How to update uiview size when orientation is changed? - ios

Question

The view loads with a height of 324 pixels. Then view updates its height to 250 pixels when I turn the device landscape, but after I turn the device from landscape to portrait it doesn't reset the height of the view back to 324 pixels.
import UIKit
class KeyboardViewController: UIInputViewController {
var calcBoard = CalcControl()
var disNum:Double = 0.0
var expandedHeight:CGFloat = 250
override func updateViewConstraints() {
super.updateViewConstraints()
// Add custom view sizing constraints here
}
override func willRotateToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
//self.view.addConstraint(heightconstraints2)
var heightconstraints3:NSLayoutConstraint = NSLayoutConstraint(item: self.view, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 0.0, constant: self.expandedHeight)
//self.view.addConstraint(heightconstraints2)
if toInterfaceOrientation == UIInterfaceOrientation.LandscapeLeft{
self.expandedHeight = 250
self.view.addConstraint(heightconstraints3) }
if toInterfaceOrientation == UIInterfaceOrientation.LandscapeRight{
self.expandedHeight = 250
self.view.addConstraint(heightconstraints3)
}
if toInterfaceOrientation == UIInterfaceOrientation.Portrait{
println("In portrait")
println("Transforming")
self.expandedHeight = 324
self.view.addConstraint(heightconstraints3)
}
}
override func didRotateFromInterfaceOrientation(fromInterfaceOrientation: UIInterfaceOrientation) {
if fromInterfaceOrientation == UIInterfaceOrientation.Portrait{
println("Adjusting...")
self.expandedHeight = 324
}
}
override func viewDidLoad() {
super.viewDidLoad()
println("Loaded")
NSNotificationCenter.defaultCenter().addObserver(self, selector: "LoadNumber:", name: "load", object: nil)
self.deleteBackward()
// Perform custom UI setup here
//self.calcBoard.frame = CGRect(x: 123, y: 0, width: 320, height: 324)
var xibView1 = NSBundle.mainBundle().loadNibNamed("CalcView", owner: nil, options: nil)
self.calcBoard = xibView1[0] as CalcControl
self.view.frame = CGRect(x: 0, y: 0, width: 320, height: 324)
self.view.addSubview(calcBoard)
}
func LoadNumber(notification:NSNotification){
println("got it")
var num = (calcBoard.number as NSNumber).stringValue
println(num)
var proxy = textDocumentProxy as UITextDocumentProxy
proxy.insertText(num)
}
func recieveNumberfromSource()->Double{
return self.disNum
}
func deleteBackward(){
}
func hasText() -> Bool{
return true
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated
}
override func textWillChange(textInput: UITextInput) {
// The app is about to change the document's contents. Perform any preparation here.
}
override func textDidChange(textInput: UITextInput) {
// The app has just changed the document's contents, the document context has been updated.
var textColor: UIColor
var proxy = self.textDocumentProxy as UITextDocumentProxy
if proxy.keyboardAppearance == UIKeyboardAppearance.Dark {
textColor = UIColor.whiteColor()
} else {
textColor = UIColor.blackColor()
}
}
override func viewDidAppear(animated: Bool) {
//self.updateViewConstraints()
var expandedHeight:CGFloat = 324
var heightconstraint:NSLayoutConstraint = NSLayoutConstraint(item: self.view, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 0.0, constant: expandedHeight)
self.view.addConstraint(heightconstraint)
}
}

Answer 1

Keep a reference to the heightConstraint when you first add it and update the constant of it when the orientation changes.
override func willRotateToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
if UIInterfaceOrientationIsLandscape(toInterfaceOrientation) {
heightConstraint.constant = 100
} else {
heightConstraint.constant = 300
}
}
An assignment to self.expandedHeight will not change the constraint after its creation.