Issue 272 proxies

ACadSharp.Tests/CadDocumentTests.cs

@@ -20,7 +20,9 @@ static CadDocumentTests()
 
 			foreach (var item in DataFactory.GetTypes<Entity>())
 			{
-				if (item == typeof(Block) || item == typeof(BlockEnd))
+				if (item == typeof(Block)
+					|| item == typeof(BlockEnd)
+					|| item == typeof(UnknownEntity))
 					continue;
 
 				EntityTypes.Add(item);

ACadSharp.Tests/Entities/EntityTests.cs

@@ -13,6 +13,11 @@ static EntityTests()
 		{
 			foreach (var item in DataFactory.GetTypes<Entity>())
 			{
+				if(item == typeof(UnknownEntity))
+				{
+					continue;
+				}
+
 				EntityTypes.Add(item);
 			}
 		}

ACadSharp.Tests/IO/CadReaderTestsBase.cs

@@ -1,9 +1,7 @@
 using ACadSharp.Header;
 using ACadSharp.IO;
-using ACadSharp.IO.DWG;
 using System;
 using System.Collections.Generic;
-using System.Text;
 using Xunit;
 using Xunit.Abstractions;
 

ACadSharp.Tests/Internal/DxfMapTests.cs

@@ -21,8 +21,14 @@ static DxfMapTests()
 
 			foreach (var item in d.GetTypes().Where(i => !i.IsAbstract && i.IsPublic))
 			{
-				if (item.IsSubclassOf(typeof(Entity)) || item.IsSubclassOf(typeof(TableEntry)))
+				if (item.IsSubclassOf(typeof(Entity)) 
+					|| item.IsSubclassOf(typeof(TableEntry)))
 				{
+					if(item == typeof(UnknownEntity))
+					{
+						continue;
+					}
+
 					Types.Add(item);
 				}
 			}

ACadSharp/Classes/DxfClass.cs

@@ -35,13 +35,15 @@ public class DxfClass
 		public int InstanceCount { get; set; }
 
 		/// <summary>
-		/// Was-a-proxy flag.Set to 1 if class was not loaded when this DXF file was created, and 0 otherwise
+		/// Was-a-proxy flag. Set to 1 if class was not loaded when this DXF file was created, and 0 otherwise
 		/// </summary>
 		[DxfCodeValue(280)]
 		public bool WasZombie { get; set; }
 
 		/// <summary>
-		/// Is-an-entity flag.Set to 1 if class was derived from the AcDbEntity class and can reside in the BLOCKS or ENTITIES section.If 0, instances may appear only in the OBJECTS section
+		/// Is-an-entity flag.
+		/// Set to 1 if class was derived from the AcDbEntity class and can reside in the BLOCKS or ENTITIES section.
+		/// If 0, instances may appear only in the OBJECTS section
 		/// </summary>
 		[DxfCodeValue(281)]
 		public bool IsAnEntity { get; set; }
@@ -54,11 +56,11 @@ public class DxfClass
 		/// <summary>
 		/// Item class id
 		/// </summary>
-		public short ItemClassId { get; set; }
+		internal short ItemClassId { get; set; }
 
 		public ACadVersion DwgVersion { get; set; }
 
-		public short MaintenanceVersion { get; set; }
+		internal short MaintenanceVersion { get; set; }
 
 		/// <inheritdoc/>
 		public override string ToString()

ACadSharp/Entities/UnknownEntity.cs

@@ -0,0 +1,32 @@
+using ACadSharp.Classes;
+
+namespace ACadSharp.Entities
+{
+	/// <summary>
+	/// Class that holds the basic information for an unknown entity
+	/// </summary>
+	/// <remarks>
+	/// Unknown entities may appear in the <see cref="CadDocument"/> if the dwg file contains proxies or entities not yet supported by ACadSharp
+	/// </remarks>
+	public class UnknownEntity : Entity
+	{
+		/// <inheritdoc/>
+		public override ObjectType ObjectType => ObjectType.UNDEFINED;
+
+		/// <inheritdoc/>
+		public override string ObjectName => this.DxfClass.DxfName;
+
+		/// <inheritdoc/>
+		public override string SubclassMarker => this.DxfClass.CppClassName;
+
+		/// <summary>
+		/// Dxf class linked to this entity
+		/// </summary>
+		public DxfClass DxfClass { get; }
+
+		internal UnknownEntity(DxfClass dxfClass)
+		{
+			this.DxfClass = dxfClass;
+		}
+	}
+}

ACadSharp/IO/CadDocumentBuilder.cs

@@ -92,7 +92,7 @@ public T GetCadObject<T>(ulong? handle) where T : CadObject
 			return null;
 		}
 
-		public bool TryGetCadObject<T>(ulong? handle, out T value) where T : CadObject
+		public virtual bool TryGetCadObject<T>(ulong? handle, out T value) where T : CadObject
 		{
 			if (!handle.HasValue)
 			{
@@ -120,6 +120,7 @@ public bool TryGetTableEntry<T>(string name, out T entry)
 			return entry != null;
 		}
 
