A method for operating an electronic device includes while a display is in low power mode, detecting based on data collected by a time of flight (ToF) sensor, a movable object within a field of view of the electronic device; in response to the detecting initiating a period of detection having a plurality of frames, the period of detection being a time period over which a distance value indicative of a distance between the movable object and the display is detected; for each of the plurality of frames, changing the distance value to reflect whether the movable object is moving near or further from the electronic device; detecting that the distance value after the period of detection is less than a threshold distance value indicative of the movable object approaching the display; if the distance value is less than the threshold distance value, waking up the display.