Xcode 5 / iOS7: Trying to add constraints to resize between iPhone 3.5" and 4" screen

Question

I am struggling to use Xcode 5's constraints to fit content (relatively) between 3.5" and 4" screens. To simplify matters, I am only concerned about portrait at this moment

Here is an example screen of a layout on a 4" screen (the tab controller at bottom isn't shown):

I want to lock the proportions of any images (such as this truck), but allow all labels, buttons etc to squeeze more closely together on the 3.5" screen. As all iPhones are the same width, I think I need to leave the x-constraints as-is, but configure dynamic y-co-ordinates, but would appreciate advice on this.

Many thanks.

Answer 1

You can pin the width and height of your image in your storyboard by selecting the image and then adding the necessary constraints (your numbers will be different):

You can add constraints to automatically change the vertical layout by making the relation by "greater than or equal" or "less than or equal", but, in my experience, it is difficult that the result is exactly what you want, as the autolayout engine will not make the line separations the same.

My suggestion is that once you have the layout for one of the screen sizes, you add outlets for the vertical constraints and then adjust those constraints constant property in code on -viewDidLoad. That way the distribution of space will be exactly what you want.