embedding navbar/tabbar breaks constraints of a normally functional view - swift

I have a simple
UIViewController that normally works:
view.backgroundColor
UITextView
UIView (as a spacer between the bottom and the textview)
constraints to pin textview to the view which in turn is pinned to the bottomlayoutguide
tapping textview loads keyboard and the spacer view expands accordingly to avoid the keyboard overlapping my textview
...
//var memoArea = UITextView(frame: CGRectMake(20, 291, 275, 225))
memoArea.addConstraint(NSLayoutConstraint(item: memoArea, attribute: .Width, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 275.0))
memoArea.addConstraint(NSLayoutConstraint(item: memoArea, attribute: .Height, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 225.0))
self.view.addConstraint(NSLayoutConstraint(item: memoArea, attribute: .Leading, relatedBy: .Equal,
toItem: self.view, attribute: .Leading, multiplier: 1.0, constant: 20.0))
// var spacer:UIView = UIView(frame: CGRectMake(84, 518, 160, 6))
spacer.addConstraint(NSLayoutConstraint(item: spacer, attribute: .Width, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 160.0))
spacer.addConstraint(NSLayoutConstraint(item: spacer, attribute: .Height, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 6.0))
self.view.addConstraint(NSLayoutConstraint(item: spacer, attribute: .Leading, relatedBy: .Equal,
toItem: self.view, attribute: .Leading, multiplier: 1.0, constant: 84.0))
view.setTranslatesAutoresizingMaskIntoConstraints(false)
spacer.setTranslatesAutoresizingMaskIntoConstraints(false)
memoArea.setTranslatesAutoresizingMaskIntoConstraints(false)
...
...
func updateBottomLayoutConstraintWithNotification(notification: NSNotification) {
let userInfo = notification.userInfo!
let animationDuration = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as NSNumber).doubleValue
let keyboardEndFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as NSValue).CGRectValue()
let convertedKeyboardEndFrame = view.convertRect(keyboardEndFrame, fromView: view.window)
let rawAnimationCurve = (notification.userInfo![UIKeyboardAnimationCurveUserInfoKey] as NSNumber).unsignedIntValue << 16
let animationCurve = UIViewAnimationOptions.init(UInt(rawAnimationCurve))
let frame = self.tabBarController?.tabBar.frame
let height = frame?.size.height
spacerToBottom.constant = CGRectGetMaxY(view.bounds) - CGRectGetMinY(convertedKeyboardEndFrame) - height! - 5
UIView.animateWithDuration(animationDuration, delay: 0.0, options: .BeginFromCurrentState | animationCurve, animations: {
self.view.layoutIfNeeded()
}, completion: nil)
...
But, after adding either a tab bar or a nav bar to a view that has normally working constraints,
3 things break:
the background no longer renders, yielding a black background
the textview doesn't register taps i.e. keyboard doesn't load
view disregards the bottomlayoutguide. it just shifts my objects up as high as their .Top constraints allow them. the constraints between the textview and uiview are still honored though.

commenting out view.setTranslatesAutoresizingMaskIntoConstraints(false) got rid of all errors.

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)

Setting 2 label in header programatically - not label seen

I'm trying to set 2 labels, one under other with different font size in the header. The function is called like this:
viewController.navigationItem.titleView = self.setHeader()
And code responsible for generating label is :
private func setHeader(agentName: String = "", isTyping: Bool = false) -> UIView {
let headerLabel: UILabel = {
let label = UILabel()
label.text = self.title
label.font = UIFont.systemFont(ofSize: 21)
label.textColor = UIColor.white
return label
}()
let subheaderLabel: UILabel = {
let label = UILabel()
label.font = UIFont.systemFont(ofSize: 10)
return label
}()
let headerView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(headerLabel)
view.addConstraints([
NSLayoutConstraint(item: headerLabel, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .leading, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16),
NSLayoutConstraint(item: headerLabel, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16)
])
return view
}()
if (!agentName.isEmpty) {
if (isTyping) {
subheaderLabel.text = agentName + " is typing ..."
} else {
subheaderLabel.text = agentName
}
headerView.addSubview(subheaderLabel)
}
return headerView
}
When I running IOS app there is nothing shown in the header. What is a reason?
I think you need to set the frame for the headerView. So in the initialization code for the headerView, use initializer with frame:
let headerView: UIView = {
// initialize the view with frame
let view = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 35))
// you want to call this on the headerLabel, not on view
headerLabel.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(headerLabel)
view.addConstraints([
NSLayoutConstraint(item: headerLabel, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .leading, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16),
NSLayoutConstraint(item: headerLabel, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16)
])
return view
}()
Moreover, I believe headerLabel you want to set translatesAutoresizingMaskIntoConstraints on headerLabel rather than on headerView (headerView is positioned through frame and not Autolayout).
Also, notice that you add subheaderLabel to the view, but you never position it, don't forget about it either (although this should cause only subheaderLabel not to be rendered properly).

