UIDevice Orientation

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 {

}

Do you mean that it skips over the if and the else, or that it always goes to the else? — Joe Cannatti, May 30 '09 at 17:15
Yes there data in the if and else; and Yes it skips over the whole thing. — Jordan, May 30 '09 at 20:14

score 54 · Answer 1 · edited Jan 28 '14 at 22:57

54

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.

edited Jan 28 '14 at 22:57

brainray

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answered Jun 14 '11 at 13:23

srgtuszy

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`UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];` combined with the `UIDeviceOrientationIsLandscape` and `UIDeviceOrientationIsPortait` is the way to go. – Joe Mar 31 '13 at 02:15
Wonderful, thanks! Why is Apple recommending code that can easily be problematic? https://developer.apple.com/library/ios/featuredarticles/ViewControllerPGforiPhoneOS/RespondingtoDeviceOrientationChanges/RespondingtoDeviceOrientationChanges.html#//apple_ref/doc/uid/TP40007457-CH7-SW1 – brainray Jan 28 '14 at 23:02

score 23 · Answer 2 · answered Dec 01 '09 at 06:49

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))
{
}

Corey Floyd · Accepted Answer · 2009-05-30T20:26:06.360

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.

Yes there data in the if and else; and Yes it skips over the whole thing. — Jordan, May 30 '09 at 20:15

score 2 · Answer 4 · answered Sep 22 '11 at 03:25

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.
}

Good advice. But beware that this code isn't called when user changes orientation in another view and return here. Workaround by adding this in a convenient method: myCurrentOrientation = [[UIApplication sharedApplication] statusBarOrientation]; — FeltMarker, Aug 27 '12 at 13:06

score 0 · Answer 5 · answered Aug 29 '13 at 11:23

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) 
{
}

score 0 · Answer 6 · answered May 22 '14 at 10:39

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);
}

score 0 · Answer 7 · edited Nov 17 '12 at 22:56

0

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.

edited Nov 17 '12 at 22:56

EdChum

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answered Jul 05 '11 at 13:35

Filip

1

score 0 · Answer 8 · answered Feb 03 '12 at 08:20

0

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];

answered Feb 03 '12 at 08:20

malhal

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7
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UIDevice Orientation

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