Actually it should be able do be done with wp_list_pages. The closest I have got is the following, but it also adds the code even if the page parent has no children…
<?php
//This funtion allows you to find text between any marker text
//This allows us to find the pade ID for the parent pages
function ExtractString($str, $start, $end)
{
$str_low = strtolower($str);
$pos_start = strpos($str_low, $start);
$pos_end = strpos($str_low, $end, ($pos_start + strlen($start)));
if ( ($pos_start !== false) && ($pos_end !== false) )
{
$pos1 = $pos_start + strlen($start);
$pos2 = $pos_end - $pos1;
return substr($str, $pos1, $pos2);
}
}
$parents = wp_list_pages("sort_column=menu_order&title_li=&title=&depth=1&echo=0"); //get parent pages
$parents_arr= explode("\n", $parents); //put parent pages into an array
$howmanyparents = count($parents_arr); // find out how many parent pages are in the array
for($i=0;$i<($howmanyparents - 1);$i++){ //Go through each parent to find the children for that parent
$trimmedparent = str_replace('</li>','<div class="drop">
<div class="drop-inner">
<div class="table">
<div class="top-left"></div>
<div class="top"></div>
<div class="top-right"></div>
<div class="body">
<div class="left"></div>
<div class="content">
<div class="col">
<ul>',$parents_arr[$i]); //replace the closing <li> from the parent with a <ul> for the sub-list and the custom div here.
$pagelist = $pagelist.$trimmedparent; //Add the current parent to the output list of pages - this is where we start rebuilding the wp_list_pages output
If(stristr($parents_arr[$i], 'current_page_item"') !== FALSE || stristr($parents_arr[$i], 'current_page_parent"') !== FALSE)
{ //If the parent is the current page item or parent we have to search for the page ID in a different way because the current page/parent has no trailing quote after the page ID in the link
$parentid = ExtractString($parents_arr[$i], 'page-item-', ' '); //Find the ID of the "current page item" Parent page assigned by WordPress via the "page-item-" part of the link
}
Else
{
$parentid = ExtractString($parents_arr[$i], 'page-item-', '"'); //Find the ID of the Parent page assigned by WordPress via the "page-item-" part of the link
}
$children = wp_list_pages("title_li=&child_of=".$parentid."&echo=0"); //Get the list of children for the current parent using wp_list_pages and the parent's ID
if($children == "") {$children = "<li> </li>";}
$pagelist = $pagelist.$children; //Add children to the pagelist
$pagelist = $pagelist.'</ul></div></div><div class="right"></div></div><div class="bottom-left"></div><div class="bottom"></div><div class="bottom-right"></div></div><div class="narr"></div></div></div></li>'; // Close the custom div, sublist, and original parent list item before continuing to the next parent and children
}
echo $pagelist;
?>
