Add support for figure element

java/org/chromium/distiller/extractors/embeds/ImageExtractor.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.distiller.extractors.embeds;
 
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.ImageElement;
 import org.chromium.distiller.LogUtil;
+import com.google.gwt.dom.client.NodeList;

[wychen, 2016/06/07 16:27:20]

import should be sorted.

[marcelorcorrea, 2016/06/07 17:02:25]

Done.

+import org.chromium.distiller.webdocument.WebFigure;
 import org.chromium.distiller.webdocument.WebImage;
 
 import java.util.HashSet;
 import java.util.Set;
 
 /**
  * This class treats images as another type of embed and provides heuristics for lead image
  * candidacy.
  */
 public class ImageExtractor implements EmbedExtractor {
     private static final Set<String> relevantTags = new HashSet<>();
+    private String imgSrc;
+    private int width;
+    private int height;
+
     static {
         // TODO(mdjones): Add "DIV" to this list for css images and possibly captions.
         relevantTags.add("IMG");
+        relevantTags.add("FIGURE");
     }
+
     private static final String[] LAZY_IMAGE_ATTRIBUTES =
-        {"data-src", "data-original", "datasrc", "data-url"};
+            {"data-src", "data-original", "datasrc", "data-url"};
 
     @Override
     public Set<String> getRelevantTagNames() {
         return relevantTags;
     }
 
     @Override
     public WebImage extract(Element e) {
         if (!relevantTags.contains(e.getTagName())) {
             return null;
         }
-        String imgSrc = "";
-        // Getting OffSetWidth/Height as default values, even they are
-        // affected by padding, border, etc.
-        int width = e.getOffsetWidth();
-        int height = e.getOffsetHeight();
+
         if ("IMG".equals(e.getTagName())) {
             // This will get the absolute URL of the image and
             // the displayed image dimension.
             ImageElement imageElement = ImageElement.as(e);
             // Try to get lazily-loaded images before falling back to get the src attribute.
-            for(String attr: LAZY_IMAGE_ATTRIBUTES) {
+            for (String attr : LAZY_IMAGE_ATTRIBUTES) {
                 imgSrc = imageElement.getAttribute(attr);
                 if (!imgSrc.isEmpty())
                     break;
             }
             if (!imgSrc.isEmpty()) {
                 // We cannot trust the dimension if the image is not loaded yet.
                 // In some cases there are 1x1 placeholder images.
                 width = 0;
                 height = 0;
             } else {
                 imgSrc = imageElement.getSrc();
                 // As an ImageElement is manipulated here, it is possible
                 // to get the real dimensions.
                 width = imageElement.getWidth();
                 height = imageElement.getHeight();
+                extractImageAttributes(ImageElement.as(e));
+            }
+            if (LogUtil.isLoggable(LogUtil.DEBUG_LEVEL_VISIBILITY_INFO)) {
+                LogUtil.logToConsole("Extracted WebImage: " + imgSrc);
+            }
+            return new WebImage(e, width, height, imgSrc);
+
+        } else if ("FIGURE".equals(e.getTagName())) {
+            Element img = getFirstElementByTagName(e, "IMG");
+            if (img != null) {
+                String caption = "";
+                extractImageAttributes(ImageElement.as(img));
+                Element cap = getFirstElementByTagName(e, "FIGCAPTION");
+                if (cap != null) {
+                    caption = cap.getInnerText();
+                }
+                return new WebFigure(img, width, height, imgSrc, caption);
             }
         }
+        return null;
+    }
 
-        if (LogUtil.isLoggable(LogUtil.DEBUG_LEVEL_VISIBILITY_INFO)) {
-            LogUtil.logToConsole("Extracted WebImage: " + imgSrc);
+    private void extractImageAttributes(ImageElement img) {

[wychen, 2016/06/07 16:27:20]

Let's support lazily-loaded images in <figure> as well.

[marcelorcorrea, 2016/06/07 17:02:25]

Done.

+        imgSrc = img.getSrc();
+        width = img.getWidth();
+        height = img.getHeight();
+    }
+
+    private Element getFirstElementByTagName(Element e, String tagName) {
+        NodeList<Element> elements = e.getElementsByTagName(tagName);
+        if (elements.getLength() > 0) {
+            return elements.getItem(0);
         }
-        return new WebImage(e, width, height, imgSrc);
+        return null;
     }
 }