CODEWITHSUNDEEP
iosswift
Volodymyr
Volodymyr

Reputation: 1442

Swift: Autolayout constraints issue. Portrait vs Landscape

I have stuck with an issue of Autolayout constraints based on screen orientation. For implementing constraints I use Autolayout anchors, override of traitCollectionDidChange method and create two function where I setup constraints. Something like that:

    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
    super.traitCollectionDidChange(previousTraitCollection)

    switch (traitCollection.horizontalSizeClass, traitCollection.verticalSizeClass) {

    case (.compact, .compact):
        print("compact-compact")
        setupLandscapeLayout()

    case (.compact, .regular):
        print("compact-regular")
        setupPortraitLayout()

    default: break
    }
}

private func setupPortraitLayout() {                
        myButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20).isActive = true
        myButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true

}

private func setupLandscapeLayout() {       
    myButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 20).isActive = true
    myButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = false

}

So the problem here is constraints which work only one time during change of orientation. Every next try it doesn't work. I also tried to use view.layoutIfNeeded() and it didn't help. And even tried to set isActive=false and create a new constraint - also unsuccessfully(

So is it possible to set constraints in the way I do or there is another better way how to update constraints for screen orientation programmatically?

Upvotes: 0

Views: 224

Answers (1)

Shehata Gamal
Shehata Gamal

Reputation: 100503

Currently you're duplicating constraints and this makes conflicts so Put these 2 constraints in viewDidLoad (set bot to 20 or -20 according to current orientation )

botCon =  myButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20)
botCon.isActive = true
myButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true

//

private func setupPortraitLayout() {                
    self.botCon.constant = -20
    self.view.layoutIfNeeded()
}
private func setupLandscapeLayout() {  
    self.botCon.constant = 20
    self.view.layoutIfNeeded()
}

Upvotes: 1

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