Bugzilla #53902: Added possibility to define 'header' table columns (the same way as fo:table-header allows to define header rows).

When accessibility is enabled, this allows to set the appropriate Scope attribute on the corresponding TH cells.


git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1390412 13f79535-47bb-0310-9956-ffa450edef68

7 files changed, 71 insertions, 18 deletions

diff --git a/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java b/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
index 93b815d30..09a814ef5 100644
--- a/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
+++ b/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
@@ -20,6 +20,7 @@
 package org.apache.fop.accessibility.fo;
 
 import java.util.Locale;
+import java.util.Stack;
 
 import org.xml.sax.SAXException;
 import org.xml.sax.helpers.AttributesImpl;
@@ -30,6 +31,7 @@ import org.apache.fop.fo.FOEventHandler;
 import org.apache.fop.fo.FONode;
 import org.apache.fop.fo.FOText;
 import org.apache.fop.fo.extensions.ExtensionElementMapping;
+import org.apache.fop.fo.extensions.InternalElementMapping;
 import org.apache.fop.fo.flow.AbstractGraphics;
 import org.apache.fop.fo.flow.BasicLink;
 import org.apache.fop.fo.flow.Block;
@@ -70,6 +72,10 @@ class StructureTreeEventTrigger extends FOEventHandler {
 
     private LayoutMasterSet layoutMasterSet;
 
+    private final Stack<Table> tables = new Stack<Table>();
+
+    private final Stack<Boolean> inTableHeader = new Stack<Boolean>();
+
     public StructureTreeEventTrigger(StructureTreeEventHandler structureTreeEventHandler) {
         this.structureTreeEventHandler = structureTreeEventHandler;
     }
@@ -195,42 +201,51 @@ class StructureTreeEventTrigger extends FOEventHandler {
 
     @Override
     public void startTable(Table tbl) {
+        tables.push(tbl);
         startElement(tbl);
     }
 
     @Override
     public void endTable(Table tbl) {
         endElement(tbl);
+        tables.pop();
     }
 
     @Override
     public void startHeader(TableHeader header) {
+        inTableHeader.push(Boolean.TRUE);
         startElement(header);
     }
 
     @Override
     public void endHeader(TableHeader header) {
         endElement(header);
+        inTableHeader.pop();
     }
 
     @Override
     public void startFooter(TableFooter footer) {
+        // TODO Shouldn't it be true?
+        inTableHeader.push(Boolean.FALSE);
         startElement(footer);
     }
 
     @Override
     public void endFooter(TableFooter footer) {
         endElement(footer);
+        inTableHeader.pop();
     }
 
     @Override
     public void startBody(TableBody body) {
+        inTableHeader.push(Boolean.FALSE);
         startElement(body);
     }
 
     @Override
     public void endBody(TableBody body) {
         endElement(body);
+        inTableHeader.pop();
     }
 
     @Override
@@ -248,6 +263,24 @@ class StructureTreeEventTrigger extends FOEventHandler {
         AttributesImpl attributes = new AttributesImpl();
         addSpanAttribute(attributes, "number-columns-spanned", tc.getNumberColumnsSpanned());
         addSpanAttribute(attributes, "number-rows-spanned", tc.getNumberRowsSpanned());
+        boolean rowHeader = inTableHeader.peek();
+        boolean columnHeader = tables.peek().getColumn(tc.getColumnNumber() - 1).isHeader();
+        if (rowHeader || columnHeader) {
+            final String th = "TH";
+            String role = tc.getCommonAccessibility().getRole();
+            /* Do not override a custom role */
+            if (role == null) {
+                role = th;
+                addNoNamespaceAttribute(attributes, "role", th);
+            }
+            if (role.equals(th)) {
+                if (columnHeader) {
+                    String scope = rowHeader ? "Both" : "Row";
+                    addAttribute(attributes, InternalElementMapping.URI, InternalElementMapping.SCOPE,
+                            InternalElementMapping.STANDARD_PREFIX, scope);
+                }
+            }
+        }
         startElement(tc, attributes);
     }
 
diff --git a/src/java/org/apache/fop/fo/Constants.java b/src/java/org/apache/fop/fo/Constants.java
index 2d10dcdd9..6688042e2 100644
--- a/src/java/org/apache/fop/fo/Constants.java
+++ b/src/java/org/apache/fop/fo/Constants.java
@@ -785,8 +785,11 @@ public interface Constants {
      */
     int PR_X_NUMBER_CONVERSION_FEATURES = 276;
 
