follow guide

linux/my_application.cc

@@ -17,6 +17,14 @@ G_DEFINE_TYPE(MyApplication, my_application, GTK_TYPE_APPLICATION)
 // Implements GApplication::activate.
 static void my_application_activate(GApplication* application) {
   MyApplication* self = MY_APPLICATION(application);
+
+  GList *windows = gtk_application_get_windows(GTK_APPLICATION(application));
+  if (windows)
+  {
+    gtk_window_present(GTK_WINDOW(windows->data));
+    return;
+  }
+
   GtkWindow* window =
       GTK_WINDOW(gtk_application_window_new(GTK_APPLICATION(application)));
 
@@ -78,7 +86,7 @@ static gboolean my_application_local_command_line(GApplication* application, gch
   g_application_activate(application);
   *exit_status = 0;
 
-  return TRUE;
+  return FALSE;
 }
 
 // Implements GApplication::startup.
@@ -119,6 +127,6 @@ static void my_application_init(MyApplication* self) {}
 MyApplication* my_application_new() {
   return MY_APPLICATION(g_object_new(my_application_get_type(),
                                      "application-id", APPLICATION_ID,
-                                     "flags", G_APPLICATION_NON_UNIQUE,
+                                     "flags", G_APPLICATION_HANDLES_COMMAND_LINE | G_APPLICATION_HANDLES_OPEN,
                                      nullptr));
 }

linux/packaging/deb/make_config.yaml

@@ -30,3 +30,7 @@ categories:
   - Utility
 
 startup_notify: true
+
+# https://github.com/llfbandit/app_links/blob/051f53fa6039cbfaef0fcde73df20fef9e248cab/doc/README_linux.md
+supported_mime_type:
+  - x-scheme-handler/vaani