chatgui: preserve input focus on chat refresh (save/restore focusWidget in loadChannel)

tools/chatgui/src/messagelist.cpp

@@ -12,6 +12,7 @@
 #include <QPixmap>
 #include <QDateTime>
 #include <QFile>
+#include <QApplication>
 #include <QDebug>
 #include <vector>
 #include <memory>
@@ -165,6 +166,7 @@ MessageList::MessageList(DbManager* db, QWidget *parent)
 }
 
 void MessageList::loadChannel(const QString& channelId) {
+    QWidget* prevFocus = QApplication::focusWidget();
     m_model->clear();
     m_avatarCache.clear();
     m_currentChannelId = channelId;
@@ -197,7 +199,10 @@ void MessageList::loadChannel(const QString& channelId) {
 
     if (m_model->rowCount() > 0)
         m_view->scrollToBottom();
-    m_inputBar->setFocus();
+    if (prevFocus)
+        prevFocus->setFocus();
+    else
+        m_inputBar->setFocus();
 }
 
 void MessageList::refresh() {