+#if wxUSE_CONSTRAINTS
+ if (GetAutoLayout())
+ Layout();
+#endif
+}
+
+// ----------------------------------------------------------------------------
+// Keyboard handling - this is the place where the TAB traversal logic is
+// implemented. As this code is common to all ports, this ensures consistent
+// behaviour even if we don't specify how exactly the wxNavigationKeyEvent are
+// generated and this is done in platform specific code which also ensures that
+// we can follow the given platform standards.
+// ----------------------------------------------------------------------------
+
+void wxPanel::OnNavigationKey( wxNavigationKeyEvent& event )
+{
+ // the event is propagated downwards if the event emitter was our parent
+ bool goingDown = event.GetEventObject() == GetParent();
+
+ const wxWindowList& children = GetChildren();
+
+ // 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
+ wxWindow *parent = GetParent();
+ if ( goingDown ||
+ !parent || !parent->GetEventHandler()->ProcessEvent(event) )
+ {
+ event.Skip();
+ }
+
+ return;
+ }
+
+ // where are we going?
+ bool forward = event.GetDirection();
+
+ // the node of the children list from which we should start looking for the
+ // next acceptable child
+ wxWindowList::Node *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 = (wxWindow *)NULL;
+
+ // start from first or last depending on where we're going
+ node = forward ? children.GetFirst() : children.GetLast();
+
+ // we want to cycle over all nodes
+ start_node = (wxWindowList::Node *)NULL;
+ }
+ else
+ {
+ // 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;
+
+ // if still no luck, do it the hard way
+ if (!winFocus)
+ winFocus = wxWindow::FindFocus();
+
+ if ( winFocus )
+ {
+ // ok, we found the focus - now is it our child?
+ start_node = children.Find( winFocus );
+ }
+ else
+ {
+ start_node = (wxWindowList::Node *)NULL;
+ }
+
+ if ( !start_node && m_winLastFocused )
+ {
+ // window which has focus isn't our child, fall back to the one
+ // which had the focus the last time
+ start_node = children.Find( m_winLastFocused );
+ }
+
+ // if we still didn't find anything, we should start with the first one
+ if ( !start_node )
+ {
+ start_node = children.GetFirst();
+ }
+
+ // and the first child which we can try setting focus to is the next or
+ // the previous one
+ node = forward ? start_node->GetNext() : start_node->GetPrevious();
+ }
+
+ // we want to cycle over all elements passing by NULL
+ while ( node != start_node )
+ {
+ // Have we come to the last or first item on the panel?
+ if ( !node )
+ {
+ if ( !goingDown )
+ {
+ // Check if our (may be grand) parent is another panel: if this
+ // is the case, they will know what to do with this navigation
+ // key and so give them the chance to process it instead of
+ // looping inside this panel (normally, the focus will go to
+ // the next/previous item after this panel in the parent
+ // panel).
+ wxWindow *focussed_child_of_parent = this;
+ for ( wxWindow *parent = GetParent();
+ parent;
+ parent = parent->GetParent() )
+ {
+ // we don't want to tab into a different dialog or frame
+ if ( focussed_child_of_parent->IsTopLevel() )
+ break;
+
+ event.SetCurrentFocus( focussed_child_of_parent );
+ if (parent->GetEventHandler()->ProcessEvent( event ))
+ return;
+
+ focussed_child_of_parent = parent;
+ }
+ }
+ //else: as the focus came from our parent, we definitely don't want
+ // to send it back to it!
+
+ // no, we are not inside another panel so process this ourself
+ node = forward ? children.GetFirst() : children.GetLast();
+
+ continue;
+ }
+
+ wxWindow *child = node->GetData();
+
+ if ( child->AcceptsFocus() )
+ {
+ m_winLastFocused = child; // should be redundant, but it is not
+
+ // if we're setting the focus to a child panel we should prevent it
+ // from giving it to the child which had the focus the last time
+ // and instead give it to the first/last child depending from which
+ // direction we're coming
+ wxPanel *subpanel = wxDynamicCast(child, wxPanel);
+ if ( subpanel )
+ {
+ // trick the panel into thinking that it got the navigation
+ // event - instead of duplicating all the code here
+ //
+ // make sure that we do trick it by setting all the parameters
+ // correctly (consistently with the code in this very function
+ // above) and that it starts from the very beginning/end by
+ // using SetLastFocus(NULL)
+ subpanel->SetLastFocus((wxWindow *)NULL);
+ }
+
+ event.SetEventObject(this);
+ if ( !child->GetEventHandler()->ProcessEvent(event) )
+ {
+ // everything is simple: just give focus to it
+ child->SetFocus();
+ }
+ //else: the child manages its focus itself
+
+ event.Skip( FALSE );
+ return;
+ }
+
+ node = forward ? node->GetNext() : node->GetPrevious();
+ }
+
+ // we cycled through all of our children and none of them wanted to accept
+ // focus