How can I simulate mouse clicks by posting events to the Qt event system?
<p>I would like to do a rudimentary automation test of my Qt application. It records mouse events and writes them to a file (f.e. mousepress(300, 400)). When starting the automation, it reads the coordinates from the file, sends the appropriate mouse events and would do a pixel comparison with a previously saved screenshot.</p>

<p>Currently, I have an overlay widget that spans the app and has transparent mouse events. All it does is track the coordinates.
When reading the data back in, that overlay paints a rectangle on the mouse press location.
I need help when sending mousePressEvents to Qt's event system. It draws the points on the correct location but never actually does the physical click.
Is there a way to do this with Qt or would I have to use Window's SendInput()?</p>

<p>Is there a way to pause and wait until the mouse event has finished? I would need to know when the event is complete in order to start the pixel by pixel comparison.</p>

<pre><code>Widget::Widget( QWidget *parent )
: QFrame( parent )
, mPoint(QPoint(0,0))
{
   setWindowFlags(Qt::WindowStaysOnTopHint);
   setStyleSheet("background-color: rgba(0, 0,255, 2%);");
   setAttribute(Qt::WA_TransparentForMouseEvents, true);
   setGeometry(parent-&gt;geometry());
   ...
}

void Widget::run()
{
   QFile file( "coordinates.txt", NULL );
   if(!file.open( QIODevice::ReadOnly ))
       return;

   QTextStream in(&amp;file);
   int i = 0;
   while (!in.atEnd())
   {
       QString line = in.readLine();
       if(line.startsWith("mousepress"))
       {
          int startIndex = line.indexOf('(');
          int endIndex = line.indexOf(')');

          QString coord = line.mid(startIndex+1, line.size() - startIndex - 2);
          QStringList nbr = coord.split(',');
          mPoint = QPoint(nbr[0].toInt(), nbr[1].toInt());
          QWidget *receiver  = QApplication::widgetAt(mPoint);
          QMouseEvent *event = new QMouseEvent(QEvent::MouseButtonPress, mPoint, Qt::LeftButton, Qt::LeftButton,  Qt::NoModifier);
          QCoreApplication::postEvent(receiver, event); // same result with sendEvent() 
          QCoreApplication::processEvents();
          update();
          // wait till the event finished, then continue with next point
      }
   }
}


void Widget::paintEvent(QPaintEvent *event)
{
  QPainter p( this );
  QPen pen;
  pen.setBrush(Qt::NoBrush);

  if(!mPoint.isNull())
  {
    pen.setColor(Qt::red);
    pen.setWidth( 2 );
    p.setPen(pen);

    p.drawRoundRect(mPoint.x(), mPoint.y(), 10, 10, 25, 25);
    p.drawText(mPoint, QString::number(mPoint.x()) + ", " + QString::number(mPoint.y()));
  }
}
</code></pre>

<p><strong>[Edited]</strong></p>

<p>I followed ddriver's suggestion and it works after a few changes: I save global and local positions in the file, to send to the QMouseEvent.</p>

<p>How could I be sure that the mouse click is complete before doing a screenshot and comparing it to a saved image?</p>

<pre><code>void Widget::DoStep()
{
  if(!mInStream.atEnd())
  {
      QString line = mInStream.readLine();
      if(line.startsWith("MouseButtonPress"))
      {
          QPoint pos = parseGlobalPos();
          QPoint localPos = parseLocalPos();
          QWidget *receiver  = QApplication::widgetAt(pos);

          QMouseEvent *event = new QMouseEvent(QEvent::MouseButtonPress,localPos, pos, Qt::LeftButton, Qt::LeftButton,  Qt::NoModifier);
          QApplication::postEvent(receiver, event);
          QMouseEvent *eventRelease = new QMouseEvent(QEvent::MouseButtonRelease, localPos, pos, Qt::LeftButton, Qt::LeftButton,  Qt::NoModifier);
          QApplication::postEvent(receiver, eventRelease);

          // after successful click, take screenshot and compare them
      } 
   }

  if (!mInStream.atEnd())
      QMetaObject::invokeMethod(this, "DoStep", Qt::QueuedConnection);
  else
      file.close();
}
</code></pre>