I'm creating part of my application's UI with Swift and the problem I'm facing is I have a UIStackView with 3 sub views: 2 UILabels and an UIImageView. Here is my first code
let switchview = UISwitch()
let nodelableview = UILabel()
nodelableview.textAlignment = NSTextAlignment.right
nodelableview.numberOfLines = 0
nodelableview.text = nodes[i].type + " " + nodes[i].node_name
let statLabel = UILabel()
statLabel.textAlignment = NSTextAlignment.left
statLabel.text = nodes[i].stat
let stack = UIStackView()
stack.axis = .horizontal
stack.spacing = 16
stack.addArrangedSubview(statLabel)
stack.addArrangedSubview(nodelableview)
stack.addArrangedSubview(switchview)
cell.nodesView.addArrangedSubview(stack)
the problem with this code is that when the nodelabelview has long text the UIStackView not extending to make space for 2 or more lines. So I set the alignment to .center and here is the result
There is empty space left but the first UILabel is using it for nothing. How can I force the second UILabel to use available spaces?
A setup that would give priority to your second label (the one with unlimited number of lines), would be a stackview set to "Fill Proportionally" distribution (which means that views are sized based on their intrinsic size & hugging/resistance priorities)
combined with a horizontal "Content Compression Resistance Priority" of 1000 ('required') for the left label & the switch (which means 'do not compress')
which is resolved to this:
You may need to set the horizontal contentHuggingPriority and contentCompressionResistance for each label / switch to something different from the others, ensuring that the one you wish to expand to fill remaining available space has the lowest hugging value.
Related
I am trying to offset the center starting point for a UILabel. The problem that I am facing is that I can't make the label text to grow from a point that is offset from center until it reaches one end of the label. Then, I want the text to shift one character to the left with each additional added character until it reaches the the other end. Then it would be acceptable for the text to truncate with an ellipses.
So far, my code looks like this but I don't know where to go from here.
private let amountLabel: UILabel = {
let label = UILabel()
label.textColor = .blue
label.textAlignment = .center
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
I suggest you put the UILabel into a container view, center horizontally with the offset you want, but set its priority lower than the compression resistance., e.g. 750, compression resistance 999. Then create a trailing constraint >= with priority 1000, and leading constraint >= priority 1000. In that way centering will be the weakest constraint and as the text grows it will shift to the left until it reaches the leading.
Below is the code in Swift I used for a 2 line UILabel with adjustsFontSizeToFitWidth set to true, working properly for left-to-right text. I have used EasyPeasy library for setting layout constraints.
let contactLabel = UILabel()
contactLabel.text = "Tell us how we can contact you".localized()
contactView.addSubview(contactLabel)
contactLabel.easy.layout([Leading(), Trailing(), Top(20), Height(60)])
contactLabel.numberOfLines = 2
contactLabel.lineBreakMode = .byTruncatingHead
contactLabel.adjustsFontSizeToFitWidth = true
When I changed the language to Arabic, the text will be broken to two lines properly but shown in LTR mode instead of RTL. How should manage a multiline label to show Arabic text?
I also checked this behavior on iOS 11 and it is working, maybe there is a trick to it in iOS 12.
Don't set a specific height because of that is not expanding to your amount of text.
Steps 1 - Set top, leading, trailing and height constraint and change height relation to Greater Than or Equal to
Step 2 - label.numberOfLines = 0
Step 3 - label.sizeToFit()
step 4 - label.lineBreakMode = .byTruncatingTail
Although setting the label alignment to "natural" works in most cases, iOS sometimes gets it wrong. If you're out of ideas, you can always set it manually in the code based on the current layout direction of the application.
if UIApplication.shared.userInterfaceLayoutDirection == .leftToRight {
resultLabel.textAlignment = .left
} else {
resultLabel.textAlignment = .right
}
Imagine a stack view with four items, filling something. (Say, filling the screen).
Notice there are three gaps, ABC.
(Note - the yellow blocks are always some fixed height each.)
(Only the gaps change, depending on the overall height available to the stack view.)
Say UISV is able to draw everything, with say 300 left over. The three gaps will be 100 each.
In the example, 9 is left over, so A B and C are 3 each.
However.
Very often, you want the gaps themselves to enjoy a proportional relationship.
Thus - your designer may say something like
If the screen is too tall, expand the spaces at A, B and C. However. Always expand B let's say 4x as fast as the gaps at A and B."
So, if "12" is left over, that would be 2,8,2. Whereas when 18 is left over, that would be 3,12,3.
Is this concept available in stack view? Else, how would you do it?
