I'm looking for high-resolution timer API in MacOS. In Windows there is Windows Multimedia Timers API that allows to fire events with resolution of 1ms. Is there analog in MacOS?
Edit 1:
I've tried CFRunLoop timers and it seems it gives appropriate resolution. But CFRunLoopRun method blocks current thread and this is not good. I want just start timer and continue with my following code. Is it possible? At now it seems MacOS lacks API for high-resolution timers that can give steady firing intervals.
I have a graphics application that occasionally displays incorrectly after a sleep / wake cycle.
I'm wondering if there is something I should do on the Sleep or Wake events. I'm capturing these events already, because I hide the cursor in the app, and when the app wakes the cursor appears and has to be re-hidden. I'm creating my images with [[NSBitmapImageRep alloc ]initWithBitmapDataPlanes:outplanes, doing lots of bit manipulation on multiple images. I display the image full screen. Xcode 7.1, OSX 10.10
The error I get is a shimmering on the display as if my merge routines are using the wrong data.
I was assuming the sleep took a snapshot of all my data, including whatever is on the stack? It's hard to reproduce the problem, but my App is going to be running every day in a public space and uses the scheduler to sleep each night and autowake in the morning.
Should I reinitialise all my variables on a wake?
I can't see anything on the apple docs about actions you should take on these events.
It should not be necessary to worry about this. If it is, that is likely to be either a bug in your app, or a bug in Apple's code. Indeed, the cursor issue you mention sounds like a bug to me, and you should log a bug in Apple's bug reporter about that. Sleep/wake should be entirely transparent for apps that don't have a specific reason to care. You will need to try to pin down the issue you are seeing, somehow, and diagnose it.
I've seen claims on the net that the newly released iOS 7.1's iBeacon support.
Specifically:
The system is supposed to still notify your app about
didEnterRegion/didExitRegion events, even if the user explicitly
kills your app.
didEnterRegion/didExitRegion notifications are
supposed to be faster from the background and/or with the device
locked.
I have not been able to confirm either of these claims with my own testing. In fact, I seem to be less likely to get didEnterRegion/didExitRegion notifications from a locked device. (more accurately I seem to get didEnterRegion notices, but not didExitRegion notices). That could be because Apple made me remove my BLE background mode entries in my info.plist - I'm not completely sure. I'm still trying to sort this out.
I had trouble setting up my tests at first, but I have witnessed background region entry callbacks after killing an app in iOS 7.1 on both iPhone 4s and iPhone 5s models. See comments below for testing details and instructions to reproduce.
I have also done tests on background detection times on an iPhone 4S, and I still see delays of 15 minutes on iOS 7.1. My full test results and methodology are described here.
Finally, I have also done some tests on the fluctuations on the "accuracy" (distance in meters) measurement on the same device before and after the upgrade to iOS 7.1. I do not see an obvious difference in the noise on the estimate. The graphs below show results before and after the upgrade, with an iBeacon 0.5 meters away for 60 seconds then moved to 3 meters away for 60 seconds. In both cases, the transmitter was a properly calibrated iPhone 4S w/ iOS 7.1 and the receiver was an iPhone 5S.
iOS 7.0.6 Estimated distance
iOS 7.1 Estimated distance
As has been mentioned in several articles circulating around the internet, beacon sensing is available even when you swipe your app away from the multi-tasking view. However in my experiments, a region enter/exit event doesn't call the didDetermineState: directly (Probably because I hadn't been using the AppDelegate to initiate any beacon sensing but instead triggering monitoring based on UI events). Instead if you have registered for Background Location Updates, your AppDelegate's didFinishLaunchingWithOptions: method would get called with the value for key UIApplicationLaunchOptionsLocationKey in the parameter launchOptions set.
You can do a simple check like this to test if this is indeed a location update that has bought your app into the background to perform some task.
if ([launchOptions objectForKey:UIApplicationLaunchOptionsLocationKey])
You can then either register your monitored regions again or start ranging immediately.
P.S. CLLocationManager retains your previously monitoredRegions on app restore but without starting monitoring again using the same UUID and identity, you would not get the enter/exit region event in CLLocationManagerDelegate (which had brought your back up to life)
David has done some wonderful work on this, so I'm writing this cautiously... but I'm seeing something quite different from him in my tests.
