CBitmapButton and ENTER

Annabel -- Annabel.Worthington@FMR.Com
Tuesday, January 09, 1996


Is there a trick to making it so that when a CBitmapButton is in focus and 
the user presses the Enter key, the message map function for that button 
gets called?

I would think that mapping the resource ID of the button to a function with 
either ON_COMMAND or ON_BN_CLICKED (I've tried both) would work just like it 
does in regular CButtons, that is you can either click on the button or 
press Enter, and the mapped function will get called.  The CBitmapButton 
only seems to respond correctly to the mouse click.  Pressing Enter on the 
CBitmapButton causes the dialog to exit directly with IDOK, without hitting 
any of my mapped functions along the way.  When I change the button back to 
being a regular CButton, the Enter key causes my mapped function to be 
called, as it should.

I'm using MSVC++ 2.2, and setting up the CBitmapButton exactly the way the 
online help describes.  It displays fine, and the right bitmaps appear when 
it is up or down or in focus (I never disable it).  The only problem is it 
doesn't respond correctly to the Enter key.

 I haven't been able to find anything in the online help, the FAQ, MSDN, or 
the Web that describes a problem like this; perhaps there is somewhere I 
haven't looked yet that I don't know about?  I also tried the CTRLTEST 
sample application provided with MSVC++ 2.2, and ran into the same problem.

Any clues will be greatly appreciated.

Thanks,
Annabel
 

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bop@gandalf.se
Thursday, January 11, 1996

[Mini-digest: 2 responses]

> From "Worthington, Annabel" 
> Is there a trick to making it so that when a CBitmapButton is in focus and 
> the user presses the Enter key, the message map function for that button 
> gets called?
>
> I would think that mapping the resource ID of the button to a function with 
> either ON_COMMAND or ON_BN_CLICKED (I've tried both) would work just like it 
> does in regular CButtons, that is you can either click on the button or 
> press Enter, and the mapped function will get called.  The CBitmapButton 
> only seems to respond correctly to the mouse click.  Pressing Enter on the 
> CBitmapButton causes the dialog to exit directly with IDOK, without hitting 
> any of my mapped functions along the way.  When I change the button back to 
> being a regular CButton, the Enter key causes my mapped function to be 
> called, as it should.
> [..]
> Any clues will be greatly appreciated.

Not _exactly_ a solution to your problem, but here's what I did:

In the dialog class, override the OnOK function and check which
button has the focus when Enter is pressed. (My code is from a 
chess program where you have to select a new piece when a 
pawn is promoted.)

void CLitePromotionDlg::OnOK()
{
   const UINT HasFocus = 0x0008;

   if (QueenButton.GetState() & HasFocus)
      EndDialog(LiteQueen);
   else if (RookButton.GetState() & HasFocus)
      EndDialog(LiteRook);
   else if (BishopButton.GetState() & HasFocus)
      EndDialog(LiteBishop);
   else if (KnightButton.GetState() & HasFocus)
      EndDialog(LiteKnight);
   else
      ASSERT(FALSE);

}



A related(?) tip:
How to stop the Esc key from closing the dialog.

// Cannot cancel, MUST select!
void CLitePromotionDlg::OnCancel()
{  };


Bo Persson
bop@gandalf.se

-----From: "Paul D. Bartholomew" 

>>Is there a trick to making it so that when a CBitmapButton is in focus and 

the user presses the Enter key, the message map function for that button
gets called?<<

Yes.  When you press  in a dialog, you are actually telling the 
dialog to press the "default" button, which is usually the OK button.  When 
you tab to, say, the Cancel button, this becomes the default button, and 
pressing  activates it.  The trouble is that a CBitmapButton can get 
the focus of the dialog and still not be the default button.  Therefore, 
when you press , it doesn't press your CBitmapButton.

There are several ways to handle this, including trapping the various other 
button functions (e.g., OnOK, OnCancel) and checking to see which button 
actually has the focus.  If it's your CBitmapButton, then you should call 
its function and exit e.g., the OnOK function without calling the equivalent 
CDialog::OnOK function.

The way I'm currently handling it is to override the CDialog::OnDrawItem 
function as follows:

void CMyDlg::OnDrawItem(int nIDCtl, LPDRAWITEMSTRUCT lpDrawItemStruct)
{
     if ( nIDCtl == MY_BUTTON && lpDrawItemStruct->itemAction & ODA_FOCUS )
     {
          if (lpDrawItemStruct->itemState & ODS_FOCUS)
               SetDefID(nIDCtl);
          else
               SetDefID(IDOK);
     }
     CDialog::OnDrawItem(nIDCtl, lpDrawItemStruct);
}

Now that I think about it, I wonder if I can't handle it in a focus changed 
message.....

Paul Bartholomew
pauldb@datastorm.com

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