DISPLAY_BRIGHTNESS
What it is
Property to represent brightness of the display.
Some cars have single control for the brightness of all displays and this property is to share change in that control. In cars which have displays whose brightness is controlled separately, they must use PER_DISPLAY_BRIGHTNESS.
Only one of DISPLAY_BRIGHTNESS and PER_DISPLAY_BRIGHTNESS should be implemented. If both are available, PER_DISPLAY_BRIGHTNESS is used by AAOS.
If this is writable, android side can set this value when user changes display brightness from Settings. If this is read only, user may still change display brightness from Settings, but that must not be reflected to other displays.
If this is writable, writing this property must cause an on property change event even if the new display brightness is the same as the current value.
How the ID is built
A property ID is a 32-bit value packing four fields. Reading 0x11400a03 apart:
| Field | Mask | Value | Means |
|---|---|---|---|
| Group | 0xf0000000 | 0x10000000 | SYSTEM |
| Area | 0x0f000000 | 0x01000000 | GLOBAL |
| Type | 0x00ff0000 | 0x00400000 | INT32 |
| Ordinal | 0x0000ffff | 0x00000a03 | 0xa03 |
Reading it from an app
CarPropertyManager mgr = (CarPropertyManager)
car.getCarManager(Car.PROPERTY_SERVICE);
int value =
mgr.getIntProperty(VehiclePropertyIds.DISPLAY_BRIGHTNESS, 0);This property can be read and written, though an OEM may implement it as read-only. It fires a callback whenever the value changes.