# Inactivity Measurement (/main-modules/display/inactivity)



A user's inactivity time is measured and stored with each `lv_display_t` object.
Every use of an [Input Device](/main-modules/indev) counts as activity. To get time elapsed since the last
activity, use <ApiLink name="lv_display_get_inactive_time" display="lv_display_get_inactive_time(display1)" />. If `NULL` is
passed, the lowest inactivity time among all displays will be returned (in this case
NULL does *not* mean the [Default Display](/main-modules/display/setup)).

You can manually trigger an activity using
<ApiLink name="lv_display_trigger_activity" display="lv_display_trigger_activity(display1)" />.  If `display1` is `NULL`, the
[Default Display](/main-modules/display/setup) will be used (**not all displays**).

<Callout type="info" title="Further Reading">
  * [lv\_port\_disp\_template.c](https://github.com/lvgl/lvgl/blob/master/examples/porting/lv_port_disp_template.c)
    for a template for your own driver.
  * [Drawing](/main-modules/draw) to learn more about how rendering works in LVGL.
</Callout>

API [#api]