I'm using two phones: an iPhone 4S running iOS 7.1 (11D167) and an iPhone 5S running iOS 7.0.6 (11B651). My iBeacons are manufactured and sold by Bluecats (www.bluecats.com), although I'm not yet using their SDK (ie. I'm just using CoreLocation) and I don't think the manufacturer makes much difference.
I'm getting response times of around 1-2 seconds on both devices when the app is running in the foreground and also when running in the background. The only difference is when I remove the app from the app switcher: iOS 7.0.6 never responds (or perhaps will do in 15 minutes), but iOS 7.1 responds in roughly the same time. When I say "respond", I mean that the CLLocationManager's locationManager:didDetermineState:forRegion: delegate is called by iOS.
I'm testing by actually wandering around my office with phones in hand, so I'm physically moving in and out of range. Strangely (?), in my early testing, where I was sitting at my desk and simulating moving in and out of range by removing and reinserting batteries, I was seeing much slower response times. Perhaps this is part of the difference?
In my testing I have seen the presence of a beacon go un-noticed by an app for up to 15 minutes, but I found something that's interesting. I'm using RedBearLabs mini BTLE sensors as ibeacons and their app to program the beacons, http://redbearlab.com/ibeacon/ (http://redbearlab.com/s/MiniBeacon_v1.zip), seems to have an something in it that immediately starts a scan / update of beacons. If I start a beacon up, and in my app it goes unnoticed, by starting then quitting the MiniBeacon app my app immediately notifies me that there are new beacons. This is the same result when entering or exiting. Their app uses CBCentralManager, which my app doesn't, so maybe a mixture between CBCentralManager and CLBeaconRegion is the way to go? I imagine CLBeaconRegion starts / restarts the bluetooth radio, so maybe that is the reason for this. Just taking a stab at it in hopes that someone with a more complete understanding can help resolve this.
Thanks
My testing also reproduces 15 mins to start scanning when my app is in background mode on iOS7.1.1. Just a bit curious, I have seen quite many youtube videos from different companies showing the app has been waken from background mode as soon as they approach their beacons. Is it sales trick?
I have an application that fires notification 5-6 times a day on some specific times set by users. Right now I'm using Notification Center fo scheduling of notifications but unfortunately it's supported only in Mac OS X 10.8. Actually, I want my app available for the users of MAC OS X 10.6 too. For that I searched the internet and found a third party app GROWL. But here the problem is, if I use Growl, 1st it requires users to install it to get notifications from apps. 2nd and main problem is I dont think there is any functionality in GROWL to schedule notifications on particular time just like we have in Notifications Center to schedule by giving fireDate.
+[GrowlApplicationBridge
notifyWithTitle:(NSString *)title
description:(NSString *)description
notificationName:(NSString *)notificationName
iconData:(NSData *)iconData
priority:(signed int)priority
isSticky:(BOOL)isSticky
clickContext:(id)clickContext]
theres nothing to fire on a particular time in GROWL, can you please guide me to the right path ? how this can be done in 10.6 ??
Well I'm using NSTimer that will call a selector after every second to keep track of the time and checks whether notification time arrived or not. But I dont think its a good practice.
I'm a complete noob when it comes to WP7. From what I know of it, in WP7 you wouldn't be able to make an alarm clock app. As in, start app, set alarm for an hour from now, close app, app launches and rings alarm after an hour is up.
Is this not possible in WP7? Or is there some way of doing it that I'm not aware of? I have seen a workaround for a stopwatch using tombstoning, but that doesn't seem like it would work here.
With Windows Phone 7 [for 3rd party developers] it's not possible to write an application that runs in the background on the phone. (This was a deliberate decision with regards to maintaining performance and battery life - not a limitation of the OS which is fully multi-tasking.)
If you really want the user to be notified of something at a specific time, regardless of whether your application is running you'll need to have this monitored from a process on an external server and then send a [toast] notification to the user at the appropriate time.
Learn more about push notifications at http://msdn.microsoft.com/en-us/library/ff402537(VS.92).aspx