After some googling, I can understand that the "proximity sensor" which is used to on/off screen when the device is away/near from the user. I watched this video (watch from 30th sec) and surprised about this cool stuff. I want to implement it in my app.
But I come to know that there is no public API is available that can protect the screen lock when proximityMonitoringEnabled is YES. Then how can the above app did this?
For clear understanding, I'm copying some code.
Enable the proximity sensor:
[[UIDevice currentDevice] setProximityMonitoringEnabled:YES];
Setup an observer for sensor change:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(sensorStateMonitor:) name:#"UIDeviceProximityStateDidChangeNotification" object:nil];
Finally you can find the state of proximity sensor from this method:
- (void)sensorStateMonitor:(NSNotificationCenter *)notification
{
if ([[UIDevice currentDevice] proximityState] == YES)
{
NSLog(#"Device is close to user.");
}
else
{
NSLog(#"Device is not closer to user.");
}
}
Question:
I want to show some view when the "Device is close to user" state was called. And want to remove the view if "Device is not closer to user" state was called.
So I added a view and removed inside the sensorStateMonitor: method. But the view was visible only for some fraction of seconds and the screen goes off.
Can I prevent the screen from auto off?
Just confused!!
The screen lock can be enabled/disabled.
[UIApplication sharedApplication].idleTimerDisabled = YES;
UIDeviceOrientationDidChangeNotification is calling multiple times when the device changes orientation. I am unsure why this happens or how to fix it.
What I am trying to do is to keep the contentoffset of the scrollview the same, so when the user rotates the screen the app keeps the page they were on.
The odd thing is when I rotate the screen the first time the code executes like I would want. But every time after that the code executes multiple times and eventually the contentoffset is set o 0.
Here's what I have.
- (void)loadView {
//some code that sizes itself depending on the current orientation
//WILL BE CALLED AFTER EVERY ORIENTATION CHANGE
}
- (void)viewDidLoad {
//begin generating messages
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter]
addObserver:self selector:#selector(orientationChanged:)
name:UIDeviceOrientationDidChangeNotification
object:[UIDevice currentDevice]];
//if is portrait and was landscape
if (orientation==1 && temp==2) {
int cal = offsetHolder.x/screenframe.size.height;
offsetHolder.x = cal * screenframe.size.width;
ScrollView.contentOffset = offsetHolder;
}
//if is landscape and was portrait
if (orientation==2 && temp==1) {
int cal = offsetHolder.x/screenframe.size.width;
offsetHolder.x = cal * screenframe.size.height;
ScrollView.contentOffset = offsetHolder;
}
}
On orientation change I change the value of 'int orientation' then call loadview to change the sizing of the view. Then I call viewdidload to get the proper contentoffset
- (void) orientationChanged:(NSNotification *)note {
CGRect screenframe = [[UIScreen mainScreen] bounds];
//holding the current offset
offsetHolder = ScrollView.contentOffset;
if ([[UIDevice currentDevice] orientation] == 1 || [[UIDevice currentDevice] orientation] == 0 || [[UIDevice currentDevice] orientation] == UIDeviceOrientationPortraitUpsideDown) {
temp=orientation;
orientation = 1;
[self loadView];
[self viewDidLoad];
}
else if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationFaceDown || [[UIDevice currentDevice] orientation] == UIDeviceOrientationFaceUp){
temp=orientation;
}
else{
temp=orientation;
orientation = 2;
[self loadView];
[self viewDidLoad];
}
}
EDIT:
I have found the problem. What I am doing is creating another instance of self.view instead of overwriting this one. Is there an easy way to destroy this view and re-initialize it?
EDIT2:
Have found a fix. I stopped calling loadview and viewdidload as per jsds' instructions. And instead moved all code in my loadview to another function that I called from loadview. All this code does is instantiate the UI (initview) objects and places them in the correct places depending upon orientation.
Then I create another function that removes all subviews from the view. Then on orientation change I call this function and my initview to destroy all subviews and then recreate them on orientation change.
UIDeviceOrientation basically has 6 different states, namely two portrait, two landscape, and face up and face down. So lets say when you pick up your device from flat position to vertical position, the notification will be triggered.
You can filter the faceup, facedown, and unknown states by using the macro UIDeviceOrientationIsValidInterfaceOrientation
UIDeviceOrientation currentOrientation = [[UIDevice currentDevice] orientation];
// Ignore changes in device orientation if unknown, face up, or face down.
if (!UIDeviceOrientationIsValidInterfaceOrientation(currentOrientation)) {
return;
}
If you still find the notification getting triggered multiple times, I am afraid you may need to use your custom logic with flags to check the previous and current value.
