Webkit and jQuery draggable jumping

19,356

Solution 1

This is a result of draggable's reliance on the jquery offset() function and offset()'s use of the native js function getBoundingClientRect(). Ultimately this is an issue with the jquery core not compensating for the inconsistencies associated with getBoundingClientRect(). Firefox's version of getBoundingClientRect() ignores the css3 transforms (rotation) whereas chrome/safari (webkit) don't.

here is an illustration of the issue.

A hacky workaround:

replace following in jquery.ui.draggable.js


//The element's absolute position on the page minus margins
this.offset = this.positionAbs = this.element.offset();

with


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

and finally a monkeypatched version of your jsbin.

Solution 2

I draw a image to indicate the offset after rotate on different browsers as @David Wick's answer.

offset after rotate

Here's the code to fix if you don't want patch or modify jquery.ui.draggable.js

$(document).ready(function () {
    var recoupLeft, recoupTop;
    $('#box').draggable({
        start: function (event, ui) {
            var left = parseInt($(this).css('left'),10);
            left = isNaN(left) ? 0 : left;
            var top = parseInt($(this).css('top'),10);
            top = isNaN(top) ? 0 : top;
            recoupLeft = left - ui.position.left;
            recoupTop = top - ui.position.top;
        },
        drag: function (event, ui) {
            ui.position.left += recoupLeft;
            ui.position.top += recoupTop;
        }
    });
});

or you can see the demo

Solution 3

David Wick is right about the general direction above, but computing the right coordinates is way more involved than that. Here's a more accurate monkey patch, based on MIT licensed Firebug code, which should work in far more situations where you have a complex DOM:

Instead replace:

    //The element's absolute position on the page minus margins
    this.offset = this.positionAbs = this.element.offset();

with the less hacky (be sure to get the whole thing; you'll need to scroll):

    //The element's absolute position on the page minus margins
    this.offset = this.positionAbs = getViewOffset(this.element[0]);

    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;
        }
      }
    }

It's a shame the DOM doesn't expose these calculations natively.

Solution 4

@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:

<script src="javascripts/jquery/jquery.js"></script>
<script src="javascripts/jquery/jquery-ui.js"></script>

<!-- the file containing the monkey-patch to draggable -->
<script src="javascripts/jquery/patch_draggable.js"></script>

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();

Solution 5

I prefer this workaround as it preserves the original handler
It removes the transform then restores it

$(document).ready(function(){

    // backup original handler
    var _mouseStart = $.ui.draggable.prototype._mouseStart;

    $.ui.draggable.prototype._mouseStart = function(event) {

        //remove the transform
        var transform = this.element.css('transform');
        this.element.css('transform', 'none');

        // call original handler
        var result = _mouseStart.call(this, event);

        //restore the transform
        this.element.css('transform', transform);

        return result;
    };
});

demo (started from @Liao San-Kai jsbin)

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19,356
gobbledygook88
Author by

gobbledygook88

Updated on June 19, 2022

Comments

  • gobbledygook88
    gobbledygook88 almost 2 years

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

        .items { 
            position: absolute;
            cursor: pointer;
            background: #FFC400;
            -moz-box-shadow: 0px 0px 2px #E39900;
            -webkit-box-shadow: 1px 1px 2px #E39900; 
            box-shadow: 0px 0px 2px #E39900;
            -moz-border-radius: 2px; 
            -webkit-border-radius: 2px;
            border-radius: 2px;
        }
    

    I then randomly styled them and made them draggable via jQuery.

        $('.items').each(function() {
            $(this).css({
                top: (80 * Math.random()) + '%',
                left: (80 * Math.random()) + '%',
                width: (100 + 200 * Math.random()) + 'px',
                height: (10 + 10 * Math.random()) + 'px',
                '-moz-transform': 'rotate(' + (180 * Math.random()) + 'deg)',
                '-o-transform': 'rotate(' + (180 * Math.random()) + 'deg)',
                '-webkit-transform': 'rotate(' + (180 * Math.random()) + 'deg)',
            });
        });
    
        $('.items').draggable();
    

    The dragging works, but I am noticing a sudden jump while dragging the div's only in webkit browsers, while everything is fine in Firefox.

    If I remove the position: absolute style, the 'jumping' is even worse. I thought there was maybe a difference in the transform origin between webkit and gecko, but they are both at the centre of the element by default.

    I have searched around already, but only came up with results about scrollbars or sortable lists.

    Here is a working demo of my problem. Try to view it in both Safari/Chrome and Firefox. http://jsbin.com/ucehu/

    Is this a bug within webkit or how the browsers render webkit?