I'm programmatically adding a UITextField to a Horizontal UIStackView, which is inside a Vertical UIStackView, but it gets displayed with both rounded and sharp corners.
What I think the problem is is that the UITextField is being drawn twice, first with the default appearance and then with the custom appearance that I added to its layer.
The UITextField looks like this
If you look closely, you can see that the sharp corners color is the default one, while the rest of the border is darker.
The code that I use to modify its appearance is the following
myTextField.layer.borderWidth = 1.0
myTextField.layer.cornerRadius = 6.0
myTextField.layer.borderColor = UIColor.darkGray.cgColor
I think I'm missing something but I'm not sure what. Do you have any ideas?
Thanks in advance
EDIT
Before those lines of code, I call the UITextField initializer with no parameters like this
myTextField = UITextField()
EDIT 2
This is the entire code relating to the TextField
myTextField.layer.borderWidth = 1.0
myTextField.layer.cornerRadius = 6.0
myTextField.clipsToBounds = true
myTextField.layer.borderColor = UIColor.darkGray.cgColor
myTextField.isUserInteractionEnabled = false
// Create the constraints
constraints.append(NSLayoutConstraint(item: horizontalStackView, attribute: .width, relatedBy: .equal, toItem: verticalStackView, attribute: .width, multiplier: 1.0, constant: 0.0))
// Add the components to the Horizontal Stack View
horizontalStackView.addArrangedSubview(myTextField)
horizontalStackView.addArrangedSubview(myStepper) // A stepper that resides next to the conflicting TextField
verticalStackView.addArrangedSubview(horizontalStackView)
Try adding your subviews to your stack view like this.
let stackView = UIStackView(arrangedSubviews: [myTextView, myStepper])
stackView.axis = .vertical
stackView.distribution = .fillEqually
Also add in this
stackView.translatesAutoresizingMaskIntoConstraints = false
perhaps there is something funky with your constraints from the two stackviews
You may need
myTextField.clipsToBounds = true
I tried Sh_Khan solution and it worked, but after reading the comments I decided to try something else so there would be no performance cost. After commenting that line of code (the clipToBounds one) and running the app again, the corners didn't show up.
I'm completely positive there is no other change besides adding that line, running the app, and then commenting the same line out.
I'm not really sure what the problem (or even the solution) was. Maybe all I needed to do was to clean the build folder (Product -> Clean Build Folder) but that doesn't make sense to me.
Related
I created stackView and added three labels to it. Also I put these constraints
let nameLabel = UILabel()
//set .text, .mode and other for nameLabel
let ellipsisLabel = UILabel()
//set .text, .mode and other for ellipsisLabel
let amountAndMeasureLabel = UILabel()
//set .text, .mode and other for amountAndMeasureLabel
for label in [nameLabel, ellipsisLabel, amountAndMeasureLabel] {
stackView.addArrangedSubview(label)
}
NSLayoutConstraint.activate([
nameLabel.leadingAnchor.constraint(equalTo: stackView.leadingAnchor, constant: 0.0),
nameLabel.trailingAnchor.constraint(equalTo: ellipsisLabel.leadingAnchor, constant: 0.0),
nameLabel.widthAnchor.constraint(equalToConstant: nameLabel.intrinsicContentSize.width),
amountAndMeasureLabel.leadingAnchor.constraint(equalTo: ellipsisLabel.trailingAnchor, constant: 0.0),
amountAndMeasureLabel.trailingAnchor.constraint(equalTo: stackView.trailingAnchor, constant: 0.0),
amountAndMeasureLabel.widthAnchor.constraint(equalToConstant: amountAndMeasureLabel.intrinsicContentSize.width)
])
nameLabel.frame.width // 0
ellipsisLabel.frame.width // 0
amountAndMeasureLabel.frame.width // 0
I will demonstrate the situation on .xib for better understanding (I don't use this .xib)
But when I tried to get their .frame.width I got zeros.
