void ResetPlaceholder()
    {
        List <App>        appList  = launcherController.appList;
        List <GameObject> iconList = launcherController.pageChildList;

        int[] dragPageBound = launcherController.getPageBoundByIndex(swapInfo.dragPage);
        for (int i = dragPageBound[0]; i <= dragPageBound[1]; i++)
        {
            App  app           = appList [i];
            bool isPlaceholder = app.isPlaceholder;
            if (isPlaceholder)
            {
                int index = i;
                swapInfo.firstEmptyIconIndexOnDragPage    = index;
                swapInfo.firstEmptyIconModelOnDragPage    = appList [index];
                swapInfo.firstEmptyIconIconOnDragPage     = iconList [index];
                swapInfo.firstEmptyIconLocationOnDragPage = iconList [index].GetComponent <IconController> ().originLocation;

                break;
            }
            swapInfo.firstEmptyIconIndexOnDragPage = -1;
        }
//		launcherController.Log (TAG, "drag page firstPlaceholder index:"+swapInfo.firstEmptyIconIndexOnDragPage);

        int[] dropPageBound = launcherController.getPageBoundByIndex(swapInfo.dropPage);
        for (int i = dropPageBound[0]; i <= dropPageBound[1]; i++)
        {
            App  app           = appList [i];
            bool isPlaceholder = app.isPlaceholder;
            if (isPlaceholder)
            {
                int index = i;
                swapInfo.firstEmptyIconIndexOnDropPage    = index;
                swapInfo.firstEmptyIconModelOnDropPage    = appList [index];
                swapInfo.firstEmptyIconIconOnDropPage     = iconList [index];
                swapInfo.firstEmptyIconLocationOnDropPage = iconList [index].GetComponent <IconController> ().originLocation;
                break;
            }
            swapInfo.firstEmptyIconIndexOnDropPage = -1;
        }
//		launcherController.Log (TAG, "drop page firstPlaceholder index:"+swapInfo.firstEmptyIconIndexOnDropPage);
    }