public DrawingGroup(Origin o) 
{
              
    origin = o;
    initialized = o == Origin.WRITE ? true : false;
    drawings = new ArrayList();
    imageFiles = new HashMap();
    drawingsOmitted = false;
    maxObjectId = 1;
    maxShapeId = 1024;
}

Constructor

Parameters:

o - the origin of this drawing group

 public DrawingGroup(DrawingGroup dg) 
{
    drawingData = dg.drawingData;
    escherData = dg.escherData;
    bstoreContainer = dg.bstoreContainer;
    initialized = dg.initialized;
    drawingData = dg.drawingData;
    escherData = dg.escherData;
    bstoreContainer = dg.bstoreContainer;
    numBlips = dg.numBlips;
    numCharts = dg.numCharts;
    drawingGroupId = dg.drawingGroupId;
    drawingsOmitted = dg.drawingsOmitted;
    origin = dg.origin;
    imageFiles = (HashMap) dg.imageFiles.clone();
    maxObjectId = dg.maxObjectId;
    maxShapeId = dg.maxShapeId;
    // Create this as empty, because all drawings will get added later
    // as part of the sheet copy process
    drawings = new ArrayList();
}

Copy constructor Uses a shallow copy for most things, since as soon as anything is changed, the drawing group is invalidated and all the data blocks regenerated

Parameters:

dg - the drawing group to copy

 public  void add(MsoDrawingGroupRecord mso) 
{
    addData(mso.getData());
}

/** Adds in a drawing group record to this drawing group. The binary data is extracted from the drawing group and added to a single byte array

 public  void add(Record cont) 
{
    addData(cont.getData());
}

Adds a continue record to this drawing group. the binary data is extracted and appended to the byte array

 public  void add(Chart c) 
{
    numCharts++;
}

Adds a chart to the drawing group

 public  void add(DrawingGroupObject d) 
{
    if (origin == Origin.READ)
    {
      origin = Origin.READ_WRITE;
      BStoreContainer bsc = getBStoreContainer(); // force initialization
      Dgg dgg = (Dgg) escherData.getChildren()[0];
      drawingGroupId = dgg.getCluster(1).drawingGroupId - numBlips - 1;
      numBlips = bsc != null ? bsc.getNumBlips() : 0;
      if (bsc != null)
      {
        Assert.verify(numBlips == bsc.getNumBlips());
      }
    }
    if (!(d instanceof Drawing))
    {
      // Assign a new object id and add it to the list
      //      drawings.add(d);
      maxObjectId++;
      maxShapeId++;
      d.setDrawingGroup(this);
      d.setObjectId(maxObjectId, numBlips + 1, maxShapeId);
      if (drawings.size()  > maxObjectId)
      {
        logger.warn("drawings length " + drawings.size() +
                    " exceeds the max object id " + maxObjectId);
      }
      //      numBlips++;
      return;
    }
    Drawing drawing = (Drawing) d;
    // See if this is referenced elsewhere
    Drawing refImage =
      (Drawing) imageFiles.get(d.getImageFilePath());
    if (refImage == null)
    {
      // There are no other references to this drawing, so assign
      // a new object id and put it on the hash map
      maxObjectId++;
      maxShapeId++;
      drawings.add(drawing);
      drawing.setDrawingGroup(this);
      drawing.setObjectId(maxObjectId, numBlips + 1, maxShapeId);
      numBlips++;
      imageFiles.put(drawing.getImageFilePath(), drawing);
    }
    else
    {
      // This drawing is used elsewhere in the workbook.  Increment the
      // reference count on the drawing, and set the object id of the drawing
      // passed in
      refImage.setReferenceCount(refImage.getReferenceCount() + 1);
      drawing.setDrawingGroup(this);
      drawing.setObjectId(refImage.getObjectId(),
                          refImage.getBlipId(),
                          refImage.getShapeId());
    }
}

Adds a drawing from the public, writable interface

 final  void addDrawing(DrawingGroupObject d) 
{
    drawings.add(d);
    maxObjectId = Math.max(maxObjectId, d.getObjectId());
    maxShapeId = Math.max(maxShapeId, d.getShapeId());
}

Adds a drawing to the drawing group

 public byte[] getData() 
{
    return drawingData;
}

Gets hold of the binary data

 byte[] getImageData(int blipId) 
{
    numBlips = getBStoreContainer().getNumBlips();
    Assert.verify(blipId < = numBlips);
    Assert.verify(origin == Origin.READ || origin == Origin.READ_WRITE);
    // Get the blip
    EscherRecord[] children = getBStoreContainer().getChildren();
    BlipStoreEntry bse = (BlipStoreEntry) children[blipId - 1];
    return bse.getImageData();
}

