Qt 4.8.4 - Problem generating click - coordinates used by QPoint
-
Hello guys,
I am working on an embedded linux project using Qt 4.8.4 and I want to generate click to a given position.
First I will give you a sum-up of my code and then explains the problem.
main.cpp : Declare a new QApplication
@int main( int argc, char *argv[] )
{
main_app = new QApplication( argc, argv ) ;[....]
}@
mainwindow.h : header of the mainwindow
@class MainWindow : public QMainWindow
{
Q_OBJECTpublic :
void generate_click( int coord_x, int coord_y ) ;
[...]
}@mainwindow.cpp: definition of my function
@void MainWindow::generate_click(int x, int y)
{printf("Enter generate_click : (%d/%d)\n", x, y) ;
QPoint _pos_click( x, y ) ;
QWidget *receiver = QApplication::widgetAt( _pos_click ) ;if(receiver == 0)
printf("No element at the position (%d, %d)\n", x, y) ;
else
{
QMouseEvent *event = new QMouseEvent(QEvent::MouseButtonPress, receiver->mapFromGlobal(_pos_click), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
main_app->postEvent(receiver, event);
QMouseEvent *release = new QMouseEvent(QEvent::MouseButtonRelease, receiver->mapFromGlobal(_pos_click), Qt::LeftButton, Qt::LeftButton,Qt::NoModifier);
main_app->postEvent(receiver, release);
}
}@This way it is NOT working, even if the coordinates are good in my first printf. I never see the error "receiver == 0 ). If we modify the Qt library to add a log in the function PostEvent we see that x or y (randomly) equal 0 or 1 so that's why there is no click.
If I modify x and y this way (give a value to x / y ) it WORKS all the time :
@void MainWindow::generate_click(int x, int y)
{x = 20 ;
y = 80 ;printf("Enter generate_click : (%d/%d)\n", x, y) ;
QPoint _pos_click( x, y ) ;
QWidget *receiver = QApplication::widgetAt( _pos_click ) ;if(receiver == 0)
printf("No element at the position (%d, %d)\n", x, y) ;
else
{
QMouseEvent *event = new QMouseEvent(QEvent::MouseButtonPress, receiver->mapFromGlobal(_pos_click), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
main_app->postEvent(receiver, event);
QMouseEvent *release = new QMouseEvent(QEvent::MouseButtonRelease, receiver->mapFromGlobal(_pos_click), Qt::LeftButton, Qt::LeftButton,Qt::NoModifier);
main_app->postEvent(receiver, release);
}
}@If I add an addition to the coordinate I receive, it also WORKS !
@void MainWindow::generate_click(int x, int y)
{x = x + 5;
y = y + 5;printf("Enter generate_click : (%d/%d)\n", x, y) ;
QPoint _pos_click( x, y ) ;
QWidget *receiver = QApplication::widgetAt( _pos_click ) ;if(receiver == 0)
printf("No element at the position (%d, %d)\n", x, y) ;
else
{
QMouseEvent *event = new QMouseEvent(QEvent::MouseButtonPress, receiver->mapFromGlobal(_pos_click), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
main_app->postEvent(receiver, event);
QMouseEvent *release = new QMouseEvent(QEvent::MouseButtonRelease, receiver->mapFromGlobal(_pos_click), Qt::LeftButton, Qt::LeftButton,Qt::NoModifier);
main_app->postEvent(receiver, release);
}
}@Even if the Qt documentation says that QPoint is expecting an integer, I think that the addition or the fact that we give fixed coordinates will cast them in a type expected by QPoint.
Are you able to tell me why the first example is not working ?
I hope my problem is clear and let me know if you need more information.
Thanks in advance.Gaël
