The AtmPressureEvent interface provides web developers information about the atmospheric pressure levels measured at the hosting device.
This is achieved by interrogating a barometer or similar detectors of the hosting device. Not all devices contain a barometer, and when there is no barometer, this API is still exposed to the scripting environment but it does nothing.
Altitude sensing applications which make use of the relationship between changes in pressure relative to the altitude.
Weather prediction applications which make use of barometric pressure to predict weather conditions such as rain is coming.
Simple informative weather application that reports atmospheric pressure along with other data.
This specification defines conformance criteria that apply to a single product: the user agent that implements the interfaces that it contains.
EventHandler interface represents a callback function used for event
handlers as defined in [[!HTML5]].
The concepts queue a task and fires a simple event are defined in [[!HTML5]].
The terms event handlers and event handler event types are defined in [[!HTML5]].
The concepts create an event and fire an event are defined in [[!DOM4]].
The current atmospheric pressure is a value that represents the force per unit area exerted onto the hosting device around the pressure sensor by the weight of air above that surface in the atmosphere of Earth in hPA (millibar).
The HTML5 specification [[!HTML5]] defines a Window interface, which this specification extends:
onatmpressure event handler and its corresponding
event handler event type
atmpressure MUST be supported
as an IDL attribute by all objects implementing the Window
When a user agent is required to fire an atmospheric pressure event, the user agent MUST run the following steps:
atmpressure, which bubbles, is not cancelable, and has no default action, that also meets the following conditions:
valueattribute to positive Infinity, otherwise initialize the attribute to the current atmospheric pressure.
When the current atmospheric pressure changes, the user agent MUST fire a atmospheric pressure event.
The following are the event handlers (and their corresponding
event handler event types) that MUST be supported as
attributes by the
|event handler||event handler event type|