1 files changed, 59 insertions, 0 deletions
diff --git a/xmpp-vala/src/module/util.vala b/xmpp-vala/src/module/util.vala
index 365170b0..e6626049 100644
--- a/xmpp-vala/src/module/util.vala
+++ b/xmpp-vala/src/module/util.vala
@@ -1,3 +1,5 @@
+using Gee;
+
 namespace Xmpp {
     public string get_bare_jid(string jid) {
         return jid.split("/")[0];
@@ -20,4 +22,61 @@ namespace Xmpp {
         uint32 b5_2 = Random.next_int();
         return "%08x-%04x-%04x-%04x-%04x%08x".printf(b1, b2, b3, b4, b5_1, b5_2);
     }
+
+public abstract class StanzaListener<T> : Object {
+    public abstract string action_group { get; }
+    public abstract string[] after_actions { get; }
+    public abstract async void run(Core.XmppStream stream, T stanza);
+}
+
+public class StanzaListenerHolder<T> : Object {
+    private Gee.List<StanzaListener<T>> listeners = new ArrayList<StanzaListener<T>>();
+
+    public new void connect(StanzaListener<T> listener) {
+        listeners.add(listener);
+        resort_list();
+    }
+
+    public async void run(Core.XmppStream stream, T stanza) {
+        foreach (StanzaListener<T> l in listeners) {
+            yield l.run(stream, stanza);
+        }
+    }
+
+    private Gee.List<StanzaListener<T>> set_minus(Gee.List<StanzaListener<T>> main_set, Gee.List<StanzaListener<T>> minus) {
+        Gee.List<StanzaListener<T>> res = new ArrayList<StanzaListener<T>>();
+        foreach (StanzaListener<T> l in main_set) {
+            if (!minus.contains(l)) {
+                res.add(l);
+            }
+        }
+        return res;
+    }
+
+    private bool set_contains_action(Gee.List<StanzaListener<T>> s, string[] actions) {
+        foreach(StanzaListener<T> l in s) {
+            if (l.action_group in actions) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void resort_list() {
+        Gee.List<StanzaListener<T>> new_list = new ArrayList<StanzaListener<T>>();
+        while (listeners.size > new_list.size) {
+            bool changed = false;
+            foreach (StanzaListener<T> l in listeners) {
+                Gee.List<StanzaListener<T>> remaining = set_minus(listeners, new_list);
+                if (!set_contains_action(remaining, l.after_actions)) {
+                    new_list.add(l);
+                    changed = true;
+                }
+            }
+            if (!changed) warning("Can't sort listeners");
+        }
+        listeners = new_list;
+    }
+}
+
 }