Fix for ClassCastException when using PdfA

The test in this commit shows the class cast exception when using background color with PdfA. The change to AbstractRenderer shows a "fix", however I really doubt this is a correct fix for this issue.

Test to show problem with background color in PdfA

Fix to abstract renderer for class cast exception... Note I do not believe this is the correct fix :)

Author: eamonnmoloney

layout/src/main/java/com/itextpdf/layout/renderer/AbstractRenderer.java

@@ -294,7 +294,19 @@ public PdfFont getPropertyAsFont(int property) {
      * @return a {@link Color}
      */
     public Color getPropertyAsColor(int property) {
-        return this.<Color>getProperty(property);
+        Object object = getProperty(property);
+
+        if(object == null) {
+            return null;
+        }
+
+        if(object instanceof Color) {
+            return (Color) object;
+        } else if (object instanceof Background) {
+            return ((Background)object).getColor();
+        }
+
+        throw new IllegalStateException("The type of property is unexpected.. property: " + property + ", class: " + object.getClass());
     }
 
     /**

layout/src/test/java/com/itextpdf/layout/BackgroundColorTest.java

@@ -0,0 +1,68 @@
+package com.itextpdf.layout;
+
+import com.itextpdf.kernel.color.Color;
+import com.itextpdf.kernel.pdf.PdfDocument;
+import com.itextpdf.kernel.pdf.PdfWriter;
+import com.itextpdf.kernel.utils.CompareTool;
+import com.itextpdf.kernel.xmp.XMPException;
+import com.itextpdf.layout.element.Paragraph;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+import com.itextpdf.layout.element.Text;
+import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.test.annotations.type.IntegrationTest;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.rules.ExpectedException;
+
+
+@Category(IntegrationTest.class)
+public class BackgroundColorTest extends ExtendedITextTest {
+
+    public static final String sourceFolder = "./src/test/resources/com/itextpdf/layout/BackgroundColorTest/";
+    public static final String destinationFolder = "./target/test/com/itextpdf/layout/BackgroundColorTest/";
+    public static final String cmpPrefix = "cmp_";
+
+    String fileName;
+    String outFileName;
+    String cmpFileName;
+
+    @BeforeClass
+    public static void beforeClass() {
+        createDestinationFolder(destinationFolder);
+    }
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    @Test
+    public void shouldAddBackgroundColorAttributeToAccessiblityWhenBackgroundColorIsSet() throws IOException, XMPException, InterruptedException {
+        fileName = "simpleBackgroundColorTest.pdf";
+        outFileName = destinationFolder + fileName;
+        cmpFileName = sourceFolder + cmpPrefix + fileName;
+
+        PdfDocument pdfDocument = new PdfDocument(new PdfWriter(new FileOutputStream(outFileName)));
+        pdfDocument.setTagged();
+        Document doc = new Document(pdfDocument);
+
+        Text foo = new Text("foo");
+        foo.setBackgroundColor(Color.BLUE);
+        doc.add(new Paragraph(foo));
+
+        closeDocumentAndCompareOutputs(doc);
+    }
+
+    private void closeDocumentAndCompareOutputs(Document document) throws IOException, InterruptedException {
+        document.close();
+        String compareResult = new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder, "diff");
+        if (compareResult != null) {
+            Assert.fail(compareResult);
+        }
+    }
+}
+