Programmatically adding root view to view controller does not position correctly

I am trying to add the root view and subviews to a viewcontroller programmatically, but the view is not filling to screen as expected:
override func loadView() {
self.view = UIView(frame: CGRect(x: 0.0, y: 0.0, width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height))
self.view.backgroundColor = UIColor.blue
}
override func viewDidLoad() {
let alertView = Bundle.main.loadNibNamed("CHRApptTakenAlertView", owner: self, options: nil)![0] as! CHRApptTakenAlertView
self.view.translatesAutoresizingMaskIntoConstraints = false
alertView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(alertView)
self.view.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.centerX, multiplier: 1, constant: 0))
self.view.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.centerY, multiplier: 1, constant: 0))
alertView.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.width, multiplier: 1, constant: 350))
alertView.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.height, multiplier: 1, constant: 250))
alertView.closeBtn.addTarget(self, action: #selector(self.closeBtnTouch), for: UIControlEvents.touchUpInside)
}
Remove the line self.view.translatesAutoresizingMaskIntoConstraints = false, and call self.view.layoutIfNeeded() after the adding the constraints.

Resize superview with autolayout depending on largest subview

What is the best practice to resize superview with autolayout if we have inner NSView columns with dynamic heights?
For example. If we have two column layout, where left column height is bigger than right column, the superview height should be as right column height. Than, if we change right column height to be bigger than left column height, superview height should change to height of right column. How to accomplish this?
I made sample project to test this:
Initially we have layout with two columns, where .Bottom constraint of left NSView is attached to bottom of superview.
If we press Make Right Bigger button, I make height of right NSView bigger than left one.
So I want here superview to change height depending on bigger column (right column). Is there a good practice to do so?
Code:
import Cocoa
class ViewController: NSViewController {
let leftView = NSView()
let rightView = NSView()
let button = NSButton()
var rightViewHeightConstraint: NSLayoutConstraint?
override func loadView() {
self.view = TestView()
}
override func viewDidLoad() {
super.viewDidLoad()
leftView.backgroundColor = NSColor.redColor()
rightView.backgroundColor = NSColor.orangeColor()
layoutLeft(view, insertView: leftView)
layoutRight(view, insertView: rightView)
button.title = "Make Right Bigger"
button.target = self
button.action = "makeBigger:"
ViewControllerLayout.layoutBotton(view, insertView: button, bottom: -20)
}
func makeBigger(sender: AnyObject) {
rightViewHeightConstraint?.animator().constant = 150.0
}
func layoutLeft(containerView: NSView, insertView: NSView) {
insertView.translatesAutoresizingMaskIntoConstraints = false
containerView.addSubview(insertView)
let c1 = NSLayoutConstraint(item: insertView, attribute: .Left, relatedBy: .Equal, toItem: containerView, attribute: .Left, multiplier: 1.0, constant: 0.0)
let c2 = NSLayoutConstraint(item: insertView, attribute: .Width, relatedBy: .Equal, toItem: containerView, attribute: .Width, multiplier: 0.5, constant: 0.0)
