Android：根据JB上的接近发送器关闭屏幕

Question

I need to replicate the functionality of the stock dialer in my app - when the proximity sensor detects the phone is close to my face, turn the screen off, and turn it back on when I take the phone away from my face.

There's a partially working solution in this thread . It relies on a private API which is suboptimal, but what's way worse, works on one out of 3 devices I've tested. I'm targeting Android 4.03 and above and I'm testing against the Galaxy S3, Galaxy Nexus and Nexus 4. The solution I linked to works on the GN. On the Nexus 4, it doesn't nothing whatsoever (which I find particularly puzzling seeing that the official androidnadroid dialer uses the same code and it works there. On the S3, acquiring the wakeLock seems to perform the same action as pushing the power button (locks the phone, and thus turns off the proximity sensor).

As calling powerManager.goToSleep requires permissions that require a phone root this is off the table, setting screen brightness seems hit and miss (and doesn't work properly on any of my 3 phones - I can vary brightness but never manage to turn the screen off) and the only other way seems to be yet another private API (setScreenState - which in my case would mean Java interop as I'm using Mono4Android), I'm wondering - is there any way to comprehensively get this done, or is this just one of those things that we're not supposed to do? Still though, there's plenty of call making apps where such functionality is required, so the Skypes, Vibers & Co. of the world need to have this figured out somehow and I'd appreciate some insight as I'm at the end of my wisdom.

Answer 1

Here's what I learned in the meantime - don't try to acquire that special wakeLock unless the call state is something other than idle. If there is a call, the lock works, but there's a catch: On Google Phones (tried with GN and G4), the activity stays active even though the screen is off. On my S3, once I acquire the lock, the activity is stopped (not paused... stopped!). So, you need to write your code in a way to keep the proximity sensor active (I had it unregister after onPause which lead me to believe it didn't work on the S3) - having to keep the sensor with an stopped activity sure makes things harder on you, but it's still doable.