Fixed a few warnings

src/domain/UBGraphicsMediaItemDelegate.cpp

@@ -259,6 +259,7 @@ void UBGraphicsMediaItemDelegate::mediaStatusChanged(QMediaPlayer::MediaStatus s
 
 void UBGraphicsMediaItemDelegate::mediaStateChanged(QMediaPlayer::State state)
 {
+    Q_UNUSED(state);
     // Possible states are StoppedState, PlayingState and PausedState
 
     // updatePlayPauseState handles this functionality

src/domain/UBGraphicsWidgetItem.cpp

@@ -855,7 +855,7 @@ UBGraphicsW3CWidgetItem::UBGraphicsW3CWidgetItem(const QUrl& pWidgetUrl, QGraphi
 
         QDomNodeList propertiesDomList = widgetElement.elementsByTagName("preference");
 
-        for (uint i = 0; i < propertiesDomList.length(); i++) {
+        for (int i = 0; i < propertiesDomList.length(); i++) {
             QDomElement preferenceElement = propertiesDomList.at(i).toElement();
             QString prefName = preferenceElement.attribute("name", "");
 

src/gui/UBScreenMirror.cpp

@@ -92,7 +92,7 @@ void UBScreenMirror::grabPixmap()
 
         mRect.setTopLeft(topLeft);
         mRect.setBottomRight(bottomRight);
-        mLastPixmap = QPixmap::grabWidget(mSourceWidget);
+        mLastPixmap = mSourceWidget->grab();
     }
     else{
         // WHY HERE?
@@ -103,7 +103,8 @@ void UBScreenMirror::grabPixmap()
         mLastPixmap = screen->grabWindow(desktop->effectiveWinId(), mRect.x(), mRect.y(), mRect.width(), mRect.height());
     }
 
-    mLastPixmap = mLastPixmap.scaled(width(), height(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
+    if (!mLastPixmap.isNull())
+        mLastPixmap = mLastPixmap.scaled(width(), height(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
 }