Two labels alignment and its constraints - ios

I have 2 labels: the description label (w/ red background) and the results label (gray text)
How do i set constraints for this example in order to have the results label with the size of its content and the description label until the results leadingAnchor? (like i have in the second row)
Objective C
[self.customTextLabel.trailingAnchor constraintLessThanOrEqualToAnchor:self.counterLabel.leadingAnchor].active = YES;
[self.counterLabel.widthAnchor constraintGreaterThanOrEqualToConstant:0].active = YES;
swift
titleLabel.trailingAnchor.constraint(lessThanOrEqualTo: counterLabel.leadingAnchor).isActive = true
counterLabel.widthAnchor.constraint(greaterThanOrEqualToConstant: 0).isActive = true
I have a solution that i think it's ugly.
self.counterLabelWidthConstraint = [self.counterLabel.widthAnchor constraintEqualToConstant:0];
self.counterLabelWidthConstraint.active = YES;
And then after i set the text:
self.counterLabelWidthConstraint.constant = [self.counterLabel sizeThatFits:CGSizeMake(CGFLOAT_MAX, self.counterLabel.height)].width;

The way to do this with auto layout is by using the contentCompressionResistancePriority of the 2 labels. Set the pririty to NSLayoutPriorityRequired for the second label and something lower like NSLayoutPriorityDefaultLow for the first label. Then, as long as the 2 labels have proper constraints anchoring them to their superview and each other, the first label should compress while the second label should not.

You just need to increase the horizontal compression resistance of the right/gray label to be higher than that of the left/red label. This tells the visual layout that, in the event that there is not enough space for both labels, the one on the left will be compressed before shrinking the label on the right. 750 is the default for all views, so just increase the right/gray label's horizontal compression resistance to 751 and you should be good to go.

Swift 5 programatically:
<#label#>.setContentCompressionResistancePriority(.required, for: .horizontal)
Labels with this property will not compress horizontally.

You can set constraints for in storyboard itself. Select Label 1 (red back ground) and label's superview set widths are equal constraint. Select Label 1 and double tap on its width constraint, from the resultant window, you could see Lable 1 width equal to superview with value constant as '1'. change '1' to 0.7 or whichever the percentage you want.

Related

Multicolumn list with flexible columns width - iOS

I want to create list with two columns. Text in first column should be aligned to left and text in second column should be aligned to right. Space between columns should be constant. Different cases depends on texts length should be covered:
1.
Text 123
TextText 12
Tex 123
Text 1
Te 123456
T 12
Te 1234
Te 1
Text 123
TextText 12
TextTextTextTextText 123
Text 1
Both columns should have flexible width depends on the longest text. They also should have some minimum width so it will not be completely invisible if text in other column will be too long. Whole list also should have flexible width, of course there is some max width and then text in first column should be divided into lines. I don't want to divide into lines text in second column as long as I don't have to.
How to create such list?
I try to use for it two stack views one next to the other. These two stack views I have in my custom control. My custom control is added to container view using xib and have constraints equals to 0 for top, leading and bottom and greater or equals 0 for trailing. To these stack views I add labels programatically and I also set content hugging priority for them (first label has lower priority than second one). One think stil doesn't work, first stack view is as width as first label in this stack view. It doesn't change his width when other labels with longer texts are added. Is it possible to have working solution without calculating stack views width manually?
private void Initialize()
{
_firstStackView = new UIStackView
{
TranslatesAutoresizingMaskIntoConstraints = false,
Axis = UILayoutConstraintAxis.Vertical,
Spacing = 4
};
_secondStackView = new UIStackView
{
TranslatesAutoresizingMaskIntoConstraints = false,
Axis = UILayoutConstraintAxis.Vertical,
Spacing = 4,
Alignment = UIStackViewAlignment.Trailing
};
Add(_firstStackView);
Add(_secondStackView);
AddConstraints();
}
private void AddConstraints()
{
NSLayoutConstraint.ActivateConstraints(
new[]
{
_firstStackView.LeadingAnchor.ConstraintEqualTo(LeadingAnchor),
_secondStackView.LeadingAnchor.ConstraintEqualTo(_firstStackView.TrailingAnchor, 20),
TrailingAnchor.ConstraintEqualTo(_secondStackView.TrailingAnchor),
_firstStackView.TopAnchor.ConstraintEqualTo(TopAnchor),
_firstStackView.BottomAnchor.ConstraintEqualTo(BottomAnchor),
_secondStackView.CenterYAnchor.ConstraintEqualTo(_firstStackView.CenterYAnchor),
_secondStackView.WidthAnchor.ConstraintGreaterThanOrEqualTo(WidthAnchor, 0.25f),
_firstStackView.WidthAnchor.ConstraintGreaterThanOrEqualTo(WidthAnchor, 0.25f),
});
}
You can use UICollectionView to create list with two columns. Space between columns and grid size can be adjusted by changing UICollectionViewLayout.
Implement text adaptive width and height:
Instantiate UILabel
Set the UILabel property to get the text content and font
Calculate the size according to text and font
Use CGSize to set the maximum width you want
Set the frame according to the size
You can see some useful info here
For more details, you can refer to the following doc:
Collection Views in Xamarin.iOS | Microsoft Docs

