Android 16 and Haptic feedback

[Marco Polo]

I recently moved to an old Honor with Android 9 to a Pixel 9 pro with Android 16.

I lost Haptic feedback in Plus42, despite the app settings.

I am running versio 1.3.10e

What am i doing wrong?

Thank you

[Thomas Okken]

Go to Main Menu -> Preferences, and move the Haptic Feedback slider to the right. Does that have an effect?

[Marco Polo]

No effect, unfortunatey

[Thomas Okken]

Does the key click sound work? And BEEP?

[Thomas Okken]

If everything else looks normal, could you try installing this apk and checking if the haptic feedback works there:

    https://thomasokken.com/free42/download/test/Free42Android.apk

This is a Free42 test build, not Plus42, but both apps use the same logic for haptic feedback. It looks like the API I'm using for haptic feedback is deprecated, and maybe it no longer works on Android 16? In the test build, I added some logic to use the newer vibration API when it is available.

[Steve Falco]

I just tried that test build. I don't get any haptic feedback. Key clicks work properly. My phone is using Android 16, build BP3A.250905.014.
Steve

[Marco Polo]

same results here

[Thomas Okken]

Hmmm... It looks like the APIs are both still supported, but there has been some incompatible change in Android 16, and now I have to figure out what the issue is and how to work around it. I've done some investigation and haven't found the answer yet.

Poor documentation, google searches that come up empty, and the Android Emulator is no help either. Another day in Android development land. :-/ I'll keep looking; I'll post here when I find something.

[Vincent Weber]

If it can be of any help, I'm running Plus42 on Android 16 on my Google Pixel 9 fold pro, and I have no issue whatsoever with Haptic feedback... 

[Thomas Okken]

That is good to know, but it does make the mystery even more mysterious :-D

[Marco Polo]

In my case the phone is brand new: shipped with Android 14 and updated to 16 before any app installation, so the system is fresh and free.

The build is BP3A.250905.014

[Thomas Okken]

Marco, Steve: are you able to capture the console logs from your devices, using adb logcat or any other means?

[Marco Polo]

Urgh!!!

This is quite out of my knowledege.

I need detailed instructions to to this....

[Thomas Okken]

I'll try to avoid using adb then... It's usually a great source of information, but maybe we won't need it here.

I uploaded a new test build, under the same URL as before. This one uses the latest and greatest vibration APIs, and it extends the range of the slider from up to 181 ms to 1024 ms. If that doesn't help either, the next thing to try would be playing with the vibration amplitude, but that's a setting that isn't guaranteed to be available, so I'm not touching that just yet.

[Steve Falco]

I have installed adb and I can run logcat.  But I don't know how to use it.  Is there a filter I should apply?  Right now it is putting out lots of messages that are probably unrelated to what we are trying to examine.

[Steve Falco]

Something interesting.  If I move the haptic slider all the way to the right, I get a long vibration / buzz.  At any other setting, there is no vibration.

I've attached the results of grepping for "thomasokken" in the logcat output if that helps.

[Thomas Okken]

I don't see anything in that logcat output that looks like it has something to do with our problem, looking for "haptic" and "vibrate" etc. and just eyeballing the rest. Which is good news, I guess; at least there's no indication in that log that Free42 is doing something wrong.

The vibrator working, but only for very long vibrations, is really odd, though. I can't come up with any explanation for what's going on here other than it being an OS bug.

Tomorrow, I'll create another test build that uses VibrationEffect.createPredefined(EFFECT_CLICK). That's the "official" way of doing a key click haptic feedback effect, available since Android 10. You'd hope that that at least should work, assuming that's what the system uses itself. Fingers crossed!

[Thomas Okken]

I uploaded another test build. In this one, the top three positions (14-16) of the haptic feedback slider select click effects TICK, CLICK, and HEAVY_CLICK, respectively; positions 0 through 13 still cover the same scale of no feedback (0) and 1 to 1024 ms of vibration, using a logarithmic scale (1 through 13).

Note that the experimental code is conditional on running Android 16, as in the previous test builds.

[Steve Falco]

Now, the top three positions are silent, while position 13 gives a very long vibration, and the bottom ones (1-12) are silent.

I attached a new log.

[Steve Falco]

I also have CalcTastic and RealCalc installed.  For them, none of the haptic settings perform properly - no vibration at all, although audible clicks work.  So I do start to wonder if Android broke this.

[Marco Polo]

Just tried EMU48 for Android.

Haptic feedback works properly

[Steve Falco]

Confirmed.  Whatever "EMU48 for Android" is doing for haptic feedback is working correctly.

[Steve Falco]

It looks like the code is getting a vibrator via `vibrator = ((VibratorManager)getSystemService(Context.VIBRATOR_MANAGER_SERVICE)).getDefaultVibrator();` and then does `Utils.vibrate(vibrator, settings.getInt("settings_haptic_feedback_duration", 25));` to perform the actual feedback.

[Thomas Okken]

I uploaded a new test build, using the same call as the one used by Emu48.

The relevant API call is:

    long[] vibratePattern = { 0, durationInMilliSecond, 1000 };
    vibrator.vibrate(VibrationEffect.createWaveform(vibratePattern, -1));

I don't understand why the pattern has an odd length, that final 1000 seems redundant. The array of timings is supposed to be alternating durations of the vibrator being off and on, so ending it with an 'off' duration seems like it shouldn't do anything, and the other code examples I could find all have even numbers of entries in the pattern array. But I left it in just in case; if this code works, I'll try if it still works without that final 1000. But for now, one change at a time.

[Steve Falco]

I just tried it and it worked as expected.  Thanks for your persistence!

[Marco Polo]

It works as expected also on my phone.

As a side note, Plus42 is not the only app which has problems with Android 16.
I have other three apps which crash immediately, and they are apps from credit card company, phone company., magazines.....

So, Thomas, you are not alone :-D

But you are the only author, in my case, who solved his app's issue. And even quickly!!!

Thank you for your effort

[Thomas Okken]

Great, that is good to hear!

Could I ask you to try one more test build? It's at the same location as before, and this one has the seemingly-redundant final element removed from the vibration pattern.

If this works, this is going to be the version I release, and otherwise, I'll go with the version that includes that final 1000.

[Steve Falco]

Does not work.  I guess that final 1000 is necessary.

[Thomas Okken]

I guess it is. Thanks for trying!

OK, I'll clean up the code, apply the patch to Plus42 as well, and push out new releases.

[Thomas Okken]

The Free42 and Plus42 updates are in the Play Store now.

Note: If you installed any of the test builds, you'll have to install the update from the store manually. Subsequent updates will be installed automatically again.

[Steve Falco]

I manually updated both free42 and plus42.  Both now have working haptic feedback.  Thanks for the fix.