/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkPNGReader.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
// .NAME vtkPNGReader - read PNG files
// .SECTION Description
// vtkPNGReader is a source object that reads PNG files.
// It should be able to read most any PNG file
//
// .SECTION See Also
// vtkPNGWriter

#ifndef vtkPNGReader_h
#define vtkPNGReader_h

#include "vtkIOImageModule.h" // For export macro
#include "vtkImageReader2.h"

class VTKIOIMAGE_EXPORT vtkPNGReader : public vtkImageReader2
{
public:
  static vtkPNGReader *New();
  vtkTypeMacro(vtkPNGReader,vtkImageReader2);
  virtual void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Is the given file a PNG file?
  virtual int CanReadFile(const char* fname);

  // Description:
  // Get the file extensions for this format.
  // Returns a string with a space separated list of extensions in
  // the format .extension
  virtual const char* GetFileExtensions()
    {
      return ".png";
    }

  // Description:
  // Return a descriptive name for the file format that might be useful in a GUI.
  virtual const char* GetDescriptiveName()
    {
      return "PNG";
    }

  // Description:
  // Given a 'key' for the text chunks, fills in 'beginEndIndex'
  // with the begin and end indexes. Values are stored between
  // [begin, end) indexes.
  void GetTextChunks(const char* key, int beginEndIndex[2]);
  // Description:
  // Returns the text key stored at 'index'.
  const char* GetTextKey(int index);
  // Description:
  // Returns the text value stored at 'index'. A range of indexes
  // that store values for a certain key can be obtained by calling
  // GetTextChunks.
  const char* GetTextValue(int index);
  // Description:
  // Return the number of text chunks in the PNG file.
  // Note that we don't process compressed or international text entries
  size_t GetNumberOfTextChunks();

protected:
  vtkPNGReader();
  ~vtkPNGReader();

  virtual void ExecuteInformation();
  virtual void ExecuteDataWithInformation(vtkDataObject *out, vtkInformation *outInfo);
  template <class OT>
    void vtkPNGReaderUpdate(vtkImageData *data, OT *outPtr);
  template <class OT>
    void vtkPNGReaderUpdate2(
      OT *outPtr, int *outExt, vtkIdType *outInc, long pixSize);


private:
  vtkPNGReader(const vtkPNGReader&);  // Not implemented.
  void operator=(const vtkPNGReader&);  // Not implemented.

  class vtkInternals;
  vtkInternals* Internals;
};
#endif
