Re: [Interest] Key_Cancel on Macintosh
On 20-Mar-2012, at 10:24 AM, Konstantin Tokarev wrote: On Windows, I can filter keypress events looking for Qt::Key_Cancel, which is generated by pressing Ctrl+Break.The Macintosh equivalent is Cmd-period. As far as I can make out, the Cocoa system catches that key combination and sends some sort of cancel event instead of a key event. My question: is there a way to catch this in Qt on Macintosh? Try to catch it with event filter. If it fails you probably will need to write custom ObjC code. That was fast! Thanks! In fact, my first attempt was an event filter. But on Macintosh, I get no key event when I press cmd-period. I expect the Objective C code will be required (groan). I wonder if anyone has already written something already that they would be willing to share. I get confused by having all those brackets in the wrong places :) -John ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Key_Cancel on Macintosh
On 20/03/12 19:31, John Weeks wrote: On 20-Mar-2012, at 10:24 AM, Konstantin Tokarev wrote: On Windows, I can filter keypress events looking for Qt::Key_Cancel, which is generated by pressing Ctrl+Break.The Macintosh equivalent is Cmd-period. As far as I can make out, the Cocoa system catches that key combination and sends some sort of cancel event instead of a key event. My question: is there a way to catch this in Qt on Macintosh? Try to catch it with event filter. If it fails you probably will need to write custom ObjC code. That was fast! Thanks! In fact, my first attempt was an event filter. But on Macintosh, I get no key event when I press cmd-period. Maybe this is relevant: http://qt-project.org/doc/qt-4.8/qapplication.html#macEventFilter ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Key_Cancel on Macintosh
On 20-Mar-2012, at 10:53 AM, Nikos Chantziaras wrote:
Maybe this is relevant:
http://qt-project.org/doc/qt-4.8/qapplication.html#macEventFilter
OK- that was a good lead. It seems that at that point the Cmd-period key event
*IS* available. Here is my code:
In my subclass of QApplication:
#ifdef MACIGOR
bool IgorAppObject::macEventFilter(EventHandlerCallRef caller, EventRef event)
{
if (WMNSEventIsCmdPeriod(reinterpret_castvoid *(event)))
emit cancelEvent();
return false;
}
#endif
In a .mm (objective C++) file:
bool
WMNSEventIsCmdPeriod(void *event)
{
NSEvent * nsevent = reinterpret_castNSEvent *(event);
if ([nsevent type] == NSKeyUp) // presumably, if we see the key up it
was preceded by a key down. Action should take place on key up.
{
std::cout NSEvent keydown event std::endl;
if ([nsevent modifierFlags] NSCommandKeyMask)
{
NSString * chars = [nsevent
charactersIgnoringModifiers];
return [chars characterAtIndex:0] == 0x2E; // Unicode
encoding for period
}
}
return false;
}
The header containing the prototype for this function declares it to be extern
C. It is my understanding that that is required because Objective C++ mangles
names differently than regular C++.
In addition to the above, I have regular QApplication::notify event filter
looking for QKeyEvents that match Qt::Key_Cancel. That will provide the same
functionality on platforms where Qt allows this access (empirically, Windows
works this way).
Seems like since QApplication::macEventFilter() can see the relevant key
events, it would be possible for Qt on Cocoa/Macintosh could just Do the Right
Thing. But maybe not...
-John Weeks
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