STYLE: Make PrintSelf implementation style consistent

Make `PrintSelf`implementation style consistent following the ITK SWG
coding style guideline and the available ITK macros:
- Always print the superclass first.
- Print only the class instance variables.
- Use the `os << indent << "{ivarName}: " << m_ivarName << std::endl`
  recipe: do not print the leading `m_` of the ivar; use a colon after
  printing its name; leave a whitespace between the colon and the
  printed value of the ivar.
- For boolean ivars print `On`/`Off` according to their values using the
  ternary operator.
- Use `itkPrintSelfObjectMacro` to print objects inheriting from
  `itk::LightObject` that can be null.
- For pointers that do not inherit from `itk::LightObject` check whether
  they are non-null before attempting to print them and print the
  `(empty)` string otherwise.
- Rely on the self printing ability of the ITK classes to avoid
  boilerplate code when printing the corresponding ivars in other
  classes' `PrintSelf` methods.
- Take advantage of the output stream `<<` insertion operator overload
  for `std::vector` types in the `itk::print_helper` namespace defined
  in `itkPrintHelper.h` to print such types consistently.
- Cast custom types to their numerical values using
  `itk::NumericTraits::PrinType` so that they are printed as expected.
- Remove statements printing the hard-coded class name and its own
  pointer, e.g.
  ```
  os << indent << "ArrowSpatialObject(" << this << ")" << std::endl;
  ```
  `PrintSelf` does this without requiring the removed line.
- Save typing `this->` to point to the instance of the current class.

Apply the same principles to the `<<` operator overloads.

Overload the ostream operator for the `FixedImageSamplePoint` class used
by the `itk::ImageToImageMetric` class.

Overload the ostream operator for the `ImageVoxel` class used by the
`itk::DeformableSimplexMesh3DGradientConstraintForceFilter` class.

Examples/Filtering/CompositeFilterExample.cxx

@@ -237,7 +237,7 @@ CompositeExampleImageFilter<TImage>::PrintSelf(std::ostream & os,
 {
   Superclass::PrintSelf(os, indent);
 
-  os << indent << "Threshold:" << this->m_Threshold << std::endl;
+  os << indent << "Threshold: " << m_Threshold << std::endl;
 }
 
 } // end namespace itk

Modules/Compatibility/Deprecated/include/itkVectorCentralDifferenceImageFunction.hxx

@@ -33,7 +33,8 @@ void
 VectorCentralDifferenceImageFunction<TInputImage, TCoordRep>::PrintSelf(std::ostream & os, Indent indent) const
 {
   this->Superclass::PrintSelf(os, indent);
-  os << indent << "UseImageDirection = " << this->m_UseImageDirection << std::endl;
+
+  os << indent << "UseImageDirection: " << m_UseImageDirection << std::endl;
 }
 
 template <typename TInputImage, typename TCoordRep>

Modules/Core/Common/include/itkBSplineKernelFunction.h

@@ -82,7 +82,8 @@ class ITK_TEMPLATE_EXPORT BSplineKernelFunction : public KernelFunctionBase<TRea
   PrintSelf(std::ostream & os, Indent indent) const override
   {
     Superclass::PrintSelf(os, indent);
-    os << indent << "Spline Order: " << SplineOrder << std::endl;
+
+    os << indent << "SplineOrder: " << SplineOrder << std::endl;
   }
 
 private:

Modules/Core/Common/include/itkColorTable.hxx

@@ -19,6 +19,7 @@
 #define itkColorTable_hxx
 
 #include "itkNumericTraits.h"
+#include "itkPrintHelper.h"
 #include "vnl/vnl_sample.h"
 
 #include <sstream>
@@ -365,14 +366,13 @@ template <typename TComponent>
 void
 ColorTable<TComponent>::PrintSelf(std::ostream & os, Indent indent) const
 {
+  using namespace print_helper;
+
   Superclass::PrintSelf(os, indent);
 
