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I'm creating new UIViewController dynamycally using this code
#IBAction func newVCBtnPressed(_ sender: Any) {
let controller = DynamicVC()
show(controller, sender: sender)
}
In the new UIViewController I'm using this code for creation of the new UIView:
override func loadView() {
view = UIView()
view.backgroundColor = .lightGray
}
In result I have view with .lightGray backgroundcolor.
I want to add custom UIView and setup the constraints programmatically, and in result i want UIView with following constraints:
top: 0
bottom:(view.frame.height*0.9)
leading:0
trailing:(view.frame.width*0.15)
width:(view.frame.width*0.85)
height:(view.frame.height*0.1)
Example:
Here is my code:
topMenuView = UIView()
topMenuView.backgroundColor = .red
view.addSubview(topMenuView)
topMenuView.translatesAutoresizingMaskIntoConstraints = false
setupConstraints(item: topMenuView, topC: 0, topToItem: view, bottomC: (view.frame.height*0.9), bottomToItem: view, widthC: (view.frame.width*0.85), heightC: (view.frame.height*0.1), leadingCon: 0, trailingCon: (view.frame.width*0.15))
I'm using this constructed function for constraints:
func setupConstraints(item:UIView, topC:CGFloat, topToItem:UIView, bottomC:CGFloat, bottomToItem:UIView, widthC:CGFloat, heightC:CGFloat, leadingCon:CGFloat, trailingCon:CGFloat) {
let topConstraint = NSLayoutConstraint(item: item, attribute: .top, relatedBy: .equal, toItem: topToItem, attribute: .bottom, multiplier: 1, constant: topC)
let bottomConstraint = NSLayoutConstraint(item: item, attribute: .bottom, relatedBy: .equal, toItem: bottomToItem, attribute: .top, multiplier: 1, constant: bottomC)
let widthConstraint = NSLayoutConstraint(item: item, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: widthC)
let heightConstraint = NSLayoutConstraint(item: item, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: heightC)
let leading = NSLayoutConstraint(item: item,attribute: .leading,relatedBy: .equal, toItem: view, attribute: .leadingMargin, multiplier: 1.0, constant: leadingCon)
let trailing = NSLayoutConstraint(item: item,attribute: .trailing, relatedBy: .equal, toItem: view, attribute: .trailingMargin,multiplier: 1.0,constant: trailingCon)
view?.addConstraints([topConstraint, bottomConstraint, widthConstraint, heightConstraint, leading, trailing])
NSLayoutConstraint.activate([topConstraint, bottomConstraint, widthConstraint, heightConstraint, leading, trailing])
}
But in the result i receive only UIView with gray background, the new UIView with red background doesn't appears.
What I'm doing wrong???
You should only specify bottom OR height and width OR trailing, otherwise you are going to get conflicts here.
see playground:
import PlaygroundSupport
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let red = UIView()
red.backgroundColor = .red
view.addSubview(red)
red.translatesAutoresizingMaskIntoConstraints = false
red.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
red.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
red.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.85).isActive = true
red.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.1).isActive = true
}
}
PlaygroundPage.current.liveView = ViewController()
How to give programmatically constraints equal width and equal height with multiple views.I check google but not perfect answer for programmatically equal width and height constraints through auto layout.
my code look like below:
var countNoOfViews:Int = 3
#IBOutlet var viewForRow1: UIView!
override func viewDidLoad() {
super.viewDidLoad()
self.specialButtonViewLeft()
}
func specialButtonViewLeft(){
for i in 0..<countNoOfViews{
var customView:UIView!
customView = UIView(frame: CGRect.zero)
customView.translatesAutoresizingMaskIntoConstraints = false
viewForRow1.addSubview(customView)
let widthConstraint = NSLayoutConstraint(item: customView, attribute: .width, relatedBy: .equal,toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 20.0)
let topConstraint = NSLayoutConstraint(item: customView, attribute: .top, relatedBy: .equal,toItem: self.viewForRow1, attribute: .top, multiplier: 1.0, constant: 0)
let bottomConstraint = NSLayoutConstraint(item: customView, attribute: .bottom, relatedBy: .equal,toItem: self.viewForRow1, attribute: .bottom, multiplier: 1.0, constant: 0)
let leadingConstraint = NSLayoutConstraint(item: customView, attribute: .leading, relatedBy: .equal, toItem: self.viewForRow1, attribute: .leading, multiplier: 1, constant: customLeadingSpaceLeft)
customLeadingSpaceLeft = customLeadingSpaceLeft + customViewWidth
arrayLeftBtnConstraints.append(widthConstraint)
if i == 0{
customView.backgroundColor = UIColor.red
}else if i == 1{
customView.backgroundColor = UIColor.green
}else if i == 2{
leftViewVal = customLeadingSpaceLeft
customView.backgroundColor = UIColor.black
}
customView.alpha = 0.50
viewForRow1.addConstraints([widthConstraint, leadingConstraint,topConstraint,bottomConstraint])
}
}
I want to add equal width constraint programmatically.
