CODEWITHSUNDEEP
swiftuiviewcontrollerconstraintsios9
Vah.Sah
Vah.Sah

Reputation: 532

IOS9 programmatically constraints for iphone and ipad

In view controller i have created uitextfield programmatically. For this textField I would like to have the following constraints: 90 pixel from top, 50 pixel for height, 8 pixels from right and left sides for iphone devices (so the width is adjusted) and 400 pixel fixed width in case of ipad devices.

Here is the part of my code where these constraints are specified:

text.topAnchor.constraint(equalTo: view.topAnchor, constant: 90).isActive = true
text.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 8).isActive = true
text.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -8).isActive = true
text.heightAnchor.constraint(equalToConstant: 50).isActive = true

This code provide right result for iphone devices, however for ipad devices it is not what I want to get (the width of text field is adjusted). I understand that the block of code is not correct for ipad.

My question is how can i set the constraints programmatically for iphone and ipad devices for the logics described above?

I think the possible solution might be to check screen size width before setting constraints, but I don't know is it proper solution for this task.

Upvotes: 1

Views: 1459

Answers (3)

Sanzio Angeli
Sanzio Angeli

Reputation: 3922

Using the leftAnchor and rightAnchor instead of leading/trailing might be more friendly across devices, although Apple recommends using leading trailing whenever possible.

Upvotes: 0

matt
matt

Reputation: 535304

8 pixels from right and left sides for iphone devices (so the width is adjusted) and 400 pixel fixed width in case of ipad devices

First, let's notice that for iPad your constraints are insufficiently specified, as you are not saying where the x-origin of the view should be on iPad. So, for purposes of discussion, I will have to make something up: I'll say that you want the view horizontally centered.

So, having stipulated that, all you have to do is look at the traitCollection and examine its userInterfaceIdiom. This tells you whether we are on iPad or iPhone (.pad or .phone), and a simple if/else construct will allow you to supply the appropriate set of constraints.

So, without my actually writing the constraints for you, here's the structure you'll use:

text.topAnchor.constraint(equalTo: view.topAnchor, constant: 90).isActive = true
text.heightAnchor.constraint(equalToConstant: 50).isActive = true
let dev = self.traitCollection.userInterfaceIdiom
if dev == .phone {
    text.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 8).isActive = true
    text.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -8).isActive = true
} else {
    text.widthAnchor.constraint...
    text.centerXAnchor.constraint...
}

Upvotes: 2

user7219266
user7219266

Reputation:

In order to complete @matt's great answer, here is an example of how you can check if the device is iPad or iPhone.

enum UIUserInterfaceIdiom : Int {
    case unspecified

    case phone // iPhone
    case pad // iPad
}

You can then use it like this :

UIDevice.current.userInterfaceIdiom == .pad
UIDevice.current.userInterfaceIdiom == .phone
UIDevice.current.userInterfaceIdiom == .unspecified

Or if you prefer with a Switch :

switch UIDevice.current.userInterfaceIdiom {
case .phone:
    // It's an iPhone
case .pad:
    // It's an iPad
case .unspecified:
    // Error handling
}

For your case, you can simply use an if/else statement.

You just have to check IF the device is an iPad or an iPhone, and then set your constraints accordingly.

Upvotes: 4

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