Webkit and jQuery draggable jumping

Question

As an experiment, I created a few div\'s and rotated them using CSS3.

    .items { 
        position: absolute;
        cursor: pointer;
        background:          


        

Answer 1

@ecmanaut: Great solution. Thanks for your efforts. To assist others I turned your solution into a monkey-patch. Copy below code to a file. Include the file after loading jquery-ui.js as follows:

Here's the code to copy/paste into patch_draggable.js:

function monkeyPatch_mouseStart() {
     // don't really need this, but in case I did, I could store it and chain
     var oldFn = $.ui.draggable.prototype._mouseStart ;
     $.ui.draggable.prototype._mouseStart = function(event) {

            var o = this.options;

           function getViewOffset(node) {
              var x = 0, y = 0, win = node.ownerDocument.defaultView || window;
              if (node) addOffset(node);
              return { left: x, top: y };

              function getStyle(node) {
                return node.currentStyle || // IE
                       win.getComputedStyle(node, '');
              }

              function addOffset(node) {
                var p = node.offsetParent, style, X, Y;
                x += parseInt(node.offsetLeft, 10) || 0;
                y += parseInt(node.offsetTop, 10) || 0;

                if (p) {
                  x -= parseInt(p.scrollLeft, 10) || 0;
                  y -= parseInt(p.scrollTop, 10) || 0;

                  if (p.nodeType == 1) {
                    var parentStyle = getStyle(p)
                      , localName   = p.localName
                      , parent      = node.parentNode;
                    if (parentStyle.position != 'static') {
                      x += parseInt(parentStyle.borderLeftWidth, 10) || 0;
                      y += parseInt(parentStyle.borderTopWidth, 10) || 0;

                      if (localName == 'TABLE') {
                        x += parseInt(parentStyle.paddingLeft, 10) || 0;
                        y += parseInt(parentStyle.paddingTop, 10) || 0;
                      }
                      else if (localName == 'BODY') {
                        style = getStyle(node);
                        x += parseInt(style.marginLeft, 10) || 0;
                        y += parseInt(style.marginTop, 10) || 0;
                      }
                    }
                    else if (localName == 'BODY') {
                      x += parseInt(parentStyle.borderLeftWidth, 10) || 0;
                      y += parseInt(parentStyle.borderTopWidth, 10) || 0;
                    }

                    while (p != parent) {
                      x -= parseInt(parent.scrollLeft, 10) || 0;
                      y -= parseInt(parent.scrollTop, 10) || 0;
                      parent = parent.parentNode;
                    }
                    addOffset(p);
                  }
                }
                else {
                  if (node.localName == 'BODY') {
                    style = getStyle(node);
                    x += parseInt(style.borderLeftWidth, 10) || 0;
                    y += parseInt(style.borderTopWidth, 10) || 0;

                    var htmlStyle = getStyle(node.parentNode);
                    x -= parseInt(htmlStyle.paddingLeft, 10) || 0;
                    y -= parseInt(htmlStyle.paddingTop, 10) || 0;
                  }

                  if ((X = node.scrollLeft)) x += parseInt(X, 10) || 0;
                  if ((Y = node.scrollTop))  y += parseInt(Y, 10) || 0;
                }
              }
            }


                //Create and append the visible helper
                this.helper = this._createHelper(event);

                //Cache the helper size
                this._cacheHelperProportions();

                //If ddmanager is used for droppables, set the global draggable
                if($.ui.ddmanager)
                    $.ui.ddmanager.current = this;

                /*
                 * - Position generation -
                 * This block generates everything position related - it's the core of draggables.
                 */

                //Cache the margins of the original element
                this._cacheMargins();

                //Store the helper's css position
                this.cssPosition = this.helper.css("position");
                this.scrollParent = this.helper.scrollParent();

                //The element's absolute position on the page minus margins
            this.offset = this.positionAbs = getViewOffset(this.element[0]);
                this.offset = {
                    top: this.offset.top - this.margins.top,
                    left: this.offset.left - this.margins.left
                };

                $.extend(this.offset, {
                    click: { //Where the click happened, relative to the element
                        left: event.pageX - this.offset.left,
                        top: event.pageY - this.offset.top
                    },
                    parent: this._getParentOffset(),
                    relative: this._getRelativeOffset() //This is a relative to absolute position minus the actual position calculation - only used for relative positioned helper
                });

                //Generate the original position
                this.originalPosition = this.position = this._generatePosition(event);
                this.originalPageX = event.pageX;
                this.originalPageY = event.pageY;

                //Adjust the mouse offset relative to the helper if 'cursorAt' is supplied
                (o.cursorAt && this._adjustOffsetFromHelper(o.cursorAt));

                //Set a containment if given in the options
                if(o.containment)
                    this._setContainment();

                //Trigger event + callbacks
                if(this._trigger("start", event) === false) {
                    this._clear();
                    return false;
                }

                //Recache the helper size
                this._cacheHelperProportions();

                //Prepare the droppable offsets
                if ($.ui.ddmanager && !o.dropBehaviour)
                    $.ui.ddmanager.prepareOffsets(this, event);

                this.helper.addClass("ui-draggable-dragging");
                //JWL: Hier vindt de jump plaats
                this._mouseDrag(event, true); //Execute the drag once - this causes the helper not to be visible before getting its correct position

                //If the ddmanager is used for droppables, inform the manager that dragging has started (see #5003)
                if ( $.ui.ddmanager ) $.ui.ddmanager.dragStart(this, event);

                return true;

     };

 }
monkeyPatch_mouseStart();