自学教程：C++ HasClientObjectData函数代码示例

void wxChoice::SetString(unsigned int n, const wxString& s){    wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::SetString") );    // we have to delete and add back the string as there is no way to change a    // string in place    // we need to preserve the client data manually    void *oldData = NULL;    wxClientData *oldObjData = NULL;    if ( HasClientUntypedData() )        oldData = GetClientData(n);    else if ( HasClientObjectData() )        oldObjData = GetClientObject(n);    ::SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);    ::SendMessage(GetHwnd(), CB_INSERTSTRING, n, (LPARAM)s.wx_str() );    // restore the client data    if ( oldData )        SetClientData(n, oldData);    else if ( oldObjData )        SetClientObject(n, oldObjData);    InvalidateBestSize();}

bool wxChoice::OS2Command(  WXUINT                            uParam, WXWORD                            WXUNUSED(wId)){    if (uParam != LN_SELECT)    {        //        // "selection changed" is the only event we're after        //        return false;    }    int                             n = GetSelection();    if (n > -1)    {        wxCommandEvent              vEvent( wxEVT_CHOICE                                           ,m_windowId                                          );        vEvent.SetInt(n);        vEvent.SetEventObject(this);        vEvent.SetString(GetStringSelection());        if (HasClientObjectData())            vEvent.SetClientObject(GetClientObject(n));        else if (HasClientUntypedData())            vEvent.SetClientData(GetClientData(n));        ProcessCommand(vEvent);    }    return true;} // end of wxChoice::OS2Command

void wxChoice::SetString(unsigned int n, const wxString& s){    wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::SetString") );    // we have to delete and add back the string as there is no way to change a    // string in place    // we need to preserve the client data manually    void *oldData = NULL;    wxClientData *oldObjData = NULL;    if ( HasClientUntypedData() )        oldData = GetClientData(n);    else if ( HasClientObjectData() )        oldObjData = GetClientObject(n);    // and also the selection if we're going to delete the item that was    // selected    const bool wasSelected = static_cast<int>(n) == GetSelection();    ::SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);    ::SendMessage(GetHwnd(), CB_INSERTSTRING, n, (LPARAM)s.wx_str() );    // restore the client data    if ( oldData )        SetClientData(n, oldData);    else if ( oldObjData )        SetClientObject(n, oldObjData);    // and the selection    if ( wasSelected )        SetSelection(n);    // the width could have changed so the best size needs to be recomputed    InvalidateBestSize();}

void wxListBox::Clear(){    wxCHECK_RET( m_list != NULL, wxT("invalid listbox") );    gtk_list_clear_items( m_list, 0, (int)GetCount() );    if ( GTK_LIST(m_list)->last_focus_child != NULL  )    {        // This should be NULL, I think.        GTK_LIST(m_list)->last_focus_child = NULL;    }    if ( HasClientObjectData() )    {        // destroy the data (due to Robert's idea of using wxList<wxObject>        // and not wxList<wxClientData> we can't just say        // m_clientList.DeleteContents(true) - this would crash!        wxList::compatibility_iterator node = m_clientList.GetFirst();        while ( node )        {            delete (wxClientData *)node->GetData();            node = node->GetNext();        }    }    m_clientList.Clear();    if ( m_strings )        m_strings->Clear();}

wxClientData *wxItemContainer::GetClientObject(unsigned int n) const{    wxCHECK_MSG( HasClientObjectData(), NULL,                  wxT("this window doesn't have object client data") );    return static_cast<wxClientData *>(DoGetItemClientData(n));}

bool wxListBox::SendEvent(wxEventType type, int item){    wxCommandEvent event(type, m_windowId);    event.SetEventObject(this);    // use the current item by default    if ( item == -1 )    {        item = m_current;    }    // client data and string parameters only make sense if we have an item    if ( item != -1 )    {        if ( HasClientObjectData() )            event.SetClientObject(GetClientObject(item));        else if ( HasClientUntypedData() )            event.SetClientData(GetClientData(item));        event.SetString(GetString(item));    }    event.SetInt(item);    return GetEventHandler()->ProcessEvent(event);}

void wxListBox::DoSetItems(const wxArrayString& items, void** clientData){    Widget listBox = (Widget) m_mainWidget;    if( HasClientObjectData() )        m_clientDataDict.DestroyData();    XmString *text = new XmString[items.GetCount()];    unsigned int i;    for (i = 0; i < items.GetCount(); ++i)        text[i] = wxStringToXmString (items[i]);    if ( clientData )        for (i = 0; i < items.GetCount(); ++i)            m_clientDataDict.Set(i, (wxClientData*)clientData[i], false);    XmListAddItems (listBox, text, items.GetCount(), 0);    for (i = 0; i < items.GetCount(); i++)        XmStringFree (text[i]);    delete[] text;    // It seems that if the list is cleared, we must re-ask for    // selection policy!!    SetSelectionPolicy();    m_noItems = items.GetCount();}

