diff --git a/src/msw/choice.cpp b/src/msw/choice.cpp index 698c61b259..e35fab7117 100644 --- a/src/msw/choice.cpp +++ b/src/msw/choice.cpp @@ -633,23 +633,61 @@ WXLRESULT wxChoice::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam) bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id)) { + /* + 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): + + A. Selecting with just the arrows without opening the dropdown: + 1. CBN_SELENDOK + 2. CBN_SELCHANGE + + B. Opening dropdown with F4 and selecting with arrows: + 1. CBN_DROPDOWN + 2. many CBN_SELCHANGE while changing selection in the list + 3. CBN_SELENDOK + 4. CBN_CLOSEUP + + C. Selecting with the mouse: + 1. CBN_DROPDOWN + -- no intermediate CBN_SELCHANGEs -- + 2. CBN_SELENDOK + 3. CBN_CLOSEUP + 4. CBN_SELCHANGE + + 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. + */ switch ( param ) { case CBN_DROPDOWN: - // we don't want to track selection using CB_GETCURSEL while the - // dropdown is opened + // we use this value both because we don't want to track selection + // using CB_GETCURSEL while the dropdown is opened and because we + // need to reset the selection back to it if it's eventually + // cancelled by user m_lastAcceptedSelection = GetCurrentSelection(); break; case CBN_CLOSEUP: - // it should be safe to use CB_GETCURSEL again - m_lastAcceptedSelection = wxID_NONE; + // 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 ) + { + SetSelection(m_lastAcceptedSelection); + m_lastAcceptedSelection = wxID_NONE; + } break; - case CBN_SELCHANGE: - // don't generate any events while the dropdown is opened as the - // selection is not final yet - if ( m_lastAcceptedSelection == wxID_NONE ) + 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; + { const int n = GetSelection(); @@ -668,10 +706,19 @@ bool wxChoice::MSWCommand(WXUINT param, WXWORD WXUNUSED(id)) ProcessCommand(event); } - return true; + 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 + + default: + return false; } - return false; + return true; } WXHBRUSH wxChoice::MSWControlColor(WXHDC hDC, WXHWND hWnd)