Hi,
In dev-7.0 @embeddedt implemented that the display refresh, the indev read and the animation tasks shuts down themself when they have nothing to do. So from LittlevGL’s side no task will be executed if you UI does nothing.
lv_task_handler returns the time to the next task to execute, i.e. you can sleep this long. LV_NO_TASK_READY will be returned if there are no tasks to run.
It allows you to sleep until any external event (e.g. touch interrupt) happens.