© The LEGO Group
Here two watchers monitor the touch sensor attached to port 1, each watching for a different event. One asks, “Is the sensor pressed?” The other asks, “Is the sensor released?” as indicated by the arrows. Each watcher will trigger its stack as soon as its condition becomes true.
Note that click is yet another event a touch sensor watcher could test for. A program recognizes a click as a press followed by a release within 0.25 seconds.