You have three possible ways to do that:
1) By using anchors:
view.widthAnchor.constraint(equalTo: otherView.widthAnchor, multiplier: 1.0).isActive = true
2) Visual format:
simple example - "H:|[otherView]-[view(==otherView)]|"
3) "Old school" constraints:
NSLayoutConstraint(item: #view, attribute: .width, relatedBy: .equal, toItem: #otherView, attribute: .width, multiplier: 1.0, constant: 0.0).isActive = true
hope it will help somebody.
Try this:
let widthConstraint = NSLayoutConstraint(item: customView, attribute: .width, relatedBy: .equal, toItem: viewForRow1, attribute: .width, multiplier: 0.25, constant: 0.0)
multiplier: 0.25, denotes that customView's width will be 1/4th of the parent view, viewForRow1.
I have UIWebView and in its scrollView, I added a UIImageView like so:
self.webview.scrollView.addSubview(image)
my problem is when I rotate my device from portrait to landscape the UIImageView does not stay at the position I originally set it to on the scrollView, I understand the width and height of the screen change, I guess what I am trying to do it change the the position on my UIImageView so it appears it did not change.
I have this method in place:
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
var newScrollViewFrame = webview.scrollView.frame
var newFrame = webview.frame
newFrame.size.width = size.width
newFrame.size.height = size.height
newScrollViewFrame.size.width = size.width
newScrollViewFrame.size.height = size.height
webview.frame = newFrame
webview.scrollView.frame = newScrollViewFrame
}
The current code inside this method just resize the UIWebView and its scroll view, but not the UIImageViews in the scrollView
Any help would be appreciated.
Thanks,
I have tried the following:
for views in webview.scrollView.subviews
{
if(views.isKindOfClass(UIImageView))
{
views.transform = CGAffineTransformMakeRotation(CGFloat(M_PI)/2);
}
}
but this puts on UIImageView sideways on rotate
Here is how I am adding the webview to the view:
webview = UIWebView()
webview.frame = self.view.bounds
webview.scrollView.frame = webview.frame
webview.userInteractionEnabled = true
webview.scalesPageToFit = true
webview.becomeFirstResponder()
webview.delegate = self
webview.scrollView.delegate = self
self.view.addSubview(webview)
I have half solved my problem, but doing the following:
webview.translatesAutoresizingMaskIntoConstraints = false
let horizontalConstraint = NSLayoutConstraint(item: webview, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.CenterX, multiplier: 1, constant: 0)
view.addConstraint(horizontalConstraint)
let verticalConstraint = NSLayoutConstraint(item: webview, attribute: NSLayoutAttribute.CenterY, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.CenterY, multiplier: 1, constant: 0)
view.addConstraint(verticalConstraint)
let widthConstraint = NSLayoutConstraint(item: webview, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 0.1, constant: 500)
view.addConstraint(widthConstraint)
let heightConstraint = NSLayoutConstraint(item: webview, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: 500)
view.addConstraint(heightConstraint)
However now, the UIWebView is not full width or height :( Sooooo close.