(Note that recently added to stack view, you can indeed specify the gaps individually. So, it would be possible to do it "manually", but it would be a real mess, you'd be working against the solver a lot.)
You can achieve that by following workaround. Instead of spacing, for each space add a new UIView() that would be a stretchable space. And then just add constraints between heights of these "spaces" that would constrain their heights together based on the multipliers you want, so e.g.:
space1.heightAnchor.constraint(equalTo: space2.heightAnchor, multiplier: 2).isActive = true
And to make it work I think you'd have to add one constraint that would try to stretch those spaces in case there is free space:
let stretchingConstraint = space1.heightAnchor.constraint(equalToConstant: 1000)
// lowest priority to make sure it wont override any of the rest of constraints and compression resistances
stretchingConstraint.priority = UILayoutPriority(rawValue: 1)
stretchingConstraint.isActive = true
The "normal" content views would have to have intrinsic size or explicit constraints setting their heights to work properly.
Here is an example:
class MyViewController: UIViewController {
fileprivate let stack = UIStackView()
fileprivate let views = [UIView(), UIView(), UIView(), UIView()]
fileprivate let spaces = [UIView(), UIView(), UIView()]
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = .white
self.view.addSubview(stack)
// let stack fill the whole view
stack.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
stack.topAnchor.constraint(equalTo: self.view.topAnchor),
stack.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
stack.leftAnchor.constraint(equalTo: self.view.leftAnchor),
stack.rightAnchor.constraint(equalTo: self.view.rightAnchor),
])
stack.alignment = .fill
// distribution must be .fill
stack.distribution = .fill
stack.spacing = 0
stack.axis = .vertical
for (index, view) in views.enumerated() {
stack.addArrangedSubview(view)
view.translatesAutoresizingMaskIntoConstraints = false
// give it explicit height (or use intrinsic height)
view.heightAnchor.constraint(equalToConstant: 50).isActive = true
view.backgroundColor = .orange
// intertwin it with spaces
if index < spaces.count {
stack.addArrangedSubview(spaces[index])
spaces[index].translatesAutoresizingMaskIntoConstraints = false
}
}
// constraints for 1 4 1 proportions
NSLayoutConstraint.activate([
spaces[1].heightAnchor.constraint(equalTo: spaces[0].heightAnchor, multiplier: 4),
spaces[2].heightAnchor.constraint(equalTo: spaces[0].heightAnchor, multiplier: 1),
])
let stretchConstraint = spaces[0].heightAnchor.constraint(equalToConstant: 1000)
stretchConstraint.priority = UILayoutPriority(rawValue: 1)
stretchConstraint.isActive = true
}
}
Remarkably, #MilanNosáľ 's solution works perfectly.
You do not need to set any priorities/etc - it works perfectly "naturally" in the iOS solver!
Set the four content areas simply to 50 fixed height. (Use any intrinsic content items.)
Simply don't set the height at all of "gap1".
Set gap2 and gap3 to be equal height of gap1.
Simply - set the ratios you want for gap2 and gap3 !
Versus gap1.
So, gap2 is 0.512 the height of gap1, gap3 is 0.398 the height of gap1, etc.
It does solve it in all cases.
Fantastic!!!!!!!!!!
So: in the three examples (being phones with three different screen heights). In fact the relative heights of the gaps, is always the same. Your design department will rejoice! :)
Created: a gist with a storyboard example
The key here is Equal Heights between your arranged views and your reference view:
And then change the 'Multiplier` to your desired sizes:
In this example I have 0.2 for the main view sizes (dark grey), 0.05 within the pairs (black), and 0.1 between the pairs (light grey)
Then simply changing the size of the containing view will cause the views to re-size proportionally:
This is entirely within the storyboard, but you could do the same thing in code.
Note that I'm using only proportions within the StackView to avoid having an incorrect total size, (and making sure they add up to 1.0), but it should be possible to also have some set heights within the StackView if done correctly.
I have a name label in a cell that is intrinsically sized so that the left anchor of the time label may always be 5 pixels from the left anchor of the name label. However when I introduce names from core data, it takes the initial setup name and uses that name to intrinsically size the name label frame.
Here is where I create the label view.
let nameLabel: UILabel = {
let nlabel = UILabel()
nlabel.text = "Barack Obama"
nlabel.font = UIFont.boldSystemFont(ofSize: 12)
nlabel.textAlignment = .left
nlabel.frame.size = nlabel.intrinsicContentSize
nlabel.backgroundColor = UIColor.blue
print("nlabel frame \(nlabel.frame.size)")
return nlabel
}()
nlabel.text for each cell is equal to cell?.friend?.name
I am successfully able to load the names into the cell however the frame is still sized as if nlabel.text was equal to the first nlabel.text.