Just activating constraints doesn't cause a view to layout. If you need stackView to immediately layout its subviews, you need to tell it to:
stackView.layoutIfNeeded()
Otherwise the system will automatically collect and apply all layout updates together the next time it's needed. Since forcing a layout may lead to unnecessary computations (if something later in the draw cycle changes the layout), you should generally avoid calling .layoutIfNeeded() unless you really need it. But it's fully supported if you do.
There is also .setNeedsLayout(), which tells the system that a view needs layout during the next draw cycle. You should use this if something changes layout in a way that the system won't notice. You generally don't need this if your changes are through UIKit itself. UIStackView knows that it needs layout after you call .addArrangedSubview. But if you change some piece of data that your layout relies on, you may need to tell UIKit.
I have am attempting to learn how to populate a view in my storyboard with sliders and buttons, programmatically. I am trying, currently, to get one programmed slider to adhere to a programmed NSLayoutConstraint
Here is my code:
let centerXConstraint = NSLayoutConstraint(item: self.volumeSliderP, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.centerX, multiplier: 1.0, constant: 10.0)
self.view.addConstraint(centerXConstraint)
I should mention, that when I substitute the first item for a slider which already exists on the view (which was placed via Storyboard, with it's own constraints also placed with IB/Storyboard), it does updated correctly with the above NSLayoutConstraint code. Also, I have been able to update my programmed volumeSliderP with custom code to change it's handle and rotate it to vertical successfully.
What step am I missing to allow this NSLayoutConstraint code to work upon my programmed slider?
Thank you for any help!
When working with constraints in code, you need to do two (maybe three) things, regardless of control type:
Set the translatesAutoresizingMaskIntoConstraints to false.
Failure to do so will set off constraint conflicts, which will appear in the console log. I usually create an extension to UIView for this:
public func turnOffAutoResizing() {
self.translatesAutoresizingMaskIntoConstraints = false
for view in self.subviews as [UIView] {
view.translatesAutoresizingMaskIntoConstraints = false
}
}
Then in viewDidLoad (after adding my subviews) I simply add a line:
view.turnOffAutoResizing()
Consider if any subviews have intrinsic content size.
As explained in the linked Apple doc, if you have label and a text field, the text field will expand to fit the label without the need for setting widths. A UISlider does not have an intrinsic width but it does have an intrinsic height.
So in your case you need to not only set position, it needs to define the width.
A combination of top and leading will yield enough for the layout engine to know "where" and "height", but not "width". Same would go if you defined "centerX" and something - you didn't list any code - for the Y factor (top, bottom, centerY).
If I'm stating this clearly, you should be able to see that the engine will know enough to say (in frame coordinates) "start the slider at X/Y, height is XX points (it has intrinsic height), but how long should it be?"
I typically set either top, leading, and trailing... or top, centerX, and width. But it varies with the need.
You can download a sample project demonstrating the issue below here:
https://github.com/DimaVartanian/keyboard-extension-height-bug
When creating a keyboard extension and not specifying a concrete height for its components but instead anchoring them to the view/inputView so that in theory the system will determine their height based on environment and orientation, in some situations that height instead turns into 0 and the keyboard is crushed (with the exception of anything that has a concrete height such as a self sized label or button).
This only seems to occur on iOS 10. On iOS 9, the child views resized correctly to fit the default automatic keyboard height.
There are several scenarios this can manifest and this project demonstrates a basic one. It starts with the basic keyboard extension template with the default "next keyboard" button and the 2 size constraints it comes with:
self.nextKeyboardButton.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true
self.nextKeyboardButton.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
Next, we create a single other view that we want to fill the space of the superview without defining a concrete size for itself:
let anotherView = UIView()
anotherView.backgroundColor = UIColor.red
anotherView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(anotherView)
anotherView.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true
anotherView.rightAnchor.constraint(equalTo: self.view.rightAnchor).isActive = true
anotherView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
Now, let's say we just want to anchor this new view to the bottom of our keyboard superview. We would just do something like:
anotherView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
The result looks like this:
iOS 9
iOS 10
This layout is exactly what we expect. Now instead, let's anchor the new view to the top of our next keyboard button. We get rid of the constraint we just added and replace it with
anotherView.bottomAnchor.constraint(equalTo: self.nextKeyboardButton.topAnchor).isActive = true
Logically, the resulting height should be the same (determined by the system)
The result is now this:
iOS 9
iOS 10
On iOS 9 it behaves as expected but on iOS 10, the flexible height view is resized down to 0 and all that is left is the fixed height button.
