+ auto panel = new wxPanel (this);
+ auto sizer = new wxBoxSizer (wxVERTICAL);
+
+ auto filters = Filter::all ();
+
+ map<string, list<Filter const *>> categories;
+
+ for (auto i: filters) {
+ auto j = categories.find (i->category());
+ if (j == categories.end ()) {
+ categories[i->category()] = { i };
+ } else {
+ j->second.push_back (i);
+ }
+ }