Changing class in a UIView (Swift) - ios

Question

I would like to use a button to toggle the contents of a UIView.
I set up two classes, graphClass1 and graphClass2. (The button is in the topView.)
When I click the button, I get the "my button" message from debugPrint, but I don't get the debugPrint messages from within the classes. So, I added setNeedsDisplay but that did not help.
(This is a simplified version - there are actually a lot more classes - which is why I am trying to reuse the same view instead of just creating two separate views.)
how do I get the appropriate class to display in the view?
because graphClass1 creates additional subviews when I toggle back and forth, will the number of graphClass1's subviews just keep growing? If so, how do I remove them when leaving? (I know that self.layer.sublayers = nil or textView.removeAll() would leave them until returning - if they even remove them at all.)
in the button toggle, rather than use a Bool to test which graph, I'd prefer something more intuitive like if currentGraph == GraphClass1 but this gives me the error message: Binary operator '==' cannot be applied to operands of type 'UIView' and 'GraphClass1.Type'. How would do I fix this?
class ViewController: UIViewController {
#IBOutlet var topView: UIView!
#IBOutlet var bottomView: UIView!
#IBOutlet var myButton: UIButton!
var graph1: Bool = true
var currentView = UIView()
override func viewDidLoad() {
super.viewDidLoad()
bottomView = GraphClass1()
setConstraints()
}
#IBAction func myButton(_ sender: Any) {
debugPrint("my button")
if graph1 {
currentView.removeFromSuperview()
currentView = GraphClass2()
cv2.addSubview(currentView)
graph1 = false
}
else {
currentView.removeFromSuperview()
currentView = GraphClass1()
cv2.addSubview(currentView)
graph1 = true
}
cv2.setNeedsDisplay()
}
}
class GraphClass1: UIView {
var textView = UITextView()
override func draw(_ rect: CGRect) {
super.draw(rect)
self.layer.sublayers = nil
textView.removeAll()
createTextView()
debugPrint("inside GraphClass1")
}
func createTextView() {
textView = UITextView(frame: CGRect(x: 8, y: 8, width: 300, height: 100))
textView.text = "Test, this is only a test"
textView.textAlignment = .center
textView.font = UIFont(name: "Courier", size: 16)
textView.backgroundColor = .orange
self.addSubview(textView)
}
}
class GraphClass2: UIView {
override func draw(_ rect: CGRect) {
super.draw(rect)
debugPrint("inside GraphClass2")
}
}

Answer 1

Instead of changing the UIView() to a GraphClass(), you should add GraphClass() to bottomView() as a subview. To switch out GraphClass1(), you would remove it from bottomView() and set up GraphClass2() as the subview of bottomView(). Removing a view also removes all its subviews.

Answer 2

First, create a bottomView in interface builder, just like the top view. It will be like a place holder. You will have;
#IBOutlet var bottomView: UIView!
In viewDidLoad, you add the specific view as needed with
bottomView.addSubView(myInstanceOfAGraphView.view)
myInstanceOfAGraphView.didMove(toParent: bottomView)
I would create view controllers for each graph view and switch them as needed.
When you need to change, remove its view with;
myInstanceOfAGraphView.view.removeFromSuperview()