Not receiving WM_NCMBUTTONDOWN on title bar - c++builder

Question

I am trying to create a mechanism to allow the user to right click and drag on a toolbar in order to move a window...
This is proving very difficult:
I am currently not receiving the HTCAPTION event which I have seen a really helpful post for already!
Not receiving WM_NCHitTest on title bar
The suggestion/alternative here is to use the WMNCMouseMove and inspect the HitTest to see if it is the caption.. So naively I assumed that I could extend this idea to use the WMNCMButtonDown (instead) to take me one step closer!
If this worked then I could get the type of click i.e. left, right, middle, double or single! This would have then allow me to somehow tell windows that I want this to be recognised as a drag event.
The trouble is that I never receive the WM_NCMBUTTONDOW:
void __fastcall TForm1::Dispatch( void* message )
{
switch ( static_cast<TMessage*>( message )->Msg )
{
case WM_NCHITTEST:
{
TWMNCHitTest &Message = *static_cast<TWMNCHitTest*>( message );
WMNCHitTest( Message );
break;
}
case WM_NCMOUSEMOVE:
{
TWMNCMouseMove &Message = *static_cast<TWMNCMouseMove*>( message );
WMNCMouseMove( Message );
break;
}
case WM_NCMBUTTONDOWN:
{
TWMNCMButtonDown &Message = *static_cast<TWMNCMouseMove*>( message );
WMNCMButtonDown(Message);
break;
}
default:
{
TForm::Dispatch(message);
break;
}
}
}
oes anybody have any ideas??
It is worth noting that I do in fact receive the other types of messages (WM_NCHITTEST && WM_NCMOUSEMOVE) so the mechanism is working correctly.
Please any ideas would be much appreciated!!
Thanks,
Joe

Answer 1

I do the following rather than override any methods.
In my .h
BEGIN_MESSAGE_MAP
{
VCL_MESSAGE_HANDLER( WM_NCHITTEST, TWMNCHitTest, WMNCHitTest );
VCL_MESSAGE_HANDLER( WM_NCCALCSIZE, TWMNCCalcSize, WMNCCalcSize );
VCL_MESSAGE_HANDLER( WM_NCPAINT, TWMNCPaint, WMNCPaint );
VCL_MESSAGE_HANDLER( WM_ERASEBKGND, TWMEraseBkgnd, StopFlicker );
VCL_MESSAGE_HANDLER( WM_NCLBUTTONDOWN, TWMNCLButtonDown, WMNCLButtonDown );
}
END_MESSAGE_MAP( TCustomPanel ) // change TCustomPanel to your parent class name
void __fastcall WMNCHitTest( Messages::TWMNCHitTest& inoutMessage );
void __fastcall WMNCCalcSize( Messages::TWMNCCalcSize& inoutMessage );
void __fastcall WMNCPaint( Messages::TWMNCPaint& inoutMessage );
void __fastcall StopFlicker( Messages::TWMEraseBkgnd& inoutMessage );
void __fastcall WMNCLButtonDown( Messages::TWMNCLButtonDown& inoutMessage );
And then I implement the code in the .cpp, for example:
void __fastcall TResizePanel::WMNCLButtonDown( Messages::TWMNCLButtonDown &inoutMessage )
{
if ( inoutMessage.HitTest == HTCLOSE )
{
delete this;
inoutMessage.Result = 0;
}
else
{
Dispatch( &inoutMessage );
}
}