Copy over and tweak PicturesSource from Apache Tika

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1807651 13f79535-47bb-0310-9956-ffa450edef68

src/scratchpad/src/org/apache/poi/hwpf/usermodel/PictureRunMapper.java

@@ -0,0 +1,136 @@
+/* ====================================================================
+   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.poi.hwpf.usermodel;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.poi.hwpf.HWPFDocument;
+import org.apache.poi.hwpf.model.PicturesTable;
+
+/**
+ * Helper class for mapping Pictures to Runs within
+ *  a document.
+ *  
+ * This allows for easy access to Pictures by Run,
+ *  as well as a way to find "Escher Floating"
+ *  Pictures which don't have the regular \u0001
+ *  references in the main text.
+ * 
+ * Provides access to the pictures by offset, iteration
+ *  over the un-claimed, and peeking forward.
+ */
+public class PictureRunMapper {
+    private PicturesTable picturesTable;
+    private Set<Picture> claimed = new HashSet<Picture>();
+    private Map<Integer, Picture> lookup;
+    private List<Picture> nonU1based;
+    private List<Picture> all;
+    private int pn = 0;
+
+    public PictureRunMapper(HWPFDocument doc) {
+        picturesTable = doc.getPicturesTable();
+        all = picturesTable.getAllPictures();
+
+        // Build the Offset-Picture lookup map
+        lookup = new HashMap<Integer, Picture>();
+        for (Picture p : all) {
+            lookup.put(p.getStartOffset(), p);
+        }
+
+        // Work out which Pictures aren't referenced by
+        //  a \u0001 in the main text
+        // These are \u0008 escher floating ones, ones
+        //  found outside the normal text, and who
+        //  knows what else...
+        nonU1based = new ArrayList<Picture>();
+        nonU1based.addAll(all);
+        Range r = doc.getRange();
+        for (int i = 0; i < r.numCharacterRuns(); i++) {
+            CharacterRun cr = r.getCharacterRun(i);
+            if (picturesTable.hasPicture(cr)) {
+                Picture p = getFor(cr);
+                int at = nonU1based.indexOf(p);
+                nonU1based.set(at, null);
+            }
+        }
+    }
+
+    /**
+     * Does this run have a Picture in it?
+     * 
+     * @see #getFor(CharacterRun)
+     */
+    public boolean hasPicture(CharacterRun cr) {
+        return picturesTable.hasPicture(cr);
+    }
+
+    /**
+     * Get the Picture for this run, if any
+     */
+    public Picture getFor(CharacterRun cr) {
+        return lookup.get(cr.getPicOffset());
+    }
+
+    /**
+     * Mark a Picture as claimed.
+     * Used when trying to match up non-Run based pictures 
+     */
+    public void markAsClaimed(Picture picture) {
+        claimed.add(picture);
+    }
+
+    /**
+     * Has the given Picture been claimed by a non-Run yet?
+     */
+    public boolean hasBeenClaimed(Picture picture) {
+        return claimed.contains(picture);
+    }
+
+    /**
+     * Which Picture is this one of all the Pictures in
+     *  the Document?
+     *
+     * Useful when trying to extract all Pictures with
+     *  unique numbers or references
+     */
+    public int pictureNumber(Picture picture) {
+        return all.indexOf(picture) + 1;
+    }
+
+    /**
+     * Return the next unclaimed one, used towards
+     * the end
+     */
+    public Picture nextUnclaimed() {
+        Picture p = null;
+        while (pn < nonU1based.size()) {
+            p = nonU1based.get(pn);
+            pn++;
+            if (p != null) {
+                claimed.add(p);
+                return p;
+            }
+        }
+        return null;
+    }
+}