angular拖拽指令-

angular.module('app.routes').directive('dragMvPlayer', ['$document', function($document) {    return{        restrict: 'EA',        template: `testTemplete`,        link: function(scope, element, attr) {            var bodyWidth = document.body.offsetWidth,bodyHeight = document.body.offsetHeight, startX = 0, startY = 0, x = bodyWidth-420, y = bodyHeight - 440;            element= angular.element(document.getElementById("jp_container_1"));            element.css({                position: 'fixed',                cursor: 'move',            });            element.on('mousedown', function(event) {                // Prevent default dragging of selected content                event.preventDefault();                startX = event.pageX - x;                startY = event.pageY - y;                $document.on('mousemove', mousemove);                $document.on('mouseup', mouseup);            });            function mousemove(event) {                y = event.pageY - startY;                x = event.pageX - startX;                element.css({                    top: y + 'px',                    left:  x + 'px'                });            }            function mouseup() {                $document.off('mousemove', mousemove);                $document.off('mouseup', mouseup);            }        }    }}]);