Add sort criterion and order classes to table tag

Add a class "sort-col-1", "sort-col-2", or "sort-col-3" to the table tag
to indicate by which column the data is sorted, and a class "asc" or
"desc" to indicate whether it is sorted in ascending or descending
order. This is intended to be useful for applying a style to the sorted
column or its header.

Modify the default template to slightly darken the sorted column.

ngx_http_fancyindex_module.c

@@ -853,6 +853,8 @@ make_content_buf(
         len = r->uri.len + escape_html
           + ngx_sizeof_ssz(t_body2)
           + ngx_sizeof_ssz(t_list_begin)
+          + ngx_sizeof_ssz(t_list_head)
+          + ngx_sizeof_ssz("desc sort-col-1")
           + ngx_sizeof_ssz(t_list_colhead_name1)
           + ngx_sizeof_ssz(t_list_colhead_name2)
           + ngx_sizeof_ssz(t_list_colhead_size1)
@@ -868,6 +870,8 @@ make_content_buf(
    else
         len = r->uri.len + escape_html
           + ngx_sizeof_ssz(t_list_begin)
+          + ngx_sizeof_ssz(t_list_head)
+          + ngx_sizeof_ssz("desc sort-col-1")
           + ngx_sizeof_ssz(t_list_colhead_name1)
           + ngx_sizeof_ssz(t_list_colhead_name2)
           + ngx_sizeof_ssz(t_list_colhead_size1)
@@ -1053,6 +1057,27 @@ make_content_buf(
 
     /* Open the <table> tag */
     b->last = ngx_cpymem_ssz(b->last, t_list_begin);
+    switch (sort_criterion) {
+        case NGX_HTTP_FANCYINDEX_SORT_CRITERION_NAME_DESC:
+            b->last = ngx_cpymem_ssz(b->last, "desc sort-col-1");
+            break;
+        case NGX_HTTP_FANCYINDEX_SORT_CRITERION_NAME:
+            b->last = ngx_cpymem_ssz(b->last, "asc sort-col-1");
+            break;
+        case NGX_HTTP_FANCYINDEX_SORT_CRITERION_SIZE_DESC:
+            b->last = ngx_cpymem_ssz(b->last, "desc sort-col-2");
+            break;
+        case NGX_HTTP_FANCYINDEX_SORT_CRITERION_SIZE:
+            b->last = ngx_cpymem_ssz(b->last, "asc sort-col-2");
+            break;
+        case NGX_HTTP_FANCYINDEX_SORT_CRITERION_DATE_DESC:
+            b->last = ngx_cpymem_ssz(b->last, "desc sort-col-3");
+            break;
+        case NGX_HTTP_FANCYINDEX_SORT_CRITERION_DATE:
+            b->last = ngx_cpymem_ssz(b->last, "asc sort-col-3");
+            break;
+    }
+    b->last = ngx_cpymem_ssz(b->last, t_list_head);
 
     /* Write the column headers */
     b->last = ngx_cpymem_ssz(b->last, t_list_colhead_name1);

template.h

@@ -41,6 +41,21 @@ static const u_char t_head1[] = ""
 "text-overflow: '>';"
 "overflow: hidden;"
 "}"
+".sort-col-1 th:nth-of-type(1),"
+".sort-col-2 th:nth-of-type(2),"
+".sort-col-3 th:nth-of-type(3) {"
+"background:#ddd;"
+"}"
+".sort-col-1 td:nth-of-type(1),"
+".sort-col-2 td:nth-of-type(2),"
+".sort-col-3 td:nth-of-type(3) {"
+"background:#eee;"
+"}"
+".sort-col-1 tr:nth-child(even) td:nth-of-type(1),"
+".sort-col-2 tr:nth-child(even) td:nth-of-type(2),"
+".sort-col-3 tr:nth-child(even) td:nth-of-type(3) {"
+"background:#e4e4e4;"
+"}"
 "</style>"
 "\n"
 ;
@@ -62,7 +77,10 @@ static const u_char t_body2[] = ""
 "\n"
 ;
 static const u_char t_list_begin[] = ""
-"<table id=\"list\">"
+"<table id=\"list\" class=\""
+;
+static const u_char t_list_head[] = ""
+"\">"
 "<thead>"
 "<tr>"
 ;
@@ -113,6 +131,7 @@ static const u_char t_foot[] = ""
 	+ nfi_sizeof_ssz(t_body1) \
 	+ nfi_sizeof_ssz(t_body2) \
 	+ nfi_sizeof_ssz(t_list_begin) \
+	+ nfi_sizeof_ssz(t_list_head) \
 	+ nfi_sizeof_ssz(t_list_colhead_name1) \
 	+ nfi_sizeof_ssz(t_list_colhead_name2) \
 	+ nfi_sizeof_ssz(t_list_colhead_size1) \

template.html

@@ -40,6 +40,21 @@
 				text-overflow: '>';
 				overflow: hidden;
 			}
+			.sort-col-1 th:nth-of-type(1),
+			.sort-col-2 th:nth-of-type(2),
+			.sort-col-3 th:nth-of-type(3) {
+				background:#ddd;
+			}
+			.sort-col-1 td:nth-of-type(1),
+			.sort-col-2 td:nth-of-type(2),
+			.sort-col-3 td:nth-of-type(3) {
+				background:#eee;
+			}
+			.sort-col-1 tr:nth-child(even) td:nth-of-type(1),
+			.sort-col-2 tr:nth-child(even) td:nth-of-type(2),
+			.sort-col-3 tr:nth-child(even) td:nth-of-type(3) {
+				background:#e4e4e4;
+			}
 		</style>
 
 <!-- var t_head2 -->
@@ -60,7 +75,11 @@
 		</h1>
 
 <!-- var t_list_begin -->
-		<table id="list">
+		<table id="list" class="
+<!-- var NONE -->
+asc sort-col-1
+<!-- var t_list_head -->
+">
 			<thead>
 				<tr>
 <!-- var t_list_colhead_name1 -->