FOP #2234: NPE when rendering a document with markers and accessibility is enabled

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1465599 13f79535-47bb-0310-9956-ffa450edef68

5 files changed, 170 insertions, 21 deletions

diff --git a/src/java/org/apache/fop/accessibility/DummyStructureTreeEventHandler.java b/src/java/org/apache/fop/accessibility/DummyStructureTreeEventHandler.java
index c63c721e5..be1177635 100644
--- a/src/java/org/apache/fop/accessibility/DummyStructureTreeEventHandler.java
+++ b/src/java/org/apache/fop/accessibility/DummyStructureTreeEventHandler.java
@@ -42,7 +42,7 @@ public final class DummyStructureTreeEventHandler implements StructureTreeEventH
     }
 
     /** {@inheritDoc} */
-    public StructureTreeElement startNode(String name, Attributes attributes) {
+    public StructureTreeElement startNode(String name, Attributes attributes, StructureTreeElement parent) {
         return null;
     }
 
@@ -51,12 +51,12 @@ public final class DummyStructureTreeEventHandler implements StructureTreeEventH
     }
 
     /** {@inheritDoc} */
-    public StructureTreeElement startImageNode(String name, Attributes attributes) {
+    public StructureTreeElement startImageNode(String name, Attributes attributes, StructureTreeElement parent) {
         return null;
     }
 
     /** {@inheritDoc} */
-    public StructureTreeElement startReferencedNode(String name, Attributes attributes) {
+    public StructureTreeElement startReferencedNode(String name, Attributes attributes, StructureTreeElement parent) {
         return null;
     }
 
diff --git a/src/java/org/apache/fop/accessibility/StructureTree2SAXEventAdapter.java b/src/java/org/apache/fop/accessibility/StructureTree2SAXEventAdapter.java
index 7a375ef20..0b8073e57 100644
--- a/src/java/org/apache/fop/accessibility/StructureTree2SAXEventAdapter.java
+++ b/src/java/org/apache/fop/accessibility/StructureTree2SAXEventAdapter.java
@@ -87,7 +87,7 @@ public final class StructureTree2SAXEventAdapter implements StructureTreeEventHa
     }
 
     /** {@inheritDoc} */
-    public StructureTreeElement startNode(String name, Attributes attributes) {
+    public StructureTreeElement startNode(String name, Attributes attributes, StructureTreeElement parent) {
         try {
             if (name.equals("#PCDATA")) {
                 name = "marked-content";
@@ -115,13 +115,13 @@ public final class StructureTree2SAXEventAdapter implements StructureTreeEventHa
     }
 
     /** {@inheritDoc} */
-    public StructureTreeElement startImageNode(String name, Attributes attributes) {
-        return startNode(name, attributes);
+    public StructureTreeElement startImageNode(String name, Attributes attributes, StructureTreeElement parent) {
+        return startNode(name, attributes, null);
     }
 
     /** {@inheritDoc} */
-    public StructureTreeElement startReferencedNode(String name, Attributes attributes) {
-        return startNode(name, attributes);
+    public StructureTreeElement startReferencedNode(String name, Attributes attributes, StructureTreeElement parent) {
+        return startNode(name, attributes, null);
     }
 
 }
diff --git a/src/java/org/apache/fop/accessibility/StructureTreeEventHandler.java b/src/java/org/apache/fop/accessibility/StructureTreeEventHandler.java
index 46b724626..53c27130c 100644
--- a/src/java/org/apache/fop/accessibility/StructureTreeEventHandler.java
+++ b/src/java/org/apache/fop/accessibility/StructureTreeEventHandler.java
@@ -43,9 +43,11 @@ public interface StructureTreeEventHandler {
      *
      * @param name the name of the structure tree node
      * @param attributes the node properties
+     * @param parent the parent of the node. May be null, in which case the parent node is
+     * the node corresponding to the previous call to this method
      * @return the corresponding structure tree element
      */
-    StructureTreeElement startNode(String name, Attributes attributes);
+    StructureTreeElement startNode(String name, Attributes attributes, StructureTreeElement parent);
 
