Flash feature not working on Android 8.1

[n3ix]

The recently added Flash feature does not turn on the Flash LED on a Nexus 6P running Android 8.1 The new flash icons work as expected, logcat shows a message saying the Flash was turned on, but the LED does not light.

[mattharris]

I'm thinking that it might be necessary to use the new camera2 API on some of these newer devices. This gives us the use of setTorchMode but we will need to provide fallback for lower API levels.

Unfortunately, this really needs our targetSdkVersion to be increased to 23 (from the current 19) but that brings in a host of other issues, namely the removal of org.apache.http.client

[n3ix]

@mattharris Yeah, that's why we decided to leave it alone a couple years back when Steve and I looked into this. If we are going forward with the feature (which would be great), don't think we can leave out support for the new camer2 API - that would cause too many support headaches.

I think I did some code in ConnectionActivity years ago that traps a case where a method doesn't exist in the current Android version. (see overridePendingTransition). There is other code that directly tests the API level before calling something that isn't supported in prior levels. Can we use some combination of these approaches here, or is the new camer2 API totally unavailable to us with our current build setting?

[mattharris]

@n3ix I'm going to re-visit this as part of the investigations due to being forced by Google to increase the API level to 26 - after 31st October, we can no longer submit updates to the Play Store if our targetSdkVersion is lower than 26.

I do already have proof of concept code for the use of the different camera APIs that is invoked based on device capability, but this needs to be refactored as it was written prior to the shift to Gradle builds.

[mattharris]

@n3ix Can we close this now as part of the changes made in #374?

[n3ix]

@mattharris Yes it is fixed by 374