bencripps / react-redux-grid

export const bufferTop = (

    rowHeight, viewableIndex, viewableCount, bufferMultiplier, totalCount

) => {

    const spacerCount = Math.max(

        viewableIndex - viewableCount * bufferMultiplier,

        0

    );

    // spacerCount can never be greater than (

    // totalCount - viewableCount * rowHeight)

    return Math.min(

        spacerCount * rowHeight,

        totalCount - viewableCount * rowHeight

    );

};

export const bufferBottom = (

    rowHeight, viewableIndex, viewableCount, bufferMultiplier, totalCount

) => {

    const spacerCount = Math.max(

        totalCount - viewableIndex - viewableCount * (bufferMultiplier + 1),

        0

    );

    return spacerCount * rowHeight;

};