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int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    AppSettings aps;

    uMail *ut = new uMail(&aps);

    GUIAdapter *ga = new GUIAdapter(ut);

    QThread testThread;
    ut->moveToThread(&testThread);
    testThread.start();

    ut->run();

    return a.exec();
}

class GUIAdapter : public QObject {

    Q_OBJECT

    // Engine Object
    uMail *eg;

    QDeclarativeView *mainWin, *currentWin;
    QObject *mainWinObj;
    QObject *flipobjFirstEnter;

void GUIAdapter::startMainWindow(){
    //
      
    QDeclarativeView *mw = new QDeclarativeView();

    currentWin = mainWin = mw;
    currentWin->installEventFilter(this);

  GUIAdapter *ga = new GUIAdapter(ut);

 QObject::connect(ut, SIGNAL(startMainWindow()),
                     ga, SLOT(startMainWindow()), Qt::DirectConnection);

Qt::DirectConnection	1	The slot is invoked immediately, when the signal is emitted.

Signals and Slots Across Threads
Qt supports these signal-slot connection types:
Auto Connection (default) If the signal is emitted in the thread which the receiving object has affinity then the behavior is the same as the Direct Connection. Otherwise, the behavior is the same as the Queued Connection."
Direct Connection The slot is invoked immediately, when the signal is emitted. The slot is executed in the emitter's thread, which is not necessarily the receiver's thread.
Queued Connection The slot is invoked when control returns to the event loop of the receiver's thread. The slot is executed in the receiver's thread.
Blocking Queued Connection The slot is invoked as for the Queued Connection, except the current thread blocks until the slot returns. Note: Using this type to connect objects in the same thread will cause deadlock.
Unique Connection The behavior is the same as the Auto Connection, but the connection is made only if it does not duplicate an existing connection. i.e., if the same signal is already connected to the same slot for the same pair of objects, then the connection is not made and connect() returns false.
The connection type can be specified by passing an additional argument to connect(). Be aware that using direct connections when the sender and receiver live in different threads is unsafe if an event loop is running in the receiver's thread, for the same reason that calling any function on an object living in another thread is unsafe.
QObject::connect() itself is thread-safe.
The Mandelbrot example uses a queued connection to communicate between a worker thread and the main thread. To avoid freezing the main thread's event loop (and, as a consequence, the application's user interface), all the Mandelbrot fractal computation is done in a separate worker thread. The thread emits a signal when it is done rendering the fractal.