FOP-3245 Add structure tree merging to external document

Author: Joao Goncalves

fop-core/src/main/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java

@@ -35,6 +35,7 @@
 import org.apache.fop.fo.FOText;
 import org.apache.fop.fo.FObj;
 import org.apache.fop.fo.extensions.ExtensionElementMapping;
+import org.apache.fop.fo.extensions.ExternalDocument;
 import org.apache.fop.fo.extensions.InternalElementMapping;
 import org.apache.fop.fo.flow.AbstractRetrieveMarker;
 import org.apache.fop.fo.flow.BasicLink;
@@ -407,6 +408,12 @@ public void image(ExternalGraphic eg) {
         endElement(eg);
     }
 
+    @Override
+    public void startExternalDocument(ExternalDocument externalDocument) {
+        startElementWithIDAndAltText(externalDocument, null);
+        endElement(externalDocument);
+    }
+
     @Override
     public void startInstreamForeignObject(InstreamForeignObject ifo) {
         startElementWithIDAndAltText(ifo, ifo.getAltText());

fop-core/src/main/java/org/apache/fop/fo/extensions/ExternalDocument.java

@@ -21,6 +21,7 @@
 
 import org.xml.sax.Locator;
 
+import org.apache.fop.accessibility.StructureTreeElement;
 import org.apache.fop.apps.FOPException;
 import org.apache.fop.datatypes.Length;
 import org.apache.fop.fo.FONode;
@@ -47,6 +48,7 @@ public class ExternalDocument extends AbstractPageSequence implements GraphicsPr
     private String src;
     private int textAlign;
     private Length width;
+    private StructureTreeElement structureTreeElement;
     // Unused but valid items, commented out for performance:
     //     private CommonAccessibility commonAccessibility;
     //     private CommonAural commonAural;
@@ -194,5 +196,15 @@ public String getLocalName() {
         return "external-document";
     }
 
+    @Override
+    public StructureTreeElement getStructureTreeElement() {
+        return this.structureTreeElement;
+    }
+
+    @Override
+    public void setStructureTreeElement(StructureTreeElement element) {
+        this.structureTreeElement = element;
+    }
+
 }
 

fop-core/src/main/java/org/apache/fop/layoutmgr/ExternalDocumentLayoutManager.java

@@ -197,6 +197,9 @@ private void fillPage(String uri) {
         lineArea.addInlineArea(vp);
         lineArea.updateExtentsFromChildren();
         blockArea.addLineArea(lineArea);
+
+        TraitSetter.addStructureTreeElement(vp, fobj.getStructureTreeElement());
+
         curPage.getPageViewport().getCurrentFlow().addBlock(blockArea);
         curPage.getPageViewport().getCurrentSpan().notifyFlowsFinished();
     }

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

@@ -71,6 +71,7 @@ public class PDFStructureTreeBuilder implements StructureTreeEventHandler {
         addBuilder("character", new LanguageHolderBuilder(StandardStructureTypes.InlineLevelStructure.SPAN));
         addBuilder("external-graphic",          new ImageBuilder());
         addBuilder("instream-foreign-object",   new ImageBuilder());
+        addBuilder("external-document", new ImageBuilder());
         addBuilder("inline",                    new InlineHolderBuilder());
         addBuilder("inline-container",          StandardStructureTypes.Grouping.DIV);
         addBuilder("page-number",               StandardStructureTypes.InlineLevelStructure.QUOTE);

fop-core/src/test/java/org/apache/fop/accessibility/fo/FO2StructureTreeConverterTestCase.java

@@ -93,6 +93,11 @@ public void testCompleteDocument() throws Exception {
         testConverter("/org/apache/fop/fo/complete_document.fo");
     }
 
+    @Test
+    public void testPDFUAMergeWithExternalDocument() throws Exception {
+        testConverter("/org/apache/fop/fo/pdfua_with_external_document.fo");
+    }
+
     @Test
     public void testAbbreviationProperty() throws Exception {
         testConverter("abb.fo");

fop-core/src/test/java/org/apache/fop/accessibility/fo/StructureTreeEventTriggerTestCase.java

