C++ wxNavigationKeyEvent::GetCurrentFocus方法代码示例

void wxControlContainer::HandleOnNavigationKey( wxNavigationKeyEvent& event )
{
    // for a TLW we shouldn't involve the parent window, it has nothing to do
    // with keyboard navigation inside this TLW
    wxWindow *parent = m_winParent->IsTopLevel() ? NULL
                                                 : m_winParent->GetParent();

    // the event is propagated downwards if the event emitter was our parent
    bool goingDown = event.GetEventObject() == parent;

    const wxWindowList& children = m_winParent->GetChildren();

    // if we have exactly one notebook-like child window (actually it could be
    // any window that returns true from its HasMultiplePages()), then
    // [Shift-]Ctrl-Tab and Ctrl-PageUp/Down keys should iterate over its pages
    // even if the focus is outside of the control because this is how the
    // standard MSW properties dialogs behave and we do it under other platforms
    // as well because it seems like a good idea -- but we can always put this
    // block inside "#ifdef __WXMSW__" if it's not suitable there
    if ( event.IsWindowChange() && !goingDown )
    {
        // check if we have a unique notebook-like child
        wxWindow *bookctrl = NULL;
        for ( wxWindowList::const_iterator i = children.begin(),
                                         end = children.end();
              i != end;
              ++i )
        {
            wxWindow * const window = *i;
            if ( window->HasMultiplePages() )
            {
                if ( bookctrl )
                {
                    // this is the second book-like control already so don't do
                    // anything as we don't know which one should have its page
                    // changed
                    bookctrl = NULL;
                    break;
                }

                bookctrl = window;
            }
        }

        if ( bookctrl )
        {
            // make sure that we don't bubble up the event again from the book
            // control resulting in infinite recursion
            wxNavigationKeyEvent eventCopy(event);
            eventCopy.SetEventObject(m_winParent);
            if ( bookctrl->GetEventHandler()->ProcessEvent(eventCopy) )
                return;
        }
    }

    // there is not much to do if we don't have children and we're not
    // interested in "notebook page change" events here
    if ( !children.GetCount() || event.IsWindowChange() )
    {
        // let the parent process it unless it already comes from our parent
        // of we don't have any
        if ( goingDown ||
             !parent || !parent->GetEventHandler()->ProcessEvent(event) )
        {
            event.Skip();
        }

        return;
    }

    // where are we going?
    const bool forward = event.GetDirection();

    // the node of the children list from which we should start looking for the
    // next acceptable child
    wxWindowList::compatibility_iterator node, start_node;

    // we should start from the first/last control and not from the one which
    // had focus the last time if we're propagating the event downwards because
    // for our parent we look like a single control
    if ( goingDown )
    {
        // just to be sure it's not used (normally this is not necessary, but
        // doesn't hurt neither)
        m_winLastFocused = NULL;

        // start from first or last depending on where we're going
        node = forward ? children.GetFirst() : children.GetLast();
    }
    else // going up
    {
        // try to find the child which has the focus currently

        // the event emitter might have done this for us
        wxWindow *winFocus = event.GetCurrentFocus();

        // but if not, we might know where the focus was ourselves
        if (!winFocus)
            winFocus = m_winLastFocused;

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