There are no messages about conflicting constraints. I'm trying to figure out what could be causing this and why it would only be happening on iOS 10.
Apple has responded to my DTS ticket and told me to file a bug report, so this is actually an iOS 10 bug. I have filed a radar (#28532959) and will update this answer if I ever get a response. If someone else comes up with a concrete solution that allows me to still use autolayout to achieve an automatic height, answers are still accepted.
I got it solved by setting a new constrain for the height.
Here's my workaround. It is a little laggy when the device rotates, but it will do the job until Apple fixes this bug. I first thought it had something to do with inputView.allowSelfSizing, but that variable didn't seem to change anything.
First, declare heightConstraint:
var heightConstraint: NSLayoutConstraint!
In viewDidLoad, Add your custom view:
let nibName: String! = UIDevice.isPhone ? "KeyboardViewiPhone" : "KeyboardViewiPad"
customView = Bundle.main.loadNibNamed(nibName, owner: self, options: nil)?.first as! UIView
customView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(customView)
Add a constraint for the width as you would do normally:
let widthConstraint = NSLayoutConstraint(item: view, attribute: .width, relatedBy: .equal, toItem: customView, attribute: .width, multiplier: 1.0, constant: 0.0)
Add a constant constraint for the height:
heightConstraint = NSLayoutConstraint(item: customView, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: view.frame.height)
view.addConstraints([widthConstraint, heightConstraint])
Now comes the fix:
override func viewDidLayoutSubviews() {
heightConstraint.constant = view.bounds.height
}
As viewDidLayoutSubviews is called every time view.bounds changes, it will handle orientation changes correctly.
I also faced the same issue. this is because of the Autolayout Constraints. Just remove all constraints. and set auto resizing.
I have also faced the same problem for the custom keyboard extension in Xcode 8.2. This is caused by the auto resizing. In my case, I solved this in the below manner.
Initially, my custom keyboard have 3 views.
In this, I was fixed the trailing, leading, top and height for the first and last view. And place the middle view like in the image.
after that select the middle view and open the show the size inspector in the storyboard. In the size inspector, you will find an option auto resizing. In that select the constraint indicators for that view.
After selecting that you run your project in a device and it will work correctly without missing any view.
Note: - It will work for both portrait and landscape modes. And mainly you don't have to give constraints for the middle view.
IMHO, best working solution is using "Proportional Height". For example, in my case, I finally ended with 2 views. Top one got 0.8 of height of superview, bottom - 0.2. It's not perfect solution, but you can still benefits from autolayout.
I am trying to layout some custom views and when I try to activate the constraints, Xcode says that I can't use multiplier. Here is an example of the code:
class MenuView: UIView {
var addButton: AddButton!
var settingsButton: SettingsButton!
// ........
func setConstraints (withBarReference reference: NSLayoutYAxisAnchor) {
NSLayoutConstraints.activateConstraints([
// ........
addButton.centerXAnchor.constraintEqualToAnchor(self.centerXAnchor, multiplier: 0.5),
// ........
settingsButton.centerXAnchor.constraintEqualToAnchor(self.centerXAnchor, multiplier: 1.5)
])
}
}
The thing here is that Xcode gives a syntax error on the contraintEqualToAnchor: functions and says that I should replace "multiplier" to "constant".
Why can't I use the multiplier option with the X center anchors?
You can't set multiplier using helper functions, but you can set multiplier using NSLayoutConstraint initializer. Just got stuck by this myself, but found the answer.
