[Qt-interest] Events

[Colin S. Miller]

OS Prog wrote:
> Hi,
> 
> I'm trying to disable the mouse events to QWidget and its child widgets 
> and to replace them with my custom event.
> I have event() function in my parent class and I'm receiving my custom 
> events there. After decoding them I'm trying to prepare QMouseEvend and 
> send it to the widgets, but their child widget doesn't receive it... I'm 
> kind of lost with the events.
> 
> I'll try to post some code later.
> 
> Regards,
> Nikolay

Nokolay,
IIRC,
Events are send to the widget that has focus (for keyboard), or the mouse is over (for mouse events).

If widget-class is not interested in an QEvent in MyWidget::Event()  then it should call
Event() in its parent class. If the event makes it upto QWidget::Event() (ie no-one is interested in it),
then the event is then sent to the parent (containing) widget of MyWidget.

Therefore, you can't block a child from receiving an event this way.

However, by using the following code, a widget can monitor (and block) any
events sent to another widget.
Here, the containing widget is monitoring its child, but they
don't have to be related.

MyParentWidget::MyParentWidget(...)
{
    QWidget *myChild = ....;

    myChild->installEventFilter(this);

    .....
}

MyParentWidget::eventFilter(QObject *o, QEvent*e)
{
    cout << "Object " << o << " received event " << e->type() << ", blocking." << endl;
    return TRUE;  // TRUE blocks the event, FALSE allows 'o' to see the event.
}


HTH,
Colin S. Miller