CODEWITHSUNDEEP
iosobjective-cipadios8autolayout
Oleg Danu
Oleg Danu

Reputation: 4159

Autolayout iPad for Portrait and Landscape

Given the fact that we have only common size class for both iPad Portrait and iPad Landscape, how do you finally customize your Autolayout behaviour/constraints for iPad for different orientations?

I want to have something like this in Portrait: enter image description here

And this in Landscape: enter image description here

Upvotes: 2

Views: 2042

Answers (2)

TonyMkenu
TonyMkenu

Reputation: 7667

In iOS 8 the easy way (for the moment) is to use viewWillTransitionToSize:withTransitionCoordinator

Here you have an example with your request using the above notification testLandscapePortrait_iPad

Upvotes: 2

rdelmar
rdelmar

Reputation: 104082

In iOS 8, you can use viewWillTransitionToSize:withTransitionCoordinator:, to be notified when the controller is being rotated. Use the ratio of height to width to determine which orientation you are moving to, and adjust your constraints accordingly. You could make IBOutlets to the view's height and width constraints, and change their constant values inside that method.

Another way to do this is to use the multiplier and constant together in a way that automatically adjusts the constraints on rotation. The formula for a relative width constraint, for example, would be:

subview.width = superview.width * multiplier + constant

So, for example, if you wanted the view full width (768) in portrait and 350 in landscape, you would solve these two equations,

768 = 768 * m + c   and   350 = 1024*m + c

Solving those, gives you m= -1.6328  and   c= 2022

To use this, you would give your subview a width constraint in IB, but check the "remove at build time" box so it will be removed and replaced with the one you add in code.

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.subView attribute:NSLayoutAttributeWidth relatedBy:0 toItem:self.view attribute:NSLayoutAttributeWidth multiplier:-1.6328 constant:2022]];
}

Normally, you could do this all in IB, but only if the multiplier is positive; I've tried it with these numbers, and the system won't allow me to use a negative number for the multiplier.

Upvotes: 2

Related Questions