Specifies an event listener to receive devicelight events. These events occur when the device's light level sensor detects a change in the intensity of the ambient light level.
The Window.onuserproxymity property represents an EventHandler, that is a function to be called when the userproximity event occurs. These events are of type UserProximityEvent and occur when the the device sensor detects that an object becomes nearby.
The onchange event handler of the DataStore interface fires when a change is made to the data store. Its main use is to synchronize different apps that are using the data store when a change is made. When fired, this event returns a DataStoreChangeEvent, which can be used to handle the change that was just made. Alternatively, when the event fires you could create a DataStoreCursor and iterate through all the records, if needed.
The MouseEvent.clientX read-only property provides the horizontal coordinate within the application's client area at which the event occurred (as opposed to the coordinates within the page). For example, clicking in the top-left corner of the client area will always result in a mouse event with a clientX value of 0, regardless of whether the page is scrolled horizontally.
The MouseEvent.clientY read-only property returns the vertical coordinate within the application's client area at which the event occurred (as opposed to the coordinates within the page). For example, clicking in the top-left corner of the client area will always result in a mouse event with a clientY value of 0, regardless of whether the page is scrolled vertically.
The MouseEvent.movementX read-only property provides the shift in the X coordinate of the mouse pointer between that event and the previous mousemove event. In other words, the value of that property is computed that way : currentEvent.movementX = currentEvent.screenX - previousEvent.screenX.
The MouseEvent.movementYread-only property provides the shift in the Y coordinate of the mouse pointer between that event and the previous mousemove event. In other words, the value of that property is computed that way : currentEvent.movementY = currentEvent.screenY - previousEvent.screenY.