/*
The native control provides a great variety in the events it sends in
the different selection scenarios (undoubtedly for greater amusement of
- the programmers using it). For the reference, here are the cases when
- the final selection is accepted (things are quite interesting when it
- is cancelled too):
+ the programmers using it). Here are the different cases:
A. Selecting with just the arrows without opening the dropdown:
1. CBN_SELENDOK
Admire the different order of messages in all of those cases, it must
surely have taken a lot of effort to Microsoft developers to achieve
such originality.
+
+ Additionally, notice that CBN_SELENDCANCEL doesn't seem to actually
+ cancel anything, if we get CBN_SELCHANGE before it, as it happens in
+ the case (B), the selection is still accepted. This doesn't make much
+ sense and directly contradicts MSDN documentation but is how the native
+ comboboxes behave and so we do the same thing.
*/
switch ( param )
{
break;
case CBN_CLOSEUP:
- // if the selection was accepted by the user, it should have been
- // reset to wxID_NONE by CBN_SELENDOK, otherwise the selection was
- // cancelled and we must restore the old one
- if ( m_lastAcceptedSelection != wxID_NONE )
+ if ( m_pendingSelection != wxID_NONE )
{
- SetSelection(m_lastAcceptedSelection);
- m_lastAcceptedSelection = wxID_NONE;
+ // This can only happen in the case (B), so set the item
+ // selected in the drop down as our real selection.
+ SendSelectionChangedEvent(wxEVT_CHOICE);
+ m_pendingSelection = wxID_NONE;
}
break;
case CBN_SELENDOK:
- // reset it to prevent CBN_CLOSEUP from undoing the selection (it's
- // ok to reset it now as GetCurrentSelection() will now return the
- // same thing anyhow)
- m_lastAcceptedSelection = wxID_NONE;
+ // Reset the variables to prevent CBN_CLOSEUP from doing anything,
+ // it's not needed if we do get CBN_SELENDOK.
+ m_lastAcceptedSelection =
+ m_pendingSelection = wxID_NONE;
- SendSelectionChangedEvent(wxEVT_COMMAND_CHOICE_SELECTED);
+ SendSelectionChangedEvent(wxEVT_CHOICE);
break;
+ case CBN_SELCHANGE:
+ // If we get this event after CBN_SELENDOK, i.e. cases (A) or (C)
+ // above, we don't have anything to do. But in the case (B) we need
+ // to remember that the selection should really change once the
+ // drop down is closed.
+ if ( m_lastAcceptedSelection != wxID_NONE )
+ m_pendingSelection = GetCurrentSelection();
+ break;
- // don't handle CBN_SELENDCANCEL: just leave m_lastAcceptedSelection
- // valid and the selection will be undone in CBN_CLOSEUP above
-
- // don't handle CBN_SELCHANGE neither, we don't want to generate events
- // while the dropdown is opened -- but do add it if we ever need this
+ case CBN_SELENDCANCEL:
+ // Do not reset m_pendingSelection here -- it would make sense but,
+ // as described above, native controls keep the selection even when
+ // closing the drop down by pressing Escape or TAB, so conform to
+ // their behaviour.
+ m_lastAcceptedSelection = wxID_NONE;
+ break;
default:
return false;