Your code: addButton.centerXAnchor.constraintEqualToAnchor(self.centerXAnchor, multiplier: 0.5)
Correct code: NSLayoutConstraint(item: addButton, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 0.5, constant: 0)
Also, don't forget to activate this constraint by typing isActive = true
Previous answers work very weird now.
You can simply create UILayoutGuide with multiplier width/height with view and set guide.trailing equal to the centerX of your subview.
For example, if you need to place the addButton in the first 1/3 of a view and settingsButton in 2/3 you can simply set two layout guides
let addButtonGuide = UILayoutGuide()
self.addLayoutGuide(addButtonGuide)
addButtonGuide.widthAnchor.constraint(equalTo: self.widthAnchor, multiplier: 1/3).isActive = true
addButtonGuide.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
addButton.centerXAnchor.constraint(equalTo: addButtonGuide.trailingAnchor).isActive = true
// same for settingsButton but using 2/3 for the multiplier
But the really best way is to use UIStackView and set its distribution property to equalCentering.
Another option is to use uncommon Auto Layout API to create NSLayoutDimension between two centerXAnchors and make constraint to self.widthAnchor:
addButton.centerXAnchor.anchorWithOffset(to: self.centerXAnchor)
.constraint(equalTo: self.widthAnchor, multiplier: 0.25).isActive = true
self.centerXAnchor.anchorWithOffset(to: settingsButton.centerXAnchor)
.constraint(equalTo: self.widthAnchor, multiplier: 0.25).isActive = true
It seems that in IB you can use the multiplier option with Center X and obtain the effect you're looking for (set the center of button1 at 1/4 the width of the view it's in, and the center of button2 at 2/3 of the width of the view it's in):
.
I tried to use it both in code and in IB, and in code I got the same error as you.
Surprisingly, in IB it worked, no errors, no warnings. (I am using Xcode 7, will try it in Xcode 8 to see if it still works).
You can't use multipliers on NSLayoutXAxisAnchor anchors - multiplying by a position along a line doesn't make sense in a way that the constraints system can understand. You can only use multipliers with NSLayoutDimension anchors, which measure lengths, like the width.
The layout you are trying to make would be better achieved using a stack view.
I have tried to make a UILabel that is a certain width using preferredMaxLayoutWidth but no matter what I do it won't work. Can you help me? I have tries so many different combinations to make it work.
#IBAction func addBottomTextButton(sender: AnyObject) {
if addBottomTextField.text.isEmpty == false {
let halfScreenWidth = screenSize.width * 0.5
let bottomScreenPosition = screenSize.width
memeBottomText = addBottomTextField.text
fontName = "Impact"
let memeBottomTextCaps = memeBottomText.uppercaseString // --> THIS IS A STRING!
labelBottom.text = memeBottomTextCaps
labelBottom.textColor = UIColor.blackColor()
labelBottom.textAlignment = .Center
labelBottom.font = UIFont(name: fontName, size: 32.0)
labelBottom.sizeToFit()
labelBottom.userInteractionEnabled = true
labelBottom.adjustsFontSizeToFitWidth = true
labelBottom.numberOfLines = 1
labelBottom.preferredMaxLayoutWidth = screenSize.width
labelBottom.setTranslatesAutoresizingMaskIntoConstraints(true)
var r = CGFloat(halfScreenWidth)
var s = CGFloat(bottomScreenPosition)
labelBottom.center = CGPoint(x: r, y: s)
self.view.addSubview(labelBottom)
self.view.addConstraint(NSLayoutConstraint(item: labelBottom, attribute:
NSLayoutAttribute.Top, relatedBy: NSLayoutRelation.Equal, toItem: labelBottom,
attribute: NSLayoutAttribute.Bottom, multiplier: 1, constant: 0))
dismissKeyboard()
}
}
Judging by your code I'd say your problem was you haven't got your constraints setup correctly and you're mixing using NSLayoutConstraints with setting the position using center and setting the size using sizeToFit.
