internal UIElement CreateUIElementForModel(ILayoutElement model)
        {
            if (model is LayoutPanel)
                return new LayoutPanelControl(model as LayoutPanel);
            if (model is LayoutAnchorablePaneGroup)
                return new LayoutAnchorablePaneGroupControl(model as LayoutAnchorablePaneGroup);
            if (model is LayoutDocumentPaneGroup)
                return new LayoutDocumentPaneGroupControl(model as LayoutDocumentPaneGroup);

            if (model is LayoutAnchorSide)
            {
                var templateModelView = new LayoutAnchorSideControl(model as LayoutAnchorSide);
                templateModelView.SetBinding(LayoutAnchorSideControl.TemplateProperty, new Binding("AnchorSideTemplate") { Source = this });
                return templateModelView;
            }
            if (model is LayoutAnchorGroup)
            {
                var templateModelView = new LayoutAnchorGroupControl(model as LayoutAnchorGroup);
                templateModelView.SetBinding(LayoutAnchorGroupControl.TemplateProperty, new Binding("AnchorGroupTemplate") { Source = this });
                return templateModelView;
            }

            if (model is LayoutDocumentPane)
            {
                var templateModelView = new LayoutDocumentPaneControl(model as LayoutDocumentPane);
                templateModelView.SetBinding(LayoutDocumentPaneControl.StyleProperty, new Binding("DocumentPaneControlStyle") { Source = this });
                return templateModelView;
            }
            if (model is LayoutAnchorablePane)
            {
                var templateModelView = new LayoutAnchorablePaneControl(model as LayoutAnchorablePane);
                templateModelView.SetBinding(LayoutAnchorablePaneControl.StyleProperty, new Binding("AnchorablePaneControlStyle") { Source = this });
                return templateModelView;
            }

            if (model is LayoutAnchorableFloatingWindow)
            {
                if (DesignerProperties.GetIsInDesignMode(this))
                    return null;
                var modelFW = model as LayoutAnchorableFloatingWindow;
                var newFW = new LayoutAnchorableFloatingWindowControl(modelFW)
                {
                    //Owner = Window.GetWindow(this)
                };
                newFW.SetParentToMainWindowOf(this);

                var paneForExtentions = modelFW.RootPanel.Children.OfType<LayoutAnchorablePane>().FirstOrDefault();
                if (paneForExtentions != null)
                {
                    //ensure that floating window position is inside current (or nearest) monitor
                    paneForExtentions.KeepInsideNearestMonitor();

                    newFW.Left = paneForExtentions.FloatingLeft;
                    newFW.Top = paneForExtentions.FloatingTop;
                    newFW.Width = paneForExtentions.FloatingWidth;
                    newFW.Height = paneForExtentions.FloatingHeight;
                }

                newFW.ShowInTaskbar = false;
                newFW.Show();
                return newFW;
            }

            if (model is LayoutDocumentFloatingWindow)
            {
                if (DesignerProperties.GetIsInDesignMode(this))
                    return null;
                var modelFW = model as LayoutDocumentFloatingWindow;
                var newFW = new LayoutDocumentFloatingWindowControl(modelFW)
                {
                    //Owner = Window.GetWindow(this)
                };
                newFW.SetParentToMainWindowOf(this);

                var paneForExtentions = modelFW.RootDocument;
                if (paneForExtentions != null)
                {
                    //ensure that floating window position is inside current (or nearest) monitor
                    paneForExtentions.KeepInsideNearestMonitor();

                    newFW.Left = paneForExtentions.FloatingLeft;
                    newFW.Top = paneForExtentions.FloatingTop;
                    newFW.Width = paneForExtentions.FloatingWidth;
                    newFW.Height = paneForExtentions.FloatingHeight;
                }

                newFW.ShowInTaskbar = false;
                newFW.Show();
                return newFW;
            }

            if (model is LayoutDocument)
            {
                var templateModelView = new LayoutDocumentControl() { Model = model as LayoutDocument };
                return templateModelView;
            }

            return null;
        }
        internal void StartDraggingFloatingWindowForPane(LayoutAnchorablePane paneModel)
        {
            if (paneModel.Children.Any(c => !c.CanFloat))
                return;
            var paneAsPositionableElement = paneModel as ILayoutPositionableElement;
            var paneAsWithActualSize = paneModel as ILayoutPositionableElementWithActualSize;

            double fwWidth = paneAsPositionableElement.FloatingWidth;
            double fwHeight = paneAsPositionableElement.FloatingHeight;
            double fwLeft = paneAsPositionableElement.FloatingLeft;
            double fwTop = paneAsPositionableElement.FloatingTop;

            if (fwWidth == 0.0)
                fwWidth = paneAsWithActualSize.ActualWidth;
            if (fwHeight == 0.0)
                fwHeight = paneAsWithActualSize.ActualHeight;

            var destPane = new LayoutAnchorablePane()
            {
                DockWidth = paneAsPositionableElement.DockWidth,
                DockHeight = paneAsPositionableElement.DockHeight,
                DockMinHeight = paneAsPositionableElement.DockMinHeight,
                DockMinWidth = paneAsPositionableElement.DockMinWidth,
                FloatingLeft = paneAsPositionableElement.FloatingLeft,
                FloatingTop = paneAsPositionableElement.FloatingTop,
                FloatingWidth = paneAsPositionableElement.FloatingWidth,
                FloatingHeight = paneAsPositionableElement.FloatingHeight,
            };

            bool savePreviousContainer = paneModel.FindParent<LayoutFloatingWindow>() == null;
            int currentSelectedContentIndex = paneModel.SelectedContentIndex;
            while (paneModel.Children.Count > 0)
            {
                var contentModel = paneModel.Children[paneModel.Children.Count - 1] as LayoutAnchorable;

                if (savePreviousContainer)
                {
                    var contentModelAsPreviousContainer = contentModel as ILayoutPreviousContainer;
                    contentModelAsPreviousContainer.PreviousContainer = paneModel;
                    contentModel.PreviousContainerIndex = paneModel.Children.Count - 1;
                }

                paneModel.RemoveChildAt(paneModel.Children.Count - 1);
                destPane.Children.Insert(0, contentModel);
            }

            if (destPane.Children.Count > 0)
            {
                destPane.SelectedContentIndex = currentSelectedContentIndex;
            }

            LayoutFloatingWindow fw;
            LayoutFloatingWindowControl fwc;
            fw = new LayoutAnchorableFloatingWindow()
            {
                RootPanel = new LayoutAnchorablePaneGroup(
                    destPane)
                    {
                        DockHeight = destPane.DockHeight,
                        DockWidth = destPane.DockWidth,
                        DockMinHeight = destPane.DockMinHeight,
                        DockMinWidth = destPane.DockMinWidth,
                    }
            };

            Layout.FloatingWindows.Add(fw);

            fwc = new LayoutAnchorableFloatingWindowControl(
                fw as LayoutAnchorableFloatingWindow)
            {
                Width = fwWidth,
                Height = fwHeight
            };

            //fwc.Owner = Window.GetWindow(this);
            //fwc.SetParentToMainWindowOf(this);

            _fwList.Add(fwc);

            Layout.CollectGarbage();

            InvalidateArrange();

            fwc.AttachDrag();
            fwc.Show();
        }