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Blinking flashing increasing brightness of backlight in WRT

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Article Metadata
Code ExampleTested with
Devices(s): Nokia E90 Communicator (v.210.34.75 and later), Nokia 5800 XpressMusic
Compatibility
Platform(s): S60 3rd Edition, FP2, S60 5th Edition
S60 5th Edition
S60 3rd Edition FP2
S60 3rd Edition FP1
Article
Keywords: x-systeminfo-widget, SystemInfo.lightblink(), SystemInfo.lighton()
Created: dekuykin (10 Dec 2008)
Last edited: hamishwillee (05 Oct 2012)

Contents

Overview

This code snippet demonstrates how to control the backlight of a device on Symbian Web Runtime, using the SystemInfo Service API WRT version 1.0.

The API is supported from S60 3rd Edition, Feature Pack 2 onwards. It is also supported in select S60 3rd Edition, Feature Pack 1 devices or their newest firmware versions (for example, Nokia E90 Communicator, from v.210.34.75 onwards).

Source

Embed the SystemInfo widget into the document:

<body>
<embed type="application/x-systeminfo-widget" hidden="yes" />
</body>

Add three buttons to control the backlight:

<input type="button" onclick="lightOn();" value="Light on" />
<input type="button" onclick="blink();" value="Blink" />
<input type="button" onclick="lightOff();" value="Light off" />

The JavaScript code:

var sysInfo = null;
 
window.onload = init;
 
var SMOOTH = true;
 
function init() {
// Obtain the SystemInfo object
try {
sysInfo = document.embeds[0];
} catch (ex) {
alert("SystemInfo object cannot be found.");
return;
}
}
 
// Switches the display light on
function lightOn() {
if (sysInfo == undefined) {
alert("SystemInfo object is undefined.");
return;
}
 
// Reset the backlight state to default
resetLight();
 
sysInfo.lighton(sysInfo.lighttargetsystem, sysInfo.lightinfiniteduration,
sysInfo.lightmaxintensity, SMOOTH);
}
 
// Starts blinking the display
function blink() {
if (sysInfo == undefined) {
alert("SystemInfo object is undefined.");
return;
}
 
// Reset the backlight state to default
resetLight();
 
sysInfo.lightblink(sysInfo.lighttargetsystem,
sysInfo.lightinfiniteduration, sysInfo.lightdefaultcycletime,
sysInfo.lightdefaultcycletime, sysInfo.lightmaxintensity);
}
 
// Switches the display light off
function lightOff() {
if (sysInfo == undefined) {
alert("SystemInfo object is undefined.");
return;
}
 
sysInfo.lightoff(sysInfo.lighttargetsystem, sysInfo.lightinfiniteduration,
SMOOTH);
}
 
// Sets the backlight of the display to default value
function resetLight() {
if (sysInfo == undefined) {
alert("SystemInfo object is undefined.");
return;
}
 
sysInfo.lighton(sysInfo.lighttargetsystem, sysInfo.lightinfiniteduration,
sysInfo.lightdefaultintensity, SMOOTH);
}

Postconditions

Different possibilities to control the backlight are demonstrated.

Supplementary material

For a complete example that makes use of the SystemInfo Service API to control the backlight, see Blinking flashing increasing brightness of backlight in WRT.zip

This page was last modified on 5 October 2012, at 09:41.
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