Init UserListModel.

Another model from Quaternion.
Also UI tweaks in RoomListModel.

src/userlistmodel.h

@@ -0,0 +1,56 @@
+#ifndef USERLISTMODEL_H
+#define USERLISTMODEL_H
+
+#include "room.h"
+
+#include <QObject>
+#include <QtCore/QAbstractListModel>
+
+namespace QMatrixClient {
+class Connection;
+class Room;
+class User;
+}  // namespace QMatrixClient
+
+class UserListModel : public QAbstractListModel {
+  Q_OBJECT
+  Q_PROPERTY(
+      QMatrixClient::Room* room READ room WRITE setRoom NOTIFY roomChanged)
+ public:
+  enum EventRoles {
+    NameRole = Qt::UserRole + 1,
+    AvatarRole
+  };
+
+  using User = QMatrixClient::User;
+
+  UserListModel(QObject* parent = nullptr);
+
+  QMatrixClient::Room* room() { return m_currentRoom; }
+  void setRoom(QMatrixClient::Room* room);
+  User* userAt(QModelIndex index);
+
+  QVariant data(const QModelIndex& index,
+                int role = NameRole) const override;
+  int rowCount(const QModelIndex& parent = QModelIndex()) const override;
+
+  QHash<int, QByteArray> roleNames() const override;
+
+ signals:
+  void roomChanged();
+
+ private slots:
+  void userAdded(User* user);
+  void userRemoved(User* user);
+  void refresh(User* user, QVector<int> roles = {});
+  void avatarChanged(User* user, const QMatrixClient::Room* context);
+
+ private:
+  QMatrixClient::Room* m_currentRoom;
+  QList<User*> m_users;
+
+  int findUserPos(User* user) const;
+  int findUserPos(const QString& username) const;
+};
+
+#endif  // USERLISTMODEL_H