How to set auto size text for different screens

My task is to preserve the size and position of the elements inside my cell for different screen resolutions.
I did:
Established constraints for the red and green blocks (UILabels) to
the outer container.
Set the constraint between them equal to 0. It is more priority than the limitation of the red block to the bottom and green to the top.
Set Lines = 0 for these labels.
Set Autoshrink.
As a result, the font size changes on different devices. But there are still a few problems:
How can I remove too large paddings above and below both labels?
How to make them resize evenly?
Now one of the blocks has an advantage over the other, depending on what constraint to make a higher priority. If you make them equal - it also does not work.
(I would like to do everything through Interface Builder)
Screenshot with differing priorities of constraints
My constraints
Paddings and Attributes
You can take advantage of equal height and equal width constraints.
Follow the below steps to make the UILabel spacing same on iPhone 8 and iPhone 4s. This will help you to make it proportional.
1) To achieve this simply select, your label(red), label (green) and the superview (which I think you're its a cell of UICollectionView)
2) We are interested here in keeping the height proportional.
i.e Red Label (80%) and Green Label (20%)
Currently, all heights are equal to superview height i.e height of RedLabel and Greenlabel is equal to 100% of superview.
But the goal is to make it 80% and 20% for red and green label respectively.
So select Red Label height constraint. Here you set the constraint which says's "height of the red label should be 80% of the superviews height".
Similarly for Green Label, set "height of the greeen label such that it's 20% for the superview's height".
Red Label
Green Label
3) Now complete the x and y axis position constraint, which would be straight forward
a) Red Label Leading = Leading edge of superview
b) Red Label Trailing = Trailing edge of superview
c) Red Label Top = Top edge of superview
d) Red Label Bottom = not required (as it has all the required constraint's to justify it's position i.e height = 0.8 * superview and it is top aligned, ex: super view height is 100 , keep this view top aligned with height = 80 )
e) Green Label Leading = Red Label Leading (you have already set this in point "a" no need to set the constraint again for Green label)
f) Green Label Trailing = Red Label Leading (you have already set this in point "b" no need to set the constraint again for Green label)
g) Green label bottom = bottom of superview
h) Green label top = not required (as it has all the required constraint's to justify it's position i.e height = 0.2 * superview and it is bottom aligned, ex: super view height is 100 , keep this view bottom aligned with height = 20 )
This is the final constraint list and the storyboard preview for iPhone 8 and 4s.

Custom UITableViewCell - adjust UILabel vertical alignment dynamically

I have a custom table cell. It has two labels (title and description), one below the other.
What I have right now is, title label top = topMargin. And description label top = title label bottom + 10.
But in some cases, there will be no description. In such cases, I want the title label to be centered vertically inside the cell. Is this possible? What constraints do I have to set?
A UIStackView makes it easy to do what you want.
Create a prototype cell
add two labels
embed them in a stack view
set the stack view's properties to:
Axis: Vertical
Alignment: Fill
Distribution: Fill Equally
Spacing: 10
constrain the stack view Top/Leading/Trailing/Bottom to 0 to the cell's content view's default margins (or set your own "padding")
set your fixed row height - with default labels + 10-point spacing + top and bottom margins, you'll probably want at least 67
connect the labels to IBOutlets
When you set the text of the labels in cellForRowAt indexPath:, set the description label's .isHidden property to true if it has a description, or to false if it doesn't.
The result (with background colors for clarity):
The result without background colors:

