Tasker: How to detect "Nothing is detected"

[Thomas Li]

I want to detect "screen is not touched" when an app is launched.

Currently, I am able to use the getevent to get the the touch detected.

I save the getevent output to %Touched
Then, I detect it with either "ISSET" or %TRUN ~ *,%Touched,*

but I don't know how to detect "nothing is touch"

What I want to to do is if an app launch and nothing is touch, turn off the screen in 2 secs, otherwise, do nothing.

any help is appreciated

[SunKol]

Can you check whether Context EVENT->Variable Change (invert) helping ??

[TomL]

You're right, you cannot detect 'nothing detected'. Same way you cannot prove 'Jim never lies'; you cannot prove a negative. What you can do is change the statement into a positive statement, and try to prove that. Like I can prove 'Jim lied today about eating the pie'.

So, in your case, I would break the problem down like this.

Profile Detected It Happened
Context event: it happened
Action: set var %DetectedTime = %TIMES

Profile Checking If Nothing has Happened For 2 seconds
Context event: your event here
Actions:
Wait 2 seconds
Set var %SecondsSince = %TIMES - %DetectedTime
If %SecondsSince > 2*60 then 'nothing detected in 2 seconds'

[Thomas Li]

Thanks for all the input.

I, kinda, make it work with some trick.

What I do is to

1. run the getevent command, and **Check the  "Continue Task After Error" checkbox**, and then set the timeout to 10sec.

   - I assume the getevent will return error if nothing is detected/touched

2. Then I use the condition statement to check

   - if %Output is NOT set

      - do something

   - endif

It seems working fine now. :)