ScrollNavigator.java 文件源码

public ScrollNavigator(ViewContext viewContext, Panel scrollContainer, Panel scrollee, Panel mouseLayer)
{
    m_viewContext = viewContext;
    m_scrollContainer = scrollContainer;
    m_scrollContainerInner = scrollee;
    m_mouseLayer = mouseLayer;
    m_scrollBarWidthDiv2 = (int) Math.floor(((double)U_Css.getScrollBarWidth())/2);
    m_cellHudHeight = viewContext.appConfig.cellHudHeight;

    m_scrollContainer.getElement().getStyle().setZIndex(1);

    m_args_SnapToCoord.historyShouldIgnore = true;

    m_scrollContainer.addDomHandler(new ScrollHandler()
    {
        @Override
        public void onScroll(ScrollEvent event)
        {
            State_ViewingCell viewingState =  m_viewContext.stateContext.get(State_ViewingCell.class);
            if( viewingState != null )
            {
                VisualCell cell = (VisualCell)viewingState.getCell().getVisualization();
                setTargetLayout(cell);
                //m_viewContext.cellMngr.updateCellTransforms(0.0);
            }
            else
            {
                //--- DRK > I guess when we leave viewing state and reset scroll left/top to zero,
                //---       that fires a scroll event, so valid case here...ASSERT removed for now.
                //smU_Debug.ASSERT(false, "Expected viewing state to be entered.");
            }

            if( m_scrollListener != null )  m_scrollListener.onScroll();
        }

    }, ScrollEvent.getType());

    this.toggleScrollBars(null, null);
}