Refactor event handling in Crypto

Move the event-handler registration from client.js into crypto.js

lib/crypto.js

@@ -39,6 +39,9 @@ var DeviceVerification = DeviceInfo.DeviceVerification;
  *
  * @param {module:base-apis~MatrixBaseApis} baseApis base matrix api interface
  *
+ * @param {external:EventEmitter} eventEmitter event source where we can register
+ *    for event notifications
+ *
  * @param {module:store/session/webstorage~WebStorageSessionStore} sessionStore
  *    Store to be used for end-to-end crypto session data
  *
@@ -46,7 +49,7 @@ var DeviceVerification = DeviceInfo.DeviceVerification;
  *
  * @param {string} deviceId The identifier for this device.
  */
-function Crypto(baseApis, sessionStore, userId, deviceId) {
+function Crypto(baseApis, eventEmitter, sessionStore, userId, deviceId) {
     this._baseApis = baseApis;
     this._sessionStore = sessionStore;
     this._userId = userId;
@@ -81,6 +84,28 @@ function Crypto(baseApis, sessionStore, userId, deviceId) {
     this._sessionStore.storeEndToEndDevicesForUser(
         this._userId, myDevices
     );
+
+    _registerEventHandlers(this, eventEmitter);
+}
+
+function _registerEventHandlers(crypto, eventEmitter) {
+    eventEmitter.on(
+        "RoomMember.membership",
+        crypto._onRoomMembership.bind(crypto)
+    );
+
+    eventEmitter.on("toDeviceEvent", function(event) {
+        if (event.getType() == "m.room_key") {
+            crypto._onRoomKeyEvent(event);
+        }
+    });
+
+    eventEmitter.on("event", function(event) {
+        if (!event.isState() || event.getType() != "m.room.encryption") {
+            return;
+        }
+        crypto._onCryptoEvent(event);
+    });
 }
 
 /**
@@ -772,13 +797,31 @@ Crypto.prototype.decryptEvent = function(event) {
     return alg.decryptEvent(event);
 };
 
+/**
+ * handle an m.room.encryption event
+ *
+ * @private
+ * @param {module:models/event.MatrixEvent} event encryption event
+ */
+Crypto.prototype._onCryptoEvent = function(event) {
+    var roomId = event.getRoomId();
+    var content = event.getContent();
+
+    try {
+        this.setRoomEncryption(roomId, content);
+    } catch (e) {
+        console.error("Error configuring encryption in room " + roomId +
+                      ":", e);
+    }
+};
 
 /**
  * Handle a key event
  *
+ * @private
  * @param {module:models/event.MatrixEvent} event key event
  */
-Crypto.prototype.onRoomKeyEvent = function(event) {
+Crypto.prototype._onRoomKeyEvent = function(event) {
     var content = event.getContent();
     var AlgClass = algorithms.DECRYPTION_CLASSES[content.algorithm];
     if (!AlgClass) {
@@ -795,10 +838,11 @@ Crypto.prototype.onRoomKeyEvent = function(event) {
 /**
  * Handle a change in the membership state of a member of a room
  *
+ * @private
  * @param {module:models/event.MatrixEvent} event  event causing the change
  * @param {module:models/room-member} member  user whose membership changed
  */
-Crypto.prototype.onRoomMembership = function(event, member) {
+Crypto.prototype._onRoomMembership = function(event, member) {
 
     // this event handler is registered on the *client* (as opposed to the
     // room member itself), which means it is only called on changes to the