Swift 2 Programmatically Constraints, i can't see the web view - swift

i have a webkit and under the webkit there is another view... so i have three view = view, secondView(the one contain the WKWebView) and bannerView(with ADS). I added WKWebView to the secondView programmatically but bannerView and their constraints are set in storyboard. Now i need to set the constraints for WKWebView, i saw hundreds of tutorial, run without crash and problems but i can't see the WKWebView! how can i fix that ?
Code:
class ViewController: UIViewController {
#IBOutlet var bannerView: GADBannerView!
#IBOutlet var secondView: UIView!
var webView = WKWebView()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
print("Google Mobile Ads SDK version: " + GADRequest.sdkVersion())
//bannerView.adUnitID = ""
//bannerView.rootViewController = self
//var request = GADRequest()
//request.testDevices = ["kGADSimulatorID"]
//bannerView.loadRequest(request)
let preferences = WKPreferences()
preferences.javaScriptEnabled = true
let configuration = WKWebViewConfiguration()
configuration.preferences = preferences
webView.frame = CGRectMake(0, 0, 600, 543)
webView.customUserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_4) AppleWebKit/600.7.12 (KHTML, like Gecko) Version/8.0.7 Safari/600.7.12"
let url = NSURL(string:"https://apple.com/")
let req = NSURLRequest(URL:url!)
self.webView.loadRequest(req)
secondView.addSubview(webView)
secondView.bringSubviewToFront(webView)
webView.translatesAutoresizingMaskIntoConstraints = false
let xConstraint = NSLayoutConstraint(item: webView, attribute: .CenterX, relatedBy: .Equal, toItem: secondView, attribute: .CenterX, multiplier: 1, constant: 0)
let yConstraint = NSLayoutConstraint(item: webView, attribute: .CenterY, relatedBy: .Equal, toItem: secondView, attribute: .CenterY, multiplier: 1, constant: 0)
let bottomConstraint = NSLayoutConstraint(item: webView, attribute: .Bottom, relatedBy: .Equal, toItem: secondView, attribute: .Bottom, multiplier: 1, constant: 0)
secondView.addConstraints([xConstraint, yConstraint, bottomConstraint])
/*
let topConstraint = NSLayoutConstraint(item: webView, attribute: NSLayoutAttribute.TopMargin, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: NSLayoutAttribute.BottomMargin, multiplier: 1, constant: 0)
let leadingConstraint = NSLayoutConstraint(item: webView, attribute: NSLayoutAttribute.Leading , relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: NSLayoutAttribute.Leading, multiplier: 1, constant: -20)
let trailingConstraint = NSLayoutConstraint(item: webView, attribute: NSLayoutAttribute.Leading , relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: NSLayoutAttribute.Trailing, multiplier: 1, constant: -20)
let bottomConstraints = NSLayoutConstraint(item: webView, attribute: NSLayoutAttribute.Bottom , relatedBy: NSLayoutRelation.Equal, toItem: self.bannerView, attribute: NSLayoutAttribute.Bottom, multiplier: 1, constant: 0)
*/
/* var LeftwebViewConstraints = NSLayoutConstraint(item: webView, attribute: NSLayoutAttribute.Leading, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Leading, multiplier: 1.0, constant: -20)
var RightwebViewConstraints = NSLayoutConstraint(item: webView, attribute: NSLayoutAttribute.TrailingMargin, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.TrailingMargin, multiplier: 1.0, constant: -20)
var BottomwebViewConstraints = NSLayoutConstraint(item: webView, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.Equal, toItem: bannerView, attribute: NSLayoutAttribute.BottomMargin, multiplier: 1.0, constant: 0)
// view.addConstraints([LeftwebViewConstraints, RightwebViewConstraints, BottomwebViewConstraints])
NSLayoutConstraint.activateConstraints([LeftwebViewConstraints, RightwebViewConstraints, BottomwebViewConstraints])
*/
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

Yes, it would appear that you are missing some constraints.
I might suggest adding all of the necessary constraints using VFL, which may be more intuitive:
secondView.addSubview(webView)
webView.translatesAutoresizingMaskIntoConstraints = false
let views = ["webView" : webView]
secondView.addSubview(webView)
secondView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[webView]|", options: [], metrics: nil, views: views))
secondView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[webView]|", options: [], metrics: nil, views: views))
This obviously assumes that the constraints for secondView were defined correctly in the first place. Check its frame before you start losing any sleep over the frame of the webView.
But note, I don't manually set the frame of the webView, but rather I simply defined both horizontal and vertical constraints.