I also tried this, but the UIImageView do not remain in the same spot.
let left = NSLayoutConstraint(item: self.webView, attribute: .Left, relatedBy: .Equal, toItem: self.view, attribute: .Left, multiplier: 1, constant: 0)
let right = NSLayoutConstraint(item: self.webView, attribute: .Right, relatedBy: .Equal, toItem: self.view, attribute: .Right, multiplier: 1, constant: 0)
let top = NSLayoutConstraint(item: self.webView, attribute: .Top, relatedBy: .Equal, toItem: self.view, attribute: .Top, multiplier: 1, constant: 0)
let bottom = NSLayoutConstraint(item: self.webView, attribute: .Bottom, relatedBy: .Equal, toItem: self.view, attribute: .Bottom, multiplier: 1, constant: 0)
NSLayoutConstraint.activateConstraints([top, bottom, left, right])
I have also tried adding constraints to the UIImageView
let stampView:StampAnnotation = StampAnnotation(imageIcon: UIImage(named: "approved.png"), location: CGPointMake(currentPoint.x, currentPoint.y))
self.webview.scrollView.addSubview(stampView)
let left = NSLayoutConstraint(item: stampView, attribute: .Left, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Left, multiplier: 1, constant: 0)
let right = NSLayoutConstraint(item: stampView, attribute: .Right, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Right, multiplier: 1, constant: 0)
let top = NSLayoutConstraint(item: stampView, attribute: .Top, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Top, multiplier: 1, constant: 0)
let bottom = NSLayoutConstraint(item: stampView, attribute: .Bottom, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Bottom, multiplier: 1, constant: 0)
NSLayoutConstraint.activateConstraints([top, bottom, left, right])
same result, UIImageView does not stay in the same spot.
UPDATE
My webview:
webview = UIWebView()
webview.userInteractionEnabled = true
webview.scalesPageToFit = true
webview.becomeFirstResponder()
webview.delegate = self
webview.scrollView.delegate = self
self.view.addSubview(webview)
webview.loadRequest(NSURLRequest(URL:url))
webview.gestureRecognizers = [pinchRecognizer, panRecognizer]
webview.translatesAutoresizingMaskIntoConstraints = false
let left = NSLayoutConstraint(item: webview, attribute: .Left, relatedBy: .Equal, toItem: self.view, attribute: .Left, multiplier: 1, constant: 0)
let right = NSLayoutConstraint(item: webview, attribute: .Right, relatedBy: .Equal, toItem: self.view, attribute: .Right, multiplier: 1, constant: 0)
let top = NSLayoutConstraint(item: webview, attribute: .Top, relatedBy: .Equal, toItem: self.view, attribute: .Top, multiplier: 1, constant: 0)
let bottom = NSLayoutConstraint(item: webview, attribute: .Bottom, relatedBy: .Equal, toItem: self.view, attribute: .Bottom, multiplier: 1, constant: 0)
NSLayoutConstraint.activateConstraints([top, bottom, left, right])
UIImageView
stampView.translatesAutoresizingMaskIntoConstraints = false
let left = NSLayoutConstraint(item: stampView, attribute: .Left, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Left, multiplier: 1, constant: 100)
let right = NSLayoutConstraint(item: stampView, attribute: .Right, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Right, multiplier: 1, constant: 0)
let top = NSLayoutConstraint(item: stampView, attribute: .Top, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Top, multiplier: 1, constant: 100)
let bottom = NSLayoutConstraint(item: stampView, attribute: .Bottom, relatedBy: .Equal, toItem: self.webview.scrollView, attribute: .Bottom, multiplier: 1, constant: 0)
let width = NSLayoutConstraint(item: stampView, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 0.1, constant: 150)
let height = NSLayoutConstraint(item: stampView, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: 73)
NSLayoutConstraint.activateConstraints([left, right, top, bottom, width, height])
I just need to figure out the math to have this device be at the position of touch. (in percentages ?)
I think these things are always easier to do without using autolayout. To do this, I recomend using viewDidLayoutSubviews(). Here is my code:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
webView.frame = view.bounds
let screen = UIScreen.mainScreen().fixedCoordinateSpace
//These values will give a rect half the size of the screen and centered.