-  os << indent << "NumberOfColors = " << m_NumberOfColors << std::endl;
-  for (unsigned int i = 0; i < m_NumberOfColors; ++i)
-  {
-    os << indent << "ColorName[" << i << "] = " << m_ColorName[i] << ", "
-       << "Color[" << i << "] = " << m_Color[i] << std::endl;
-  }
+  os << indent << "NumberOfColors: " << m_NumberOfColors << std::endl;
+  os << indent << "ColorName: " << m_ColorName << std::endl;
+  os << indent << "Color: " << m_Color << std::endl;
 }
 } // namespace itk
 

Modules/Core/Common/include/itkConstNeighborhoodIterator.hxx

@@ -566,6 +566,8 @@ template <typename TImage, typename TBoundaryCondition>
 void
 ConstNeighborhoodIterator<TImage, TBoundaryCondition>::PrintSelf(std::ostream & os, Indent indent) const
 {
+  Superclass::PrintSelf(os, indent);
+
   DimensionValueType i;
 
   os << indent;
@@ -623,7 +625,6 @@ ConstNeighborhoodIterator<TImage, TBoundaryCondition>::PrintSelf(std::ostream &
     os << m_InnerBoundsHigh[i] << ' ';
   }
   os << "} }" << std::endl;
-  Superclass::PrintSelf(os, indent.GetNextIndent());
 }
 
 template <typename TImage, typename TBoundaryCondition>

Modules/Core/Common/include/itkConstNeighborhoodIteratorWithOnlyIndex.hxx

@@ -399,6 +399,8 @@ template <typename TImage>
 void
 ConstNeighborhoodIteratorWithOnlyIndex<TImage>::PrintSelf(std::ostream & os, Indent indent) const
 {
+  Superclass::PrintSelf(os, indent);
+
   DimensionValueType i;
 
   os << indent;
@@ -448,7 +450,6 @@ ConstNeighborhoodIteratorWithOnlyIndex<TImage>::PrintSelf(std::ostream & os, Ind
     os << m_InnerBoundsHigh[i] << ' ';
   }
   os << "} }" << std::endl;
-  Superclass::PrintSelf(os, indent.GetNextIndent());
 }
 
 template <typename TImage>

Modules/Core/Common/include/itkConstShapedNeighborhoodIterator.hxx

@@ -23,16 +23,16 @@ template <typename TImage, typename TBoundaryCondition>
 void
 ConstShapedNeighborhoodIterator<TImage, TBoundaryCondition>::PrintSelf(std::ostream & os, Indent indent) const
 {
-  os << indent << "ConstShapedNeighborhoodIterator {this = " << this;
-  os << " m_ActiveIndexList = [";
+  Superclass::PrintSelf(os, indent);
+
+  os << "ActiveIndexList: [";
   for (auto it = m_ActiveIndexList.begin(); it != m_ActiveIndexList.end(); ++it)
   {
     os << *it << ' ';
   }
   os << "] ";
-  os << " m_CenterIsActive = " << m_CenterIsActive;
-  os << '}' << std::endl;
-  Superclass::PrintSelf(os, indent.GetNextIndent());
+
+  os << "CenterIsActive: " << (m_CenterIsActive ? "On" : "Off") << std::endl;
 }
 
 template <typename TImage, typename TBoundaryCondition>

Modules/Core/Common/include/itkImageDuplicator.hxx

@@ -60,9 +60,13 @@ void
 ImageDuplicator<TInputImage>::PrintSelf(std::ostream & os, Indent indent) const
 {
   Superclass::PrintSelf(os, indent);
-  os << indent << "Input Image: " << m_InputImage << std::endl;
-  os << indent << "Output Image: " << m_DuplicateImage << std::endl;
-  os << indent << "Internal Image Time: " << m_InternalImageTime << std::endl;
+
+  itkPrintSelfObjectMacro(InputImage);
+  itkPrintSelfObjectMacro(DuplicateImage);
+
+  os << indent
+     << "InternalImageTime: " << static_cast<typename NumericTraits<ModifiedTimeType>::PrintType>(m_InternalImageTime)
+     << std::endl;
 }
 } // end namespace itk
 

