ListHelper.java 文件源码

void trackMouseDraggedScroll(int mouseX, int mouseY, int listWidth, int listHeight){

        if (!mouseDraggedOutVertically){
            if (vsb.beforeThumb(mouseX, mouseY)) {
                vsb.setMode(AdjustmentEvent.UNIT_DECREMENT);
            } else {
                vsb.setMode(AdjustmentEvent.UNIT_INCREMENT);
            }
        }

        if(!mouseDraggedOutVertically && (mouseY < 0 || mouseY >= listHeight)){
            mouseDraggedOutVertically = true;
            vsb.startScrollingInstance();
        }

        if (mouseDraggedOutVertically && mouseY >= 0 && mouseY < listHeight && mouseX >= 0 && mouseX < listWidth){
            mouseDraggedOutVertically = false;
            vsb.stopScrollingInstance();
        }
    }