let width = screen.bounds.width / 2
let height = screen.bounds.height / 2
let x = (screen.bounds.width - width) / 2
let y = (screen.bounds.height - height) / 2
let absoluteRect = CGRect(x: x, y: y, width: width, height: height)
let stampRect = screen.convertRect(absoluteRect, toCoordinateSpace: webView)
stampView.frame = stampRect
//Change the orientation of the image
switch UIDevice.currentDevice().orientation {
case .LandscapeLeft:
stampView.image = UIImage(CGImage:originalImage.CGImage!, scale:originalImage.scale, orientation: UIImageOrientation.Left)
break
case .LandscapeRight:
stampView.image = UIImage(CGImage:originalImage.CGImage!, scale:originalImage.scale, orientation: UIImageOrientation.Right)
break
default:
stampView.image = UIImage(CGImage:originalImage.CGImage!, scale:originalImage.scale, orientation: UIImageOrientation.Up)
break
}
}
I am doing several things here...First I set the webViewFrame. Next, it is helpful here to define an absolute coordinate system relative to your screen. When the phone orientation changes, the values of screen will not change (allowing you to keep your imageView in the same place.) Next I define the desired frame for the stampView, then convert the absolute frame into its equivalent inside your scrollView (it's superView) and assign it to the stampView. Finally, if you want the image in your stampView to always be oriented correctly, you need to change the image orientation. CGAffineTransformMakeRotation only works if your view is square, but we can make it more general by actually changing the imageOrientation within the stampView. This requires a property for the original image:
let originalImage = UIImage(named: "image_name")!
Finally, because viewWillLayoutSubViews() is not called for landscape to landscape transitions, do the following:
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
view.setNeedsLayout()
}
This code doesn't make for the prettiest transitions, it should help with your layout problems.
To make the UIImageView keep the same size and stay in the same position relative to the UIWebView, you can set your views to be a percentage of their respective superView. Here I've created some mock views that illustrate the basic idea:
import UIKit
class ViewController: UIViewController {
//we create some views for testing and create references to the size and points we need for positioning
let webView = UIWebView()
let image = UIImageView()
let image2 = UIImageView()
var imageViewSize = CGSize()
var imageViewCenter = CGPoint()
override func viewDidLoad() {
super.viewDidLoad()
//set webView frame
webView.frame = self.view.bounds
webView.backgroundColor = UIColor.clearColor()
webView.userInteractionEnabled = true
webView.scalesPageToFit = true
webView.opaque = false
self.view.addSubview(webView)
//we will hold onto the original size of the UIImageView for later
imageViewSize = CGSizeMake(webView.bounds.size.width * 0.2, webView.bounds.size.height * 0.1)
//mock UIImageView
image.backgroundColor = UIColor.orangeColor()
image.frame.size = CGSizeMake(imageViewSize.width, imageViewSize.height)
image.center = CGPointMake(webView.bounds.size.width / 2, webView.bounds.size.height / 2)
webView.scrollView.addSubview(image)
//I've created a subset image to illustrate the orientation
image2.backgroundColor = UIColor.whiteColor()
image2.frame = CGRectMake(10, 10, 10, 10)
image.addSubview(image2)
}
And then change the frame when rotated (Notice that the position on the UIImageView and the width of the UIWebView are set relative to the height of their superViews and vice versa since the device is rotated):
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
image.frame.size = CGSizeMake(imageViewSize.width, imageViewSize.height)
image.center = CGPointMake(webView.bounds.size.height / 2, webView.bounds.size.width / 2)
webView.frame = CGRectMake(0, 0, self.view.bounds.size.height, self.view.bounds.size.width)
webView.scrollView.contentSize = webView.frame.size
}
}
Since you are creating the position and sizes of your views as percentages of their superViews, the code will play nicer with different device sizes (i.e. iPhone/iPad).
I'm trying to implement a popup layout like following:
This works fine in a storyboard with margins and everything. In storyboard it looks like this:
But if I make the same constraint in code I get this result:
The label has a light blue background and the view the label is inside has the dark blue background. The popup background has a border around itself. So basically the popup matches the child but the label inside the child overflows parent and grand parent BUT only because it has margins... If I remove margins it goes right to the border!
I've tryed making the exact same constraint just in code. I'm very open for alternative suggestions involving automatic adjusting width.