@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* $Id$ */
+
+package org.apache.fop.accessibility.fo;
+
+import org.junit.Test;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import org.apache.fop.accessibility.StructureTreeEventHandler;
+import org.apache.fop.fo.Constants;
+import org.apache.fop.fo.FONode;
+import org.apache.fop.fo.PropertyList;
+import org.apache.fop.fo.expr.PropertyException;
+import org.apache.fop.fo.extensions.ExternalDocument;
+import org.apache.fop.fo.properties.CommonAccessibility;
+import org.apache.fop.fo.properties.StringProperty;
+
+public class StructureTreeEventTriggerTestCase {
+
+    @Test
+    public void testStructureTreeEventTrigger() throws PropertyException {
+        PropertyList propertyList = mock(PropertyList.class);
+        when(propertyList.get(Constants.PR_SOURCE_DOCUMENT)).thenReturn(StringProperty.getInstance(""));
+        when(propertyList.get(Constants.PR_ROLE)).thenReturn(StringProperty.getInstance(""));
+        CommonAccessibility mockCommonAccessibility = CommonAccessibility.getInstance(propertyList);
+
+        StructureTreeEventHandler mockHandler = mock(StructureTreeEventHandler.class);
+        StructureTreeEventTrigger trigger = new StructureTreeEventTrigger(mockHandler);
+        FONode mockParent = mock(FONode.class);
+        ExternalDocument mockDoc = mock(ExternalDocument.class);
+        when(mockDoc.getCommonAccessibility()).thenReturn(mockCommonAccessibility);
+        when(mockDoc.getParent()).thenReturn(mockParent);
+
+        trigger.startExternalDocument(mockDoc);
+
+        verify(mockDoc, times(1)).setStructureTreeElement(any());
+        verify(mockHandler, times(1)).startImageNode(any(), any(), any());
+
+    }
+}

fop-core/src/test/java/org/apache/fop/render/pdf/PDFStructureTreeBuilderTestCase.java

@@ -25,7 +25,10 @@
 import org.junit.Before;
 import org.junit.Test;
 
+import org.xml.sax.helpers.AttributesImpl;
+
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 
 import org.apache.fop.pdf.PDFDocument;
@@ -67,4 +70,16 @@ public void testMemoryLeak() throws IOException {
         assertNull(structElem.getParentStructElem());
         assertNull(structElem.getKids());
     }
+
+    @Test
+    public void testExternalDocumentBuilder() {
+        pdfFactory.getDocument().makeStructTreeRoot(null);
+
+        PDFStructElem elem = PDFStructureTreeBuilder.createStructureElement("external-document", new PDFStructElem(),
+                new AttributesImpl(), pdfFactory, null);
+
+        assertNotNull("Must create a PDFStructElem", elem);
+        assertEquals("Elem must be of type figure", StandardStructureTypes.Illustration.FIGURE,
+                elem.getStructureType());
+    }
 }

fop-core/src/test/resources/org/apache/fop/accessibility/fo/fo2StructureTree.xsl

@@ -44,6 +44,12 @@
     </structure-tree>
   </xsl:template>
 
+  <!-- fo:page-sequence maps to structure-tree -->
+  <xsl:template match="fox:external-document">
+	<fo:external-document xmlns:fo="http://www.w3.org/1999/XSL/Format" fox:alt-text="">
+	  <xsl:apply-templates/>
+	</fo:external-document>
+  </xsl:template>
 
   <!-- Declarations and Pagination and Layout Formatting Objects -->
   <xsl:template match="fo:static-content|fo:flow">

fop-core/src/test/resources/org/apache/fop/fo/pdfua_with_external_document.fo

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format" font-family="Arial"
+xmlns:pdf="http://xmlgraphics.apache.org/fop/extensions/pdf" xmlns:fox="http://xmlgraphics.apache.org/fop/extensions">
+  <fo:layout-master-set>
+    <fo:simple-page-master master-name="simple" page-height="27.9cm" page-width="21.6cm">
+      <fo:region-body />
+    </fo:simple-page-master>
+  </fo:layout-master-set>
+  <fo:declarations>
+    <x:xmpmeta xmlns:x="adobe:ns:meta/">
+      <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+        <rdf:Description rdf:about="" xmlns:dc="http://purl.org/dc/elements/1.1/">
+          <dc:title>Document title</dc:title>
+          <dc:creator>Document author</dc:creator>
+          <dc:description>Document subject</dc:description>
+        </rdf:Description>
+      </rdf:RDF>
+    </x:xmpmeta>
+  </fo:declarations>
+  <fo:page-sequence format="1" id="th_default_sequence1" master-reference="simple">
+    <fo:flow flow-name="xsl-region-body">
+      <fo:block>page 1</fo:block>
+    </fo:flow>
+  </fo:page-sequence>
+  <fox:external-document src="/test/pdf/1.5/test.pdf"/>
+</fo:root>