let c3 = NSLayoutConstraint(item: insertView, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 100.0)
let c4 = NSLayoutConstraint(item: insertView, attribute: .Top, relatedBy: .Equal, toItem: containerView, attribute: .Top, multiplier: 1.0, constant: 0.0)
let c5 = NSLayoutConstraint(item: insertView, attribute: .Bottom, relatedBy: .Equal, toItem: containerView, attribute: .Bottom, multiplier: 1.0, constant: -60.0)
containerView.addConstraint(c1)
containerView.addConstraint(c2)
containerView.addConstraint(c3)
containerView.addConstraint(c4)
containerView.addConstraint(c5)
}
func layoutRight(containerView: NSView, insertView: NSView) {
insertView.translatesAutoresizingMaskIntoConstraints = false
containerView.addSubview(insertView)
let c1 = NSLayoutConstraint(item: insertView, attribute: .Right, relatedBy: .Equal, toItem: containerView, attribute: .Right, multiplier: 1.0, constant: 0.0)
let c2 = NSLayoutConstraint(item: insertView, attribute: .Width, relatedBy: .Equal, toItem: containerView, attribute: .Width, multiplier: 0.5, constant: 0.0)
let c3 = NSLayoutConstraint(item: insertView, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 50.0)
let c4 = NSLayoutConstraint(item: insertView, attribute: .Top, relatedBy: .Equal, toItem: containerView, attribute: .Top, multiplier: 1.0, constant: 0.0)
let c5 = NSLayoutConstraint(item: insertView, attribute: .Bottom, relatedBy: .Equal, toItem: containerView, attribute: .Bottom, multiplier: 1.0, constant: -60.0)
containerView.addConstraint(c1)
containerView.addConstraint(c2)
containerView.addConstraint(c3)
containerView.addConstraint(c4)
// containerView.addConstraint(c5) // Cant add .Bottom constraint here, because of different column sizes.
rightViewHeightConstraint = c3
}
}
struct ViewControllerLayout {
static func layoutBotton(containerView: NSView, insertView: NSView, bottom: Double) {
insertView.translatesAutoresizingMaskIntoConstraints = false
containerView.addSubview(insertView)
containerView.addConstraint(NSLayoutConstraint(item: insertView, attribute: .CenterX, relatedBy: .Equal, toItem: containerView, attribute: .CenterX, multiplier: 1.0, constant: 0.0))
containerView.addConstraint(NSLayoutConstraint(item: insertView, attribute: .Bottom, relatedBy: .Equal, toItem: containerView, attribute: .Bottom, multiplier: 1.0, constant: CGFloat(bottom)))
}
}
Download test project: GitHub
Managed to accomplish this with constraints only. Just added the container view for columns and set its height as GreaterThanOrEqual to left column and right column.
view.addConstraint(NSLayoutConstraint(item: containerView, attribute: .Height, relatedBy: .GreaterThanOrEqual, toItem: leftView, attribute: .Height, multiplier: 1, constant: 0))
view.addConstraint(NSLayoutConstraint(item: containerView, attribute: .Height, relatedBy: .GreaterThanOrEqual, toItem: rightView, attribute: .Height, multiplier: 1, constant: 0))
First create a constraint on superview with height
let heightConstraint = NSLayoutConstraint(item: view, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: greaterHeightAmongTwoColumns)
As discussed in the comment, you can post a notification and then let the super view know the updated frame. Super view would check if the updated height of any of the two columns is greater than its current height and update its heightConstraint declared above and then call
[self layoutIfNeeded]
on the superview's superview so that it is laid out with the new frame.

