expanding sub-menu items for projects page.

input/projects.md

 <!--%
 printProjectsMenu()
 %-->
+
+<script>
+    var coll = document.getElementsByClassName("collapse_menu");
+    var i;
+    for (i = 0; i < coll.length; i++) {
+        coll[i].addEventListener("click", function() {
+            this.classList.toggle("collapseactive_menu");
+            var content = this.parentElement.nextElementSibling;
+            if (content.style.maxHeight) {
+                content.style.maxHeight = null;
+            } else {
+                content.style.maxHeight = content.scrollHeight + "px";
+            }
+        });
+    }
+</script>

macros.py

             ret += ".svg?logo=git&style=flat\" /></a>"
     return ret
 
-def printMenuItem(p, yearsAsHeading = False, showDateSpan = False, showOnlyStartDate = False, nicelyFormatFullDate = False, lastyear = "0", lang = "", showLastCommit = True, hide_description = False, updates_as_heading = False):
+def printMenuItem(p, yearsAsHeading = False, showDateSpan = False, showOnlyStartDate = False, nicelyFormatFullDate = False, lastyear = "0", lang = "", showLastCommit = True, hide_description = False, updates_as_heading = False, desc_has_collapse = False):
     title = p.title
     if lang != "":
         if p.get("title_" + lang, "") != "":
         if p.get("description", "") != "":
             description = p.get("description", "")
             if lang != "":
-                if p.get("description_" + lang, "") != "":
-                    description = p.get("description_" + lang, "")
-            print("<br><span class=\"listdesc\">" + description + "</span>")
+                description = p.get("description_" + lang, description)
+            if desc_has_collapse:
+                print("<br><span class=\"listdesc collapse_menu\">" + description + "</span>")
+            else:
+                print("<br><span class=\"listdesc\">" + description + "</span>")
 
     if showLastCommit:
         link = githubCommitBadge(p)
     # prints all pages with parent 'projects' or 'stuff'.
     # first the ones without date, sorted by position.
     # this first section includes sub-headings for children
+    # in a hidden div, expanding when clicking the description.
     # then afterwards those with date, split by year.
     # also supports blog posts with parent.
     enpages = [p for p in pages if p.lang == "en"]
 
     # print all pages
     for p in mpages:
-        printMenuItem(p)
-
-        # print subpages for these top-level items
+        # fetch subpages for these top-level items
         subpages = [sub for sub in enpages if sub.get("parent", "none") == p.get("child-id", "unknown")]
         order = p.get("sort-order", "date")
         if order == "position":
             subpages.sort(key=lambda p: p["position"])
         else:
             subpages.sort(key=lambda p: p["date"], reverse = True)
+
+        printMenuItem(p, False, False, False, False, "0", "", True, False, False, len(subpages) > 0)
+
+        # print subpages
         if len(subpages) > 0:
+            print("<div class='collapsecontent_menu'>")
             print("<ul>")
             for sp in subpages:
                 printMenuItem(sp, False, True, True, False, "0", "", False, True)
             print("</ul>")
+            print("</div>")
 
     # slect pages with a date
     dpages = [p for p in enpages if p.get("date", "") != ""]
     # print all pages
     lastyear = "0"
     for p in mpages:
-        lastyear = printMenuItem(p, True, True, False, False, lastyear)
-
-        # print subpages for these top-level items
+        # fetch subpages for these top-level items
         subpages = [sub for sub in enpages if sub.get("parent", "none") == p.get("child-id", "unknown")]
         order = p.get("sort-order", "date")
         if order == "position":
             subpages.sort(key=lambda p: p["position"])
         else:
             subpages.sort(key=lambda p: p["date"], reverse = True)
+
+        lastyear = printMenuItem(p, True, True, False, False, lastyear, "", True, False, False, len(subpages) > 0)
+
+        # print subpages
         if len(subpages) > 0:
+            print("<div class='collapsecontent_menu'>")
             print("<ul>")
             for sp in subpages:
                 printMenuItem(sp, False, True, True, False, "0", "", False, True)
             print("</ul>")
+            print("</div>")
 
     print("</ul>")
 

static/css/style.css

     cursor: zoom-in;
 }
 
-.collapse {
+.collapse, .collapse_menu {
     cursor: pointer;
+}
+
+.collapse {
     padding: 15px;
 }
 
-.collapse:after {
+.collapse:after, .collapse_menu:before {
     content: '\002B';
     font-weight: bold;
+}
+
+.collapse:after {
     float: right;
     margin-left: 5px;
 }
 
-.collapseactive:after {
+.collapse_menu:before {
+    margin-right: 5px;
+}
+
+.collapseactive:after, .collapseactive_menu:before {
     content: "\2212";
 }
 
-.collapsecontent {
+.collapsecontent, .collapsecontent_menu {
     padding: 0;
-    margin: 15px;
     max-height: 0;
     overflow: hidden;
     transition: max-height 0.1s ease-out;
+}
+
+.collapsecontent {
+    margin: 15px;
     border-width: 0px;
     border-style: solid;
     border-radius: 10px;
     text-decoration-color: #FF0000;
 }
 
-.releasecard, .collapse {
+.releasecard, .collapse, .collapse_menu:before {
     background-color: #C0C0C0;
 }
 
     margin-left: 1em;
 }
 
-.collapseactive, .collapse:hover {
+.collapseactive, .collapse:hover, .collapse_menu:hover {
     background-color: #999999;
 }
 
         color: #BA55D3;
     }
 
-    .releasecard, .collapse {
+    .releasecard, .collapse, .collapse_menu:before {
         background-color: #232323;
     }
 
         color: #FFFFFF !important;
     }
 
-    .collapseactive, .collapse:hover {
+    .collapseactive, .collapse:hover, .collapse_menu:hover {
         background-color: #424242;
     }