private void ApplyTo()

in sources/Google.Solutions.Mvvm/Theme/ToolStripItemTheme.cs [37:124]
55 lines of code
14 McCabe index (conditional complexity)

        private void ApplyTo(ToolStripItem item)
        {
            //
            // Apply Rules to current item.
            //
            foreach (var rule in this.rules)
            {
                rule(item);
            }

            //
            // Recursively visit child items.
            //
            if (item is ToolStripDropDownItem dropDownItem)
            {
                //
                // Consider current child items...
                //
                List<WeakReference<ToolStripItem>>? appliedItems = null;
                if (this.IncludeControlsAddedLater)
                {
                    appliedItems = new List<WeakReference<ToolStripItem>>();
                }

                if (dropDownItem.DropDownItems != null)
                {
                    foreach (var subItem in dropDownItem.DropDownItems.OfType<ToolStripItem>())
                    {
                        ApplyTo(subItem);

                        if (this.IncludeControlsAddedLater && appliedItems != null)
                        {
                            //
                            // Memoize items we've applied already so that
                            // we don't reapply them again later.
                            //
                            appliedItems.Add(new WeakReference<ToolStripItem>(subItem));
                        }
                    }
                }

                //
                // ...and future items.
                //
                // There's no ItemAdded event, so we have to check for new items
                // every time the menu pops up.
                //
                if (this.IncludeControlsAddedLater)
                {
                    dropDownItem.DropDownOpening += OnDropDownOpening;
                }

                void OnDropDownOpening(object sender, EventArgs __)
                {
                    var openingItem = (ToolStripDropDownItem)sender;
                    if (openingItem.DropDownItems != null)
                    {
                        foreach (var subItem in openingItem.DropDownItems.OfType<ToolStripItem>())
                        {
                            if (!appliedItems.Any(i =>
                                i.TryGetTarget(out var appliedItem) && appliedItem == subItem))
                            {
                                ApplyTo(subItem);
                            }

                            Debug.Assert(appliedItems != null, "cannot be null here");
                            appliedItems!.Add(new WeakReference<ToolStripItem>(subItem));

                            Debug.Assert(
                                appliedItems.Count < 256,
                                "Cache should not grow excessively large");

                            if (subItem is ToolStripDropDownItem dropDownSubItem)
                            {
                                dropDownSubItem.DropDownOpening += OnDropDownOpening;
                            }
                        }

                    }

                    //
                    // Only allow each event to be fired once, otherwise
                    // the appliedItem list will grow too large.
                    //
                    openingItem.DropDownOpening -= OnDropDownOpening;
                }
            }
        }