this.helper.css(“opacity”, o.opacity);
}
if(o.zIndex) { // zIndex option
if (this.helper.css(“zIndex”)) this._storedZIndex = this.helper.css(“zIndex”);
this.helper.css(“zIndex”, o.zIndex);
}
//Prepare scrolling
if(this.scrollParent[0] != document && this.scrollParent[0].tagName != ‘HTML’)
this.overflowOffset = this.scrollParent.offset();
//Call callbacks
this._trigger(“start”, event, this._uiHash());
//Recache the helper size
if(!this._preserveHelperProportions)
this._cacheHelperProportions();
//Post ‘activate’ events to possible containers
if(!noActivation) {
for (var i = this.containers.length – 1; i >= 0; i–) { this.containers[i]._trigger(“activate”, event, self._uiHash(this)); }
}
//Prepare possible droppables
if($.ui.ddmanager)
$.ui.ddmanager.current = this;
if ($.ui.ddmanager && !o.dropBehaviour)
$.ui.ddmanager.prepareOffsets(this, event);
this.dragging = true;
this.helper.addClass(“ui-sortable-helper”);
this._mouseDrag(event); //Execute the drag once – this causes the helper not to be visible before getting its correct position
return true;
},
_mouseDrag: function(event) {
//Compute the helpers position
this.position = this._generatePosition(event);
this.positionAbs = this._convertPositionTo(“absolute”);
if (!this.lastPositionAbs) {
this.lastPositionAbs = this.positionAbs;
}
//Do scrolling
if(this.options.scroll) {
var o = this.options, scrolled = false;
if(this.scrollParent[0] != document && this.scrollParent[0].tagName != ‘HTML’) {
if((this.overflowOffset.top + this.scrollParent[0].offsetHeight) – event.pageY < o.scrollSensitivity)
this.scrollParent[0].scrollTop = scrolled = this.scrollParent[0].scrollTop + o.scrollSpeed;
else if(event.pageY – this.overflowOffset.top < o.scrollSensitivity)
this.scrollParent[0].scrollTop = scrolled = this.scrollParent[0].scrollTop – o.scrollSpeed;
if((this.overflowOffset.left + this.scrollParent[0].offsetWidth) – event.pageX < o.scrollSensitivity)
this.scrollParent[0].scrollLeft = scrolled = this.scrollParent[0].scrollLeft + o.scrollSpeed;
else if(event.pageX – this.overflowOffset.left < o.scrollSensitivity)
this.scrollParent[0].scrollLeft = scrolled = this.scrollParent[0].scrollLeft – o.scrollSpeed;
} else {
if(event.pageY – $(document).scrollTop() < o.scrollSensitivity)
scrolled = $(document).scrollTop($(document).scrollTop() – o.scrollSpeed);
else if($(window).height() – (event.pageY – $(document).scrollTop()) < o.scrollSensitivity)
scrolled = $(document).scrollTop($(document).scrollTop() + o.scrollSpeed);
if(event.pageX – $(document).scrollLeft() < o.scrollSensitivity)