In my case, since I use reactive cocoa framework, the following code works for me :
if (IS_IPAD) {
#weakify(self);
[[[[[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIDeviceOrientationDidChangeNotification object:nil]
takeUntil:[self rac_willDeallocSignal]]
map:^id (NSNotification *notification) {
return #([[UIDevice currentDevice] orientation]);
}]
filter:^BOOL(NSNumber *deviceOrientationNumber) {
UIDeviceOrientation currentOrientation = [deviceOrientationNumber integerValue];
//We ignore the UIDeviceOrientationUnknown, UIDeviceOrientationFaceUp and UIDeviceOrientationFaceDown
return UIDeviceOrientationIsValidInterfaceOrientation(currentOrientation);
}]
distinctUntilChanged]
subscribeNext:^(id x) {
#strongify(self);
//do something here...
}];
}
Here the distinctUntilChanged method makes sure the code gets triggered only when the orientation changes to a new valid value.
You should never call loadView or viewDidLoad yourself. That's up to the framework to manage.
If you are positioning or resizing views based on the view bounds in viewDidLoad, don't. Move that to viewWillLayoutSubviews. That will be called automatically when the device orientation changes.
Alternatively, use autolayout constraints and then you won't have to do anything at all.
I created an UIWebView inside an UIViewController. This web view contains a youtube video page like this one: http://www.youtube.com/watch?v=oL1RE8JXaIw
When I click on the video link, the iOS video player is launched. Everything is going well till here.
The problem is that when I rotate my application (in landscape mode) and I click on the done button, my View Controller is in landscape mode.
So I've added this callback in the view controller:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
{
return NO;
}
but nothing has changed.
Any idea?
That orientation code is invalid - make sure to always return YES for at least one orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
{
return UIInterfaceOrientationPortrait;
}
I handled that problem using NSNotification like this in viewDidLoad method
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(moviePlayerDidExitFullScreen)
name:#"UIMoviePlayerControllerDidExitFullscreenNotification"
object:nil];
and this method will call when video ends and you can do necessary changes
- (void)moviePlayerDidExitFullScreen
{
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight || orientation == UIInterfaceOrientationPortraitUpsideDown)
{
[[UIDevice currentDevice] setOrientation:UIInterfaceOrientationPortrait];
}
}
Hope that Helps
After reading many posts, I still haven't got a clue how to solve this problem...
The first view of my app is a tableViewController. I override
(BOOL) shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
and it always returns YES.
If I hold my iPad upright under landscape orientation, it rotates right after I launch the app. However, if I put my iPad flat on the table, even though my homepage is in landscape orientation, it launches in protrait orientation.
So I guess the problem is, how can I get the orientation of my homepage and launch my app with that orientation?
I had this same problem. There's some funky stuff that goes on with the first view controller you add to a window and whatever orientation it has. Make sure that the view controllers all return YES for orientations if you want the very first one to open with the right orientation
My app is openGL, but the way I handled this was to use notifications:
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return YES;
}
// This is called right BEFORE the view is about to rotate. Here I'm using a notification message
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
if (UIInterfaceOrientationIsPortrait(toInterfaceOrientation)) {
NSNotification* notification = [NSNotification notificationWithName:#"orientationIsPortrait" object:self];
[[NSNotificationCenter defaultCenter] postNotification:notification];
}
else {
NSNotification* notification = [NSNotification notificationWithName:#"orientationIsLandscape" object:self];
[[NSNotificationCenter defaultCenter] postNotification:notification];
}
}
willRotateToInterfaceOrientation is called right BEFORE it actually starts rotating the orientation.
Then in my EAGLView initWithFrame: I set up observers..
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(viewBecamePortrait:) name:#"orientationIsPortrait" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(viewBecameLandscape:) name:#"orientationIsLandscape" object:nil];
and in viewBecamePortrait and viewBecameLandscape I handle the changes programatically.
On application start willRotateToInterfaceOrientation used only in case if "Home" screen in Landscape mode.
This way we can detect orientation when device is "Face Up" or "Face Down".
[UIDevice currentDevice].orientation work in case if device not parallel to ground.
I used the statusbar orientation to orient my openglview, like this:
UIDeviceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
NSLog(#"%s: orientation: %i", _cmd, (int)orientation);
In a given event handler (not the "shouldAutorotateToInterfaceOrientation" method) how do I detect the current iPad orientation? I have a text field I have to animate up (when keyboard appears) in the Landscape view, but not in the portrait view and want to know which orientation I'm in to see if the animation is necessary.
Orientation information isn't very consistent, and there are several approaches. If in a view controller, you can use the interfaceOrientation property. From other places you can call:
[[UIDevice currentDevice] orientation]
Alternatively, you can request to receive orientation change notifications:
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];
Some people also like to check the status bar orientation:
[UIApplication sharedApplication].statusBarOrientation
I think
[[UIDevice currentDevice] orientation];
is not really reliable. Sometimes it works, sometimes not... In my apps, I use
[[UIApplication sharedApplication]statusBarOrientation];
and it works great!
One of:
Check the interfaceOrientation property of the active view controller.
[UIApplication sharedApplication].statusBarOrientation.
[UIDevice currentDevice].orientation. (You may need to call -beginGeneratingDeviceOrientationNotifications.)
I found a trick to solve the FaceUp orientation issue!!!
Delay the orientation check till AFTER the app has started running, then set variables, view sizes, etc.!!!