Gets the drawing data for the given blip id. Called by the Drawing object

 final int getNumberOfBlips() 
{
    return numBlips;
}

Accessor for the number of blips in the drawing group

 public boolean hasDrawingsOmitted() 
{
    return drawingsOmitted;
}

Accessor for the drawingsOmitted flag

 public  void remove(DrawingGroupObject d) 
{
    // Unless there are real images or some such, it is possible that
    // a BStoreContainer will not be present.  In that case simply return
    if (getBStoreContainer() == null)
    {
      return;
    }
    if (origin == Origin.READ)
    {
      origin = Origin.READ_WRITE;
      numBlips = getBStoreContainer().getNumBlips();
      Dgg dgg = (Dgg) escherData.getChildren()[0];
      drawingGroupId = dgg.getCluster(1).drawingGroupId - numBlips - 1;
    }
    // Get the blip
    EscherRecord[] children = getBStoreContainer().getChildren();
    BlipStoreEntry bse = (BlipStoreEntry) children[d.getBlipId() - 1];
    bse.dereference();
    if (bse.getReferenceCount() == 0)
    {
      // Remove the blip
      getBStoreContainer().remove(bse);
      // Adjust blipId on the other blips
      for (Iterator i = drawings.iterator(); i.hasNext();)
      {
        DrawingGroupObject drawing = (DrawingGroupObject) i.next();
        if (drawing.getBlipId()  > d.getBlipId())
        {
          drawing.setObjectId(drawing.getObjectId(),
                              drawing.getBlipId() - 1,
                              drawing.getShapeId());
        }
      }
      numBlips--;
    }
}

Interface method to remove a drawing from the group

 public  void setDrawingsOmitted(MsoDrawingRecord mso,
    ObjRecord obj) 
{
    drawingsOmitted = true;
    if (obj != null)
    {
      maxObjectId = Math.max(maxObjectId, obj.getObjectId());
    }
}

Indicates that at least one of the drawings has been omitted from the worksheet

 public  void updateData(DrawingGroup dg) 
{
    drawingsOmitted = dg.drawingsOmitted;
    maxObjectId = dg.maxObjectId;
    maxShapeId = dg.maxShapeId;
}

Updates this with the appropriate data from the drawing group passed in This is called during the copy process: this is first initialised as an empty object, but during the copy, the source DrawingGroup may change. After the copy process, this method is then called to update the relevant fields. Unfortunately, the copy process required the presence of a drawing group

 public  void write(File outputFile) throws IOException 
{
    if (origin == Origin.WRITE)
    {
      DggContainer dggContainer = new DggContainer();
      Dgg dgg = new Dgg(numBlips + numCharts + 1, numBlips);
      dgg.addCluster(1, 0);
      dgg.addCluster(numBlips + 1, 0);
      dggContainer.add(dgg);
      int drawingsAdded = 0;
      BStoreContainer bstoreCont = new BStoreContainer();
      // Create a blip entry for each drawing
      for (Iterator i = drawings.iterator(); i.hasNext();)
      {
        Object o = i.next();
        if (o instanceof Drawing)
        {
          Drawing d = (Drawing) o;
          BlipStoreEntry bse = new BlipStoreEntry(d);
          bstoreCont.add(bse);
          drawingsAdded++;
        }
      }
      if (drawingsAdded  > 0)
      {
        bstoreCont.setNumBlips(drawingsAdded);
        dggContainer.add(bstoreCont);
      }
      Opt opt = new Opt();
      dggContainer.add(opt);
      SplitMenuColors splitMenuColors = new SplitMenuColors();
      dggContainer.add(splitMenuColors);
      drawingData = dggContainer.getData();
    }
    else if (origin == Origin.READ_WRITE)
    {
      DggContainer dggContainer = new DggContainer();
      Dgg dgg = new Dgg(numBlips + numCharts + 1, numBlips);
      dgg.addCluster(1, 0);
      dgg.addCluster(drawingGroupId + numBlips + 1, 0);
      dggContainer.add(dgg);
      BStoreContainer bstoreCont = new BStoreContainer();
      bstoreCont.setNumBlips(numBlips);
      // Create a blip entry for each drawing that was read in
      BStoreContainer readBStoreContainer = getBStoreContainer();
      if (readBStoreContainer != null)
      {
        EscherRecord[] children = readBStoreContainer.getChildren();
        for (int i = 0; i <  children.length; i++)
        {
          BlipStoreEntry bse = (BlipStoreEntry) children[i];
          bstoreCont.add(bse);
        }
      }
      // Create a blip entry for each drawing that has been added
      for (Iterator i = drawings.iterator(); i.hasNext();)
      {
        DrawingGroupObject dgo = (DrawingGroupObject) i.next();
        if (dgo instanceof Drawing)
        {
          Drawing d = (Drawing) dgo;
          if (d.getOrigin() == Origin.WRITE)
          {
            BlipStoreEntry bse = new BlipStoreEntry(d);
            bstoreCont.add(bse);
          }
        }
      }
      dggContainer.add(bstoreCont);
      Opt opt = new Opt();
      opt.addProperty(191, false, false, 524296);
      opt.addProperty(385, false, false, 134217737);
      opt.addProperty(448, false, false, 134217792);
      dggContainer.add(opt);
      SplitMenuColors splitMenuColors = new SplitMenuColors();
      dggContainer.add(splitMenuColors);
      drawingData = dggContainer.getData();
    }
    MsoDrawingGroupRecord msodg = new MsoDrawingGroupRecord(drawingData);
    outputFile.write(msodg);
}

Writes the drawing group to the output file