TIKA-4855: Render EMF/WMF through POI and emit the OLE2 SummaryInformation thumbnail

CHANGES.txt

@@ -1,5 +1,18 @@
 Release 4.1.0 - unreleased
 
+   * Raster previews for the vector thumbnails of Office documents: the new
+     poi-metafile-renderer draws EMF and WMF images through POI (a PNG of
+     a configurable width; Word's bitmap-in-WMF thumbnails from the bitmap
+     directly), EMFParser and WMFParser are RenderingParsers that emit the
+     rendering as a RENDERING embedded document with "emf-parser" /
+     "wmf-parser": {"renderImage": true, "renderWidth": 800}, off by
+     default and restrictable to e.g. THUMBNAIL embedded documents with
+     "renderOnlyEmbeddedResourceTypes", and OfficeParser emits the
+     SummaryInformation thumbnail of the OLE2 formats (a WMF) as a THUMBNAIL
+     embedded document, as the OOXML parsers do with the docProps thumbnail,
+     switchable with "office-parser": {"extractThumbnail": false}
+     (TIKA-4855).
+
    * Add "exception-reporting" parse-context config to redact and bound
      exception text in metadata, tika-server error bodies and pipes/grpc
      messages; FileSystemEmitter writes atomically (TIKA-4848).

tika-parsers/tika-parsers-standard/tika-parsers-standard-integration-tests/src/test/java/org/apache/tika/parser/microsoft/POIContainerExtractionTest.java

@@ -160,17 +160,18 @@ public void testEmbeddedOfficeFiles() throws Exception {
         assertEquals(TYPE_PNG, handler.mediaTypes.get(15)); //    PNG inside .xls
 
 
-        // PowerPoint with excel and word
+        // PowerPoint with excel and word; its SummaryInformation thumbnail comes last
         handler = process("testPPT_embeded.ppt", extractor, false);
-        assertEquals(7, handler.filenames.size());
-        assertEquals(7, handler.mediaTypes.size());
+        assertEquals(8, handler.filenames.size());
+        assertEquals(8, handler.mediaTypes.size());
 
         // Embedded objects get OLE IDs, slide images now get generated names
         assertEquals("1", handler.filenames.get(0));
         assertEquals("2", handler.filenames.get(1));
         for (int i = 2; i < 7; i++) {
             assertNotNull(handler.filenames.get(i));
         }
+        assertEquals("thumbnail.wmf", handler.filenames.get(7));
         // But we do know their types
         assertEquals(TYPE_XLS, handler.mediaTypes.get(0)); // Embedded office doc
         assertEquals(TYPE_DOC, handler.mediaTypes.get(1)); // Embedded office doc
@@ -179,11 +180,12 @@ public void testEmbeddedOfficeFiles() throws Exception {
         assertEquals(TYPE_PNG, handler.mediaTypes.get(4)); // Embedded image
         assertEquals(TYPE_PNG, handler.mediaTypes.get(5)); // Embedded image
         assertEquals(TYPE_PNG, handler.mediaTypes.get(6)); // Embedded image
+        assertEquals(TYPE_WMF, handler.mediaTypes.get(7)); // Document thumbnail
 
         // Run again on PowerPoint but with recursion
         handler = process("testPPT_embeded.ppt", extractor, true);
-        assertEquals(11, handler.filenames.size());
-        assertEquals(11, handler.mediaTypes.size());
+        assertEquals(12, handler.filenames.size());
+        assertEquals(12, handler.mediaTypes.size());
 
         assertEquals("1", handler.filenames.get(0));
         assertEquals(null, handler.filenames.get(1));
@@ -195,6 +197,7 @@ public void testEmbeddedOfficeFiles() throws Exception {
         for (int i = 6; i < 11; i++) {
             assertNotNull(handler.filenames.get(i));
         }
+        assertEquals("thumbnail.wmf", handler.filenames.get(11));
 
         assertEquals(TYPE_XLS, handler.mediaTypes.get(0)); // Embedded office doc
         assertEquals(TYPE_PNG, handler.mediaTypes.get(1)); //    PNG inside .xls
@@ -207,6 +210,7 @@ public void testEmbeddedOfficeFiles() throws Exception {
         assertEquals(TYPE_PNG, handler.mediaTypes.get(8)); // Embedded image
         assertEquals(TYPE_PNG, handler.mediaTypes.get(9)); // Embedded image
         assertEquals(TYPE_PNG, handler.mediaTypes.get(10)); // Embedded image
+        assertEquals(TYPE_WMF, handler.mediaTypes.get(11)); // Document thumbnail
 