//CODE
- (void)viewDidLoad {
[super viewDidLoad];
//DELAY
[NSTimer scheduledTimerWithTimeInterval:0.5
target:self
selector:#selector(delayedCheck)
userInfo:nil
repeats:NO];
}
-(void)delayedCheck{
//DETERMINE ORIENTATION
if( [UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationPortrait ){
FACING = #"PU";
}
if( [UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationPortraitUpsideDown ){
FACING = #"PD";
}
if( [UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationLandscapeLeft ){
FACING = #"LL";
}
if( [UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationLandscapeRight ){
FACING = #"LR";
}
//DETERMINE ORIENTATION
//START
[self setStuff];
//START
}
-(void)setStuff{
if( FACING == #"PU" ){
//logic for Portrait
}
else
if( FACING == #"PD" ){
//logic for PortraitUpsideDown
}
else{
if( FACING == #"LL"){
//logic for LandscapeLeft
}
else
if( FACING == #"LR" ){
//logic for LandscapeRight
}
}
//CODE
You can addSubviews, position elements, etc. in the 'setStuff' function ... anything that would initially depend on the orientation!!!
:D
-Chris Allinson
You can achieve this by two ways:
1- By using the following method:
**Put the following line in the -(void)viewDidLoad Method:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(deviceRotated:) name:UIDeviceOrientationDidChangeNotification object:nil];
then put this method inside your class
-(void)deviceRotated:(NSNotification*)notification
{
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
if(orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight)
{
//Do your textField animation here
}
}
The above method will check the orientation when the device will be rotated
2- The second way is by inserting the following notification inside -(void)viewDidLoad
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(checkRotation:) name:UIApplicationDidChangeStatusBarOrientationNotification object:nil];
then put the following method inside your class
-(void)checkRotation:(NSNotification*)notification
{
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
if(orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight)
{
//Do your textField animation here
}
}
The above method will check the orientation of the status bar of the ipad or iPhone and according to it you make do your animation in the required orientation.
For determining landscape vs portrait, there is a built-in function:
UIInterfaceOrientation orientation = [[UIDevice currentDevice] orientation];
BOOL inLandscape = UIDeviceOrientationIsLandscape(orientation);
[UIApplication sharedApplication].statusBarOrientation returns portrait when it's landscape, and landscape when it's portrait at launch, in iPad
I don't know why, but every time my app starts, the first 4 are right, but subsequently I get the opposite orientation. I use a static variable to count this, then have a BOOL to flip how I manually send this to subviews.
So while I'm not adding a new stand-alone answer, I'm saying use the above and keep this in mind. Note: I'm receiving the status bar orientation, as it's the only thing that gets called when the app starts and is "right enough" to help me move stuff.
The main problem with using this is the views being lazily loaded. Be sure to call the view property of your contained and subviews "Before" you set their positions in response to their orientation. Thank Apple for not crashing when we set variables that don't exist, forcing us to remember they break OO and force us to do it, too... gah, such an elegant system yet so broken! Seriously, I love Native, but it's just not good, encourages poor OO design. Not our fault, just reminding that your resize function might be working, but Apple's Way requires you load the view by use, not by creating and initializing it
In your view controller, get the read-only value of self.interfaceOrientation (the current orientation of the interface).
I've tried many of the above methods, but nothing seemed to work 100% for me.
My solution was to make an iVar called orientation of type UIInterfaceOrientation in the Root View Controller.
- (void)viewDidLoad {
[super viewDidLoad];
orientation = self.interfaceOrientation; // this is accurate in iOS 6 at this point but not iOS 5; iOS 5 always returns portrait on app launch through viewDidLoad and viewWillAppear no matter which technique you use.
}
- (BOOL) shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation{
return YES;
}
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration{
orientation = toInterfaceOrientation;
}
Then, any place where you need to check the orientation you can do something like this:
if(UIInterfaceOrientationIsPortrait(orientation)){
// portrait
}else{
// landscape
}
There may still be a better way, but this seems to work 98% of the time (iOS5 notwithstanding) and isn't too hard. Note that iOS5 always launches iPad in portrait view, then sends a device the willRotateTo- and didRotateFromInterfaceOrientation: messages, so the value will still be inaccurate briefly.
[UIDevice currentDevice].orientation works great.
BUT!!!
... the trick is to add it to - (void)viewWillAppear:(BOOL)animated
exp:
(void)viewWillAppear:(BOOL)animated{
...
BOOL isLandscape = UIInterfaceOrientationIsLandscape(self.interfaceOrientation);
...
}
If you call it at - (void)viewDidLoad, it does not work reliable, especially if you use multiple threads (main UI thread, background thread to access massive external data, ...).
Comments:
1) Even if your app sets default orientation portrait, user can lock it at landscape. Thus setting the default is not really a solution to work around it.
2) There are other tasks like hiding the navigation bar, to be placed at viewWillAppear to make it work and at the same time prevent flickering. Same applies to other views like UITableView willDisplayCell -> use it to set cell.selected and cell.accessoryType.