[Qt-interest] Qt-interest Digest, Vol 13, Issue 202

[Ross Driedger]

On Wed, 23 Dec 2009 04:29:45 -0500, <qt-interest-request at trolltech.com>  
wrote:

> Hi All,
> We are having an issue where events are being blocked when a dialog box
> title bar is right clicked.  Right clicking the title bar pops up the
> "Move, Size, Minimise, Maximise, Close" menu box.
> We have tried to use the event filter to catch the event and force it to
> process all events via QCoreApplication::processEvents
> (QEventLoop::AllEvents ) to no avail.  So we printed to std out all the
> event types to see what the last event is whilst right clicking on the
> title bar.  There was no event at all once the right click was carried
> out.  We were expecting a right click event at least.
> So as a work around, is there a way to stop this menu from being popped
> up?  Or is there another solution?

Hi Jay,

I dealt with this issue last year in a Win32 project so I had direct  
access to the window's callback and I don't know how this hooks into the  
Qt code, but here are some of the important issues wrt to the system menu:

1) System menu clicks are sent via WM_SYSCOMMAND message.  I don't know  
how Qt deals with this message, but MS recommends that it gets passed  
directly to the default winProc.
2) WM_COMMAND messages are suspended until the system menu is dealt with.   
All subsequent messages from the menu are not WM_COMMAND messages.

The end result is that the control of the program is passed back to the  
operating system until the user dismisses the menu or executes a command  
 from it.  This can be changed if the program traps and deals with  
WM_SYSCOMMAND, but this would be against the kind of behaviour that MS  
wants for Windows apps.

How to get this specific Windows message within Qt is beyond my knowledge  
and I leave it to some of the Gurus of the Qt internals.

I will be watching if there is a solution to this problem.

Ross

-- 
"Music is essentially useless, as life is."
George Santayana

Ross Driedger
ross_at_earz.ca