iosswiftuitableviewuiimageviewios-autolayout

Reputation: 2308

How to set up different Auto Layout constraints for different screen sizes

I have a tableView with static cells. The cell contains an ImageView which fills it completely. And I have another smaller ImageViews atop. I position this ImageViews with constraints. I have a question about resizing the constraints. How can I set different constraint constants for different devices sizes without programming if/else loops. Is there a way to set it in the storyboard? I have a leading constraint to parent layout for example with an constant value of 10. This is okay for the iPhone 5 screen, but on an iPhone 6/ 6 plus screen it should be higher than 10.

iPhone5 Autolayout

Screen Shot

iPhone6 Autolayout

Screen shot

Upvotes: 33

Answers (4)

Cem

Reputation: 502

You can use BayKit for this job.

What is BayKit:

Calculates the global offset for all screen sizes by depending on given screen size and given offset.

How to use BayKit: Usage is very easy, just import BayKit and set constant value with BayKit like this:

import BayKit

class MyViewController: UIViewController {
lazy var box = UIView()
let magicOffset = BayKit()

override func viewDidLoad() {
    super.viewDidLoad()
    view.addSubview(box)
    box.translatesAutoresizingMaskIntoConstraints = false

    box.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: magicOffset.offseter(scaleFactor: 1.0,
    offset: 24, direction: .horizontal, currentDeviceBound: BayKit.DeviceList.iPhone5.screenWidth)).isActive = true
}
}

As you can see this line calculating offset for all screen sizes:

magicOffset.offseter(scaleFactor: 1.0, offset: 24, direction: .horizontal, currentDeviceBound: BayKit.DeviceList.iPhone5.screenWidth)

Offseter Features:

scaleFactor: You can set if you want bigger or smaller then given offset(for default set 1.0).
offset: Preferred constant in tested device.
direction: Which direction are you looking for,i.e. (for width, leading, trailing use .horizontal,for height, top, bottom use .vertical)
currentDeviceBound: Find your best fit device and set as a main device with this. BayKit will calculate constraints with depending on your best fit screen!

Example Result:

Upvotes: 2

Saheb Roy

Reputation: 5957

Very easy. You can change constants values for difference size classes in Storyboard. I am giving u a few steps after which you will be able to grasp it.

First we create constants as you can see on this view

Next we select the constant we want to change the value in other size classes.

Now comes the tricky part. In the attribute inspector after selecting the constant, you can see the value of the constant. Right beside you can see the PLUS (+) sign, left of the "constant".

Click on it and select your size class that you want. Here i have selected Regular Height Regular Width i.e for iPad sizes.

Next we give it a new value. So the constant, which normally is of value 61, will function as 10 when rendered in a size class of iPad size classes.

Here is the output --

iPhone 4:

iPad Air:

As you can see, the same constants has different value in runtime corresponding to different size classes.

Hope my explanation helped you.

Upvotes: 59

Kuldeep Tanwar

Reputation: 3526

Without writing a single line of Code!

Once my junior developer asked me the same question that how can I differentiate between iPhoneSE and iPhone6 for some constraint at that time there was only one solution that was writing some thing like

if device == iPhoneSE { 
   constant = 44 
} else if device == iPhone6 {
   constant = 52
}

To overcome this issue I created a library Layout Helper so now you can update constraint for each device without writing a single line of code.

Step 1

Assign the NSLayoutHelper to your constraint

Step 2

Update the constraint for the device you want

Step 3

Run the app and see the MAGIC

Upvotes: 22

Vitya Shurapov