I am facing one of the requirements where I need to detect if the user is using the iPhone or not. Even if my app is in background then also. So far I've found the following way outs, but none of them points to the unlocking mechanism:
applicationProtectedDataWillBecomeUnavailable: This will tell if the user has locked/unlocked the device but will work only If a passcode is set.
Darwin lock/unlock notifications: Not accepted on AppStore.
Proximity Sensor (UIDeviceProximityStateDidChangeNotification): This will only happen if the user is calling.
[[UIScreen mainScreen] brightness]: Can be queried during applicationDidEnterBackground state to check whether phone was locked or home button was pressed. If brightness is greater than 0, it indicates home button was pressed or there was a transition to some other app, when it is 0, it means locked.
Using motion sensors: Given the battery drainage, a fairly incorrect approach to check what's the roll of the device or acceleration in a certain coordinate system
UIDeviceOrientationDidChangeNotification: only works when app is in foreground.
What's the technology behind apple's "pick up to wake" implementation: I have seen that iPhone6s brightens the screen when you pick it up. They must be using a more efficient way than accelerometer?
I don't see any other good approaches. Did I miss something?
Related
There are two approaches for showing an app/app suggestion (incase not installed) on the iphone lock screen / app switcher. One is GPS based, in which the IOS decides which app to show as a suggestion. Another is beacon based, in which a particular beacon is identified.
If location services are enabled for multiple apps and say all these apps are also using beacon based approach to show their icons on the lock screen left corner, which app icon will be shown by the IOS?
Since location services are enabled for these apps,and say there is another relevant app which is NOT using beacon based approach (using just the GPS based approach), can IOS give preference to beacon based apps over the GPS based this new app.?
For instance, Estimote’s NYC office is on the same block as an Equinox gym and our phones intelligently and automatically alert us to use that app. It’s super easy and intuitive to open the app while walking into the gym - and in the process, streamline the check-in flow with the gym’s front desk. However, because it solely uses GPS geofences, the accuracy is poor. We actually get the Equinox icon over 1 block away, and there is no control for the brands or stores (in this case Equinox) on how this appears.
Apple's suggestion of apps not installed on the phone based on proximity uses an undocumented technique. While I have verified it uses GPS as an input, I have never been able to confirm that beacons are used at all.
Regardless of whether beacons are used, because this is an undocumented feature, it is unlikely you will find a way to customize the behavior.
AFAIK, Apple has never shared the implementation details of how the lock screen icon AKA "suggested apps" feature works.
However, we did some experiments at Estimote and noticed that being inside a CLRegion (both the "GPS" CLCircularRegion, and CLBeaconRegion work) that an app monitors for via Core Location, consistently makes the app's icon show up on the lock screen. So it seems that both beacons and GPS location fall into the same mechanism that governs the location-based suggestions. (Note that in iOS 9, that's not just the lock screen icon, but also a bar at the bottom of the app switcher.)
Unfortunately, we weren't able to establish what happens if you're inside multiple qualifying CLRegions, belonging to different apps. We suspect it might have something to do with the order in which the apps register regions for monitoring, but were never able to get consistent results.
Furthermore, since this whole behavior is undocumented, Apple can change it at any time. Just something to be aware of.
Side note: handoff always trumps suggested apps.
I'm working on an app - one of its main properties is to inform the app if the user is using the phone, interacting with it in any way, or even touching it!
What are the suitable sensors in iPhone that can help me to detect these things?
And how can I benefit from the sensors to make this property work?
Thanks
The iPhone has accelerometers, gyros, and GPS. With these, you can monitor motion of the phone, sudden shocks(like when the phone is picked up and put down), orientation, and over all motion. If outside, you can also use the GPS to pick up on motion and position (lat, long, course, speed, altitude).
When interacting with the app, you've also got touch events and multi-touch events(like using two fingers to zoom in or zoom out or rotate). Most of the 'gestures' are coded and defined by apple so you don't need to figure out the user intent, just respond to their event.
Numerous sensor monitoring apps exist... eg:
http://wavefrontlabs.com/Wavefront_Labs/Sensor_Data.html
Tutorials on how to do some of this stuff :
https://www.youtube.com/watch?v=Hml2jB_Qpds
https://www.youtube.com/watch?v=Xk5cJlhePCI
https://www.youtube.com/watch?v=qY4xCMTejH8
https://www.youtube.com/watch?v=7GHc8ySyWcY
https://developer.apple.com/library/ios/documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/GestureRecognizer_basics/GestureRecognizer_basics.html
I need to track device orientation even though device orientation is locked to Portrait mode. What I really need is to accomplish similar behaviour to what Instagram camera view has: when you rotate device, it will rotate buttons over camera view, even when your device is locked.
I used to track orientation with UIDeviceOrientationDidChangeNotification, but that is not fired when device orientation is locked :(
Is there perhaps implementation somewhere using accelerometer and/or gyroscope? I'm suprised I couldn't find something like that.
Use the accelerometer to detect device orientation yourself. You can use the Core Motion framework to get the data you need. There's a sample snippet in the linked docs that shows how to get the data. Use a low-pass filter to isolate the force of gravity from relatively short-term changes due to user movement. Apple has a sample project called AccelerometerGraph that demonstrates this.
Would it be possible to lock a device screen and unlock it again? The reason I would want to do this is we have a kiosk type app and we would like to turn of the screen between certain times.
I would think a type of push notification would be needed?
Once iPad is locked you're not going to be able to unlock it programmatically, even through a push notification. Assuming these devices are always plugged in you may be better off turning off the idleTimer (which I'm assuming you already have) then invoke some sort of screen save or idle screen that displays during those hours. That way your app never allows the iPad to lock natively and you can control when clients do & don't see the content.
That brings up a design question, though... what happens if someone is present when the idle screen is up? Should you override or keep it on the idle screen? Just thinking out loud.
Question: Is there a message/event fired when the iPad cover is flipped closed?
Purpose: I have an iPad app that collects private information, such that when someone enters the room, a user might flip the cover closed. It makes sense -- and a user has requested -- that the app close itself or otherwise mask the users information should someone else then pick up the iPad.
Thanks.
Someone was suggesting to use the AppDelegate's applicationWillResignActive and applicationDidBecomeActive delegate methods and instantiate the accelerometer. When the device is locked (cover closed), the accelerometer is disabled and won't register events, but if the app is in the background, it's still active. Never tried it but it might work.
Explanation here