void wxListBox::SetString(unsigned int n, const wxString& rsString){    wxCHECK_RET( IsValid(n),                 wxT("invalid index in wxListBox::SetString") );    //    // Remember the state of the item    //    bool           bWasSelected = IsSelected(n);    void*          pOldData = NULL;    wxClientData*  pOldObjData = NULL;    if ( HasClientUntypedData() )        pOldData = GetClientData(n);    else if ( HasClientObjectData() )        pOldObjData = GetClientObject(n);    //    // Delete and recreate it    //    ::WinSendMsg( GetHwnd()                 ,LM_DELETEITEM                 ,(MPARAM)n                 ,(MPARAM)0                );    int nNewN = n;    if (n == (m_nNumItems - 1))        nNewN = -1;    ::WinSendMsg( GetHwnd()                 ,LM_INSERTITEM                 ,(MPARAM)nNewN                 ,(MPARAM)rsString.wx_str()                );    //    // Restore the client data    //    if (pOldData)        SetClientData(n, pOldData);    else if (pOldObjData)        SetClientObject(n, pOldObjData);    //    // We may have lost the selection    //    if (bWasSelected)        Select(n);#if wxUSE_OWNER_DRAWN    if (m_windowStyle & wxLB_OWNERDRAW)        //        // Update item's text        //        m_aItems[n]->SetName(rsString);#endif  //USE_OWNER_DRAWN} // end of wxListBox::SetString

wxComboBox::~wxComboBox(){    DetachWidget((Widget) m_mainWidget); // Removes event handlers    XtDestroyWidget((Widget) m_mainWidget);    m_mainWidget = (WXWidget) 0;    if ( HasClientObjectData() )        m_clientDataDict.DestroyData();}

void wxComboBox::Clear(){    XmComboBoxDeleteAllItems((Widget) m_mainWidget);    m_stringList.Clear();    if ( HasClientObjectData() )        m_clientDataDict.DestroyData();    m_noStrings = 0;}

void wxListBox::Delete(unsigned int n){    Widget listBox = (Widget) m_mainWidget;    XmListDeletePos (listBox, n + 1);    m_clientDataDict.Delete(n, HasClientObjectData());    m_noItems --;}

void wxChoice::FreeData(){    if ( HasClientObjectData() )    {        size_t count = GetCount();        for ( size_t n = 0; n < count; n++ )        {            delete GetClientObject(n);        }    }}

void wxChoice::Free(){    if ( HasClientObjectData() )    {        unsigned int count = GetCount();        for ( unsigned int n = 0; n < count; n++ )        {            delete GetClientObject(n);        }    }}

void wxChoice::Delete(int n){    wxCHECK_RET( n < GetCount(), wxT("invalid item index in wxChoice::Delete") );    if ( HasClientObjectData() )    {        delete GetClientObject(n);    }    ::SendMessage(GetBuddyHwnd(), LB_DELETESTRING, n, 0);}

wxChoice::~wxChoice(){    if ( HasClientObjectData() )    {        unsigned int i, max = GetCount();        for ( i = 0; i < max; ++i )            delete GetClientObject( i );    }    delete m_popUpMenu;}

void wxChoice::Delete(int n){    wxCHECK_RET( n < GetCount(), wxT("invalid item index in wxChoice::Delete") );    if ( HasClientObjectData() )    {        delete GetClientObject(n);    }    ::DeleteMenuItem( MAC_WXHMENU(m_macPopUpMenuHandle) , n + 1) ;    m_strings.RemoveAt( n ) ;    m_datas.RemoveAt( n ) ;    m_peer->SetMaximum( GetCount() ) ;}

void wxComboBox::Delete(unsigned int n){    XmComboBoxDeletePos((Widget) m_mainWidget, n+1);    wxStringList::Node *node = m_stringList.Item(n);    if (node)    {        delete[] node->GetData();        delete node;    }    m_clientDataDict.Delete(n, HasClientObjectData());    m_noStrings--;}

void wxChoice::Delete(unsigned int n){    Widget w = (Widget)m_widgetArray[n];    XtRemoveCallback(w, XmNactivateCallback, (XtCallbackProc)wxChoiceCallback,                     (XtPointer)this);    m_stringList.Erase(m_stringList.Item(n));    m_widgetArray.RemoveAt(size_t(n));    m_clientDataDict.Delete(n, HasClientObjectData());    XtDestroyWidget(w);    m_noStrings--;}

