Bugzilla #53596: When PDF accessibility is enabled, the structure tree must contain information about the number of columns or rows spanned by a table cell.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1365162 13f79535-47bb-0310-9956-ffa450edef68

4 files changed, 63 insertions, 5 deletions

diff --git a/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java b/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
index 51f7f2bed..7e3ed0591 100644
--- a/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
+++ b/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
@@ -221,14 +221,17 @@ class StructureTreeEventTrigger extends FOEventHandler {
     @Override
     public void startCell(TableCell tc) {
         AttributesImpl attributes = new AttributesImpl();
-        int colSpan = tc.getNumberColumnsSpanned();
-        if (colSpan > 1) {
-            addNoNamespaceAttribute(attributes, "number-columns-spanned",
-                    Integer.toString(colSpan));
-        }
+        addSpanAttribute(attributes, "number-columns-spanned", tc.getNumberColumnsSpanned());
+        addSpanAttribute(attributes, "number-rows-spanned", tc.getNumberRowsSpanned());
         startElement(tc, attributes);
     }
 
+    private void addSpanAttribute(AttributesImpl attributes, String attributeName, int span) {
+        if (span > 1) {
+            addNoNamespaceAttribute(attributes, attributeName, Integer.toString(span));
+        }
+    }
+
     @Override
     public void endCell(TableCell tc) {
         endElement(tc);
diff --git a/src/java/org/apache/fop/pdf/PDFArray.java b/src/java/org/apache/fop/pdf/PDFArray.java
index 131830328..78f5d080b 100644
--- a/src/java/org/apache/fop/pdf/PDFArray.java
+++ b/src/java/org/apache/fop/pdf/PDFArray.java
@@ -100,6 +100,15 @@ public class PDFArray extends PDFObject {
     }
 
     /**
+     * Creates an array object made of the given elements.
+     *
+     * @param elements the array content
+     */
+    public PDFArray(List<?> elements) {
+        this(null, elements);
+    }
+
+    /**
      * Create the array object
      * @param parent the array's parent if any
      * @param values the actual array wrapped by this object
diff --git a/src/java/org/apache/fop/pdf/PDFStructElem.java b/src/java/org/apache/fop/pdf/PDFStructElem.java
index 8030e53db..2a756fe9b 100644
--- a/src/java/org/apache/fop/pdf/PDFStructElem.java
+++ b/src/java/org/apache/fop/pdf/PDFStructElem.java
@@ -33,6 +33,8 @@ import org.apache.fop.util.LanguageTags;
  */
 public class PDFStructElem extends PDFDictionary implements StructureTreeElement, CompressedObject {
 
+    private static final PDFName TABLE = new PDFName("Table");
+
     private PDFStructElem parentElement;
 
     /**
@@ -40,6 +42,8 @@ public class PDFStructElem extends PDFDictionary implements StructureTreeElement
      */
     protected List<PDFObject> kids;
 
+    private List<PDFDictionary> attributes;
+
     /**
      * Creates a new structure element.
      *
@@ -143,9 +147,21 @@ public class PDFStructElem extends PDFDictionary implements StructureTreeElement
     @Override
     protected void writeDictionary(OutputStream out, StringBuilder textBuffer) throws IOException {
         attachKids();
+        attachAttributes();
         super.writeDictionary(out, textBuffer);
     }
 
+    private void attachAttributes() {
+        if (attributes != null) {
+            if (attributes.size() == 1) {
+                put("A", attributes.get(0));
+            } else {
+                PDFArray array = new PDFArray(attributes);
+                put("A", array);
+            }
+        }
+    }
+
     /**
      * Attaches all valid kids to the kids array.
      *
@@ -175,6 +191,24 @@ public class PDFStructElem extends PDFDictionary implements StructureTreeElement
         return kidsAttached;
     }
 
+    public void setTableAttributeColSpan(int colSpan) {
+        setTableAttributeRowColumnSpan("ColSpan", colSpan);
+    }
+
+    public void setTableAttributeRowSpan(int rowSpan) {
+        setTableAttributeRowColumnSpan("RowSpan", rowSpan);
+    }
+
+    private void setTableAttributeRowColumnSpan(String typeSpan, int span) {
+        PDFDictionary attribute = new PDFDictionary();
+        attribute.put("O", TABLE);
+        attribute.put(typeSpan, span);
+        if (attributes == null) {
+            attributes = new ArrayList<PDFDictionary>(2);
+        }
+        attributes.add(attribute);
+    }
+
     /**
      * Class representing a placeholder for a PDF Structure Element.
      */
diff --git a/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java b/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java
index 3839d47bc..0f8e74515 100644
--- a/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java
+++ b/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java
@@ -90,11 +90,23 @@ class PDFStructureTreeBuilder implements StructureTreeEventHandler {
         PDFStructElem parent = ancestors.getFirst();
         String role = attributes.getValue("role");
         PDFStructElem structElem = createStructureElement(name, parent, role);
+        setSpanAttributes(structElem, attributes);
         parent.addKid(structElem);
         ancestors.addFirst(structElem);
         return structElem;
     }
 
+    private void setSpanAttributes(PDFStructElem structElem, Attributes attributes) {
+        String columnSpan = attributes.getValue("number-columns-spanned");
+        if (columnSpan != null) {
+            structElem.setTableAttributeColSpan(Integer.parseInt(columnSpan));
+        }
+        String rowSpan = attributes.getValue("number-rows-spanned");
+        if (rowSpan != null) {
+            structElem.setTableAttributeRowSpan(Integer.parseInt(rowSpan));
+        }
+    }
+
     public void endNode(String name) {
         removeFirstAncestor();
     }