refactor: minor cleanup in Widget and Friend

src/friend.cpp

@@ -86,7 +86,7 @@ void Friend::setName(QString name)
 void Friend::setAlias(QString name)
 {
     userAlias = name;
-    QString dispName = userAlias.size() == 0 ? userName : userAlias;
+    QString dispName = userAlias.isEmpty() ? userName : userAlias;
 
     widget->setName(dispName);
     chatForm->setName(dispName);
@@ -116,10 +116,7 @@ QString Friend::getStatusMessage()
 
 QString Friend::getDisplayedName() const
 {
-    if (userAlias.size() == 0)
-        return userName;
-
-    return userAlias;
+    return userAlias.isEmpty() ? userName : userAlias;
 }
 
 bool Friend::hasAlias() const

src/widget/widget.cpp

@@ -413,14 +413,14 @@ bool Widget::eventFilter(QObject *obj, QEvent *event)
     {
     case QEvent::Close:
         // It's needed if user enable `Close to tray`
-        wasMaximized = state & Qt::WindowMaximized;
+        wasMaximized = state.testFlag(Qt::WindowMaximized);
         break;
 
     case QEvent::WindowStateChange:
         ce = static_cast<QWindowStateChangeEvent*>(event);
-        if (state & Qt::WindowMinimized && obj)
+        if (state.testFlag(Qt::WindowMinimized) && obj)
         {
-             wasMaximized = ce->oldState() & Qt::WindowMaximized;
+            wasMaximized = ce->oldState().testFlag(Qt::WindowMaximized);
         }
 
 #ifdef Q_OS_MAC