Partial porting over of vector controller logic to react sdk.

src/WhoIsTyping.js

@@ -0,0 +1,49 @@
+var MatrixClientPeg = require("./MatrixClientPeg");
+
+module.exports = {
+    usersTypingApartFromMe: function(room) {
+        return this.usersTyping(
+            room, [MatrixClientPeg.get().credentials.userId]
+        );
+    },
+
+    /**
+     * Given a Room object and, optionally, a list of userID strings
+     * to exclude, return a list of user objects who are typing.
+     */
+    usersTyping: function(room, exclude) {
+        var whoIsTyping = [];
+
+        if (exclude === undefined) {
+            exclude = [];
+        }
+
+        var memberKeys = Object.keys(room.currentState.members);
+        for (var i = 0; i < memberKeys.length; ++i) {
+            var userId = memberKeys[i];
+
+            if (room.currentState.members[userId].typing) {
+                if (exclude.indexOf(userId) == -1) {
+                    whoIsTyping.push(room.currentState.members[userId]);
+                }
+            }
+        }
+
+        return whoIsTyping;
+    },
+
+    whoIsTypingString: function(room) {
+        var whoIsTyping = this.usersTypingApartFromMe(room);
+        if (whoIsTyping.length == 0) {
+            return null;
+        } else if (whoIsTyping.length == 1) {
+            return whoIsTyping[0].name + ' is typing';
+        } else {
+            var names = whoIsTyping.map(function(m) {
+                return m.name;
+            });
+            var lastPerson = names.shift();
+            return names.join(', ') + ' and ' + lastPerson + ' are typing';
+        }
+    }
+}