I have a subview in a subclass of UIView. When the device is rotated I want the subview to remove. This is my code:
- (void)awakeFromNib
{
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(orientationChanged) name:UIDeviceOrientationDidChangeNotification object:nil];
}
- (void)orientationChanged
{
[subview removeFromSuperview];
}
My problem is that even if the device is tilted a little bit, or put on for example a table the subview removes. What can I do to prevent this?
Don't track the device orientation. Track the interface orientation. Use UIApplicationWillChangeStatusBarOrientationNotification instead of UIDeviceOrientationDidChangeNotification, and get the new interface orientation out of the notification's userInfo. (You won't have to do beginGeneratingDeviceOrientationNotifications if you track interface orientation.)
Related
In a nutshell, I want to manually rotate only a few elements on the screen when the device goes landscape but keep the actual app in portrait mode. How can I hinge on this event in the background?
Have you tried using
UIDeviceOrientation deviceOrientation = [[UIDevice currentDevice] orientation];
This only caters for device orientation, so if you have other orientations disabled. It still gives correct value for which ever orientation your device is in. You can compare its values to (and more, you can view those at https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIDevice_Class/index.html#//apple_ref/c/tdef/UIDeviceOrientation)
UIDeviceOrientationPortrait,
UIDeviceOrientationPortraitUpsideDown,
UIDeviceOrientationLandscapeRight,
UIDeviceOrientationLandscapeLeft
I Hope this helps.
Edit :
For an event you have to add an observer to detect the device's orientation being changed. Register the notification/observer in appdelegate or where ever u feel it is needed and place orientationChanged method in the class where u delegated the observer. (probably in the same class in most scenarios).
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter]
addObserver:self selector:#selector(orientationChanged:)
name:UIDeviceOrientationDidChangeNotification
object:[UIDevice currentDevice]];
- (void) orientationChanged:(NSNotification *)note
{
NSLog(#"orientationChanged");
UIDevice * device = note.object;
if(device.orientation == UIDeviceOrientationPortrait)
{
}
// add other else if here
else
{
}
}
Note that orientationChanged is called when you add the observer. Only once. After every time your device changes orientation. Do let me know if you find something confusing.
I want my game to pause when device orientation is initiated. I have this method in my viewcontroller, which works fine:
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
NSLog(#"I am starting to rotate, should pause game..");
}
But how to listen for device rotation from within my SKScene, where the actual game is playing. Hope I have made myself clear enough. Thanks for any help!
You can use NSNotification. Keeping with your code, add the following line in your ViewController init:
[[NSNotificationCenter defaultCenter]
postNotificationName:#"RotateNotification"
object:self];
Then in your SKScene init add this line:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(receiveNotification:)
name:#"RotateNotification"
object:nil];
Also add the called method to SKScene:
-(void) receiveNotification:(NSNotification *)notification
{
NSLog (#"Received notification");
// do what you have to do here...
}
I have an app which has to work in both portrait and landscape more and the UITabBar should adjust to current orientation (it has custom background and selected items). So, for the rest of views I just override the - (void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation method and it works perfectly.
How would I do that for the .moreNavigationController of UITabBarController ? I've tried adding an observer (the selector is in extension of UITabBarController):
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(didRotate:)
name:UIApplicationDidChangeStatusBarOrientationNotification
object:self.moreNavigationController];
but it never get called.
Am I missing something or what would be the best way to handle this situation ?
Solution: somewhy UIDeviceOrientation is not firing correctly, so better to use statusBarOrientation, works as a charm.
the final code which work is this:
in main UITabBarController, viewDidLoad:
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(didRotate:)
name:UIApplicationDidChangeStatusBarOrientationNotification
object:nil];
the didRotate selector method:
- (void) didRotate:(NSNotification *)notification{
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
if(UIInterfaceOrientationIsPortrait(orientation)) {
// Portrait
} else {
// Landscape
}
}
Thanks for help.
You are registering your UITabBarController for a notification which never gets posted. Take a look at the documentation NSNotificationCenter Reference for the addObserver:selector:name:object method
- (void)addObserver:(id)notificationObserver selector:(SEL)notificationSelector name:(NSString *)notificationName object:(id)notificationSender
notificationSender:
The object whose notifications the observer wants to receive; that is, only notifications sent by this sender are delivered to the observer.
If you pass nil, the notification center doesn’t use a notification’s sender to decide whether to deliver it to the observer.
so, if you specify the . moreNavigationController as the sender, you wont get those notifications, because it never posts such ones. Instead pass nil to ignore the sender and listen to the status bar change regardless of who sent it.
By the way, in this SO Answer is a summary of how you can react to orientation change.
And at last. If it still doesn't work, you can try this:
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(didRotate:)
name:UIDeviceOrientationDidChangeNotification
object:nil];
Yes, you forgot to post notification, which will call you own notification:
[[NSNotificationCenter defaultCenter] postNotificationName: UIApplicationDidChangeStatusBarOrientationNotification object:self];
or if you dont wont to send anything just set object as nil:
[[NSNotificationCenter defaultCenter] postNotificationName: UIApplicationDidChangeStatusBarOrientationNotification object:nil];
The best way to implement the same is first addObserver and then remove observer to avoid the crash:-
-(void)viewDidLoad{
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(didRotate:)
name:#"UIDeviceOrientationDidChangeNotification" object:nil];
}
//Now Remove Observer
-(void)viewDidDisappear:(BOOL)animated
{
[[NSNotificationCenter defaultCenter] removeObserver:self #"UIDeviceOrientationDidChangeNotification" object:nil];
}
Im developing an application to display a gallery of images by using a UIScrollView, the sliding between images works fine on portrait mode but when changed to landscape mode it shows the image plus a portion of the next image.
If i could get some explanation on how to solve this issue i would be very thankful.
Make sure your UIScrollView and it's parent view have the right UIViewAutoResizing and autoResizesSubViews values.
Then listen for device orientation changes and take appropriate steps (= reposition subviews of the scrollview)
-(void)applicationDidFinishLaunching:(UIApplication *)application {
// ... other things
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(didRotate:)
name:#"UIDeviceOrientationDidChangeNotification" object:nil];
};
-(void)didRotate:(NSNotification *)notification {
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
if (orientation == UIDeviceOrientationLandscapeLeft) {
NSLog(#"Landscape Left!");
}
}
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.
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.
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.