My code for creating popup:
func showPopup(caller: UIView) {
closePopups()
// setup view
currentPopup = UIView()
self.view.addSubview(currentPopup)
currentPopup.backgroundColor = UIColorFromHex(Constants.Colors.white, alpha: 1)
// setup constraints
currentPopup.translatesAutoresizingMaskIntoConstraints = false
// top constraint
let topSideConstraint = NSLayoutConstraint(item: currentPopup, attribute: .Top, relatedBy: .Equal, toItem: intoWordsBar.view, attribute: .Bottom, multiplier: 1.0, constant: 0)
self.view.addConstraint(topSideConstraint)
// setup child elements
var children = [PopupChildButton]()
let childOne = createChild("writing_strategy_1", parent: currentPopup, aboveChild: nil, hasBorder: true, feature: FeatureManager.BarFeature.WriteReadLetterName)
children.append(childOne)
let childTwo = createChild("writing_strategy_2", parent: currentPopup, aboveChild: children[0], hasBorder: true, feature: FeatureManager.BarFeature.WriteReadLetterSound)
children.append(childTwo)
let childThree = createChild("writing_strategy_3", parent: currentPopup, aboveChild: children[1], hasBorder: true, feature: FeatureManager.BarFeature.WriteReadWord)
children.append(childThree)
let childFour = createChild("writing_strategy_4", parent: currentPopup, aboveChild: children[2], hasBorder: false, feature: FeatureManager.BarFeature.WriteReadSentence)
children.append(childFour)
let parentSize = getWidth(caller)
//TODO MARK: <-- here working, need to add toggle function and graphics to childrens, documentation on methods, move to constructor class?
// setup rest of constraints
// add bottom constraint, equal to bottom of last child
let bottomSideConstraint = NSLayoutConstraint(item: currentPopup, attribute: .Bottom, relatedBy: .Equal, toItem: children[children.count-1], attribute: .Bottom, multiplier: 1.0, constant: 0)
self.view.addConstraint(bottomSideConstraint)
// left constraint
let leftSideConstraint = NSLayoutConstraint(item: currentPopup, attribute: .Left, relatedBy: .Equal, toItem: caller, attribute: .Right, multiplier: 1.0, constant: (-parentSize)/2)
self.view.addConstraint(leftSideConstraint)
// add border
currentPopup.addBorder(edges: [.All], colour: UIColorFromHex(Constants.Colors.dark_grey, alpha: 1), thickness: 1)
//TODO <-- last piece
//childOne.addTarget(self, action: #selector(KeyboardViewController.childClick(_:)), forControlEvents: .TouchUpInside)
//childTwo.addTarget(self, action: #selector(KeyboardViewController.childClick(_:)), forControlEvents: .TouchUpInside)
//childThree.addTarget(self, action: #selector(KeyboardViewController.childClick(_:)), forControlEvents: .TouchUpInside)
//childFour.addTarget(self, action: #selector(KeyboardViewController.childClick(_:)), forControlEvents: .TouchUpInside)
self.view.setNeedsLayout()
self.view.layoutIfNeeded()
}
My code for creating child:
func createChild(text: String, parent: UIView, aboveChild: UIView?, hasBorder: Bool, feature: FeatureManager.BarFeature) -> PopupChildButton {
// setup child element
let childBtn = PopupChildButton()
childBtn.setRelatedFeature(feature)
// set the right background color
if intoWordsBar.getFeatureManager().isFeatureActive(feature) {
childBtn.backgroundColor = UIColorFromHex(Constants.Colors.light_blue, alpha: 1)
//childBtn.setImage(UIImage(named: "Checkmark"))
} else {
childBtn.backgroundColor = UIColorAndAlphaFromHex(Constants.Colors.transparent)//TODO Highlight implementation needs to be optimized, icon should be moved all the way to the left... somehow //TODO Add new checkmark icon
//childBtn.setImage(nil)
}
childBtn.translatesAutoresizingMaskIntoConstraints = false
parent.addSubview(childBtn)
// add constraints
// top constraint
if let aboveChild = aboveChild {
let topSideConstraint = NSLayoutConstraint(item: childBtn, attribute: .Top, relatedBy: .Equal, toItem: aboveChild, attribute: .Bottom, multiplier: 1.0, constant: 0)
parent.addConstraint(topSideConstraint)
} else {
let topSideConstraint = NSLayoutConstraint(item: childBtn, attribute: .Top, relatedBy: .Equal, toItem: parent, attribute: .Top, multiplier: 1.0, constant: 0)
parent.addConstraint(topSideConstraint)
}
// height constraint
let heightConstraint = NSLayoutConstraint(item: childBtn, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: CGFloat(Constants.Sizes.popupChildHeight))
parent.addConstraint(heightConstraint)
// left constraint