converting storyboard constraints into code

I'm trying to programmatically set up constraints for a class in my app so that when the keyboard appears everything moves up. i already got it working before in the storyboard, but when i take what it says in the size inspector and write it in code format, it doesn't work as expected.
...
//memo area
var memoArea = UITextView(frame: CGRectMake(20, 291, 275, 225))
memoArea.backgroundColor = majorColor
memoArea.delegate = self
self.view.addSubview(memoArea)
var memoLine = customShadow(theself: self.view, frame: memoArea.frame)
//Spacer View
var spacer:UIView = UIView(frame: CGRectMake(84, 518, 160, 6))
spacer.alpha = 0
self.view.addSubview(spacer)
//Constraints
var memoAreaToSpacer:NSLayoutConstraint = NSLayoutConstraint(item: spacer, attribute: NSLayoutAttribute.Top, relatedBy: NSLayoutRelation.Equal, toItem: memoArea, attribute: NSLayoutAttribute.Bottom, multiplier: 1, constant: 8)
spacerToBottom = NSLayoutConstraint(item: bottomLayoutGuide, attribute: NSLayoutAttribute.Top, relatedBy: .Equal, toItem: spacer, attribute: NSLayoutAttribute.Bottom, multiplier: 1, constant: 0)
view.addConstraint(memoAreaToSpacer)
view.addConstraint(spacerToBottom)
...
so when a keyboard fires a notification this happens.
func updateBottomLayoutConstraintWithNotification(notification: NSNotification) {
let userInfo = notification.userInfo!
let animationDuration = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as NSNumber).doubleValue
let keyboardEndFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as NSValue).CGRectValue()
let convertedKeyboardEndFrame = view.convertRect(keyboardEndFrame, fromView: view.window)
let rawAnimationCurve = (notification.userInfo![UIKeyboardAnimationCurveUserInfoKey] as NSNumber).unsignedIntValue << 16
let animationCurve = UIViewAnimationOptions.init(UInt(rawAnimationCurve))
let frame = self.tabBarController?.tabBar.frame
let height = frame?.size.height
spacerToBottom.constant = CGRectGetMaxY(view.bounds) - CGRectGetMinY(convertedKeyboardEndFrame) - height! - 5
UIView.animateWithDuration(animationDuration, delay: 0.0, options: .BeginFromCurrentState | animationCurve, animations: {
self.view.layoutIfNeeded()
}, completion: nil)
}
Here's the full app https://github.com/stanchiang/phoneHub
The code i'm talking about is in the BaseDetailViewController.swift in viewDidLoad().
The constraints i'm transferring from is the Edit Controller in the Main.storyboard file.
also, for reference i got it working through storyboard through this blog post.
http://effortlesscode.com/auto-layout-keyboard-shown-hidden/
thanks for your answers, still trying to get the hang of autolayout so general tips are welcome too.
I'm no Auto Layout expert, but I'll share what I know:
You need to turn off the AutoresizingMask for the views that you are adding constraints to:
view.setTranslatesAutoresizingMaskIntoConstraints(false)
spacer.setTranslatesAutoresizingMaskIntoConstraints(false)
memoArea.setTranslatesAutoresizingMaskIntoConstraints(false)
You are going to need a lot more constraints. I only see 2 in your code. You will need to fully constrain your layout. This includes the settings you are specifying right now with frames (width, height). Positions should probably be specified relative to other objects if you want everything to move when the keyboard shows up. When you got this working in the Storyboard, there had to be more than just 2 constraints for the entire ViewController. You'll need to bring over all of the constraints.
I suggest you add the following 6 constraints to replace the values you were setting with the frames. Put these with your other constraints. I've added the view frames in comments so that you can see where I got the values:
//var memoArea = UITextView(frame: CGRectMake(20, 291, 275, 225))
memoArea.addConstraint(NSLayoutConstraint(item: memoArea, attribute: .Width, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 275.0))
memoArea.addConstraint(NSLayoutConstraint(item: memoArea, attribute: .Height, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 225.0))
self.view.addConstraint(NSLayoutConstraint(item: memoArea, attribute: .Leading, relatedBy: .Equal,
toItem: self.view, attribute: .Leading, multiplier: 1.0, constant: 20.0))
// var spacer:UIView = UIView(frame: CGRectMake(84, 518, 160, 6))
spacer.addConstraint(NSLayoutConstraint(item: spacer, attribute: .Width, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 160.0))
spacer.addConstraint(NSLayoutConstraint(item: spacer, attribute: .Height, relatedBy: .Equal,
toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 6.0))
self.view.addConstraint(NSLayoutConstraint(item: spacer, attribute: .Leading, relatedBy: .Equal,
toItem: self.view, attribute: .Leading, multiplier: 1.0, constant: 84.0))