Android Question To find out whether my app is active or paused

I plan to add a Starter boolean variable to keep track of the state of my apps:
1. Default projects: Set it to True in Activity_Pause and to False in Activity_Resume in every activity
2. B4XPage projects: Set it to True in B4XPage_Background and to False in B4XPage_Foreground in every page.

I don't think there is any reason this approach wouldn't work, and I'm just wondering whether there is any easier way, doing it at single location with a few lines of code.

TIA