Fix bounding box for artifact

Add tests

src/UglyToad.PdfPig.Tests/Integration/MarkedContentExtractionTests.cs

@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using UglyToad.PdfPig.Content;
+using Xunit;
+
+namespace UglyToad.PdfPig.Tests.Integration
+{
+    public class MarkedContentExtractionTests
+    {
+        private const string FileName1 = "Multiple Page - from Mortality Statistics.pdf";
+        private const string FileName2 = "68-1990-01_A.pdf";
+
+        [Fact]
+        public void CanIncrementIndex()
+        {
+            using (var document = PdfDocument.Open(GetPath1()))
+            {
+                var page = document.GetPage(2);
+                var mcs = page.GetMarkedContents();
+
+                Assert.NotEmpty(mcs);
+
+                Assert.Equal(37, mcs.Count);
+
+                for (int i = 0; i < mcs.Count; i++)
+                {
+                    Assert.Equal(i, mcs[i].Index);
+                }
+            }
+        }
+
+        [Fact]
+        public void CanGetTree()
+        {
+            using (var document = PdfDocument.Open(GetPath2()))
+            {
+                var page = document.GetPage(10);
+                var mcs = page.GetMarkedContents();
+
+                Assert.NotEmpty(mcs);
+                Assert.Equal(86, mcs.Count);
+
+                int index = 8;
+                var mc = mcs[index];
+                Assert.Equal(1, mc.Children.Count);
+                Assert.Equal(index, mc.Index);
+                Assert.NotEmpty(mc.Children);
+                Assert.Equal(index, mc.Children[0].Index);
+                Assert.DoesNotContain(mc.Children[0], mcs);
+
+                index = 9;
+                mc = mcs[index];
+                Assert.Equal(1, mc.Children.Count);
+                Assert.Equal(index, mc.Index);
+                Assert.NotEmpty(mc.Children);
+                Assert.Equal(index, mc.Children[0].Index);
+                Assert.DoesNotContain(mc.Children[0], mcs);
+
+                index = 75;
+                mc = mcs[index];
+                Assert.Equal(1, mc.Children.Count);
+                Assert.Equal(index, mc.Index);
+                Assert.NotEmpty(mc.Children);
+                Assert.Equal(index, mc.Children[0].Index);
+                Assert.DoesNotContain(mc.Children[0], mcs);
+            }
+        }
+
+        [Fact]
+        public void CanGetArtifact()
+        {
+            using (var document = PdfDocument.Open(GetPath1()))
+            {
+                var page = document.GetPage(2);
+                var mcs = page.GetMarkedContents();
+
+                Assert.NotEmpty(mcs);
+
+                var content = mcs[0];
+                Assert.True(content.IsArtifact);
+                Assert.Equal(typeof(ArtifactMarkedContentElement), content.GetType());
+                var artifact = (ArtifactMarkedContentElement)mcs[0];
+
+                Assert.Equal(-1, artifact.MarkedContentIdentifier);
+
+                Assert.True(artifact.IsTopAttached);
+                Assert.False(artifact.IsRightAttached);
+                Assert.False(artifact.IsLeftAttached);
+                Assert.False(artifact.IsBottomAttached);
+
+                Assert.True(artifact.BoundingBox.HasValue);
+                Assert.Equal(89.03, artifact.BoundingBox.Value.BottomLeft.X);
+                Assert.Equal(717.756, artifact.BoundingBox.Value.BottomLeft.Y);
+                Assert.Equal(574.422, artifact.BoundingBox.Value.TopRight.X);
+                Assert.Equal(751.1398, artifact.BoundingBox.Value.TopRight.Y);
+
+                Assert.Equal(ArtifactMarkedContentElement.ArtifactType.Pagination, artifact.Type);
+                Assert.Equal("Header", artifact.SubType);
+
+                Assert.Equal(33, artifact.Letters.Count);
+                Assert.Equal(8, artifact.Paths.Count);
+                Assert.Equal(0, artifact.Images.Count);
+            }
+        }
+
+        private static string GetPath1() => IntegrationHelpers.GetDocumentPath(FileName1);
+        private static string GetPath2() => IntegrationHelpers.GetDocumentPath(FileName2);
+    }
+}

src/UglyToad.PdfPig/Graphics/MarkedContentStack.cs

@@ -152,13 +152,27 @@
                 var attributeOwners = GetOptional(NameToken.O, pdfScanner);
 
                 var boundingBox = default(PdfRectangle?);
-                if (properties.TryGet(NameToken.Bbox, pdfScanner, out ArrayToken arrayToken)
+                if (properties.TryGet(NameToken.Bbox, pdfScanner, out ArrayToken arrayToken))
-                    && arrayToken.Length == 6)
                 {
-                    var left = arrayToken[2] as NumericToken;
+                    NumericToken left = null;
-                    var bottom = arrayToken[3] as NumericToken;
+                    NumericToken bottom = null;
-                    var right = arrayToken[4] as NumericToken;
+                    NumericToken right = null;
-                    var top = arrayToken[5] as NumericToken;
+                    NumericToken top = null;
+
+                    if (arrayToken.Length == 4)
+                    {
+                        left = arrayToken[0] as NumericToken;
+                        bottom = arrayToken[1] as NumericToken;
+                        right = arrayToken[2] as NumericToken;
+                        top = arrayToken[3] as NumericToken;
+                    }
+                    else if (arrayToken.Length == 6)
+                    {
+                        left = arrayToken[2] as NumericToken;
+                        bottom = arrayToken[3] as NumericToken;
+                        right = arrayToken[4] as NumericToken;
+                        top = arrayToken[5] as NumericToken;
+                    }
 
                     if (left != null && bottom != null && right != null && top != null)
                     {