public bool ReadXref(PdfStream st)
{
if (st.PeekLine(true, true) == "xref")
{
Utility.TraceLine("Reading a XREF");
st.ReadLine();
while (st.RegexMatch("^([0-9]+ [0-9]+)", false) != "")
{
Utility.TraceLine("Found XREF value block");
// Each xref block starts with a line with the starting number of the objects in the
// block, and then a count of the number of objects in the block PDF 1.5 p70
int startat = 0;
int count = 0;
try
{
startat = Int32.Parse(st.RegexMatch("^([0-9]+)", true));
count = Int32.Parse(st.RegexMatch("^[ \t]*([0-9]+)", true));
st.ReadLine();
// The you get one line per object in the block. They contain:
// <byte offset> <generation> <n = inuse, f = free>
Utility.TraceLine("XREF reading " + count + " lines");
for (int i = 0; i < count; i++)
{
string line = st.ReadLine();
long offset = Int64.Parse(line.Substring(0, 10));
int generation = Int32.Parse(line.Substring(11, 5));
string inuse = line.Substring(17, 1);
Utility.TraceLine("XREF line: " + offset + " " + generation + " " + inuse);
if ((inuse == "n") && !m_linflag)
{
// PDF/A requires us to verify these offsets
Object obj = m_objects.Get(startat + i, generation);
if (offset != obj.StartedAt)
{
m_pdfa = false;
Utility.TraceLine("PDF/A: Object offset is incorrect " + offset + " != " +
obj.StartedAt + " (required by section 5.4)");
}
}
}
}
catch (Exception except)
{
throw new ParseException("Error reading xref block starter: " + except.Message);
}
}
}
return(false);
}
public Object ValueAsObject(ObjectCollection objs)
{
if (!Valid)
{
return(new Object());
}
if (m_objects.Count == 0)
{
return(new Object());
}
if (m_objects.Count != 1)
{
return(new Object());
}
return(objs.Get(m_objects[0]));
}
public ObjectCollection ValueAsObjects(ObjectCollection objs)
{
if (!Valid)
{
return(new ObjectCollection());
}
if (m_objects.Count == 0)
{
throw new RuntimeException("There are no objects to return");
}
ObjectCollection oc = new ObjectCollection();
foreach (ObjectReference or in m_objects)
{
oc.Add(objs.Get(or));
}
return(oc);
}