#1695 fixed arrow key events with the Qt backend

modules/highgui/src/window_QT.cpp

@@ -1555,6 +1555,8 @@ CvWindow::CvWindow(QString name, int arg2)
 	setWindowTitle(name);
         setObjectName(name);
 
+        setFocus( Qt::PopupFocusReason ); //#1695 arrow keys are not recieved without the explicit focus
+
 	resize(400, 300);
 	setMinimumSize(1, 1);
 
@@ -2060,22 +2062,18 @@ void CvWindow::keyPressEvent(QKeyEvent *event)
 	//see http://doc.trolltech.com/4.6/qt.html#Key-enum
 	int key = event->key();
 
-	//bool goodKey = false;
-	bool goodKey = true;
-
         Qt::Key qtkey = static_cast<Qt::Key>(key);
         char asciiCode = QTest::keyToAscii(qtkey);
         if (asciiCode != 0)
-	{
             key = static_cast<int>(asciiCode);
-	}
+        else
+            key = event->nativeVirtualKey(); //same codes as returned by GTK-based backend
 
 	//control plus (Z, +, -, up, down, left, right) are used for zoom/panning functions
-	if (event->modifiers() != Qt::ControlModifier && goodKey)
+        if (event->modifiers() != Qt::ControlModifier)
         {
 		mutexKey.lock();
 		last_key = key;
-		//last_key = event->nativeVirtualKey ();
 		mutexKey.unlock();
 		key_pressed.wakeAll();
 		//event->accept();