XObject.cs :  » PDF » PDF-Clown » it » stefanochizzolini » clown » documents » contents » xObjects » C# / CSharp Open Source

/*
  Copyright 2006,2007,2008 Stefano Chizzolini. http://clown.stefanochizzolini.it

  Contributors:
    * Stefano Chizzolini (original code developer, http://www.stefanochizzolini.it)

  This file should be part of the source code distribution of "PDF Clown library"
  (the Program): see the accompanying README files for more info.

  This Program is free software; you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free Software
  Foundation; either version 2 of the License, or (at your option) any later version.

  This Program is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY, either expressed or implied; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the License for more details.

  You should have received a copy of the GNU General Public License along with this
  Program (see README files); if not, go to the GNU website (http://www.gnu.org/).

  Redistribution and use, with or without modification, are permitted provided that such
  redistributions retain the above copyright notice, license and disclaimer, along with
  this list of conditions.
*/

using it.stefanochizzolini.clown.documents;
using it.stefanochizzolini.clown.files;
using it.stefanochizzolini.clown.objects;

using System;
using System.Drawing;

namespace it.stefanochizzolini.clown.documents.contents.xObjects{
  /**
    <summary>Abstract external object [PDF:1.6:4.7].</summary>
  */
  public abstract class XObject
    : PdfObjectWrapper<PdfStream>
  {
    #region static
    #region interface
    #region public
    /**
      <summary>Wraps an external object reference into an external object.</summary>
      <param name="reference">Reference to an external object.</param>
      <returns>External object associated to the reference.</returns>
    */
    public static XObject Wrap(
      PdfReference reference
      )
    {
      /*
        NOTE: This is a factory method for any xobject-derived object.
      */
      if(reference == null)
        return null;

      PdfName subtype = (PdfName)((PdfStream)reference.DataObject).Header[PdfName.Subtype];
      if(subtype.Equals(PdfName.Form))
        return new FormXObject(reference);
      else if(subtype.Equals(PdfName.Image))
        return new ImageXObject(reference);
      else
        return null;
    }
    #endregion
    #endregion
    #endregion

    #region dynamic
    #region constructors
    /**
      <summary>Creates a new external object inside the document.</summary>
    */
    protected XObject(
      Document context
      ) : this(
        context,
        new PdfStream()
        )
    {}

    /**
      <summary>Creates a new external object inside the document.</summary>
    */
    protected XObject(
      Document context,
      PdfStream baseDataObject
      ) : base(
        context.File,
        baseDataObject
        )
    {baseDataObject.Header[PdfName.Type] = PdfName.XObject;}

    /**
      <summary>Instantiates an existing external object.</summary>
    */
    protected XObject(
      PdfDirectObject baseObject
      ) : base(
        baseObject,
        null // NO container (baseObject is (by definition) a PDF stream, so it MUST be an indirect object [PDF:1.6:3.2.7]).
        )
    {}
    #endregion

    #region interface
    #region public
    /**
      Gets the mapping from external-object space to user space.
    */
    public abstract double[] GetMatrix(
      );

    /**
      <summary>Gets/Sets the external object size.</summary>
    */
    public abstract Size Size
    {
      get;
      set;
    }
    #endregion
    #endregion
    #endregion
  }
}