FOP-3264: Footnote accessibility should use reference type

Author: simonsteiner1984

fop-core/src/main/java/org/apache/fop/pdf/PDFStructElem.java

@@ -267,6 +267,9 @@ public List<PDFObject> getKids() {
     }
 
     public int output(OutputStream stream) throws IOException {
+        if (structureType == StandardStructureTypes.InlineLevelStructure.NOTE) {
+            put("ID", "Note ID " + getObjectNumber().getNumber());
+        }
         if (getDocument() != null && getDocument().getProfile().getPDFUAMode().isEnabled()) {
             if (entries.containsKey("Alt") && "".equals(get("Alt"))) {
                 put("Alt", "No alternate text specified");

fop-core/src/main/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java

@@ -94,8 +94,8 @@ public class PDFStructureTreeBuilder implements StructureTreeEventHandler {
         addBuilder("basic-link",                new LinkBuilder());
         // Out-of-Line Formatting Objects
         addBuilder("float",                     StandardStructureTypes.Grouping.DIV);
-        addBuilder("footnote",                  StandardStructureTypes.InlineLevelStructure.NOTE);
-        addBuilder("footnote-body",             StandardStructureTypes.Grouping.SECT);
+        addBuilder("footnote",                  StandardStructureTypes.InlineLevelStructure.REFERENCE);
+        addBuilder("footnote-body",             StandardStructureTypes.InlineLevelStructure.NOTE);
         // Other Formatting Objects
         addBuilder("wrapper",                   StandardStructureTypes.InlineLevelStructure.SPAN);
         addBuilder("marker",                    StandardStructureTypes.Grouping.PRIVATE);

fop-core/src/test/java/org/apache/fop/pdf/PDFStructureTreeTestCase.java

@@ -91,4 +91,31 @@ private ByteArrayOutputStream foToOutput(String fo)
         transformer.transform(src, res);
         return bos;
     }
+
+    @Test
+    public void testFootnote() throws Exception {
+        String fo = "<fo:root xmlns:fo=\"http://www.w3.org/1999/XSL/Format\">\n"
+                + "  <fo:layout-master-set>\n"
+                + "    <fo:simple-page-master master-name=\"simple\" page-height=\"27.9cm\" page-width=\"21.6cm\">\n"
+                + "      <fo:region-body />\n"
+                + "    </fo:simple-page-master>\n"
+                + "  </fo:layout-master-set>\n"
+                + "  <fo:page-sequence master-reference=\"simple\">\n"
+                + "    <fo:flow flow-name=\"xsl-region-body\">\n"
+                + "      <fo:block>Text<fo:footnote>\n"
+                + "      <fo:inline>1</fo:inline>\n"
+                + "      <fo:footnote-body>\n"
+                + "         <fo:block>footnote</fo:block>\n"
+                + "          </fo:footnote-body>\n"
+                + "        </fo:footnote>\n"
+                + "      </fo:block>\n"
+                + "    </fo:flow>\n"
+                + "  </fo:page-sequence>\n"
+                + "</fo:root>\n";
+        ByteArrayOutputStream bos = foToOutput(fo);
+        String pdf = bos.toString();
+        Assert.assertTrue(pdf.contains("/ID (Note ID "));
+        Assert.assertTrue(pdf.contains("/S /Note"));
+        Assert.assertTrue(pdf.contains("/S /Reference"));
+    }
 }