     /**
      * Ends a structure tree node.
@@ -59,9 +61,11 @@ public interface StructureTreeEventHandler {
      *
      * @param name the name of the structure tree node
      * @param attributes the node properties
+     * @param parent the parent of the node. May be null, in which case the parent node is
+     * the node corresponding to the previous call to this method
      * @return the corresponding structure tree element
      */
-    StructureTreeElement startImageNode(String name, Attributes attributes);
+    StructureTreeElement startImageNode(String name, Attributes attributes, StructureTreeElement parent);
 
     /**
      * Starts a node that can be referenced by other nodes. This is usually a
@@ -69,9 +73,11 @@ public interface StructureTreeEventHandler {
      *
      * @param name the name of the structure tree node
      * @param attributes the node properties
+     * @param parent the parent of the node. May be null, in which case the parent node is
+     * the node corresponding to the previous call to this method
      * @return the corresponding structure tree element
      */
-    StructureTreeElement startReferencedNode(String name, Attributes attributes);
+    StructureTreeElement startReferencedNode(String name, Attributes attributes, StructureTreeElement parent);
 
     /**
      * Ends a page sequence structure tree node.
diff --git a/src/java/org/apache/fop/accessibility/fo/FO2StructureTreeConverter.java b/src/java/org/apache/fop/accessibility/fo/FO2StructureTreeConverter.java
index aaf112cb5..4614a7005 100644
--- a/src/java/org/apache/fop/accessibility/fo/FO2StructureTreeConverter.java
+++ b/src/java/org/apache/fop/accessibility/fo/FO2StructureTreeConverter.java
@@ -19,6 +19,8 @@
 
 package org.apache.fop.accessibility.fo;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Stack;
 
 import org.xml.sax.SAXException;
@@ -29,6 +31,7 @@ import org.apache.fop.fo.DelegatingFOEventHandler;
 import org.apache.fop.fo.FOEventHandler;
 import org.apache.fop.fo.FOText;
 import org.apache.fop.fo.extensions.ExternalDocument;
+import org.apache.fop.fo.flow.AbstractRetrieveMarker;
 import org.apache.fop.fo.flow.BasicLink;
 import org.apache.fop.fo.flow.Block;
 import org.apache.fop.fo.flow.BlockContainer;
@@ -46,6 +49,8 @@ import org.apache.fop.fo.flow.ListItemLabel;
 import org.apache.fop.fo.flow.PageNumber;
 import org.apache.fop.fo.flow.PageNumberCitation;
 import org.apache.fop.fo.flow.PageNumberCitationLast;
+import org.apache.fop.fo.flow.RetrieveMarker;
+import org.apache.fop.fo.flow.RetrieveTableMarker;
 import org.apache.fop.fo.flow.Wrapper;
 import org.apache.fop.fo.flow.table.Table;
 import org.apache.fop.fo.flow.table.TableBody;
@@ -70,14 +75,30 @@ public class FO2StructureTreeConverter extends DelegatingFOEventHandler {
     /** The top of the {@link converters} stack. */
     private FOEventHandler converter;
 
-    private final Stack<FOEventHandler> converters = new Stack<FOEventHandler>();
+    private Stack<FOEventHandler> converters = new Stack<FOEventHandler>();
 
-    private final FOEventHandler structureTreeEventTrigger;
+    private final StructureTreeEventTrigger structureTreeEventTrigger;
 
     /** The descendants of some elements like fo:leader must be ignored. */
     private final FOEventHandler eventSwallower = new FOEventHandler() {
     };
 
+    private final Map<AbstractRetrieveMarker, State> states = new HashMap<AbstractRetrieveMarker, State>();
+
+    private static final class State {
+
+        private final FOEventHandler converter;
+
+        private final Stack<FOEventHandler> converters;
+
+        @SuppressWarnings("unchecked")
+        State(FO2StructureTreeConverter o) {
+            this.converter = o.converter;
+            this.converters = (Stack<FOEventHandler>) o.converters.clone();
+        }
+
+    }
+
     /**
      * Creates a new instance.
      *
@@ -459,6 +480,57 @@ public class FO2StructureTreeConverter extends DelegatingFOEventHandler {
     }
 