Modules/Core/Common/include/itkInPlaceImageFilter.hxx

@@ -37,17 +37,9 @@ void
 InPlaceImageFilter<TInputImage, TOutputImage>::PrintSelf(std::ostream & os, Indent indent) const
 {
   Superclass::PrintSelf(os, indent);
+
   os << indent << "InPlace: " << (m_InPlace ? "On" : "Off") << std::endl;
-  if (this->CanRunInPlace())
-  {
-    os << indent << "The input and output to this filter are the same type. The filter can be run in place."
-       << std::endl;
-  }
-  else
-  {
-    os << indent << "The input and output to this filter are different types. The filter cannot be run in place."
-       << std::endl;
-  }
+  os << indent << "RunningInPlace: " << (m_RunningInPlace ? "On" : "Off") << std::endl;
 }
 
 template <typename TInputImage, typename TOutputImage>

Modules/Core/Common/include/itkLoggerThreadWrapper.hxx

@@ -226,12 +226,15 @@ LoggerThreadWrapper<SimpleLoggerType>::PrintSelf(std::ostream & os, Indent inden
 {
   Superclass::PrintSelf(os, indent);
 
-  os << indent << "Thread ID: " << this->m_Thread.get_id() << std::endl;
-  os << indent << "Low-priority Message Delay: " << this->m_Delay << std::endl;
-  os << indent << "Operation Queue Size: " << this->m_OperationQ.size() << std::endl;
-  os << indent << "Message Queue Size: " << this->m_MessageQ.size() << std::endl;
-  os << indent << "Level Queue Size: " << this->m_LevelQ.size() << std::endl;
-  os << indent << "Output Queue Size: " << this->m_OutputQ.size() << std::endl;
+  os << indent << "Thread ID: " << m_Thread.get_id() << std::endl;
+  os << indent << "TerminationRequested: " << m_TerminationRequested << std::endl;
+
+  os << indent << "OperationQ size: " << m_OperationQ.size() << std::endl;
+  os << indent << "MessageQ size: " << m_MessageQ.size() << std::endl;
+  os << indent << "LevelQ size: " << m_LevelQ.size() << std::endl;
+  os << indent << "OutputQ size: " << m_OutputQ.size() << std::endl;
+
+  os << indent << "Delay: " << m_Delay << std::endl;
 }
 
 } // namespace itk

Modules/Core/Common/include/itkNeighborhood.h

@@ -327,10 +327,10 @@ template <typename TPixel, unsigned int VDimension, typename TContainer>
 std::ostream &
 operator<<(std::ostream & os, const Neighborhood<TPixel, VDimension, TContainer> & neighborhood)
 {
-  os << "Neighborhood:" << std::endl;
-  os << "    Radius:" << neighborhood.GetRadius() << std::endl;
-  os << "    Size:" << neighborhood.GetSize() << std::endl;
-  os << "    DataBuffer:" << neighborhood.GetBufferReference() << std::endl;
+  os << "Neighborhood: " << std::endl;
+  os << "    Radius: " << neighborhood.GetRadius() << std::endl;
+  os << "    Size: " << neighborhood.GetSize() << std::endl;
+  os << "    DataBuffer: " << neighborhood.GetBufferReference() << std::endl;
 
   return os;
 }

Modules/Core/Common/include/itkObjectStore.hxx

@@ -18,6 +18,9 @@
 #ifndef itkObjectStore_hxx
 #define itkObjectStore_hxx
 
+#include "itkNumericTraits.h"
+#include "itkPrintHelper.h"
+
 
 namespace itk
 {
@@ -136,14 +139,16 @@ template <typename TObjectType>
 void
 ObjectStore<TObjectType>::PrintSelf(std::ostream & os, Indent indent) const
 {
+  using namespace print_helper;
+
   Superclass::PrintSelf(os, indent);
 
