code: public void setDragView(View dragView) {
          if (mDragView != null) {
              mDragView.setOnClickListener(null);
          }
          mDragView = dragView;
          if (mDragView != null) {
              mDragView.setClickable(true);
              mDragView.setFocusable(false);
              mDragView.setFocusableInTouchMode(false);
              mDragView.setOnClickListener(new OnClickListener() {
                  @Override
                  public void onClick(View v) {
                      if (!isEnabled()) return;
                      if (!isPanelExpanded()) {
                          expandPanel(mAnchorPoint);
                      } else {
                          collapsePanel();
                      }
                  }
              });;
          }
      }
docs: Set the draggable view portion. Use to null, to allow the whole panel to be draggable
  
  @param dragView A view that will be used to drag the panel.