.center.y + translation.y)
            gesture.setTranslation(.zero, in: imageView)

            // Show the overlay
            UIView.animate(withDuration: 0.2) {
                self.overlay.alpha = 0.8
            }
            break;
        default:
            // If the gesture has cancelled/terminated/failed or everything else that's not performing
            // Smoothly restore the transform to the "original"
            UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseInOut, animations: {
                gesture.view!.center = self.view.center
                gesture.setTranslation(.zero, in: self.background)
            }) { _ in
              // Hide the overaly
              UIView.animate(withDuration: 0.2) {
                self.overlay.alpha = 0
              }
            }
            break
        }
    }
}