-  os << indent << "m_GrowthStrategy: " << m_GrowthStrategy << std::endl;
-  os << indent << "m_Size: " << m_Size << std::endl;
-  os << indent << "m_LinearGrowthSize: " << static_cast<SizeValueType>(m_LinearGrowthSize) << std::endl;
-  os << indent << "Free list size: " << static_cast<SizeValueType>(m_FreeList.size()) << std::endl;
-  os << indent << "Free list capacity: " << static_cast<SizeValueType>(m_FreeList.capacity()) << std::endl;
-  os << indent << "Number of blocks in store: " << static_cast<SizeValueType>(m_Store.size()) << std::endl;
+  os << indent << "GrowthStrategy: " << m_GrowthStrategy << std::endl;
+  os << indent << "Size: " << static_cast<typename NumericTraits<SizeValueType>::PrintType>(m_Size) << std::endl;
+  os << indent
+     << "LinearGrowthSize: " << static_cast<typename NumericTraits<SizeValueType>::PrintType>(m_LinearGrowthSize)
+     << std::endl;
+  os << indent << "FreeList: " << m_FreeList << std::endl;
 }
 } // end namespace itk
 

Modules/Core/Common/include/itkPhasedArray3DSpecialCoordinatesImage.hxx

@@ -39,10 +39,10 @@ PhasedArray3DSpecialCoordinatesImage<TPixel>::PrintSelf(std::ostream & os, Inden
 {
   Superclass::PrintSelf(os, indent);
 
-  os << indent << "m_RadiusSampleSize = " << m_RadiusSampleSize << std::endl;
-  os << indent << "m_AzimuthAngularSeparation = " << m_AzimuthAngularSeparation << std::endl;
-  os << indent << "m_ElevationAngularSeparation = " << m_ElevationAngularSeparation << std::endl;
-  os << indent << "m_FirstSampleDistance = " << m_FirstSampleDistance << std::endl;
+  os << indent << "RadiusSampleSize: " << m_RadiusSampleSize << std::endl;
+  os << indent << "AzimuthAngularSeparation: " << m_AzimuthAngularSeparation << std::endl;
+  os << indent << "ElevationAngularSeparation: " << m_ElevationAngularSeparation << std::endl;
+  os << indent << "FirstSampleDistance: " << m_FirstSampleDistance << std::endl;
 }
 } // end namespace itk
 

Modules/Core/Common/include/itkSparseFieldLayer.hxx

@@ -42,8 +42,8 @@ SparseFieldLayer<TNodeType>::PrintSelf(std::ostream & os, Indent indent) const
 {
   Superclass::PrintSelf(os, indent);
 
-  os << indent << "m_HeadNode:  " << m_HeadNode << std::endl;
-  os << indent << "Empty? : " << this->Empty() << std::endl;
+  os << indent << "HeadNode: " << m_HeadNode << std::endl;
+  os << indent << "Size: " << m_Size << std::endl;
 }
 
 template <typename TNodeType>

Modules/Core/Common/src/itkThreadLogger.cxx

@@ -208,12 +208,15 @@ ThreadLogger::PrintSelf(std::ostream & os, Indent indent) const
 {
   Superclass::PrintSelf(os, indent);
 
