iPad Orientation Checking UIView Class? - objective-c

Question

I have a UIView class which I add to my main UIViewController and I need to check the orientation of the device (iPad) at the launch of the app, in the viewDidLoad method. However because the class is a UIView (not UIViewController) I can't use methods such as willAnimateRotationToInterfaceOrientation.
So I attempted to use this in my UIView class:
if (([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft) ||
([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight)) {
However, testing with some breakpoints, whatever the orientation is, the of statement is never called, its skips right passed it. So what do you suggest I do to overcome this issue?
I need to somehow detect the orientation from the UIView class.
Thanks.

Answer 1

Where are you placing the check? The location could easily explain why it's not being called. To get rotation info, you could register for a notification, or have your view controller call a method in your view. Sample code for the latter:
// ViewController.m
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
[self.customView willRotateToOrientation:toInterfaceOrientation];
}
// CustomView.m
- (void)willRotateToOrientation:(UIInterfaceOrientation)newOrientation {
// Handle rotation
}
The view controller method is one you override; the view's method should be declared in a header.
Update:
Alternatively, you can find out the rotation in the controller's `viewWillAppear':
// ViewController.m
- (void)viewWillAppear {
[self.customView willRotateToOrientation:[[UIDevice currentDevice] orientation];
}
The method in your view will be called accordingly.

Answer 2

One thing you can to is to register for orientation notification from NSNotificationCenter:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];
...
- (void)orientationChanged:(NSNotification *)notification
{
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
// do things
}
This is however suboptimal since iPad may be laying flat on the table when app starts, and you'll get UIDeviceOrientationUnknown then. Been here, done that...
I ended up doing a trivial check like this:
BOOL landscape = self.bounds.size.width > self.bounds.size.height;
if (landscape)
// landscape stuff
else
// portrait stuff
But in my case the view changed aspect ratio upon rotation. If this is your case too, it should work fine.