CODEWITHSUNDEEP
iosuibuttonuicontrolstate
MH175
MH175

Reputation: 2334

UIButton: manually calling touchesBegan does not set isHighlighted

The isHighlighted property on UIButtonis mostly analogous to whether the button is pressed or not.

The Apple docs are vague about it:

Controls automatically set and clear this state in response to appropriate touch events. https://developer.apple.com/documentation/uikit/uicontrol/1618231-ishighlighted

Which method is the system calling to set this?

It appears to be touchesBegan, because you can override this method to prevent it.

But, surprisingly, if you manually call touchesBegan it doesn't get set (for example, from a superview-- see code below).

So it seems it's not simple as touchesBegan. I've tried overriding every method I could...pressesBegan, pressesChanged, pressesCancelled, pressesEnded, touchesCancelled, beginTracking, continueTracking, hitTest, etc.

Only touchesBegan had any effect.

Here's how I tried calling touchesBegan from a superview:

class MyView: UIView {

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        return self
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let point = touches.first?.location(in: self) else { return }
        for view in self.subviews {
            if let button = view as? UIButton {
                if button.frame.contains(point) {
                    button.touchesBegan(touches, with: event)
                    print("\(button.isHighlighted)") //prints false
                }
            }
        }
    }
}

Upvotes: 2

Views: 342

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