     @Override
+    public void startRetrieveMarker(RetrieveMarker retrieveMarker) {
+        converter.startRetrieveMarker(retrieveMarker);
+        saveState(retrieveMarker);
+        super.startRetrieveMarker(retrieveMarker);
+    }
+
+    private void saveState(AbstractRetrieveMarker retrieveMarker) {
+        states.put(retrieveMarker, new State(this));
+    }
+
+    @Override
+    public void endRetrieveMarker(RetrieveMarker retrieveMarker) {
+        converter.endRetrieveMarker(retrieveMarker);
+        super.endRetrieveMarker(retrieveMarker);
+    }
+
+    @Override
+    public void restoreState(RetrieveMarker retrieveMarker) {
+        restoreRetrieveMarkerState(retrieveMarker);
+        converter.restoreState(retrieveMarker);
+        super.restoreState(retrieveMarker);
+    }
+
+    @SuppressWarnings("unchecked")
+    private void restoreRetrieveMarkerState(AbstractRetrieveMarker retrieveMarker) {
+        State state = states.get(retrieveMarker);
+        this.converter = state.converter;
+        this.converters = (Stack<FOEventHandler>) state.converters.clone();
+    }
+
+    @Override
+    public void startRetrieveTableMarker(RetrieveTableMarker retrieveTableMarker) {
+        converter.startRetrieveTableMarker(retrieveTableMarker);
+        saveState(retrieveTableMarker);
+        super.startRetrieveTableMarker(retrieveTableMarker);
+    }
+
+    @Override
+    public void endRetrieveTableMarker(RetrieveTableMarker retrieveTableMarker) {
+        converter.endRetrieveTableMarker(retrieveTableMarker);
+        super.endRetrieveTableMarker(retrieveTableMarker);
+    }
+
+    @Override
+    public void restoreState(RetrieveTableMarker retrieveTableMarker) {
+        restoreRetrieveMarkerState(retrieveTableMarker);
+        converter.restoreState(retrieveTableMarker);
+        super.restoreState(retrieveTableMarker);
+    }
+
+    @Override
     public void character(Character c) {
         converter.character(c);
         super.character(c);
diff --git a/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java b/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
index 6a763a6f6..1a59bebfb 100644
--- a/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
+++ b/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
@@ -19,7 +19,9 @@
 
 package org.apache.fop.accessibility.fo;
 
+import java.util.HashMap;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Stack;
 
 import javax.xml.XMLConstants;
@@ -34,6 +36,7 @@ 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.AbstractRetrieveMarker;
 import org.apache.fop.fo.flow.BasicLink;
 import org.apache.fop.fo.flow.Block;
 import org.apache.fop.fo.flow.BlockContainer;
@@ -50,6 +53,8 @@ import org.apache.fop.fo.flow.ListItemLabel;
 import org.apache.fop.fo.flow.PageNumber;
 import org.apache.fop.fo.flow.PageNumberCitation;
 import org.apache.fop.fo.flow.PageNumberCitationLast;
+import org.apache.fop.fo.flow.RetrieveMarker;
+import org.apache.fop.fo.flow.RetrieveTableMarker;
 import org.apache.fop.fo.flow.Wrapper;
 import org.apache.fop.fo.flow.table.Table;
 import org.apache.fop.fo.flow.table.TableBody;
@@ -76,11 +81,30 @@ class StructureTreeEventTrigger extends FOEventHandler {
 
     private LayoutMasterSet layoutMasterSet;
 
-    private final Stack<Table> tables = new Stack<Table>();
+    private Stack<Table> tables = new Stack<Table>();
 
-    private final Stack<Boolean> inTableHeader = new Stack<Boolean>();
+    private Stack<Boolean> inTableHeader = new Stack<Boolean>();
 
-    private final Stack<Locale> locales = new Stack<Locale>();
+    private Stack<Locale> locales = new Stack<Locale>();
+
+    private final Map<AbstractRetrieveMarker, State> states = new HashMap<AbstractRetrieveMarker, State>();
+
+    private static final class State {
+
+        private final Stack<Table> tables;
+
+        private final Stack<Boolean> inTableHeader;
+
+        private final Stack<Locale> locales;
+
+        @SuppressWarnings("unchecked")
+        State(StructureTreeEventTrigger o) {
+            this.tables = (Stack<Table>) o.tables.clone();
+            this.inTableHeader = (Stack<Boolean>) o.inTableHeader.clone();
+            this.locales = (Stack<Locale>) o.locales.clone();
+        }
+
+    }
 
     public StructureTreeEventTrigger(StructureTreeEventHandler structureTreeEventHandler) {
         this.structureTreeEventHandler = structureTreeEventHandler;
@@ -415,6 +439,50 @@ class StructureTreeEventTrigger extends FOEventHandler {
     }
 
