Page List Display Logic

pageList.html

<script>
    for(var page = 1; page <= 20; ++page) {
        for(var pageNum = 1; pageNum <= 20; ++pageNum) {
            if (page <= pageNum) {
                console.log(getPageDetail(page, pageNum));
            }
        }
    }


    function getPageDetail(page, pageNum) {
        var o = {
                page : page,
                pageNum : pageNum
            },
            base = page,
            temp = pageNum - 2;

        if (base > temp) {
            base = temp;
        }

        if (base < 3) {
            base = 3;
        }

        var start = base - 2,
            end = base + 2;

        if (end > pageNum) {
            end = pageNum;
        }

        o.start = start;
        o.end = end;
        o.prev = page !== 1;
        o.next = page !== pageNum;

        return o;
    }
</script>

http://blog.xuite.net/vexed/tech/35595653