Make libappstream and GCR3 optional.

Though I'd heavily discourage dropping the latter, and I quite value the former.

meson_options.txt

@@ -1 +1,2 @@
-option('nofts5', type: 'boolean', value: false)
+option('appstream', type: 'boolean', value: true, description: 'Use appstream to recommend compatible apps')
+option('gcr', type: 'boolean', value: true, description: 'Use GCR to show certificate details, HEAVILY RECOMMENDED')

src/Services/Prosody/misc/AppStream.vala

@@ -27,6 +27,7 @@ And given I can link to app descriptions where they can be installed via simple
         URLs, it looks quite trivial to write that UI in Prosody. The
         challenging bit is getting at the data, which is what's done here. */
 namespace Odysseus.Templating.xAppStream {
+#if HAVE_APPSTREAM
     using AppStream;
 
     public class AppStreamBuilder : TagBuilder, Object {
@@ -61,6 +62,7 @@ namespace Odysseus.Templating.xAppStream {
             }
         }
     }
+
     private class AppStreamTag : Template {
         private AppStream.Pool pool;
         private Variable[] vars;
@@ -138,4 +140,11 @@ namespace Odysseus.Templating.xAppStream {
             yield renderer.exec(data, output);
         }
     }
+#else
+    public class AppStreamBuilder : TagBuilder, Object {
+        public Template? build(Parser parser, WordIter args) throws SyntaxError {
+            return null;
+        }
+    }
+#endif
 }

src/Traits/status/https.vala

@@ -73,15 +73,18 @@ namespace Odysseus.Traits {
         scrolled.add(list);
         list.selection_mode = Gtk.SelectionMode.NONE;
 
+#if HAVE_GCR3
         // FIXME the commented out code hangs.
         //for (var chain = cert; chain != null; chain = cert.get_issuer()) {
             var gcr = new Gcr.SimpleCertificate (cert.certificate.data);
             list.add(build_certificate_row(gcr));
         //}
+#endif
 
         return ret;
     }
 
+#if HAVE_GCR3
     private Gtk.Widget build_certificate_row(Gcr.Certificate cert) {
         var ret = new Gtk.Grid();
         ret.column_spacing = 10; ret.row_spacing = 10;
@@ -107,4 +110,5 @@ namespace Odysseus.Traits {
         ret.halign = Gtk.Align.START;
         return ret;
     }
+#endif
 }

src/meson.build

@@ -83,23 +83,33 @@ endforeach
 c_args = ['-DGCR_API_SUBJECT_TO_CHANGE', '-include', 'config.h']
 posix_dep = meson.get_compiler('vala').find_library('posix')
 
+dependencies = [
+    dependency('gtk+-3.0'),
+    dependency('granite'),
+    dependency('webkit2gtk-4.0'),
+    dependency('json-glib-1.0'),
+    dependency('gee-0.8'),
+    dependency('libsoup-2.4'),
+    dependency('sqlite3'),
+    posix_dep,
+    dependency('libxml-2.0'),
+]
+vala_args = []
+if get_option('appstream')
+    dependencies += [dependency('appstream')]
+    vala_args += ['--define=HAVE_APPSTREAM']
+endif
+if get_option('gcr')
+    dependencies += [dependency('gcr-3')]
+    vala_args += ['--define=HAVE_GCR3']
+endif
+
 executable('com.github.alcinnz.odysseus',
     source_files,
 
     c_args: c_args,
     link_args: ['-lm'],
-    dependencies: [
-        dependency('gtk+-3.0'),
-        dependency('granite'),
-        dependency('webkit2gtk-4.0'),
-        dependency('json-glib-1.0'),
-        dependency('gee-0.8'),
-        dependency('libsoup-2.4'),
-        dependency('sqlite3'),
-        dependency('appstream'),
-        posix_dep,
-        dependency('libxml-2.0'),
-        dependency('gcr-3')
-    ],
+    vala_args: vala_args,
+    dependencies: dependencies,
     install: true
 )