UIDevice Orientation - iphone

Question

I have the following code in a method. When I run this in the simulator the debugger skips right over the code?? What am I missing?
if (([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft) ||
([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight))
{
} else {
}

Answer 1

The best way to determine interface orientation is to look at status bar orientation:
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
if(orientation == UIInterfaceOrientationPortrait ||
orientation == UIInterfaceOrientationPortraitUpsideDown) {
//Portrait orientation
}
if(orientation == UIInterfaceOrientationLandscapeRight ||
orientation == UIInterfaceOrientationLandscapeLeft) {
//Landscape orientation
}
UIDevice class measures orientation based on accelerometer and if device lays flat, it won't return the correct orientation.

Answer 2

Note that there's a macro UIDeviceOrientationIsLandscape and UIDeviceOrientationIsPortrait, so instead of comparing it separately to LandscapeLeft and LandscapeRight you could just do it like this:
if (UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation))
{
}

Answer 3

Update 2
This shouldn't matter, but try turning on orientation notifications:
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(detectOrientation) name:#"UIDeviceOrientationDidChangeNotification" object:nil];
Update
My bad, I assumed it was empty.
Try removing the or statement and just test for a single orientation. See if that fixes it. Maybe there is a bracket problem or something silly.
I have the following test working in production code, so your technique should work:
if (([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft) ||
([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight)) {
}
Original Answer
You have to actually put statements in the if blocks to get it to step in.
The debugger is smart enough to skip over empty blocks.

Answer 4

Another way of doing this without turning on orientation notification would be to
Step 1: Save the current orientation in a local variable myCurrentOrientation and assign it like this:
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
duration:(NSTimeInterval)duration
{
myCurrentOrientation = toInterfaceOrientation;
}
Step 2: Use myCurrentOrientation for your check
if (UIInterfaceOrientationIsLandscape(myCurrentOrientation) == YES) {
// landscape
}
else {
// portrait.
}

Answer 5

Say you are inside a Springboard tweak and want to show something depending on the orientation of the current app, then you can use this (jailbreak only):
UIInterfaceOrientation o = [[UIApplication sharedApplication] _frontMostAppOrientation];

Answer 6

Heh you need to call [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications]
before obtaining the value. Have a look at documentation of this method. Took me a while to track this down.

Answer 7

I recommend you to use my highlighted code instead of yours to safe some code of lines.
-(void) viewDidLoad
{
[super viewDidLoad];
[self rotations];
}
-(void)rotations
{
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(orientationChanged:)
name:UIDeviceOrientationDidChangeNotification
object:nil];
}
-(void) orientationChanged:(NSNotification *)notification
{
//USE THIS PART
//USE THIS PART
//USE THIS PART
//USE THIS PART
//USE THIS PART
if (UIDeviceOrientationIsPortrait([UIDevice currentDevice].orientation))
{
}
}
INSTEAD OF
if([[UIDevice currentDevice] orientation] == UIInterfaceOrientationPortrait ||
[[UIDevice currentDevice] orientation] == UIInterfaceOrientationPortraitUpsideDown)
{
}

Answer 8

Here is a method to find the orientation and the true center of the screen. I used Tuszy's method so I could set UIActivityIndicatorView properly.
- (BOOL) isPortraitOrientation {
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
if(orientation == UIInterfaceOrientationPortrait ||
orientation == UIInterfaceOrientationPortraitUpsideDown) {
return true;
}
if(orientation == UIInterfaceOrientationLandscapeRight ||
orientation == UIInterfaceOrientationLandscapeLeft) {
return false;
}
return false;
}
And the way to get center...
- (void) findMyUIViewCenter {
CGPoint myCenter;
if ([self isPortraitOrientation]) {
myCenter = self.view.center;
}
else {
myCenter = CGPointMake(self.view.frame.size.height / 2.0, self.view.frame.size.width / 2.0);
}
NSLog(#"true center -- x:%f y:%f )",myCenter.x,myCenter.y);
}