Function start

static/editor.md/editormd.js:4517–4525

(e)

            dialogHeader.touchDraggable = function() {
                var offset = null;
                var start  = function(e) {
                    var orig = e.originalEvent; 
                    var pos  = $(this).parent().position();

                    offset = {
                        x : orig.changedTouches[0].pageX - pos.left,
                        y : orig.changedTouches[0].pageY - pos.top
                    };
                };

                var move = function(e) {
                    e.preventDefault();