// Global variable for capturing of System Info object reference
var sysinfo;
// Menu command ids
var lightItemId = 2001;
var blinkItemId = 2002;
var flashItemId = 2003;
var offItemId = 2004;
var exitItemId = 2005;
 
/**
* Function switches display light on for infinitive time.
*/
function lightOn() {
    // First we should reset backlight state to default
    off();
    sysinfo.lighton(sysinfo.lighttargetsystem, 
        sysinfo.lightinfiniteduration, sysinfo.lightmaxintensity, true);
}
 
/**
* Function switches on display blinking for infinitive time. 
*/
function blinkOn() {
    // First we should reset backlight state to default
    off();
    sysinfo.lightblink(sysinfo.lighttargetsystem, 
        sysinfo.lightinfiniteduration, 
        sysinfo.lightdefaultcycletime, 
        sysinfo.lightdefaultcycletime, sysinfo.lightmaxintensity);
}
 
/**
* Function switches light on for short time ( makes flash effect ).  
*/
function flash() {
    // First we should reset backlight state to default
    off();
    // Duration of flash in milliseconds
    var flashDuration = 200;
 
    if (flashDuration >= sysinfo.lightmaxduration) {
        // If our flash duration is less then minimum available 
        // set this to minimum available duration
        flashDuration = sysinfo.lightmaxduration;
    }
 
    sysinfo.lighton(sysinfo.lighttargetsystem, flashDuration, 
        sysinfo.lightmaxintensity, false);
}
 
/**
* Function sets lightening intensity of the display to default value.
*/
function off() {
    sysinfo.lighton(sysinfo.lighttargetsystem, 
        sysinfo.lightinfiniteduration, sysinfo.lightdefaultintensity, true);
}
 
/**
* Function creates and initializes menu and right softkey.  
*/
function setup() {
    try {
        // Get access to SystemInfo API
        sysinfo = document.embeds[0]; 
    } catch (e) {
        alert('Setup error: ' + e);
    }
 
    // Create a right soft key
    try {
        if (menu != undefined) {
            menu.clear();
            menu.showSoftkeys();
    // Create menu items
 
            var lightItem = new MenuItem('Light', lightItemId);
            var blinkItem = new MenuItem('Blink', blinkItemId);
            var flashItem = new MenuItem('Flash', flashItemId);
            var offItem = new MenuItem('Off', offItemId);
            var exitItem = new MenuItem('Exit', exitItemId);
 
            lightItem.onSelect = menuEventHandler;      
            blinkItem.onSelect = menuEventHandler; 
            flashItem.onSelect = menuEventHandler;      
            offItem.onSelect = menuEventHandler; 
            exitItem.onSelect = menuEventHandler;
 
            menu.append(lightItem);
            menu.append(blinkItem);
            menu.append(flashItem);
            menu.append(offItem);
            menu.append(exitItem);
 
        } else {
            alert("Menu not found!");
        }
    } catch (e) {
        alert("Menu Initialization error!");
    }
 
    setFocus();
}
 
/**
 * Function handles menu events.
 * @param id - menu item identifier.
 */
 function menuEventHandler (id) {
    switch (id) {
    case lightItemId:
        lightOn();
        break;
    case blinkItemId:
        blinkOn();
        break;
    case flashItemId:
        flash();
        break; 
    case offItemId:
        off();
        break;
    case exitItemId:
        exitFunc();
        break; 
    default:
        break;
    }
}
 
/**
 * Function sets lightning to default value and exit program.
 */
function exitFunc() {
   off();
   window.close();
}
 
/**
 * Function gives focus to document.
 */
function setFocus() {
    document.getElementById('lightButton').focus();
}