How to apply multiple masks to UIView

Question

I have a question about how to apply multiple masks to a UIView that already has a mask.

The situation:
I have a view with an active mask that creates a hole in its top left corner, this is a template UIView that is reused everywhere in the project. Later in the project I would like to be able to create a second hole but this time in the bottom right corner, this without the need to create a completely new UIView.

The problem:
When I apply the bottom mask, it of course replaces the first one thus removing the top hole ... Is there a way to combine them both? And for that matter to combine any existing mask with a new one?

Thank you in advance!

Answer 1

Based on @Sharad's answer, I realised that re-adding the view's rect would enable me to combine the original and new mask into one.

Here is my solution:

func cutCircle(inView view: UIView, withRect rect: CGRect) {

    // Create new path and mask
    let newMask = CAShapeLayer()
    let newPath = UIBezierPath(ovalIn: rect)

    // Create path to clip
    let newClipPath = UIBezierPath(rect: view.bounds)
    newClipPath.append(newPath)

    // If view already has a mask
    if let originalMask = view.layer.mask,
        let originalShape = originalMask as? CAShapeLayer,
        let originalPath = originalShape.path {

        // Create bezierpath from original mask's path
        let originalBezierPath = UIBezierPath(cgPath: originalPath)

        // Append view's bounds to "reset" the mask path before we re-apply the original
        newClipPath.append(UIBezierPath(rect: view.bounds))

        // Combine new and original paths
        newClipPath.append(originalBezierPath)

    }

    // Apply new mask
    newMask.path = newClipPath.cgPath
    newMask.fillRule = kCAFillRuleEvenOdd
    view.layer.mask = newMask
}