Related

A layout issue (NSLayoutConstraint) in an iOS app

In an iOS app I have an autolayout issue.
The 2 following screenshots show the problem.
The switch (UISwitch object) on the right is displaced horizontally, when it should be fixed. Can anyone see what is happening?
It is true that the string on the left is changing length, but I think (according to the way I have set the constraints up) the font should be resized or the string split in 2 lines; but not the switch displaced.
Here is the relevant swift code:
import UIKit
class My_ViewController: UIViewController {
let xPanel = UILabel(), yPanel = UILabel(),
khToggle = UISwitch(), khLabel = UILabel()
....
override func viewDidLoad() {
super.viewDidLoad()
layOutUI()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
.....
toggleKeepHide(khToggle)
}
func layOutUI() {
for component in [xPanel,yPanel,khLabel,khToggle] {
component.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(component)
}
...........
khLabel.numberOfLines = 0
khLabel.adjustsFontSizeToFitWidth = true
khToggle.addTarget(self,
action: #selector(toggleKeepHide(_:)),
for: .valueChanged)
view.addConstraints([
.........
NSLayoutConstraint(item: khToggle, attribute: .right, relatedBy: .equal,
toItem: view, attribute: .right, multiplier: 1.0, constant: -30.0),
NSLayoutConstraint(item: khToggle, attribute: .top, relatedBy: .equal,
toItem: yPanel, attribute: .bottom, multiplier: 1.0,
constant: 50.0),
NSLayoutConstraint(item: khLabel, attribute: .right, relatedBy: .equal,
toItem: khToggle, attribute: .left, multiplier: 1.0, constant: -23.0),
NSLayoutConstraint(item: khLabel, attribute: .centerY, relatedBy: .equal,
toItem: khToggle, attribute: .centerY, multiplier: 1.0, constant: 0.0),
NSLayoutConstraint(item: khLabel, attribute: .left, relatedBy: .equal,
toItem: view, attribute: .left, multiplier: 1.0, constant: 30.0)])
}
#objc func toggleKeepHide(_ sender: UISwitch) {
if sender.isOn {khLabel.text = "Hide this object from the wyxoug list."}
else {khLabel.text = "Keep this object in the wyxoug list."}
}
}
You haven't provided sufficient information to reproduce the problem. Here's a reduction of your code, in my view controller's viewDidLoad (I eliminated everything but the label and the switch, fixed your left and right (you should never use those), and changed the alignment between the two views to top instead of center):
khToggle = UISwitch()
khToggle.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(khToggle)
khLabel = UILabel()
khLabel.text = String(repeating: "word ", count: 40)
khLabel.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(khLabel)
// Do any additional setup after loading the view.
khLabel.numberOfLines = 0
view.addConstraints([
NSLayoutConstraint(item: khToggle!, attribute: .trailing, relatedBy: .equal,
toItem: view, attribute: .trailing, multiplier: 1.0, constant: -30.0),
NSLayoutConstraint(item: khToggle!, attribute: .top, relatedBy: .equal,
toItem: view, attribute: .top, multiplier: 1.0,
constant: 50.0),
NSLayoutConstraint(item: khLabel!, attribute: .trailing, relatedBy: .equal,
toItem: khToggle, attribute: .leading, multiplier: 1.0, constant: -23.0),
NSLayoutConstraint(item: khLabel!, attribute: .top, relatedBy: .equal,
toItem: khToggle, attribute: .top, multiplier: 1.0, constant: 0.0),
NSLayoutConstraint(item: khLabel!, attribute: .leading, relatedBy: .equal,
toItem: view, attribute: .leading, multiplier: 1.0, constant: 30.0)])
The result displays fine; there are no constraint conflicts or ambiguities, and it looks as one would expect:
The horizontal constraints for the label and the toggle are competing against each other.
(If you step in to Xcode's visual debugger, you'll find that there is a warning: the UISwitch instance has an ambiguous width and horizontal position.)
Solution
You have provided absolute values to AutoLayout, and it cannot resolve the requirements. To fix this, introduce some flexibility in to the requirements by setting the compression resistance of the label to a lower value:
khLabel.setCompressionResistance(.defaultLow, for: .horizontal)

Changing position of UIProgressView?

