// Preloader Class v2.2
// by Jonas Galvez
// 
// Description: Preloads content that will be loaded by one or more
// instances of either MovieClip, Sound, LoadVars or XML classes
//
// Properties: kbTotal, kbLoaded, kbLeft, percentComplete, instances
// Events: onPreloadStart, onPreloadUpdate, onPreloadComplete
//
// If you have any comments or suggestions about the code,
// please send them to jonasgalvez@uol.com.br

// Custom functions and methods used in the Preloader Class

// --> hasArray Function
// Checks if the first item of an array or 
// arguments object contains an array

_global.hasArray = function(obj) {
    if(typeof obj[0] == "object" && obj[0].length) return obj.shift();
    else return obj;
};

// --> Object.isInstanceOf Method
// Returns true if the object belongs to any of the specified classes

Object.prototype.isInstanceOf = function() {
    if(arguments.length) for(i in arguments) {
        if(this instanceof arguments[i]) return true;
    };
    return false;
};

// --> Object.addProperties Method
// Adaptation of the Object.addProperty Method
// that allows you to add more than one property at a time

Object.prototype.addProperties = function() {
    var properties = hasArray(arguments);
    var prop, hasGetter, hasSetter;
    for(property in properties) {
        prop = properties[property];
        if(this["get" + prop] instanceof Function) hasGetter = true;
        if(this["set" + prop] instanceof Function) hasSetter = true;
        if(hasGetter && hasSetter) {
            this.addProperty(prop, this["get" + prop], this["set" + prop]);
        } else if(hasGetter) {
            this.addProperty(prop, this["get" + prop], null);
        };
        hasGetter = hasSetter = false;
    };
};

_global.Preloader = function() {
    var args = hasArray(arguments);
    this._total = this._loaded = this.left = 0;
    this.total = this.loaded = this.left;
    this.percentage = this._started = 0;
    this._instances = this._tempInstances = new Array();
    for(var i = 0; i < args.length; i++) {
        if(args[i].isInstanceOf(MovieClip, Sound, LoadVars, XML)) {
            args[i]._tempTotal = args[i].getBytesTotal();
            ASSetPropFlags(args[i], "_tempTotal", 1);
            this._instances[this._instances.length] = args[i];
        };
    };
    this._interval = setInterval(this, "_main", 100);
};

Preloader.prototype.getKBTotal = function() { return this.total; };
Preloader.prototype.getKBLoaded = function() { return this.loaded; };
Preloader.prototype.getKBLeft = function() { return this.left; };
Preloader.prototype.getPercentComplete = function() { return this._percentage; };
Preloader.prototype.getInstances = function() { return this._instances; };

var props = ["kbTotal", "kbLoaded", "kbLeft", "percentComplete", "instances"];
Preloader.prototype.addProperties(props);

Preloader.prototype._main = function() {
    this._total = this._loaded = 0;
    for(var j = 0; j < this._instances.length; j++) {
        this._total += this._instances[j].getBytesTotal();
        this._loaded += this._instances[j].getBytesLoaded();
        if(this._instances[j].getBytesTotal() != this._instances[j]._tempTotal) {
            if(!this._tempInstances[this._instances[j]] && this._instances[j].getBytesTotal() > 0) {
                this._tempInstances[this._instances[j]] = this._instances[j];
                this._started++;
            };
        };
    };
    if(this._instances.length == this._started) {
        this.total = Math.round(this._total / 1024);
        this.loaded = Math.round(this._loaded / 1024);
        if(!this._OPScalled) {
            this.onPreloadStart(); this._OPScalled = true;
        };
        this.left = this.total - this.loaded;
        this._percentage = Math.round(this.loaded*100/this.total);
        this.onPreloadUpdate();
        if(this._percentage == 100) {
            this.onPreloadComplete();
            clearInterval(this._interval);
        };
    };
};
ASSetPropFlags(_global, "Preloader", 1);

delete props;

// --> Usage Example 1
//
// _root.myMovieClip.load("file.swf");
// _root.mySound.loadSound("file.mp3", false);
// 
// myPreloader = new Preloader(_root.myMovieClip, _root.mySound);
//
// myPreloader.onPreloadUpdate = function() {
//     _root.total_kb.text = this.kbTotal + "Kb";
//     _root.loaded_kb.text = this.kbLoaded + "Kb";
//     _root.left_kb.text = this.kbLeft + "Kb";
//     _root.percentage_loaded.text = this.percentComplete + "%";
// };
//
// myPreloader.onPreloadComplete = function() {
//     _root.message.gotoAndStop("Loaded");
// };
//
//
// --> Usage Example 2
//
// var instances = [];
//
// for(var i = 0; i < 10; i++) {
//     _root["photo" + i].loadMovie("file" + i + ".jpg");
//     instances.push(_root["photo" + i]);
// };
// 
// myPreloader = new Preloader(instances);
//
// _root.message.text = "Receiving Files Headers...";
//
// myPreloader.onPreloadStart = function() {
//
//     _root.message.text = "Loading Files...";
//
//     this.onPreloadUpdate = function() {
//         _root.progressBar._xscale = this.percentComplete;
//     };
//
// };
//
// myPreloader.onPreloadComplete = function() {
//
//     _root.message.text = "Done!";
//
//     for(var i = 0; i < this.instances.length; i++) {
//         this.instances[i].gotoAndStop(2);
//     };
//
// };