code: private void stopDrag(final CmsDNDHandler handler) {
  
          removeDragOverlay();
          for (I_CmsDropTarget target : m_dragInfos.keySet()) {
              target.getElement().removeClassName(I_CmsLayoutBundle.INSTANCE.dragdropCss().dragging());
              target.getElement().removeClassName(I_CmsLayoutBundle.INSTANCE.dragdropCss().clearFix());
              Style targetStyle = target.getElement().getStyle();
              if (!(target instanceof CmsGroupContainerElementPanel)) {
                  targetStyle.clearPosition();
              }
              targetStyle.clearMarginTop();
              targetStyle.clearMarginBottom();
              if (target instanceof I_CmsDropContainer) {
                  ((I_CmsDropContainer)target).removeHighlighting();
              }
          }
          handler.getDragHelper().removeFromParent();
          m_copyGroupId = null;
          m_currentTarget = null;
          m_currentIndex = -1;
          m_isNew = false;
          m_controller.getHandler().deactivateMenuButton();
          final List<I_CmsDropTarget> dragTargets = new ArrayList<I_CmsDropTarget>(m_dragInfos.keySet());
          m_dragInfos.clear();
          Scheduler.get().scheduleDeferred(new ScheduledCommand() {
  
              /**
               * @see com.google.gwt.user.client.Command#execute()
               */
              public void execute() {
  
                  handler.clearTargets();
                  m_controller.resetEditButtons();
                  // in case of group editing, this will refresh the container position and size
                  for (I_CmsDropTarget target : dragTargets) {
                      if (target instanceof I_CmsDropContainer) {
                          ((I_CmsDropContainer)target).refreshHighlighting();
                          // reset the nested container infos
                          ((I_CmsDropContainer)target).clearDnDChildren();
                      }
                  }
              }
          });
          if (handler.getDraggable() instanceof CmsContainerPageElementPanel) {
              ((CmsContainerPageElementPanel)(handler.getDraggable())).removeHighlighting();
          }
      }
docs: Function which is called when the drag process is stopped, either by cancelling or dropping.<p>
  
  @param handler the drag and drop handler