Microsoft.Windows.Controls.Ribbon.RibbonGalleryItem.OnSelected C# (CSharp) Method

        protected internal virtual void OnSelected(RoutedEventArgs e)
        {
            RaiseEvent(e);

            RibbonGalleryItemAutomationPeer peer = UIElementAutomationPeer.CreatePeerForElement(this) as RibbonGalleryItemAutomationPeer;
            if (peer != null)
            {
                peer.RaiseAutomationIsSelectedChanged(true);
                peer.RaiseAutomationSelectionEvent(AutomationEvents.SelectionItemPatternOnElementSelected);
            }
        }

        // Update all selection properties viz.
        // - SelectedItem
        // - SelectedValue
        // - CurrentItem
        // - IsSelected
        // - SelectedContainers
        internal void ChangeSelection(object item, RibbonGalleryItem container, bool isSelected)
        {
            if (IsSelectionChangeActive)
            {
                return;
            }

            object oldItem = SelectedItem;
            object newItem = item;
            bool selectedItemChanged = !VerifyEqual(oldItem, newItem);

            try
            {
                IsSelectionChangeActive = true;

                if (isSelected == selectedItemChanged)
                {
                    // Deselecting a single container. This can only happen
                    // when setting IsSelected to false on a specific container.
                    // Note that neither SelectedItem nor CurrentItem are updated
                    // in this case. We only updated the _selectedContainers and
                    // ContainsSelection properties both of which are specific to
                    // the containers in view.
                    if (!isSelected && container != null)
                    {
                        container.IsSelected = false;
                        int index = _selectedContainers.IndexOf(container);
                        if (index > -1)
                        {
                            _selectedContainers.RemoveAt(index);
                            container.OnUnselected(new RoutedEventArgs(RibbonGalleryItem.UnselectedEvent, container));
                        }
                    }
                    else
                    {
                        // This is the case where SelectedItem is changing.
                        // We start the processing by deselecting all existing
                        // containers.
                        for (int i = 0; i < _selectedContainers.Count; i++)
                        {
                            RibbonGalleryItem galleryItem = _selectedContainers[i];
                            galleryItem.IsSelected = false;
                            galleryItem.OnUnselected(new RoutedEventArgs(RibbonGalleryItem.UnselectedEvent, galleryItem));

                            if (!isSelected)
                            {
                                MoveCurrentToPosition(galleryItem.RibbonGalleryCategory.CollectionView, -1);
                            }
                        }
                        _selectedContainers.Clear();

                        if (!isSelected)
                        {
                            SelectedItem = null;
                            SelectedValue = null;

                            MoveCurrentToPosition(CollectionView, -1);
                            MoveCurrentToPosition(SourceCollectionView, -1);
                        }
                    }

                    // Select the item
                    if (isSelected)
                    {
                        SelectedItem = item;
                        SelectedValue = GetSelectableValueFromItem(item);

                        // Synchronize currency with the specified SelectedItem.
                        if (container != null)
                        {
                            // This is the case where a single container is selected
                            SynchronizeWithCurrentItem(container.RibbonGalleryCategory, item);
                        }
                        else
                        {
                            // This is the case where the selected item is directly
                            // set in which case we need to additionally find the category
                            // that contains it to perform the currency synchronization
                            SynchronizeWithCurrentItem();
                        }
                    }
                }

                // Select the container and synchronize currency
                if (isSelected && container != null && !_selectedContainers.Contains(container))
                {
                    _selectedContainers.Add(container);
                    container.IsSelected = true;
                    container.OnSelected(new RoutedEventArgs(RibbonGalleryItem.SelectedEvent, container));
                }
            }
            finally
            {
                IsSelectionChangeActive = false;
            }

            if (selectedItemChanged)
            {
                RoutedPropertyChangedEventArgs<object> args = new RoutedPropertyChangedEventArgs<object>(oldItem, isSelected ? newItem : null, SelectionChangedEvent);
                this.OnSelectionChanged(args);
            }
        }