Firstly, in the constraint you've setup you're relating labelBottom (the item argument) to itself (the toItem argument). I'm not exactly sure what you were trying to achieve with that? I'd recommend having a look at some tutorials on AutoLayout if you're unfamiliar with its concepts. Here's a good one: http://www.raywenderlich.com/50317/beginning-auto-layout-tutorial-in-ios-7-part-1
Secondly, just a small point, on the line let memeBottomTextCaps = memeBottomText.uppercaseString you've written // --> THIS IS A STRING. An easier way to remind yourself of the variable type when looking back at your code could be to use: let memeBottomTextCaps: String = memeBottomText.uppercaseString.
Thirdly, preferredMaxLayoutWidth isn't used to set the width of a UILabel - that's what the frame is for (or NSLayoutConstraints if you're using AutoLayout).
Lets get on with it!
Here's an example of how to create a label that is pinned to the bottom edge of its container view and is not allowed to be wider than it's container: (Keep in mind that all this can be done in IB)
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let label = UILabel()
// 1.
label.setTranslatesAutoresizingMaskIntoConstraints(false)
// 2.
label.text = // Put your text here.
// 3.
self.view.addSubview(label)
// 4.
let pinToBottomConstraint = NSLayoutConstraint(item: label,
attribute: .Bottom,
relatedBy: .Equal,
toItem: self.view,
attribute: .Bottom,
multiplier: 1.0,
constant: -8.0)
// 5.
let horizontalConstraints = NSLayoutConstraint.constraintsWithVisualFormat("|-8-[label]-8-|",
options: .DirectionLeadingToTrailing,
metrics: nil,
views: ["label" : label])
// 6.
self.view.addConstraint(pinToBottomConstraint)
self.view.addConstraints(horizontalConstraints)
}
}
The following referrers to the commented numbers in the code above.
1. You need to set setTranslatesAutoresizingMaskIntoConstraints to false to stop constraints being created that would otherwise conflict with the constraints we're going to create later. Here's the what Apple have to say about it:
Because the autoresizing mask naturally gives rise to constraints that fully specify a view’s position, any view that you wish to apply more flexible constraints to must be set to ignore its autoresizing mask using this method. You should call this method yourself for programmatically created views. Views created using a tool that allows setting constraints should have this set already.
2. You need to make sure you put your own text here, otherwise the code won't run.
3. The label must be added to the view hierarchy before adding constraints between it and it's superview! Otherwise, in this case, you'll get a runtime error saying:
Unable to parse constraint format:
Unable to interpret '|' character, because the related view doesn't have a superview
|-8-[label]-8-|
This is due to our horizontalConstraints needing to know the label's superview (the superview is denoted by the "|") but the label doesn't have a superview.
4. The pinToBottomConstraint constraint does what it says. The constant of -8 just specifies that I want the label to be 8 points from the bottom of its container view.
We don't need to create a constraint to specify the label's size - that's an intrinsic property of the UILabel which is determined, for example, by the number of lines and font.
5. The horiontalConstraints are created using Visual Format Language. Here's a good tutorial: http://code.tutsplus.com/tutorials/introduction-to-the-visual-format-language--cms-22715 Basically, "|-8-[label]-8-|" creates constraints to pin the left and right edges of the label to the left and right edges of its superview.
6. Finally add the constraints!
This is what it looks like:
I hope that answers your question.
I think the property only work for multiline situation.
// Support for constraint-based layout (auto layout)
// If nonzero, this is used when determining -intrinsicContentSize for multiline labels
#available(iOS 6.0, *)
open var preferredMaxLayoutWidth: CGFloat
And it indeed true after my test. So, we need set multiline. It will work.
titleLabel.numberOfLines = 0
I don't why Apple limit it to only multiline. In fact, we often need to set max width on label easily by one property.
Finally, if we want set max width , we need set max constaint, like the following
if device.isNew == "1" {
self.title.mas_updateConstraints { (make) in
make?.width.lessThanOrEqualTo()(163.w)
}
self.newTag.isHidden = false
} else {
self.newTag.isHidden = true
self.title.mas_updateConstraints { (make) in
make?.width.lessThanOrEqualTo()(207.w)
}
}