+    /** Scope for table header */
+    int PR_X_HEADER_COLUMN = 277;
+
     /** Number of property constants defined */
-    int PROPERTY_COUNT = 276;
+    int PROPERTY_COUNT = 277;
 
     // compound property constants
 
diff --git a/src/java/org/apache/fop/fo/FOPropertyMapping.java b/src/java/org/apache/fop/fo/FOPropertyMapping.java
index d0d13fc17..a92b71ef9 100644
--- a/src/java/org/apache/fop/fo/FOPropertyMapping.java
+++ b/src/java/org/apache/fop/fo/FOPropertyMapping.java
@@ -2513,6 +2513,12 @@ public final class FOPropertyMapping implements Constants {
         m.setInherited(false);
         m.setDefault("false");
         addPropertyMaker("table-omit-header-at-break", m);
+
+        // fox:scope
+        m = new EnumProperty.Maker(PR_X_HEADER_COLUMN);
+        m.useGeneric(genericBoolean);
+        m.setDefault("false");
+        addPropertyMaker("fox:header", m);
     }
 
     private void createWritingModeProperties() {
diff --git a/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java b/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java
index f0e03399f..a040edf1a 100644
--- a/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java
+++ b/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java
@@ -52,6 +52,7 @@ public class ExtensionElementMapping extends ElementMapping {
         PROPERTY_ATTRIBUTES.add("disable-column-balancing");
         //These are FOP's extension properties for accessibility
         PROPERTY_ATTRIBUTES.add("alt-text");
+        PROPERTY_ATTRIBUTES.add("header");
     }
 
     /**
diff --git a/src/java/org/apache/fop/fo/extensions/InternalElementMapping.java b/src/java/org/apache/fop/fo/extensions/InternalElementMapping.java
index 687952d25..f257dd79d 100644
--- a/src/java/org/apache/fop/fo/extensions/InternalElementMapping.java
+++ b/src/java/org/apache/fop/fo/extensions/InternalElementMapping.java
@@ -43,12 +43,15 @@ public class InternalElementMapping extends ElementMapping {
     /** The "struct-ref" attribute, to refer to a structure tree element. */
     public static final String STRUCT_REF = "struct-ref";
 
+    public static final String SCOPE = "scope";
+
     private static final Set<String> PROPERTY_ATTRIBUTES = new java.util.HashSet<String>();
 
     static {
         //These are FOP's extension properties for accessibility
         PROPERTY_ATTRIBUTES.add(STRUCT_ID);
         PROPERTY_ATTRIBUTES.add(STRUCT_REF);
+        PROPERTY_ATTRIBUTES.add(SCOPE);
     }
 
     /**
diff --git a/src/java/org/apache/fop/fo/flow/table/TableColumn.java b/src/java/org/apache/fop/fo/flow/table/TableColumn.java
index 5047822da..33cbff884 100644
--- a/src/java/org/apache/fop/fo/flow/table/TableColumn.java
+++ b/src/java/org/apache/fop/fo/flow/table/TableColumn.java
@@ -24,6 +24,7 @@ import org.xml.sax.Locator;
 
 import org.apache.fop.apps.FOPException;
 import org.apache.fop.datatypes.Length;
+import org.apache.fop.fo.Constants;
 import org.apache.fop.fo.FONode;
 import org.apache.fop.fo.PropertyList;
 import org.apache.fop.fo.ValidationException;
@@ -44,6 +45,7 @@ public class TableColumn extends TableFObj {
     private Length columnWidth;
     private int numberColumnsRepeated;
     private int numberColumnsSpanned;
+    private boolean isHeader;
     // Unused but valid items, commented out for performance:
     //     private int visibility;
     // End of property values
@@ -120,6 +122,7 @@ public class TableColumn extends TableFObj {
         if (!this.implicitColumn) {
             this.pList = pList;
         }
+        isHeader = (pList.get(Constants.PR_X_HEADER_COLUMN).getEnum() == Constants.EN_TRUE);
     }
 
