//
// Author: J. Odeyer
// Date: 2011/03/08
// Last modif date: 
//
// This script builds a loading progress widget
//
// Dependencies:
// This class relies on jQuery core library and jQuery UI css 
// It extends jQuery object with a CSPprogressWidget plugin function

//js class used to bring the logic to build and display the loading widget
function CSPprogressWidget(container) {
	//default values
	//properties which can be set and read 
	this.modal = false;
	this.destroyAfterClosing = false;
	this.positionContainer = $(document.body); //is the container element that will be used to position the image and to apply the modal div layer
	this.loadingImage = '';
	this.zIndex = 100;
	this.showText = false;
	this.text = 'loading...';
	this.buildContent = false; //indicates whether image and text have to be build or if they already exist in the provided container element
	//properties which should be accessed in read only
	this.isDOMcreated = false;
	this.container = container; //is the jQuery div element which will contain the loading image
	this.modalDiv = null; //overlayer div to make the widget modal
	this.isVisible = false;
	this.initialCssPosition = 'static';
}

//destroy all elements from DOM
CSPprogressWidget.prototype.destroy = function() {
	this.hide();
	this.container.removeAttr('cspprogresswidget');
	this.container.removeClass('ui-widget');
	this.positionContainer.css('position',this.initialCssPosition);
	if(this.modalDiv != null) {
		this.modalDiv.remove();
	}
	this.modalDiv = null;
	if(this.buildContent) {
		this.container.empty();
	}
}

//create HTML dom element
CSPprogressWidget.prototype.createHtmlDOM = function() {
	if(this.positionContainer[0] !== $(document.body)[0] && this.positionContainer.css('position') == 'static') {
		//if positionContainer element position css property is static we make it relative to ensure a right posisioning of all elements
		this.positionContainer.css('position','relative');
	}
	this.container.css({'position': 'absolute','display': 'none', 'zIndex': this.zIndex});
	if(this.buildContent) {
		//empty container element
		this.container.empty();
		this.container.css({'text-align':'center'});
		//rebuild the content
		var imgElt = $('<img />');
		imgElt.attr('src',this.loadingImage);
		imgElt.attr('alt','loading in progress...');
		imgElt.attr('title','loading in progress...');
		this.container.append(imgElt);
		if(this.showText) {
			$('<br />').appendTo(this.container);
			var spanElt = $('<span></span>');
			spanElt.text(this.text);
			this.container.append(spanElt);
		}
	}
	
	if(this.modalDiv != null) {
		//we remove the modal overlayer div
		this.modalDiv.remove();
	}
	
	if(!this.container.hasClass('ui-widget')) {
		this.container.addClass('ui-widget');
	}
	
	if(this.modal) {
		//build the modal overlayer div
		this.modalDiv = $('<div></div>').addClass('ui-widget-overlay').css({'zIndex': this.zIndex-1, 'display': 'none', 'position': 'absolute', 'top': 0 + 'px', 'left': 0 + 'px'}).appendTo(this.positionContainer);
	}
	
	//set isDOMcreated to true
	this.isDOMcreated = true;
}

//set position of the widget(loading image + text) //and the modal overlayer
//NB: to get right size and position, element must be displayed
CSPprogressWidget.prototype.setPosition = function() {
	var topPosition = 0;
	var leftPosition = 0;
	var xposContainer = 0;
	var yposContainer = 0;
	var initialDisplay = this.container.css('display');
	//make container visible to ensure we can calculate the position correctly
	this.container.css('display','block');
	if(this.positionContainer.length>0 && this.positionContainer[0].ownerDocument != null) {
		xposContainer = this.positionContainer.offset().left;
	}
	leftPosition = xposContainer + Math.floor((this.positionContainer.width() - this.container.width()) / 2);
	if(this.isTopPosWithPosContainerOk()) {
		yposContainer = this.positionContainer.offset().top;
		topPosition = yposContainer + Math.floor((this.positionContainer.height() - this.container.height()) / 2);
	} else {
		topPosition = $(window).scrollTop() + Math.floor(($(window).height() - this.container.height()) / 2);
	}
	
	this.container.css({"display": initialDisplay, "top": topPosition + "px", "left": leftPosition + "px"});
}

