View source for Backboardd

{{DISPLAYTITLE:backboardd}}
'''backboardd''', or '''BackBoard''', is a daemon introduced in iOS 6 to take some of the workload off of [[SpringBoard]]. Its chief purpose is to handle events from the hardware, such as touches, button presses, and accelerometer information. It communicates with SpringBoard through [[BackBoardServices.framework]]. In iOS 6, it serves as the bridge between IOKit and userland processes.

BackBoard also manages the launching, suspension, and termination of application processes.

== Hardware Management ==

BackBoard is responsible for forwarding the following hardware events to processes:

* Touch events
* Accelerometer input
* Hardware keyboard input
* Orientation events
* Proximity sensor events
* TV/Video out events

The above events are received from IOKit and processed into the corresponding [[GSEvent]], which is then sent to the destination process via the [[GSEvent]] framework.

Going in the opposite direction, backboardd also allows processes (such as [[Preferences.app]] and [[SpringBoard]]) to interact with some parts of the hardware, such as changing the brightness level. This interaction is mainly handled by [[BackBoardServices.framework]].

== Handling Touch Events ==

BackBoard is responsible for deciding what application should receive the touch events that come in from IOKit. When a digitizer event is received, BackBoard calls the ''-contextIdAtPosition:'' method of the current [[CAWindowDisplayServer]] to get the context ID which the touch should be sent to. This is how it decides the process that should receive the touch.

[[Category:Daemons]]