     /** {@inheritDoc} */
@@ -263,4 +266,13 @@ public class TableColumn extends TableFObj {
         this.pList = null;
     }
 
+    /**
+     * Returns {@code true} if this column is made of header cells.
+     *
+     * @return {@code true} if cells in this column are like TH cells in HTML
+     */
+    public boolean isHeader() {
+        return isHeader;
+    }
+
 }
diff --git a/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java b/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java
index 0d4a6b7fb..031224ffb 100644
--- a/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java
+++ b/src/java/org/apache/fop/render/pdf/PDFStructureTreeBuilder.java
@@ -30,6 +30,7 @@ import org.apache.fop.accessibility.StructureTreeElement;
 import org.apache.fop.accessibility.StructureTreeEventHandler;
 import org.apache.fop.events.EventBroadcaster;
 import org.apache.fop.fo.extensions.ExtensionElementMapping;
+import org.apache.fop.fo.extensions.InternalElementMapping;
 import org.apache.fop.fo.pagination.Flow;
 import org.apache.fop.pdf.PDFFactory;
 import org.apache.fop.pdf.PDFParentTree;
@@ -138,7 +139,7 @@ class PDFStructureTreeBuilder implements StructureTreeEventHandler {
             PDFStructElem structElem = createStructureElement(parent, structureType);
             setAttributes(structElem, attributes);
             addKidToParent(structElem, parent, attributes);
-            registerStructureElement(structElem, pdfFactory);
+            registerStructureElement(structElem, pdfFactory, attributes);
             return structElem;
         }
 
@@ -155,7 +156,8 @@ class PDFStructureTreeBuilder implements StructureTreeEventHandler {
             parent.addKid(kid);
         }
 
-        protected void registerStructureElement(PDFStructElem structureElement, PDFFactory pdfFactory) {
+        protected void registerStructureElement(PDFStructElem structureElement, PDFFactory pdfFactory,
+                Attributes attributes) {
             pdfFactory.getDocument().registerStructureElement(structureElement);
         }
 
@@ -240,22 +242,15 @@ class PDFStructureTreeBuilder implements StructureTreeEventHandler {
         }
 
         @Override
-        protected PDFStructElem createStructureElement(StructureHierarchyMember parent,
-                StructureType structureType) {
-            PDFStructElem grandParent = ((PDFStructElem) parent).getParentStructElem();
-            //TODO What to do with cells from table-footer? Currently they are mapped on TD.
-            if (grandParent.getStructureType() == StandardStructureTypes.Table.THEAD) {
-                structureType = StandardStructureTypes.Table.TH;
-            } else {
-                structureType = StandardStructureTypes.Table.TD;
-            }
-            return super.createStructureElement(parent, structureType);
-        }
-
-        @Override
-        protected void registerStructureElement(PDFStructElem structureElement, PDFFactory pdfFactory) {
+        protected void registerStructureElement(PDFStructElem structureElement, PDFFactory pdfFactory,
+                Attributes attributes) {
             if (structureElement.getStructureType() == Table.TH) {
-                pdfFactory.getDocument().registerStructureElement(structureElement, Scope.COLUMN);
+                String scopeAttribute = attributes.getValue(InternalElementMapping.URI,
+                        InternalElementMapping.SCOPE);
+                Scope scope = (scopeAttribute == null)
+                        ? Scope.COLUMN
+                        : Scope.valueOf(scopeAttribute.toUpperCase(Locale.ENGLISH));
+                pdfFactory.getDocument().registerStructureElement(structureElement, scope);
             } else {
                 pdfFactory.getDocument().registerStructureElement(structureElement);
             }