joint.all.js
function() {

        this.model.trigger('batch:start');

        this._z = this.model.get('z');
        this.model.set('z', Number.MAX_VALUE);

        // Let the pointer propagate throught the link view elements so that
        // the `evt.target` is another element under the pointer, not the link itself.
        this.el.style.pointerEvents = 'none';
    }
function() {

        this.model.trigger('batch:start');

        this._z = this.model.get('z');
        this.model.set('z', Number.MAX_VALUE);

        // Let the pointer propagate throught the link view elements so that
        // the `evt.target` is another element under the pointer, not the link itself.
        this.el.style.pointerEvents = 'none';
    }
Interaction. The controller part. ---------------------------------