Label doesn't show all the text inside scrollView

I want the DecriptionLabel (the Lorem Ipsum one) to have all the text inside it visible. As you can see, it is getting trimmed.
The two buttons should be under everything else, but in the case where DescriptionLabel contains a small text, the buttons should stick to the bottom of the view.
This is why I chose a >= 20 distance between the buttons and DescriptionLabel if it makes any sense.
How can I solve the trimming of the text?
Thanks.
I was originally answering How to make button stick to bottom of scroll view if the content isn't large enough? but since it is marked as duplicate of this one I am posting my answer here. Please try to set your constraints the following way: https://imageshack.com/a/img923/6671/Txzu98.png
The trick is that you set Button.Bottom Equal To ContainerView.Bottom with lower priority (I use 750) than Button.Top Greater Than Or Equal To Label.Bottom (Here I use default 1000)
The Label has to have number of lines set to 0. The height of the button should be set by height constraint (in this case is 50). The Container View Height constraint should be with low priority (in this case 250)
You should run the code to see actual result on device or simulator. Storyboard shows it a bit differently. For the current question:
https://imageshack.com/a/img923/7276/tQeT0h.png The basic idea is the same. Button Down has the same constraints as Button from above answer without Button.Top Greater Than Or Equal To Label.Bottom. There should be fixed vertical constraint between Button Up and Button Down. I am setting Button Up with fixed Height and setting trailing and leading constraint equal to trailing and leading of Button Down. The constraint Button.Top Greater Than Or Equal To Label.Bottom is now Button Up.Top Greater Than Or Equal To Label.Bottom
Have you set numberOfLines for label to 0 (that means autosize the label according to its text length)?
You should add the following constraints:
(following in sudo code)
// Constraints for ScrollView
scrollView.top = ViewController.view.top
scrollView.leading = ViewController.view.leading
scrollView.trailing = ViewController.view.trailing
scrollView.bottom = ViewController.view.bottom
// Constraints for View
view.top = scrollView.top
view.leading = scrollView.leading
view.trailing = scrollView.trailing
view.bottom = scrollView.bottom
// Width of view
view.width = ViewController.view.width
Now you just need to make sure you have layout constraints for each child of the 'view' and it's height will be correct and display the full size of the textview.
Add the following constraint:
scrollview.contentview.height >= safearea.height
This may show an error in interface builder but works in my tests:
To remove the design time error you could set a design time intrinsic content size for the scrollview's contentview (in my case I used the safe area's height of 554):
Another option (without placeholder values in IB) is to create the following constraint...
scrollview.contentview.height = safearea.height
... and change its priority to a value lower than the label's vertical content compression resistancy.

Which Constraint we need to make dynamic View height in iOS

As I am new to iOS. So forgive me if it is duplicate or very basic question.
I am taking one View. Approx below is the size .
x : 5 y : 5
Width : 590 Height : 100
and I set constraint it
Top to superView 5
Trailing to superView 5
Leading to superView 5
Now I have one Label which have dynamic Text and the Text is too large.
And the Label Constraint is below
Top to superView 5
Trailing to superView 5
Leading to superView 5
and when i set the background color of the View the color is not set. If the Text is to Long. So how to set the Height of the View and also set background so that it looks clear.
Code :
public override void ViewDidLoad()
{
base.ViewDidLoad();
lbl_one.Text = "This is a long label which have long text inside the writing. This is a long label which have long text inside the writing. This is a long label which have long text inside the writing. This is a long label which have long text inside the writing";
lbl_one.LineBreakMode = UILineBreakMode.WordWrap;
lbl_one.Lines = 0;
view_main.BackgroundColor = UIColor.Red;
}
If I give fix Height then it look like this .
Output :
1. Give the below constraints to your view, height is according to your need. here I'm giving 80.
2. Change the height relationship.
3. Add aUILabel in your above UIview, and give below constraints.
--> leading, top, bottom, trailing to uiview and height i.e. 80.
4. set height relationship as you do with UIView.
5. Change the property of UILabel , Lines to zero
6. Now enjoy with your constraints.
EDIT: Add bottom constraint to your view instead of height constraint.
I don't see and bottom constraint added to UIView, so the view height will be 0.
If you have added the height constraint to UIView, there is a probability that UILablel might be overlapping the UIView, so you are not able to see the background color.
Set the UIView height constraint this will solve your problem
You can also add height or bottom constraint to your UIView.

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