 
         // Word, with a non-office file (PDF)

tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/AbstractMetafileParser.java

@@ -0,0 +1,74 @@
+/*
+ * 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.
+ */
+package org.apache.tika.parser.microsoft;
+
+import java.io.IOException;
+
+import org.apache.tika.config.ParseContextConfig;
+import org.apache.tika.exception.TikaException;
+import org.apache.tika.io.TikaInputStream;
+import org.apache.tika.metadata.Metadata;
+import org.apache.tika.parser.ParseContext;
+import org.apache.tika.parser.Parser;
+import org.apache.tika.parser.RenderingParser;
+import org.apache.tika.renderer.Renderer;
+
+/**
+ * What {@link EMFParser} and {@link WMFParser} share: the configuration of
+ * the metafile parsers and the renderer they may be handed.
+ */
+abstract class AbstractMetafileParser implements Parser, RenderingParser {
+
+    private final MetafileParserConfig defaultConfig;
+    private Renderer renderer;
+
+    AbstractMetafileParser(MetafileParserConfig defaultConfig) {
+        this.defaultConfig = defaultConfig;
+    }
+
+    /**
+     * The component name this parser reads its configuration from,
+     * {@code emf-parser} or {@code wmf-parser}.
+     */
+    abstract String componentName();
+
+    MetafileParserConfig getConfig(ParseContext context) throws TikaException, IOException {
+        return ParseContextConfig.getConfig(context, componentName(), MetafileParserConfig.class,
+                defaultConfig);
+    }
+
+    /**
+     * Spools the stream when the image is going to be rendered, so the
+     * renderer can read the metafile itself rather than only the parsed
+     * picture.
+     */
+    static void prepareForRendering(TikaInputStream tis, MetafileParserConfig config,
+                                    Metadata metadata) throws IOException {
+        if (config.shouldRender(metadata)) {
+            tis.getFile();
+        }
+    }
+
+    Renderer getRenderer() {
+        return renderer;
+    }
+
+    @Override
+    public void setRenderer(Renderer renderer) {
+        this.renderer = renderer;
+    }
+}

tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/EMFParser.java

@@ -35,16 +35,19 @@
 import org.xml.sax.SAXException;
 
 import org.apache.tika.annotation.TikaComponent;
+import org.apache.tika.config.ConfigDeserializer;
+import org.apache.tika.config.JsonConfig;
 import org.apache.tika.exception.TikaException;
 import org.apache.tika.extractor.EmbeddedDocumentExtractor;
 import org.apache.tika.extractor.EmbeddedDocumentUtil;
 import org.apache.tika.io.TikaInputStream;
 import org.apache.tika.metadata.HttpHeaders;
 import org.apache.tika.metadata.Metadata;
 import org.apache.tika.metadata.Property;
+import org.apache.tika.metadata.TikaCoreProperties;
 import org.apache.tika.mime.MediaType;
 import org.apache.tika.parser.ParseContext;
-import org.apache.tika.parser.Parser;
+import org.apache.tika.renderer.Renderer;
 import org.apache.tika.sax.EmbeddedContentHandler;
 import org.apache.tika.sax.XHTMLContentHandler;
 
@@ -61,13 +64,40 @@
  * We're also relying on storage order for text order, which isn't great.
  * We'd have to do something like what PDFBox or XPS do to sort the
  * runs and then put the cow back together from the hamburger...lol...
+ * <p/>
+ * With {@link MetafileParserConfig#setRenderImage(boolean)}
+ * ("emf-parser": {"renderImage": true}) the image is rendered through the
+ * configured {@link Renderer}, the
+ * {@link org.apache.tika.renderer.microsoft.POIMetafileRenderer} by
+ * default, and emitted as a
+ * {@link TikaCoreProperties.EmbeddedResourceType#RENDERING} embedded document,
+ * the way the PDF parser emits page renderings, so a client can obtain a
+ * raster preview of a vector thumbnail such as the docProps thumbnail of a
+ * Word document.
  */
 @TikaComponent
-public class EMFParser implements Parser {
+public class EMFParser extends AbstractMetafileParser {
 
     public static Property EMF_ICON_ONLY = Property.internalBoolean("emf:icon-only");
     public static Property EMF_ICON_STRING = Property.internalText("emf:icon-string");
 
