Understanding scaling sizes for UIViews and objects

Question

I am trying to better understand how to control the size of Views in terms of older iphones and the new iphones difference in size.

If I have a design like the below example, how should this be coded programatically in terms of the subviews.

Excuse the badly drawn diagram but it should help to explain.

In this example, the fieldView and buttonView would always need to remain a fixed size as they have objects which would not look great when made smaller. However the logoview has another sub view for the logo itself, so could be shrinked depending on device/screen size.

How would this be accomplished? Setting up the example subviews programatically. The part I do not understand is that in viewDidLoad where the subviews are created would you not have to create in order like this:

-(void)ViewDidLoad {
CGRect screen = [[UIScreen mainScreen] applicationFrame];
wholeView = [[UIView alloc] initWithFrame:CGRectMake(self.view.bounds.origin.x, self.view.bounds.origin.y, self.view.bounds.size.width, self.view.bounds.size.height)];

 logoView = [[UIView alloc] initWithFrame:CGRectMake(0,0,320,150);
fieldView = [[UITableView alloc] initWithFrame:CGRectMake(0, logoView.bounds.size.height, 320, 100);

I understand about using

autoresizingMask

but how would it come into use in terms of working out a height depending on the actual view size available?

Answer 1

Not sure I understand your doubts, but adding the following should do the trick:

self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
logoView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

The remaining view would keep both their margins and height/width fixed (i.e., the default value of UIViewAutoresizingNone for their autoresizingMask is fine.)

how would it come into use in terms of working out a height depending on the actual view size available?

basically, what you see on your iPhone display is a hierarchy of views; the topmost view in this hierarchy is a UIWindow. This has the same size as the device screen (it is initialized that way).

Now, in the code above, our logoView has fixed margins: this means that it will remain at the same distance from the container view frame; if we specify that is size is flexible, then the logoView will simply occupy the whole space to keep the margins fixed.