Revert thumbnail changes

src/Umbraco.Core/IO/SystemDirectories.cs

@@ -39,8 +39,6 @@ namespace Umbraco.Core.IO
 
         public static string Preview => Data + "/preview";
 
-        public static string Thumbnails => Config + "/thumbnails";
-
         private static string _root;
 
         /// <summary>

src/Umbraco.Core/Models/ContentTypeBase.cs

@@ -2,10 +2,8 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Diagnostics;
-using System.IO;
 using System.Linq;
 using System.Runtime.Serialization;
-using Umbraco.Core.IO;
 using Umbraco.Core.Models.Entities;
 using Umbraco.Core.Strings;
 
@@ -22,6 +20,7 @@ namespace Umbraco.Core.Models
         private string _alias;
         private string _description;
         private string _icon = "icon-folder";
+        private string _thumbnail = "folder.png";
         private bool _allowedAsRoot; // note: only one that's not 'pure element type'
         private bool _isContainer;
         private bool _isElement;
@@ -153,14 +152,8 @@ namespace Umbraco.Core.Models
         [DataMember]
         public string Thumbnail
         {
-            get
-            {
-                var thumbsFolder = new DirectoryInfo(IOHelper.MapPath(SystemDirectories.Thumbnails));
-                var files = Directory.GetFiles(thumbsFolder.FullName, $"{Alias}.*");
-
-                return files.Length == 1 ?
-                    IOHelper.ResolveVirtualUrl($"{SystemDirectories.Thumbnails}/{System.IO.Path.GetFileName(files[0])}") : null;
-            }
+            get => _thumbnail;
+            set => SetPropertyValueAndDetectChanges(value, ref _thumbnail, nameof(Thumbnail));
         }
 
         /// <summary>
@@ -479,7 +472,7 @@ namespace Umbraco.Core.Models
         {
             base.PerformDeepClone(clone);
 
-            var clonedEntity = (ContentTypeBase)clone;
+            var clonedEntity = (ContentTypeBase) clone;
 
             if (clonedEntity._noGroupPropertyTypes != null)
             {
@@ -488,14 +481,14 @@ namespace Umbraco.Core.Models
                 // we end up with duplicates, see: http://issues.umbraco.org/issue/U4-4842
 
                 clonedEntity._noGroupPropertyTypes.CollectionChanged -= PropertyTypesChanged;                    //clear this event handler if any
-                clonedEntity._noGroupPropertyTypes = (PropertyTypeCollection)_noGroupPropertyTypes.DeepClone(); //manually deep clone
+                clonedEntity._noGroupPropertyTypes = (PropertyTypeCollection) _noGroupPropertyTypes.DeepClone(); //manually deep clone
                 clonedEntity._noGroupPropertyTypes.CollectionChanged += clonedEntity.PropertyTypesChanged;              //re-assign correct event handler
             }
 
             if (clonedEntity._propertyGroups != null)
             {
                 clonedEntity._propertyGroups.CollectionChanged -= PropertyGroupsChanged;              //clear this event handler if any
-                clonedEntity._propertyGroups = (PropertyGroupCollection)_propertyGroups.DeepClone(); //manually deep clone
+                clonedEntity._propertyGroups = (PropertyGroupCollection) _propertyGroups.DeepClone(); //manually deep clone
                 clonedEntity._propertyGroups.CollectionChanged += clonedEntity.PropertyGroupsChanged;        //re-assign correct event handler
             }
         }

src/Umbraco.Core/Models/IContentTypeBase.cs

@@ -33,7 +33,7 @@ namespace Umbraco.Core.Models
         /// <summary>
         /// Gets or Sets the Thumbnail for the ContentType
         /// </summary>
-        string Thumbnail { get; }
+        string Thumbnail { get; set; }
 
         /// <summary>
         /// Gets or Sets a boolean indicating whether this ContentType is allowed at the root

src/Umbraco.Core/Packaging/PackageDataInstallation.cs

@@ -572,6 +572,7 @@ namespace Umbraco.Core.Packaging
 
             contentType.Name = infoElement.Element("Name").Value;
             contentType.Icon = infoElement.Element("Icon").Value;
+            contentType.Thumbnail = infoElement.Element("Thumbnail").Value;
             contentType.Description = infoElement.Element("Description").Value;
 
             //NOTE AllowAtRoot is a new property in the package xml so we need to verify it exists before using it.