//check if we can top position the loading widget with the DOM element provided for this.positionContainer
CSPprogressWidget.prototype.isTopPosWithPosContainerOk = function() {
	if(this.positionContainer.length<1 || this.positionContainer[0].ownerDocument == null) {
		return false;
	}
	var topPosContainer = this.positionContainer.offset().top;
	var bottomPosContainer  = this.positionContainer.offset().top + this.positionContainer.height();
	var windowTopPos = $(window).scrollTop();
	var windowBottomPos = $(window).scrollTop() + $(window).height();
	
	if(topPosContainer < windowTopPos
	|| topPosContainer > windowBottomPos
	|| bottomPosContainer < windowTopPos
	|| bottomPosContainer > windowBottomPos) {
		//this.positionContainer DOM element is not fully visible by the current window position, return false
		return false;
	}
	//can be top positioned depending on top position of this.positionContainer element
	return true;
}

// allow to access to object properties
// if a value is provided, try to set this property with the provided value and return true if successfull, otherwise return the property value
CSPprogressWidget.prototype.option = function(propertyName, value) {
	try {
		for(var propName in this) {
			if(propName ==  propertyName) {
				if(value != null) {
					//value is provided, we set the value
					this[propName] = value;
					//if an option is set, we recreate DOM
					this.createHtmlDOM();
					return true;
				}
				//value is not provided we return the property value
				return this[propName];
			}
		}
		if(value == null) {
			//if value is not provided, and we have not found the property we return null
			return null;
		}
	} catch(e) {
		if(showError != null && showError) {
			alert(e);
		}
		if(value != null) {
			return false;
		} else {
			return null;
		}
	}
}

//show the loading widget
CSPprogressWidget.prototype.show = function() {
	if(!this.isDOMcreated) {
		//if DOM has not been created yet, we create it first
		this.createHtmlDOM();
	}
	//set position of the widget(loading image + text) and the modal overlayer
	this.setPosition();
	
	if(this.modal && this.modalDiv != null) {
		//show the modal overlayer
		this.modalDiv.css('display','block');
	}
	//show the progress widget
	this.container.css('display','block');
	this.isVisible = true;
}

//hide the loading widget
CSPprogressWidget.prototype.hide = function() {
	//hide the progress widget
	this.container.css('display','none');
	if(this.modalDiv != null) {
		//show the modal overlayer
		this.modalDiv.css('display','none');
	}
	this.isVisible = false;
}

//add jQuery extension plugin
jQuery.fn.extend({
	//this function returns an object of type CSPprogressWidget with the first matching element, null otherwise
	//if an object is passed and the first matching element does not contain an instance of CSPprogressWidget, we create a new instance of CSPprogressWidget initialized with passed object properties 
	CSPprogressWidget: function(obj) {
		if(this.length < 1) {
			//jQuery object does not contain any matching element for the selector, return null 
			return null
		}
		//get CSPprogressWidget object for the first matching element
		if($(this).data('cspprogresswidget') !== undefined)
		{
			//return $.data(this, 'cspprogresswidget');
			return $(this).data('cspprogresswidget');
		}
		//if CSPprogressWidget attribute does not exists, 
		//we create a new instance of CSPprogressWidget js class and add a reference to the dom element through an attribute
		var CSPprogressWidgetObj = new CSPprogressWidget(this);
		if(obj != null) {
			if(obj.modal != null) {
				CSPprogressWidgetObj.modal = obj.modal;
			}
			if(obj.destroyAfterClosing != null) {
				CSPprogressWidgetObj.destroyAfterClosing = obj.destroyAfterClosing;
			}
			if(obj.positionContainer != null) {
				CSPprogressWidgetObj.positionContainer = $(obj.positionContainer);
			}
			if(obj.buildContent != null) {
				CSPprogressWidgetObj.buildContent = obj.buildContent;
			}
			if(obj.loadingImage != null) {
				CSPprogressWidgetObj.loadingImage = obj.loadingImage;
			}
			if(obj.zIndex != null) {
				CSPprogressWidgetObj.zIndex = obj.zIndex;
			}
			if(obj.showText != null) {
				CSPprogressWidgetObj.showText = obj.showText;
			}
			if(obj.text != null) {
				CSPprogressWidgetObj.text = obj.text;
			}
		}
		//we get initial value for position css property to do a rollback if we have to change it
		CSPprogressWidgetObj.initialCssPosition = CSPprogressWidgetObj.positionContainer.css('position');
		
		//associate settings data to the DOM element
		$(this).data('cspprogresswidget', CSPprogressWidgetObj);
		
		return CSPprogressWidgetObj;
	}
});
if (typeof (Sys) !== 'undefined') Sys.Application.notifyScriptLoaded();