Retry decryption after receiving keys

m.room_keys may arrive after the messages themselves, so allow events to be
decrypted after the event (haha).

lib/models/event.js

@@ -21,6 +21,10 @@ limitations under the License.
  * @module models/event
  */
 
+var EventEmitter = require("events").EventEmitter;
+
+var utils = require('../utils.js');
+
 /**
  * Enum for event statuses.
  * @readonly
@@ -79,8 +83,10 @@ module.exports.MatrixEvent = function MatrixEvent(
     this._keysProved = {};
     this._keysClaimed = {};
 };
+utils.inherits(module.exports.MatrixEvent, EventEmitter);
 
-module.exports.MatrixEvent.prototype = {
+
+utils.extend(module.exports.MatrixEvent.prototype, {
 
     /**
      * Get the event_id for this event.
@@ -251,6 +257,7 @@ module.exports.MatrixEvent.prototype = {
         this._clearEvent = clearEvent;
         this._keysProved = keysProved || {};
         this._keysClaimed = keysClaimed || {};
+        this.emit("Event.decrypted", this);
     },
 
     /**
@@ -367,7 +374,7 @@ module.exports.MatrixEvent.prototype = {
      setPushActions: function(pushActions) {
         this._pushActions = pushActions;
      },
-};
+});
 
 
 /* http://matrix.org/docs/spec/r0.0.1/client_server.html#redactions says:
@@ -408,3 +415,15 @@ var _REDACT_KEEP_CONTENT_MAP = {
                            },
     'm.room.aliases': {'aliases': 1},
 };
+
+
+
+
+/**
+ * Fires when an event is decrypted
+ *
+ * @event module:models/event.MatrixEvent#"Event.decrypted"
+ *
+ * @param {module:models/event.MatrixEvent} event
+ *    The matrix event which has been decrypted
+ */