src/Umbraco.Core/Persistence/Factories/ContentTypeFactory.cs

@@ -110,6 +110,7 @@ namespace Umbraco.Core.Persistence.Factories
             entity.Alias = dto.Alias;
             entity.Name = dto.NodeDto.Text;
             entity.Icon = dto.Icon;
+            entity.Thumbnail = dto.Thumbnail;
             entity.SortOrder = dto.NodeDto.SortOrder;
             entity.Description = dto.Description;
             entity.CreateDate = dto.NodeDto.CreateDate;

src/Umbraco.Core/Persistence/Mappers/ContentTypeMapper.cs

@@ -35,6 +35,7 @@ namespace Umbraco.Core.Persistence.Mappers
             DefineMap<ContentType, ContentTypeDto>(nameof(ContentType.Icon), nameof(ContentTypeDto.Icon));
             DefineMap<ContentType, ContentTypeDto>(nameof(ContentType.IsContainer), nameof(ContentTypeDto.IsContainer));
             DefineMap<ContentType, ContentTypeDto>(nameof(ContentType.IsElement), nameof(ContentTypeDto.IsElement));
+            DefineMap<ContentType, ContentTypeDto>(nameof(ContentType.Thumbnail), nameof(ContentTypeDto.Thumbnail));
         }
     }
 }

src/Umbraco.Web/Models/Mapping/ContentTypeMapDefinition.cs

@@ -184,6 +184,7 @@ namespace Umbraco.Web.Models.Mapping
             target.Name = source.Name;
             target.ParentId = source.ParentId;
             target.Path = source.Path;
+            target.Thumbnail = source.Thumbnail;
             target.Trashed = source.Trashed;
             target.UpdateDate = source.UpdateDate;
         }
@@ -386,6 +387,7 @@ namespace Umbraco.Web.Models.Mapping
             target.Name = source.Name;
             target.ParentId = source.ParentId;
             target.Path = source.Path;
+            target.Thumbnail = source.Thumbnail;
 
             target.AllowedAsRoot = source.AllowAsRoot;
             target.AllowedContentTypes = source.AllowedContentTypes.Select((t, i) => new ContentTypeSort(t, i));
@@ -481,6 +483,7 @@ namespace Umbraco.Web.Models.Mapping
             target.Name = source.Name;
             target.ParentId = source.ParentId;
             target.Path = source.Path;
+            target.Thumbnail = source.Thumbnail;
             target.Udi = MapContentTypeUdi(source);
             target.UpdateDate = source.UpdateDate;
 
@@ -517,6 +520,7 @@ namespace Umbraco.Web.Models.Mapping
             target.Name = source.Name;
             target.ParentId = source.ParentId;
             target.Path = source.Path;
+            target.Thumbnail = source.Thumbnail;
             target.Trashed = source.Trashed;
             target.Udi = source.Udi;
         }

src/Umbraco.Web/Models/Trees/TreeNode.cs

@@ -75,6 +75,48 @@ namespace Umbraco.Web.Models.Trees
         [DataMember(Name = "menuUrl")]
         public string MenuUrl { get; set; }
 
+        /// <summary>
+        /// Returns true if the icon represents a CSS class instead of a file path
+        /// </summary>
+        [DataMember(Name = "iconIsClass")]
+        public bool IconIsClass
+        {
+            get
+            {
+                if (Icon.IsNullOrWhiteSpace())
+                {
+                    return true;
+                }
+
+                if (Icon.StartsWith(".."))
+                    return false;
+
+
+                //if it starts with a '.' or doesn't contain a '.' at all then it is a class
+                return Icon.StartsWith(".") || Icon.Contains(".") == false;
+            }
+        }
+
+        /// <summary>
+        /// Returns the icon file path if the icon is not a class, otherwise returns an empty string
+        /// </summary>
+        [DataMember(Name = "iconFilePath")]
+        public string IconFilePath
+        {
+            get
+            {
+                if (IconIsClass)
+                    return string.Empty;
+
+                //absolute path with or without tilde
+                if (Icon.StartsWith("~") || Icon.StartsWith("/"))
+                    return IOHelper.ResolveUrl("~" + Icon.TrimStart('~'));
+
+                //legacy icon path
+                return string.Format("{0}images/umbraco/{1}", Current.Configs.Global().Path.EnsureEndsWith("/"), Icon);
+            }
+        }
+
         /// <summary>
         /// A list of additional/custom css classes to assign to the node
         /// </summary>