I am back to square one - I've managed to create a new tinymce button that adds a link to an anchor on a page.

Now, I have a new challange - I have to do the same for the linkitemcollection.

I have managed to render the dropdown in a link item using:

[EditorDescriptorRegistration(TargetType = typeof(LinkItemCollection), UIHint = SiteUiHints.ExtendedLinkCollection)]
    public class ExtendedLinkCollectionEditorDescriptor : ItemCollectionEditorDescriptor
    {
        public ExtendedLinkCollectionEditorDescriptor(
            IEnumerable<IContentRepositoryDescriptor> contentRepositoryDescriptors)
        {
            AllowedTypesFormatSuffix = "link"; 
            AllowedTypes = (from d in contentRepositoryDescriptors
                            where d.LinkableTypes != null && d.LinkableTypes.Any() 
                            select d).SelectMany(d => d.LinkableTypes).Distinct().ToArray();
        }
        public override void ModifyMetadata(ExtendedMetadata metadata, IEnumerable<Attribute> attributes)
        {
            ClientEditingClass = "myproject/editors/ExtendedItemCollectionEditor";

            base.ModifyMetadata(metadata, attributes);
            var anonymousType = new
            {
                ItemModelType = "epi-cms/contentediting/viewmodel/LinkItemModel", 
                CustomTypeIdentifier = typeof(LinkItem).FullName.ToLower()
            }; 
            
            var value = new
            {
                DialogContentParams = new
                {
                    ModelType = typeof(ExtendedEPiLinkModel).FullName.ToLower()
                }
            };

            metadata.OverlayConfiguration["modelParams"] = anonymousType;
            metadata.EditorConfiguration["itemModelType"] = anonymousType.ItemModelType;
            metadata.EditorConfiguration["customTypeIdentifier"] = anonymousType.CustomTypeIdentifier; 
            metadata.EditorConfiguration["commandOptions"] = value;
        }

I "just" need to get hold of the Page widget, so that I can connect on its onChange event. The rest I can easily reuse. Can I do that from ExtendedItemCollectionEditor (at the moment, a copy paste of ItemCollectionEditor)?

Every help appreciated.