Focus on the text input when switching rooms

include/TextInputWidget.h

@@ -46,6 +46,7 @@ public:
 
 public slots:
 	void onSendButtonClicked();
+	inline void focusLineEdit();
 
 private slots:
 	void addSelectedEmoji(const QString &emoji);
@@ -64,3 +65,8 @@ private:
 	FlatButton *send_message_button_;
 	EmojiPickButton *emoji_button_;
 };
+
+inline void TextInputWidget::focusLineEdit()
+{
+	input_->setFocus();
+}

src/ChatPage.cc

@@ -125,6 +125,7 @@ ChatPage::ChatPage(QSharedPointer<MatrixClient> client, QWidget *parent)
 	connect(client_.data(), SIGNAL(loggedOut()), this, SLOT(logout()));
 
 	connect(room_list_, &RoomList::roomChanged, this, &ChatPage::changeTopRoomInfo);
+	connect(room_list_, &RoomList::roomChanged, text_input_, &TextInputWidget::focusLineEdit);
 	connect(room_list_, &RoomList::roomChanged, view_manager_, &TimelineViewManager::setHistoryView);
 
 	connect(view_manager_, &TimelineViewManager::unreadMessages, this, [=](const QString &roomid, int count) {