+		[Obsolete]
 		public T GetObjectTemplate<T>(ulong handle) where T : CadTemplate
 		{
 			if (this.templates.TryGetValue(handle, out CadTemplate builder))

ACadSharp/IO/DWG/DwgDocumentBuilder.cs

@@ -1,6 +1,8 @@
-using ACadSharp.IO.Templates;
+using ACadSharp.Entities;
+using ACadSharp.IO.Templates;
 using ACadSharp.Tables;
 using ACadSharp.Tables.Collections;
+using System;
 using System.Collections.Generic;
 
 namespace ACadSharp.IO.DWG
@@ -13,6 +15,8 @@ internal class DwgDocumentBuilder : CadDocumentBuilder
 
 		public List<CadBlockRecordTemplate> BlockRecordTemplates { get; set; } = new List<CadBlockRecordTemplate>();
 
+		public List<UnknownEntity> UnknownEntities { get; } = new();
+
 		public DwgDocumentBuilder(CadDocument document, DwgReaderConfiguration configuration)
 			: base(document)
 		{
@@ -41,5 +45,18 @@ public override void BuildDocument()
 
 			base.BuildDocument();
 		}
+
+		public override bool TryGetCadObject<T>(ulong? handle, out T value)
+		{
+			bool result = base.TryGetCadObject(handle, out value);
+
+			if (value is UnknownEntity && !this.Configuration.KeepUnknownEntities)
+			{
+				value = null;
+				result = false;
+			}
+
+			return result;
+		}
 	}
 }

ACadSharp/IO/DWG/DwgReaderConfiguration.cs

@@ -3,12 +3,21 @@
 	public class DwgReaderConfiguration : CadReaderConfiguration
 	{
 		/// <summary>
-		/// Use the Standard Cycling Redundancy Check to verify the integrity of the file.
+		/// Use the Standard Cycling Redundancy Check to verify the integrity of the file, default value is set to false.
 		/// </summary>
 		/// <remarks>
 		/// DWG file format uses a modification of a standard Cyclic Redundancy Check as an error detecting mechanism, 
 		/// if this flag is enabled the reader will perform this verification to detect any possible error, but it will greatly increase the reading time.
 		/// </remarks>
 		public bool CrcCheck { get; set; } = false;
+
+		/// <summary>
+		/// The reader will try to read and add to the document all <see cref="ObjectType.UNLISTED"/> that are linked to a <see cref="Classes. DxfClass"/> 
+		/// which may be a proxy or an entity that is not yet supported by ACadSharp, default value is set to false.
+		/// </summary>
+		/// <remarks>
+		/// These entities do not contain any geometric information and will be ignored by the writers
+		/// </remarks>
+		public bool KeepUnknownEntities { get; set; } = false;
 	}
 }

ACadSharp/IO/DWG/DwgStreamReaders/DwgClassesReader.cs

@@ -92,6 +92,18 @@ public DxfClassCollection Read(IDwgStreamReader sreader)
 				dxfClass.WasZombie = sreader.ReadBit();
 				//BS : itemclassid -- 0x1F2 for classes which produce entities, 0x1F3 for classes which produce objects.
 				dxfClass.ItemClassId = sreader.ReadBitShort();
+				if (dxfClass.ItemClassId == 0x1F2)
+				{
+					dxfClass.IsAnEntity = true;
+				}
+				else if (dxfClass.ItemClassId == 0x1F3)
+				{
+					dxfClass.IsAnEntity = false;
+				}
+				else
+				{
+					this.notify($"Invalid DxfClass id value: {dxfClass.ItemClassId} for {dxfClass.CppClassName}", NotificationType.Error);
+				}
 
 				if (this._fileHeader.AcadVersion >= ACadVersion.AC1018)
 				{

ACadSharp/IO/DWG/DwgStreamReaders/DwgObjectReader.cs

@@ -696,7 +696,7 @@ private CadTemplate readObject(ObjectType type)
 
 			switch (type)
 			{
-				case ObjectType.UNUSED:
+				case ObjectType.UNDEFINED:
 					break;
 				case ObjectType.TEXT:
 					template = this.readText();
@@ -1041,14 +1041,34 @@ private CadTemplate readUnlistedType(short classNumber)
 					break;
 			}
 
+			if (template == null && c.IsAnEntity)
+			{
+				template = this.readUnknownEntity(c);
+				this._builder.Notify($"Unlisted object with DXF name {c.DxfName} has been read as an UnknownEntity", NotificationType.Warning);
+			}
+
 			if (template == null)
+			{
 				this._builder.Notify($"Unlisted object not implemented, DXF name: {c.DxfName}", NotificationType.NotImplemented);
+			}
 
 			return template;
 		}
 
 		#region Text entities
 
+		private CadTemplate readUnknownEntity(DxfClass dxfClass)
+		{
+			UnknownEntity entity = new UnknownEntity(dxfClass);
+			CadUnknownEntityTemplate template = new CadUnknownEntityTemplate(entity);
+
+			this._builder.UnknownEntities.Add(entity);
+
+			this.readCommonEntityData(template);
+
+			return template;
+		}
+
 		private CadTemplate readText()
 		{
 			TextEntity text = new TextEntity();

