static void ProcessElements(ElementReader reader, ElementWriter writer, XSet visited)
{
Element element;
while ((element = reader.Next()) != null) // Read page contents
{
switch (element.GetType())
{
case Element.Type.e_image:
case Element.Type.e_inline_image:
// remove all images by skipping them
break;
case Element.Type.e_path:
{
// Set all paths to red color.
GState gs = element.GetGState();
gs.SetFillColorSpace(ColorSpace.CreateDeviceRGB());
gs.SetFillColor(new ColorPt(1, 0, 0));
writer.WriteElement(element);
break;
}
case Element.Type.e_text:
{
// Set all text to blue color.
GState gs = element.GetGState();
gs.SetFillColorSpace(ColorSpace.CreateDeviceRGB());
gs.SetFillColor(new ColorPt(0, 0, 1));
writer.WriteElement(element);
break;
}
case Element.Type.e_form:
{
writer.WriteElement(element); // write Form XObject reference to current stream
Obj form_obj = element.GetXObject();
if (!visited.Contains(form_obj.GetObjNum())) // if this XObject has not been processed
{
// recursively process the Form XObject
visited.Add(form_obj.GetObjNum());
ElementWriter new_writer = new ElementWriter();
reader.FormBegin();
new_writer.Begin(form_obj, true);
reader.ClearChangeList();
new_writer.SetDefaultGState(reader);
ProcessElements(reader, new_writer, visited);
new_writer.End();
reader.End();
}
break;
}
default:
writer.WriteElement(element);
break;
}
}
}
