From b6585292fb3f981ff1bf15059ff0708c78ff41ec Mon Sep 17 00:00:00 2001
From: Eliot Jones <elioty@hotmail.co.uk>
Date: Sat, 21 Apr 2018 16:24:37 +0100
Subject: [PATCH] start adding support for reading and applying XObjects

---
 .../Integration/PigProductionHandbookTests.cs | 12 ++++++++
 .../Content/ResourceContainer.cs              | 15 ++++++++++
 .../Graphics/Operations/InvokeNamedXObject.cs | 28 +++++++++++++++++++
 ...ReflectionGraphicsStateOperationFactory.cs |  6 +++-
 4 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 src/UglyToad.PdfPig/Graphics/Operations/InvokeNamedXObject.cs

diff --git a/src/UglyToad.PdfPig.Tests/Integration/PigProductionHandbookTests.cs b/src/UglyToad.PdfPig.Tests/Integration/PigProductionHandbookTests.cs
index ea20bb48..67ec57d8 100644
--- a/src/UglyToad.PdfPig.Tests/Integration/PigProductionHandbookTests.cs
+++ b/src/UglyToad.PdfPig.Tests/Integration/PigProductionHandbookTests.cs
@@ -24,6 +24,18 @@
             }
         }
 
+        [Fact]
+        public void CanReadPage9()
+        {
+            using (var document = PdfDocument.Open(GetFilename()))
+            {
+                var page = document.GetPage(9);
+
+                // TODO: This page requires a CFF font parser for Type 1 fonts, see 5.5.1
+                Assert.Contains("BreedsNative breeds of pig can be found throughout the country. They are a small body size compared to other exotic and crosses pig types. There name varies from region to region, for example", page.Text);
+            }
+        }
+
         [Fact]
         public void HasCorrectNumberOfPages()
         {
diff --git a/src/UglyToad.PdfPig/Content/ResourceContainer.cs b/src/UglyToad.PdfPig/Content/ResourceContainer.cs
index 9a321039..468fe814 100644
--- a/src/UglyToad.PdfPig/Content/ResourceContainer.cs
+++ b/src/UglyToad.PdfPig/Content/ResourceContainer.cs
@@ -30,6 +30,21 @@
                 
                 LoadFontDictionary(fontDictionary, isLenientParsing);
             }
+
+            if (resourceDictionary.TryGet(NameToken.Xobject, out var xobjectBase))
+            {
+                var xobjectDictionary = DirectObjectFinder.Get<DictionaryToken>(xobjectBase, scanner);
+
+                foreach (var pair in xobjectDictionary.Data)
+                {
+                    if (!(pair.Value is IndirectReferenceToken reference))
+                    {
+                        throw new InvalidOperationException($"Expected the XObject dictionary value for key /{pair.Key} to be an indirect reference, instead got: {pair.Value}.");
+                    }
+
+                    currentResourceState[NameToken.Create(pair.Key)] = reference.Data;
+                }
+            }
         }
 
         private void LoadFontDictionary(DictionaryToken fontDictionary, bool isLenientParsing)
diff --git a/src/UglyToad.PdfPig/Graphics/Operations/InvokeNamedXObject.cs b/src/UglyToad.PdfPig/Graphics/Operations/InvokeNamedXObject.cs
new file mode 100644
index 00000000..3f877ce8
--- /dev/null
+++ b/src/UglyToad.PdfPig/Graphics/Operations/InvokeNamedXObject.cs
@@ -0,0 +1,28 @@
+namespace UglyToad.PdfPig.Graphics.Operations
+{
+    using Content;
+    using Tokenization.Tokens;
+
+    internal class InvokeNamedXObject : IGraphicsStateOperation
+    {
+        public const string Symbol = "Do";
+
+        public string Operator => Symbol;
+
+        public NameToken Name { get; }
+
+        public InvokeNamedXObject(NameToken name)
+        {
+            Name = name;
+        }
+
+        public void Run(IOperationContext operationContext, IResourceStore resourceStore)
+        {
+        }
+
+        public override string ToString()
+        {
+            return $"{Name} {Symbol}";
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/UglyToad.PdfPig/Graphics/ReflectionGraphicsStateOperationFactory.cs b/src/UglyToad.PdfPig/Graphics/ReflectionGraphicsStateOperationFactory.cs
index b7b601fb..04b44cb3 100644
--- a/src/UglyToad.PdfPig/Graphics/ReflectionGraphicsStateOperationFactory.cs
+++ b/src/UglyToad.PdfPig/Graphics/ReflectionGraphicsStateOperationFactory.cs
@@ -163,7 +163,11 @@ namespace UglyToad.PdfPig.Graphics
                 {
                     if (operands[offset] is NameToken name)
                     {
-                        arguments.Add(name.Data);
+                        arguments.Add(name);
+                    }
+                    else if (operands[offset] is StringToken s)
+                    {
+                        arguments.Add(NameToken.Create(s.Data));
                     }
                     else
                     {