I added a progress bar to my screen. I want it to be centered horizontally in my container, but I want to move it to the bottom of my screen. How do I edit the third line to change its position?
func addControls() {
progressView = UIProgressView(progressViewStyle: UIProgressViewStyle.Default)
progressView?.center = self.view.center
view.addSubview(progressView!)
}
You could use NSLayoutConstraints and do something like this. The 3rd line being where you put the progress bar on top or beneath the other object.
var otherObject = UIView()
self.view.addSubview(progressView)
let topConstraint = NSLayoutConstraint(item: progressView, attribute: .topMargin, relatedBy: .equal, toItem: otherObject, attribute: .bottomMargin, multiplier: 1, constant: 0)
let leftConstraint = NSLayoutConstraint(item: progressView, attribute: .leftMargin, relatedBy: .equal, toItem: self.view, attribute: .leftMargin, multiplier: 1, constant: 0)
let rightConstraint = NSLayoutConstraint(item: progressView, attribute: .rightMargin, relatedBy: .equal, toItem: self.view, attribute: .rightMargin, multiplier: 1, constant: 0)
let bottomConstraint = NSLayoutConstraint(item: progressView, attribute: .bottomMargin, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 50)
self.view.addConstraints([topConstraint, leftConstraint, rightConstraint, bottomConstraint])
That's really simple.
If you want to add a subview above another one, use this function:
func insertSubview(_ view: UIView, aboveSubview siblingSubview: UIView)
To add a subview below another one, use this function:
func insertSubview(_ view: UIView, belowSubview siblingSubview: UIView)

How to put a uiview back in a stackview after I took it out?

I have a viewcontroller that holds multiple stackviews. There is a button that when pressed, the corresponding uiview wil become fullscreen inside the original view. There is a different button that is supposed to make the uiview go back to its original stackview. The uiview itself contains other views. I am having some problems doing that. The uiview does end up in the stackview, but not near the same size/place it used to be. I am not sure how to solve this, and been going at it for several hours now, looking at multiple sources.
This is the code that makes the uiview go fullscreen:
private func moveToFrontOfCardView(v: UIView) {
originalView = v.superview
if let stack = originalView as? UIStackView {
stack.removeArrangedSubview(v)
}
myCardView.addSubview(v)
let topConstraint = NSLayoutConstraint(item: v, attribute: .top, relatedBy: .equal, toItem: myCardView, attribute: .top, multiplier: 1, constant: 10)
let bottomConstraint = NSLayoutConstraint(item: v, attribute: .bottom, relatedBy: .equal, toItem: myCardView, attribute: .bottom, multiplier: 1, constant: -10)
let leftConstraint = NSLayoutConstraint(item: v, attribute: .left, relatedBy: .equal, toItem: myCardView, attribute: .left, multiplier: 1, constant: 10)
let rightConstraint = NSLayoutConstraint(item: v, attribute: .right, relatedBy: .equal, toItem: myCardView, attribute: .right, multiplier: 1, constant: -10)
myCardView.addConstraints([topConstraint, bottomConstraint, leftConstraint, rightConstraint])
}
And this is the code I use when I want it to go back:
private func moveToOriginalPosition(v: UIView) {
if let stack = originalView as? UIStackView {
stack.addArrangedSubview(v)
}
}
Does anyone have a clue how I could fix this?
EDIT
I've tried Saqib and Bilals answer, but I get this as a result:
Declare a class variable for tracking view's index
var selectedIndex = 0 // Contains Current Seleceted view's index
overrie func viewDidLoad() { ...
Before removing view from stackview get the view index like this selectedIndex = stack.subviews.index(of: v)
keep reference to all the constraints.
Before adding it back disable all the constraints topConstraint.isActive = false
Now add the view at the same index using stack.insertArrangedSubview(view, at: selectedIndex)
An other option is to create a same new view and just hide/unhide the one in stackview. StackView automatically fills the space accordingly for the hidden views.
You should deActivate the constraints you added to view when removed it from stackView, at the time you want add the view to the stackView again.
For this you should make the constraints instance of your viewController class and next, write your moveToOriginalPosition(v: UIView) method like this:
private func moveToOriginalPosition(v: UIView) {
if let stack = originalView as? UIStackView {
stack.addArrangedSubview(v)
topConstraint.isActive = false
bottomConstraint.isActive = false
leftConstraint.isActive = false
rightConstraint.isActive = false
}
}
Ofcourse, you should remove, these lines of codes from moveToFrontOfCardView(v: UIView) method:
self.topConstraint = NSLayoutConstraint(item: v, attribute: .top, relatedBy: .equal, toItem: myCardView, attribute: .top, multiplier: 1, constant: 10)
self.bottomConstraint = NSLayoutConstraint(item: v, attribute: .bottom, relatedBy: .equal, toItem: myCardView, attribute: .bottom, multiplier: 1, constant: -10)
self.leftConstraint = NSLayoutConstraint(item: v, attribute: .left, relatedBy: .equal, toItem: myCardView, attribute: .left, multiplier: 1, constant: 10)
self.rightConstraint = NSLayoutConstraint(item: v, attribute: .right, relatedBy: .equal, toItem: myCardView, attribute: .right, multiplier: 1, constant: -10)
myCardView.addConstraints([topConstraint, bottomConstraint, leftConstraint, rightConstraint])
and add them where you make your view initialized. and replace below lines with above lines in moveToFrontOfCardView(v: UIView) method:
topConstraint.isActive = true
bottomConstraint.isActive = true
leftConstraint.isActive = true
rightConstraint.isActive = true
By the looks of things you don't need to remove the original view. You could make a copy of it then display the copy full screen. Then when you dismiss this copy you release the reference to it