ACadSharp/IO/DWG/DwgStreamWriters/DwgObjectWriter.Common.cs

@@ -126,7 +126,7 @@ private void writeCommonData(CadObject cadObject)
 					}
 					break;
 				case ObjectType.INVALID:
-				case ObjectType.UNUSED:
+				case ObjectType.UNDEFINED:
 					this.notify($"CadObject type: {cadObject.ObjectType} fullname: {cadObject.GetType().FullName}", NotificationType.NotImplemented);
 					return;
 				default:

ACadSharp/IO/DWG/DwgStreamWriters/DwgObjectWriter.Entities.cs

@@ -16,6 +16,7 @@ private void writeEntity(Entity entity)
 			//Ignored Entities
 			switch (entity)
 			{
+				case UnknownEntity:
 				case AttributeEntity:
 				case Shape:
 				case Solid3D:
@@ -859,7 +860,7 @@ private void writeHatch(Hatch hatch)
 					for (var i = 0; i < pline.Vertices.Count; ++i)
 					{
 						var vertex = pline.Vertices[i];
-						var bulge  = pline.Bulges[i];
+						var bulge = pline.Bulges[i];
 
 						this._writer.Write2RawDouble(new XY(vertex.X, vertex.Y));
 						if (pline.HasBulge)

ACadSharp/IO/DXF/DxfStreamWriter/DxfSectionWriterBase.Entities.cs

@@ -18,6 +18,7 @@ protected void writeEntity<T>(T entity)
 				case Solid3D:
 				case MultiLeader:
 				case Wipeout:
+				case UnknownEntity:
 					this.notify($"Entity type not implemented : {entity.GetType().FullName}", NotificationType.NotImplemented);
 					return;
 			}

ACadSharp/IO/Templates/CadBlockRecordTemplate.cs

@@ -40,25 +40,18 @@ public override void Build(CadDocumentBuilder builder)
 
 			if (this.FirstEntityHandle.HasValue)
 			{
-				var entities = this.getEntitiesCollection<Entity>(builder, this.FirstEntityHandle.Value, this.LastEntityHandle.Value);
-				this.CadObject.Entities.AddRange(entities);
+				foreach (Entity e in this.getEntitiesCollection<Entity>(builder, this.FirstEntityHandle.Value, this.LastEntityHandle.Value))
+				{
+					this.addEntity(e);
+				}
 			}
 			else
 			{
 				foreach (ulong handle in this.OwnedObjectsHandlers)
 				{
 					if (builder.TryGetCadObject<Entity>(handle, out Entity child))
 					{
-						switch (child)
-						{
-							case Viewport viewport:
-								this.CadObject.Viewports.Add(viewport);
-								break;
-							default:
-								this.CadObject.Entities.Add(child);
-								break;
-						}
-
+						this.addEntity(child);
 					}
 				}
 			}
@@ -87,5 +80,18 @@ public void SetBlockToRecord(CadDocumentBuilder builder)
 				this.CadObject.BlockEnd = blockEnd;
 			}
 		}
+
+		private void addEntity(Entity entity)
+		{
+			switch (entity)
+			{
+				case Viewport viewport:
+					this.CadObject.Viewports.Add(viewport);
+					break;
+				default:
+					this.CadObject.Entities.Add(entity);
+					break;
+			}
+		}
 	}
 }

ACadSharp/IO/Templates/CadTemplate.cs

@@ -80,7 +80,6 @@ protected IEnumerable<T> getEntitiesCollection<T>(CadDocumentBuilder builder, ul
 					template = builder.GetObjectTemplate<CadEntityTemplate>(template.NextEntity.Value);
 				else
 					template = builder.GetObjectTemplate<CadEntityTemplate>(template.CadObject.Handle + 1);
-
 			}
 
 			return collection;
@@ -99,6 +98,7 @@ protected bool getTableReference<T>(CadDocumentBuilder builder, ulong? handle, s
 				{
 					builder.Notify($"{typeof(T).FullName} table reference with handle: {handle} | name: {name} not found for {this.CadObject.GetType().FullName} with handle {this.CadObject.Handle}", NotificationType.Warning);
 				}
+
 				return false;
 			}
 		}

ACadSharp/IO/Templates/CadUnknownEntityTemplate.cs

@@ -0,0 +1,9 @@
+using ACadSharp.Entities;
+
+namespace ACadSharp.IO.Templates
+{
+	internal class CadUnknownEntityTemplate : CadEntityTemplate
+	{
+		public CadUnknownEntityTemplate(UnknownEntity entity) : base(entity) { }
+	}
+}

ACadSharp/Types/ObjectType.cs

@@ -7,7 +7,7 @@ public enum ObjectType : short
 	{
 		UNLISTED = -999,
 		INVALID = -1,
-		UNUSED = 0,
+		UNDEFINED = 0,
 
 		TEXT = 1,
 		ATTRIB = 2,