Any suggestions?
Assuming you are using Auto Layout, remove this line:
nlabel.frame.size = nlabel.intrinsicContentSize
And add this line:
nlabel.translatesAutoresizingMaskIntoConstraints = false
With Auto Layout, you must not set the frame size yourself.
You are giving the same size to every label you create. The size is not going to change just because you change the text it contains.
Labels have intrinsic size, but when you create labels in code, not the storyboard, you need to set translatesAutoResizingMaskIntoConstraints to false in order for this to work. When you create labels in the storyboard, this is done for you automatically.
For more info, see https://developer.apple.com/reference/uikit/uiview/1622572-translatesautoresizingmaskintoco?language=objc
Say I have three UILabels whose positions are like below:
[Label1] [Label2]
[Label3]
Label1 and Label2 are in the same row and Label3 is below them. All the labels will have a fixed width and will contain dynamic text, so their height will vary.
How do I make the Label3 10 points below the label which has a higher height using AutoLayout?
For example, if Label1's height is 100 points, Label2's height is 120 points (their Y positions are the same), then Label3 should be 10 points below Label2, but if Label1 is 120 points high and Label2 is 100 points high, then Label3 should be 10 points below Label1.
You simply make constraints between both Label3->Label1 and Label3->Label2. Use inequality constraints. There will be only one way to satisfy both!
You will also need a top constraint for Label3; its constant should be very small and its priority should be very low. This will give the two inequality constraints something to "aim at".
Here is an example. This as achieved entirely without code - the buttons have code to add text to the labels, of course, but the constraints are configured entirely in Interface Builder; the labels are resizing, and the bottom label is moving down, automatically. (You can construct the same layout in code if you want to, naturally.)
I suggest you to wrap top two labels to UIView and setup constraints so these labels fit all space inside that view. Then you simple add vertical spacing constraint to bottom label3 with constant = 10. In that case top view will have size of larger label and will satisfy your conditions
I thought this would be an interesting exercise so I create a little test project. The gist of the code is below. You can just copy/paste it in the standard Single View iOS template.
(Note that I use SnapKit for programmatic Auto Layout because it is so much simpler than the UIKit API. I find it even much simpler than doing things in Xcode.)
The result is exactly the same as Matt's great screencast.
// ViewController.swift
import UIKit
import SnapKit
class ViewController: UIViewController
{
override func viewDidLoad() {
super.viewDidLoad()
let leftLabel = UILabel()
leftLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "addText:"))
leftLabel.userInteractionEnabled = true
view.addSubview(leftLabel)
leftLabel.numberOfLines = 0
leftLabel.text = "All the world's a stage, and all the men and women merely players: they have their exits and their entrances; and one man in his time plays many parts, his acts being seven ages."
leftLabel.snp_makeConstraints { (make) -> Void in
make.top.equalTo(40)
make.left.equalTo(self.view)
make.right.equalTo(self.view.snp_centerX)
}
let rightLabel = UILabel()
rightLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "addText:"))
rightLabel.userInteractionEnabled = true
view.addSubview(rightLabel)
rightLabel.numberOfLines = 0
rightLabel.text = "There is a tide in the affairs of men, Which taken at the flood, leads on to fortune. Omitted, all the voyage of their life is bound in shallows and in miseries. On such a full sea are we now afloat. And we must take the current when it serves, or lose our ventures."
rightLabel.snp_makeConstraints { (make) -> Void in
make.top.equalTo(40)
make.right.equalTo(self.view)
make.left.equalTo(self.view.snp_centerX)
}
let bottomView = UIView()
view.addSubview(bottomView)
bottomView.backgroundColor = UIColor.redColor()
bottomView.snp_makeConstraints { (make) -> Void in
make.height.equalTo(20)
make.left.right.equalTo(self.view)
make.top.greaterThanOrEqualTo(leftLabel.snp_bottom)
make.top.greaterThanOrEqualTo(rightLabel.snp_bottom)
}
}
#objc func addText(recognizer: UIGestureRecognizer) {
if let label = recognizer.view as? UILabel {
label.text = label.text! + " I like cheese."
}
}
}
Updated the code to add some additional text to the labels when tapped.
First of all remove height constraints and set all 3 labels vertical Content Compression Resistance Priority to 1000. This is the most important part.
Then add vertical space from Label3 to Label 1, and set instead of Equal, Greater Than or Equal with priority say 500. Add same space constraint to Label2.
Last add constraint from Label3 to Top = 0, but set priority to 1.