Group menu items into per-category submenus

Parse the Categories key from .desktop files and have the renderer
emit one <menu> submenu per category (via xmerl), with items sorted
within each; entries in multiple categories appear in each submenu,
and uncategorized entries fall into a catch-all "Other" submenu.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/src/er_xdg_pipe_menu_desktop_entry.erl b/src/er_xdg_pipe_menu_desktop_entry.erl
index bbd2594..9a71013 100644
--- a/src/er_xdg_pipe_menu_desktop_entry.erl
+++ b/src/er_xdg_pipe_menu_desktop_entry.erl
@@ -3,8 +3,9 @@
 %%
 %% Reads the `[Desktop Entry]' group of a desktop entry file and
 %% extracts the fields needed to build a menu item: `Name', `Exec'
-%% and (optionally) `Icon'. Other groups (e.g. `[Desktop Action ...]')
-%% and localized keys (e.g. `Name[fr]') are ignored.
+%% and (optionally) `Icon' and `Categories'. Other groups (e.g.
+%% `[Desktop Action ...]') and localized keys (e.g. `Name[fr]') are
+%% ignored.
 %% @end
 %%%-------------------------------------------------------------------
 
@@ -16,7 +17,7 @@
 
 -define(GROUP, <<"Desktop Entry">>).
 -define(WANTED_KEYS, [
-    <<"Name">>, <<"Exec">>, <<"Icon">>, <<"NoDisplay">>, <<"Hidden">>, <<"Type">>
+    <<"Name">>, <<"Exec">>, <<"Icon">>, <<"Categories">>, <<"NoDisplay">>, <<"Hidden">>, <<"Type">>
 ]).
 -define(FIELD_CODES, "fFuUdDnNickvm").
 
@@ -99,11 +100,20 @@ to_entry(Fields) ->
                         name = Name,
                         exec = strip_field_codes(Exec),
                         icon = maps:get(<<"Icon">>, Fields, undefined),
+                        categories = parse_categories(maps:get(<<"Categories">>, Fields, undefined)),
                         hidden = is_hidden(Fields)
                     }}
             end
     end.
 
+%% `Categories' is a `;'-separated list, conventionally with a
+%% trailing separator (e.g. `Utility;Development;'); empty segments
+%% from that trailing separator (or repeated ones) are dropped.
+parse_categories(undefined) ->
+    [];
+parse_categories(Bin) ->
+    [C || C <- binary:split(Bin, <<";">>, [global]), C =/= <<>>].
+
 %% Niche variations (e.g. a Type-less override dropped into
 %% ~/.local/share/applications) are left to be special-cased there
 %% rather than accounted for here.