void wxChoice::Delete(unsigned int n){    wxCHECK_RET( IsValid(n) , wxT("wxChoice::Delete: invalid index") );    if ( HasClientObjectData() )        delete GetClientObject( n );    ::DeleteMenuItem( MAC_WXHMENU(m_macPopUpMenuHandle) , n + 1 ) ;    m_strings.RemoveAt( n ) ;    m_datas.RemoveAt( n ) ;    m_peer->SetMaximum( GetCount() ) ;}

voidwxControlWithItemsBase::InitCommandEventWithItems(wxCommandEvent& event, int n){    InitCommandEvent(event);    if ( n != wxNOT_FOUND )    {        if ( HasClientObjectData() )            event.SetClientObject(GetClientObject(n));        else if ( HasClientUntypedData() )            event.SetClientData(GetClientData(n));    }}

void wxItemContainer::Clear(){    if ( HasClientObjectData() )    {        const unsigned count = GetCount();        for ( unsigned i = 0; i < count; ++i )            ResetItemClientObject(i);    }    SetClientDataType(wxClientData_None);    DoClear();}

wxChoice::~wxChoice(){    if ( HasClientObjectData() )    {        size_t i, max = GetCount();        for ( i = 0; i < max; ++i )            delete GetClientObject(i);    }        // DeleteMenu( m_macPopUpMenuId ) ;    // DisposeMenu( m_macPopUpMenuHandle ) ;}

void wxItemContainer::Delete(unsigned int pos){    wxCHECK_RET( pos < GetCount(), wxT("invalid index") );    if ( HasClientObjectData() )        ResetItemClientObject(pos);    DoDeleteOneItem(pos);    if ( IsEmpty() )    {        SetClientDataType(wxClientData_None);    }}

void wxChoice::DoDeleteOneItem(unsigned int n){    wxCHECK_RET( IsValid(n) , wxT("wxChoice::Delete: invalid index") );    if ( HasClientObjectData() )        delete GetClientObject( n );    m_popUpMenu->Delete( m_popUpMenu->FindItemByPosition( n ) );    m_strings.RemoveAt( n ) ;    m_datas.RemoveAt( n ) ;    DoAfterItemCountChange();}

void wxListBox::Clear(){    if (m_noItems <= 0)        return;    wxSizeKeeper sk( this );    Widget listBox = (Widget) m_mainWidget;    XmListDeleteAllItems (listBox);    if( HasClientObjectData() )        m_clientDataDict.DestroyData();    sk.Restore();    m_noItems = 0;}

void wxChoice::Delete(unsigned int n){    wxCHECK_RET( IsValid(n), wxT("invalid item index in wxChoice::Delete") );    if ( HasClientObjectData() )    {        delete GetClientObject(n);    }    SendMessage(GetHwnd(), CB_DELETESTRING, n, 0);    if ( !IsFrozen() )        UpdateVisibleHeight();    InvalidateBestSize();}

bool wxListBoxBase::SendEvent(wxEventType evtType, int item, bool selected){    wxCommandEvent event(evtType, GetId());    event.SetEventObject(this);    event.SetInt(item);    event.SetString(GetString(item));    event.SetExtraLong(selected);    if ( HasClientObjectData() )        event.SetClientObject(GetClientObject(item));    else if ( HasClientUntypedData() )        event.SetClientData(GetClientData(item));    return HandleWindowEvent(event);}

bool wxListBox::OS2Command(  WXUINT                            uParam, WXWORD                            WXUNUSED(wId)){    wxEventType                     eEvtType;    if (uParam == LN_SELECT)    {        eEvtType = wxEVT_COMMAND_LISTBOX_SELECTED;    }    else if (uParam == LN_ENTER)    {        eEvtType = wxEVT_COMMAND_LISTBOX_DOUBLECLICKED;    }    else    {        //        // Some event we're not interested in        //        return false;    }    wxCommandEvent                  vEvent( eEvtType                                           ,m_windowId                                          );    vEvent.SetEventObject(this);    wxArrayInt                      aSelections;    int                             n;    int                             nCount = GetSelections(aSelections);    if (nCount > 0)    {        n = aSelections[0];        if (HasClientObjectData())            vEvent.SetClientObject(GetClientObject(n));        else if ( HasClientUntypedData() )            vEvent.SetClientData(GetClientData(n));        vEvent.SetString(GetString(n));    }    else    {        n = -1;    }    vEvent.SetInt(n);    return GetEventHandler()->ProcessEvent(vEvent);} // end of wxListBox::OS2Command

void wxListBox::Free(){#if wxUSE_OWNER_DRAWN    if ( m_windowStyle & wxLB_OWNERDRAW )    {        WX_CLEAR_ARRAY(m_aItems);    }    else#endif // wxUSE_OWNER_DRAWN    if ( HasClientObjectData() )    {        for ( unsigned int n = 0; n < m_noItems; n++ )        {            delete GetClientObject(n);        }    }}