UIScrollView with NSLayoutConstraint

UIScrollView is not scrolling the subviews but it does show a scroll-bar.
Here is what I am trying to do
class SetupViewController: UIViewController {
let scrollView = UIScrollView()
let pageLabel = UILabel()
override func viewDidLoad() {
super.viewDidLoad()
self.setupViews()
self.setupConstraints()
self.setText()
}
func setupViews() {
self.scrollView.backgroundColor = .red
self.scrollView.translatesAutoresizingMaskIntoConstraints = false
// Page Label
self.pageLabel.font = UIFontLocalized(englishFontSize: 22, arabicFontSize: 22)
self.pageLabel.textAlignment = .center
self.pageLabel.translatesAutoresizingMaskIntoConstraints = false
}
func setupConstraints() {
// Add To Sub Views
self.view.addSubview(self.pageLabel)
self.view.addSubview(self.scrollView)
// Page Label
NSLayoutConstraint(item: self.pageLabel, attribute: .top, relatedBy: .equal, toItem: self.topLayoutGuide, attribute: .bottom, multiplier: 1.0, constant: 30.0).isActive = true
NSLayoutConstraint(item: self.pageLabel, attribute: .leading, relatedBy: .equal, toItem: self.view, attribute: .leading, multiplier: 1.0, constant: 20.0).isActive = true
NSLayoutConstraint(item: self.pageLabel, attribute: .width, relatedBy: .equal, toItem: self.view, attribute: .width, multiplier: 1.0, constant: -40.0).isActive = true
NSLayoutConstraint(item: self.pageLabel, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 36.0).isActive = true
// Scroll View
NSLayoutConstraint(item: self.scrollView, attribute: .top, relatedBy: .equal, toItem: self.line1, attribute: .bottom, multiplier: 1.0, constant: 0.0).isActive = true
NSLayoutConstraint(item: self.scrollView, attribute: .leading, relatedBy: .equal, toItem: self.view, attribute: .leading, multiplier: 1.0, constant: 0.0).isActive = true
NSLayoutConstraint(item: self.scrollView, attribute: .width, relatedBy: .equal, toItem: self.view, attribute: .width, multiplier: 1.0, constant: 0.0).isActive = true
NSLayoutConstraint(item: self.scrollView, attribute: .height, relatedBy: .equal, toItem: self.view, attribute: .height, multiplier: 1.0, constant: -100.0).isActive = true
self.scrollView.contentSize.height = 2000
// NSLayoutConstraint for rest of elements are removed in this example code.
}
}
I can confirm UIScrollView is added in the view because I checked by giving background red color to scrollview and it does show the background red color in correct position. My issue is the subviews does not move only the scroll bar is moving.
What could be the possible issue here?
Note: NSLayoutConstraint exist for all UIKit elements, I have not added it in the code.
I got this issue sorted our. As pointed out in the comment, the issue was related to superview in constraint which was set to self.view changing it to self.scrollView solved the issue.

Swift Assign Button Position from Plist

I have Add Constraint in My func
func CreateButtonWithIndex(var index:Int) {
let path = loadPath()
var data = NSMutableDictionary(contentsOfFile: path)
let newButton = UIButton.buttonWithType(UIButtonType.System) as UIButton newButton.setTranslatesAutoresizingMaskIntoConstraints(false)
self.view.addSubview(newButton)
let newButtonConstraintL = NSLayoutConstraint(item: newButton, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 50)
let newButtonConstraintH = NSLayoutConstraint(item: newButton, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 50)
// Read from Plist the coordinate
var reloadCoordX:[String] = data!.valueForKey("\(strDaPassare) X") as[String]
var reloadCoordY:[String] = data!.valueForKey("\(strDaPassare) Y") as[String]
var coordX: Int = ("\(reloadCoordX[index-1])").toInt()!
var coordY: Int = ("\(reloadCoordY[index-1])").toInt()!
// Add Constraint
newButtonConstraintX = NSLayoutConstraint(item: newButton, attribute: .CenterX, relatedBy: .Equal, toItem: view, attribute: .CenterX, multiplier: 1, constant: CGFloat(coordX))
newButtonConstraintY = NSLayoutConstraint(item: newButton, attribute: .CenterY, relatedBy: .Equal, toItem: view, attribute: .CenterY, multiplier: 1, constant: CGFloat(coordY))
}
And it's ok !!!! but this takes as a reference center of the UIView it self for the values ​​of newButtonConstraintX and newButtonConstraintY . but if I want to set attribute for newButtonConstraintX and newButtonConstraintY for the Top left corner ?