KeyLight Module

RhoElements 2.x API


The KeyLight Module controls the keyboard backlight and its intensity.

This API is not supported on Android.


keylight (Module) <META> Syntax

<META HTTP-Equiv="Keylight" content="[method / parameter]">

Keylight JavaScript Object Syntax:
By default the JavaScript Object 'keylight' will exist on the current page and can be used to interact directly with the keylight.
To Invoke keylight methods via JavaScript use the following syntax: keylight.method();

e.g. keylight.on();

To Set keylight parameters via JavaScript use the following syntax: keylight.parameter = 'value'; remembering to enclose your value in quotes where appropriate.

e.g. keylight.intensity = 'value';

To set multiple EMML parameters / events on a single line use the following syntax: keylight.setEMML("[Your EMML Tags]");

e.g. keylight.setEMML("intensity:valueon");


Items listed in this section indicate methods or, in some cases, indicate parameters which will be retrieved.

NameDescriptionDefault Value
onTurns the keyboard backlight on.Device Dependant
offTurns the keyboard backlight off.Device Dependant


Items listed in this section indicate parameters, or attributes which can be set.

NamePossible ValuesDescriptionDefault Value
intensity:[Value] Positive Number, see remarks for rangeSets the keyboard backlight to the specified intensity.Device Dependant

Multi Instance

When multiple RhoElememts applications are running the following considerations should be made: The keylight settings are application specific. Switching to another application which uses the keylight module will cause the keyboard illumination settings to change to those of the application with focus. Only the application with Focus will have the ability to change the keylight settings.



The intensity tag will only have an observable effect if the keyboard backlight is turned on, setting the intensity by its self is insufficient to illuminate the backlight.

Device Limits

The levels of supported keylight intensity is device dependant. When the Keylight module is first loaded it writes the supported levels to the log file as INFORMATION so you can determine the maximum setting from the log file.


RhoElements Version1.0.0 or above
Supported DevicesAll supported devices except Enterprise Tablet.
Minimum RequirementsThis tag requires appropriate hardware and drivers to run, i.e. a device with a keyboard backlight.
PersistencePersistent - Changes to this module will persist when navigating to a new page.

HTML/JavaScript Examples

The following example turns the keyboard backlight on with an intensity of 3:

<META HTTP-Equiv="Keylight-On" Content="Intensity:3">