let leftSideConstraint = NSLayoutConstraint(item: parent, attribute: .Leading, relatedBy: .Equal, toItem: childBtn, attribute: .Leading, multiplier: 1.0, constant: 0)
parent.addConstraint(leftSideConstraint)
// right constraint
let rightSideConstraint = NSLayoutConstraint(item: parent, attribute: .Trailing, relatedBy: .Equal, toItem: childBtn, attribute: .Trailing, multiplier: 1.0, constant: 0)
parent.addConstraint(rightSideConstraint)
// add border
if hasBorder {
childBtn.addBorder(edges: .Bottom, colour: UIColorFromHex(Constants.Colors.dark_grey, alpha: 1), thickness: 1)
}
// create grandchildren
let label = UILabel()
// setup looks
label.textColor = UIColorFromHex(Constants.Colors.black, alpha: 1)
label.textAlignment = .Center
childBtn.backgroundColor = UIColorFromHex(Constants.Colors.dark_blue, alpha: 1)
label.backgroundColor = UIColorFromHex(Constants.Colors.light_blue, alpha: 1)
label.text = text.localized
label.translatesAutoresizingMaskIntoConstraints = false
childBtn.addSubview(label)
// add constraints
// left constraint label
let leftLabelConstraint = NSLayoutConstraint(item: label, attribute: .Left, relatedBy: .Equal, toItem: childBtn, attribute: .Left, multiplier: 1.0, constant: CGFloat(Constants.Sizes.popupMargin))
childBtn.addConstraint(leftLabelConstraint)
// right constraint label
let rightLabelConstraint = NSLayoutConstraint(item: label, attribute: .Right, relatedBy: .Equal, toItem: childBtn, attribute: .Right, multiplier: 1.0, constant: CGFloat(Constants.Sizes.popupMargin))
childBtn.addConstraint(rightLabelConstraint)
// top constraint
let labelTopSideConstraint = NSLayoutConstraint(item: label, attribute: .Top, relatedBy: .Equal, toItem: childBtn, attribute: .Top, multiplier: 1.0, constant: 0)
childBtn.addConstraint(labelTopSideConstraint)
// bottom constraint
//let labelBottomSideConstraint = NSLayoutConstraint(item: label, attribute: .Bottom, relatedBy: .Equal, toItem: childBtn, attribute: .Bottom, multiplier: 1.0, constant: 0)
//childBtn.addConstraint(labelBottomSideConstraint)
return childBtn
}
No, it is not broken.
When defining trailing constraints you must set the parent view as the first item and the child view as the second item. This is in reversed order compared to a leading constraint.
I pulled to constraints from a storyboard to illustrate this. These constraints make sure the header has a 10px margin from leading and trailing of parent view.
I added the following code to center a programmatically added view:
let horizontalConstraint = NSLayoutConstraint(item: newView!, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.CenterX, multiplier: 1, constant: 0)
view.addConstraint(horizontalConstraint)
It doesn't work. The view is not centered. It is on the left still.
EDIT:
override func viewDidLoad() {
super.viewDidLoad()
newView = LineChartView(frame: CGRectMake(0, 0, 50, 50))
newView?.delegate = self
newView?.drawBordersEnabled = true
newView?.noDataText = "No Data"
newView?.noDataTextDescription = "No Data"
newView?.borderColor = UIColor.blackColor()
self.view.addSubview(newView!)
You need to pick a side my friend, If you are using auto layout, don't initialise your objects with a frame. Try something like this...
var newView:LineChartView!
override func viewDidLoad() {
super.viewDidLoad()
newView = LineChartView()
newView.translatesAutoresizingMaskIntoConstraints = false
newView.delegate = self
newView.drawBordersEnabled = true
newView.noDataText = "No Data"
newView.noDataTextDescription = "No Data"
newView.borderColor = UIColor.blackColor()
self.view.addSubview(newView)
let width = NSLayoutConstraint(item: newView, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: 50)
let height = NSLayoutConstraint(item: newView, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: 50)
newView.addConstraint(width)
newView.addConstraint(height)
let x = NSLayoutConstraint(item: newView, attribute: .CenterX, relatedBy: .Equal, toItem: self.view, attribute: .CenterX, multiplier: 1, constant: 0)
let y = NSLayoutConstraint(item: newView, attribute: .CenterY, relatedBy: .Equal, toItem: self.view, attribute: .CenterY, multiplier: 1, constant: 0)
self.view.addConstraint(x)
self.view.addConstraint(y)
}
If your LineChartView object is a subclass of UIView then this should work, and you should have a 50x50 object in the middle of your superview.
If you are going to be doing constraints like this in code you should consider using Apples Visual Formatting Language.