/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#ifndef __itkImageIterator_h
#define __itkImageIterator_h

#include "itkImageConstIterator.h"

namespace itk
{
/**
 * \class ImageIterator
 * \brief A multi-dimensional iterator templated over image type.
 *
 * This is a base class of ImageConstIterator that adds write-access
 * functionality.  Please see ImageConstIterator for more information.
 *
 * \par MORE INFORMATION
 * For a complete description of the ITK Image Iterators and their API, please
 * see the Iterators chapter in the ITK Software Guide.  The ITK Software Guide
 * is available in print and as a free .pdf download from http://www.itk.org.
 *
 * \ingroup ImageIterators
 *
 * \sa ImageConstIterator \sa ConditionalConstIterator
 * \sa ConstNeighborhoodIterator \sa ConstShapedNeighborhoodIterator
 * \sa ConstSliceIterator  \sa CorrespondenceDataStructureIterator
 * \sa FloodFilledFunctionConditionalConstIterator
 * \sa FloodFilledImageFunctionConditionalConstIterator
 * \sa FloodFilledImageFunctionConditionalIterator
 * \sa FloodFilledSpatialFunctionConditionalConstIterator
 * \sa FloodFilledSpatialFunctionConditionalIterator
 * \sa ImageConstIterator \sa ImageConstIteratorWithIndex
 * \sa ImageIterator \sa ImageIteratorWithIndex
 * \sa ImageLinearConstIteratorWithIndex  \sa ImageLinearIteratorWithIndex
 * \sa ImageRandomConstIteratorWithIndex  \sa ImageRandomIteratorWithIndex
 * \sa ImageRegionConstIterator \sa ImageRegionConstIteratorWithIndex
 * \sa ImageRegionExclusionConstIteratorWithIndex
 * \sa ImageRegionExclusionIteratorWithIndex
 * \sa ImageRegionIterator  \sa ImageRegionIteratorWithIndex
 * \sa ImageRegionReverseConstIterator  \sa ImageRegionReverseIterator
 * \sa ImageReverseConstIterator  \sa ImageReverseIterator
 * \sa ImageSliceConstIteratorWithIndex  \sa ImageSliceIteratorWithIndex
 * \sa NeighborhoodIterator \sa PathConstIterator  \sa PathIterator
 * \sa ShapedNeighborhoodIterator  \sa SliceIterator
 *
 *
 * \ingroup ITKCommon
 */
template< typename TImage >
class ImageIterator:public ImageConstIterator< TImage >
{
public:
  /** Standard class typedefs. */
  typedef ImageIterator Self;

  /** Dimension of the image the iterator walks.  This constant is needed so
   * functions that are templated over image iterator type (as opposed to
   * being templated over pixel type and dimension) can have compile time
   * access to the dimension of the image that the iterator walks. */
  itkStaticConstMacro(ImageIteratorDimension, unsigned int,
                      TImage::ImageDimension);

  /** Define the superclass */
  typedef ImageConstIterator< TImage > Superclass;

  /** Inherit types from the superclass */
  typedef typename Superclass::IndexType             IndexType;
  typedef typename Superclass::SizeType              SizeType;
  typedef typename Superclass::OffsetType            OffsetType;
  typedef typename Superclass::RegionType            RegionType;
  typedef typename Superclass::ImageType             ImageType;
  typedef typename Superclass::PixelContainer        PixelContainer;
  typedef typename Superclass::PixelContainerPointer PixelContainerPointer;
  typedef typename Superclass::InternalPixelType     InternalPixelType;
  typedef typename Superclass::PixelType             PixelType;
  typedef typename Superclass::AccessorType          AccessorType;

  /** Default Constructor. Need to provide a default constructor since we
   * provide a copy constructor. */
  ImageIterator();

  /** Default Destructor */
  ~ImageIterator() {}

  /** Copy Constructor. The copy constructor is provided to make sure the
   * handle to the image is properly reference counted. */
  ImageIterator(const Self & it);

  /** Constructor establishes an iterator to walk a particular image and a
   * particular region of that image. */
  ImageIterator(TImage *ptr, const RegionType & region);

  /** operator= is provided to make sure the handle to the image is properly
   * reference counted. */
  Self & operator=(const Self & it);

  /** Set the pixel value */
  void Set(const PixelType & value) const
  {
    // const_cast is needed here because m_Buffer is declared as a const
    // pointer in the superclass which is the ConstIterator.
    this->m_PixelAccessorFunctor.Set(
      *( const_cast< InternalPixelType * >( this->m_Buffer ) + this->m_Offset ), value);
  }

  /** Return a reference to the pixel
   * This method will provide the fastest access to pixel
   * data, but it will NOT support ImageAdaptors. */
  PixelType & Value(void)
  {
    // const_cast is needed here because m_Buffer is declared as a const
    // pointer in the superclass which is the ConstIterator.
    return *( const_cast< InternalPixelType * >( this->m_Buffer ) + this->m_Offset );
  }

  /** Return an iterator for the beginning of the region. "Begin"
   * is defined as the first pixel in the region.
   * \deprecated Use GoToBegin() instead */
  itkLegacyMacro(Self Begin(void) const);

  /** Return an iterator for the end of the region. "End" is defined
  * as one pixel past the last pixel of the region.
  * \deprecated Use GoToEnd() instead */
  itkLegacyMacro(Self End(void) const);

  /** Get the image that this iterator walks. */
  ImageType * GetImage() const
  {
    // const_cast is needed here because m_Image is declared as a const pointer
    // in the base class which is the ConstIterator.
    return const_cast< ImageType * >( this->m_Image.GetPointer() );
  }

protected:

  /** This constructor is declared protected in order to enforce
    const-correctness */
  ImageIterator(const ImageConstIterator< TImage > & it);
  Self & operator=(const ImageConstIterator< TImage > & it);
};
} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkImageIterator.hxx"
#endif

#endif