     @Override
+    public void startRetrieveMarker(RetrieveMarker retrieveMarker) {
+        startElementWithID(retrieveMarker);
+        saveState(retrieveMarker);
+    }
+
+    void saveState(AbstractRetrieveMarker retrieveMarker) {
+        states.put(retrieveMarker, new State(this));
+    }
+
+    @Override
+    public void endRetrieveMarker(RetrieveMarker retrieveMarker) {
+        endElement(retrieveMarker);
+    }
+
+    @Override
+    public void restoreState(RetrieveMarker retrieveMarker) {
+        restoreRetrieveMarkerState(retrieveMarker);
+    }
+
+    @SuppressWarnings("unchecked")
+    private void restoreRetrieveMarkerState(AbstractRetrieveMarker retrieveMarker) {
+        State state = states.get(retrieveMarker);
+        tables = (Stack<Table>) state.tables.clone();
+        inTableHeader = (Stack<Boolean>) state.inTableHeader.clone();
+        locales = (Stack<Locale>) state.locales.clone();
+    }
+
+    @Override
+    public void startRetrieveTableMarker(RetrieveTableMarker retrieveTableMarker) {
+        startElementWithID(retrieveTableMarker);
+        saveState(retrieveTableMarker);
+    }
+
+    @Override
+    public void endRetrieveTableMarker(RetrieveTableMarker retrieveTableMarker) {
+        endElement(retrieveTableMarker);
+    }
+
+    @Override
+    public void restoreState(RetrieveTableMarker retrieveTableMarker) {
+        restoreRetrieveMarkerState(retrieveTableMarker);
+    }
+
+    @Override
     public void character(Character c) {
         AttributesImpl attributes = createLangAttribute(c.getCommonHyphenation());
         startElementWithID(c, attributes);
@@ -429,8 +497,8 @@ class StructureTreeEventTrigger extends FOEventHandler {
     }
 
 
-    private void startElement(FONode node) {
-        startElement(node, new AttributesImpl());
+    private StructureTreeElement startElement(FONode node) {
+        return startElement(node, new AttributesImpl());
     }
 
     private void startElementWithID(FONode node) {
@@ -443,7 +511,8 @@ class StructureTreeEventTrigger extends FOEventHandler {
             addRole((CommonAccessibilityHolder) node, attributes);
         }
         node.setStructureTreeElement(
-                structureTreeEventHandler.startReferencedNode(localName, attributes));
+                structureTreeEventHandler.startReferencedNode(localName, attributes,
+                        node.getParent().getStructureTreeElement()));
     }
 
     private void startElementWithIDAndAltText(AbstractGraphics node) {
@@ -453,7 +522,8 @@ class StructureTreeEventTrigger extends FOEventHandler {
         addAttribute(attributes, ExtensionElementMapping.URI, "alt-text",
                 ExtensionElementMapping.STANDARD_PREFIX, node.getAltText());
         node.setStructureTreeElement(
-                structureTreeEventHandler.startImageNode(localName, attributes));
+                structureTreeEventHandler.startImageNode(localName, attributes,
+                        node.getParent().getStructureTreeElement()));
     }
 
     private StructureTreeElement startElement(FONode node, AttributesImpl attributes) {
@@ -461,7 +531,8 @@ class StructureTreeEventTrigger extends FOEventHandler {
         if (node instanceof CommonAccessibilityHolder) {
             addRole((CommonAccessibilityHolder) node, attributes);
         }
-        return structureTreeEventHandler.startNode(localName, attributes);
+        return structureTreeEventHandler.startNode(localName, attributes,
+                node.getParent().getStructureTreeElement());
     }
 
     private void addNoNamespaceAttribute(AttributesImpl attributes, String name, String value) {