+    public EMFParser() {
+        this(new MetafileParserConfig());
+    }
+
+    public EMFParser(MetafileParserConfig config) {
+        super(config);
+    }
+
+    public EMFParser(JsonConfig jsonConfig) {
+        this(ConfigDeserializer.buildConfig(jsonConfig, MetafileParserConfig.class));
+    }
+
+    @Override
+    String componentName() {
+        return "emf-parser";
+    }
+
     private static String ICON_ONLY = "IconOnly";
 
     private static final MediaType MEDIA_TYPE = MediaType.image("emf");
@@ -102,6 +132,8 @@ public void parse(TikaInputStream tis, ContentHandler handler, Metadata metadata
         XHTMLContentHandler xhtml = new XHTMLContentHandler(handler, metadata, context);
         xhtml.startDocument();
         try {
+            MetafileParserConfig config = getConfig(context);
+            prepareForRendering(tis, config, metadata);
             HemfPicture ex = new HemfPicture(tis);
             ParseState parseState = new ParseState();
             long fudgeFactorX = 10;//derive this from the font or frame/bounds information
@@ -139,6 +171,10 @@ public void parse(TikaInputStream tis, ContentHandler handler, Metadata metadata
                 xhtml.characters(buffer.toString());
                 xhtml.endElement("p");
             }
+            if (config.shouldRender(metadata)) {
+                MetafileRendering.render(getRenderer(), config, MEDIA_TYPE, tis, ex, xhtml,
+                        metadata, context);
+            }
 
         } catch (RecordFormatException e) { //POI's hemfparser can throw these for "parse
             // exceptions"

tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/MetafileParserConfig.java

@@ -0,0 +1,104 @@
+/*
+ * 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.
+ */
+package org.apache.tika.parser.microsoft;
+
+import java.io.Serializable;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.tika.metadata.Metadata;
+import org.apache.tika.metadata.TikaCoreProperties;
+import org.apache.tika.renderer.microsoft.POIMetafileRenderer;
+
+/**
+ * Configuration of the {@link EMFParser} ("emf-parser") and the
+ * {@link WMFParser} ("wmf-parser").
+ */
+public class MetafileParserConfig implements Serializable {
+
+    private static final long serialVersionUID = -6371049153052164071L;
+
+    private boolean renderImage = false;
+    private int renderWidth = 800;
+    private Set<String> renderOnlyEmbeddedResourceTypes = new HashSet<>();
+
+    /**
+     * Whether to render the image and emit the rendering as a RENDERING
+     * embedded document. Off by default.
+     */
+    public boolean isRenderImage() {
+        return renderImage;
+    }
+
+    public void setRenderImage(boolean renderImage) {
+        this.renderImage = renderImage;
+    }
+
+    /**
+     * Width of the rendering in pixels when the default
+     * {@link POIMetafileRenderer} is used; the height follows the image's
+     * aspect ratio. Default 800.
+     */
+    public int getRenderWidth() {
+        return renderWidth;
+    }
+
+    /**
+     * Restricts the rendering to images that are embedded documents of one
+     * of these {@code tk:embedded-resource-type}s, e.g. {@code ["THUMBNAIL"]}
+     * to render the thumbnail of an Office document but not the pictures of
+     * its embedded objects. Empty (the default) renders every image.
+     */
+    public Set<String> getRenderOnlyEmbeddedResourceTypes() {
+        return renderOnlyEmbeddedResourceTypes;
+    }
+
+    public void setRenderOnlyEmbeddedResourceTypes(Set<String> renderOnlyEmbeddedResourceTypes) {
+        if (renderOnlyEmbeddedResourceTypes == null) {
+            this.renderOnlyEmbeddedResourceTypes = new HashSet<>();
+            return;
+        }
+        Set<String> types = new HashSet<>();
+        for (String type : renderOnlyEmbeddedResourceTypes) {
+            //a typo would silently disable rendering
+            types.add(TikaCoreProperties.EmbeddedResourceType.valueOf(type).name());
+        }
+        this.renderOnlyEmbeddedResourceTypes = types;
+    }
+
+    /**
+     * Whether an image with this metadata is to be rendered.
+     */
+    public boolean shouldRender(Metadata metadata) {
+        if (!renderImage) {
+            return false;
+        }
+        if (renderOnlyEmbeddedResourceTypes.isEmpty()) {
+            return true;
+        }
+        String type = metadata.get(TikaCoreProperties.EMBEDDED_RESOURCE_TYPE);
+        return type != null && renderOnlyEmbeddedResourceTypes.contains(type);
+    }
+
+    public void setRenderWidth(int renderWidth) {
+        if (renderWidth < 1 || renderWidth > 10000) {
+            throw new IllegalArgumentException(
+                    "renderWidth must be between 1 and 10000, got: " + renderWidth);
+        }
+        this.renderWidth = renderWidth;
+    }
+}