-  os << indent << "Thread ID: " << this->m_Thread.get_id() << std::endl;
-  os << indent << "Low-priority Message Delay: " << this->m_Delay << std::endl;
-  os << indent << "Operation Queue Size: " << this->m_OperationQ.size() << std::endl;
-  os << indent << "Message Queue Size: " << this->m_MessageQ.size() << std::endl;
-  os << indent << "Level Queue Size: " << this->m_LevelQ.size() << std::endl;
-  os << indent << "Output Queue Size: " << this->m_OutputQ.size() << std::endl;
+  os << indent << "Thread ID: " << m_Thread.get_id() << std::endl;
+  os << indent << "TerminationRequested: " << m_TerminationRequested << std::endl;
+
+  os << indent << "OperationQ size: " << m_OperationQ.size() << std::endl;
+  os << indent << "MessageQ size: " << m_MessageQ.size() << std::endl;
+  os << indent << "LevelQ size: " << m_LevelQ.size() << std::endl;
+  os << indent << "OutputQ size: " << m_OutputQ.size() << std::endl;
+
+  os << indent << "Delay: " << m_Delay << std::endl;
 }
 
 } // namespace itk

Modules/Core/GPUCommon/include/itkGPUReduction.hxx

@@ -50,7 +50,17 @@ GPUReduction<TElement>::PrintSelf(std::ostream & os, Indent indent) const
 {
   Superclass::PrintSelf(os, indent);
 
-  // GetTypenameInString( typeid(TElement), os);
+  itkPrintSelfObjectMacro(GPUKernelManager);
+  itkPrintSelfObjectMacro(GPUDataManager);
+
+  os << indent << "ReduceGPUKernelHandle: " << m_ReduceGPUKernelHandle << std::endl;
+  os << indent << "TestGPUKernelHandle: " << m_TestGPUKernelHandle << std::endl;
+
+  os << indent << "Size: " << m_Size << std::endl;
+  os << indent << "SmallBlock: " << (m_SmallBlock ? "On" : "Off") << std::endl;
+
+  os << indent << "GPUResult: " << static_cast<typename NumericTraits<TElement>::PrintType>(m_GPUResult) << std::endl;
+  os << indent << "CPUResult: " << static_cast<typename NumericTraits<TElement>::PrintType>(m_CPUResult) << std::endl;
 }
 
 template <typename TElement>

Modules/Core/GPUCommon/src/itkGPUDataManager.cxx

@@ -264,12 +264,16 @@ GPUDataManager::Initialize()
 void
 GPUDataManager::PrintSelf(std::ostream & os, Indent indent) const
 {
-  os << indent << "GPUDataManager (" << this << ')' << std::endl;
-  os << indent << "m_BufferSize: " << m_BufferSize << std::endl;
-  os << indent << "m_IsGPUBufferDirty: " << m_IsGPUBufferDirty << std::endl;
-  os << indent << "m_GPUBuffer: " << m_GPUBuffer << std::endl;
-  os << indent << "m_IsCPUBufferDirty: " << m_IsCPUBufferDirty << std::endl;
-  os << indent << "m_CPUBuffer: " << m_CPUBuffer << std::endl;
+  Superclass::PrintSelf(os, indent);
+
+  os << indent << "BufferSize: " << m_BufferSize << std::endl;
+  os << indent << "ContextManager: " << m_ContextManager << std::endl;
+  os << indent << "CommandQueueId: " << m_CommandQueueId << std::endl;
+  os << indent << "MemFlags: " << m_MemFlags << std::endl;
+  os << indent << "GPUBuffer: " << m_GPUBuffer << std::endl;
+  os << indent << "CPUBuffer: " << m_CPUBuffer << std::endl;
+  os << indent << "IsGPUBufferDirty: " << (m_IsGPUBufferDirty ? "On" : "Off") << std::endl;
+  os << indent << "IsCPUBufferDirty: " << m_IsCPUBufferDirty ? "On" : "Off") << std::endl;
 }
 
 } // namespace itk

Modules/Core/GPUFiniteDifference/include/itkGPUFiniteDifferenceImageFilter.hxx

@@ -294,22 +294,20 @@ GPUFiniteDifferenceImageFilter<TInputImage, TOutputImage, TParentImageFilter>::P
                                                                                          Indent         indent) const
 {
   GPUSuperclass::PrintSelf(os, indent);
-  CPUSuperclass::PrintSelf(os, indent);
-  /*
-    os << indent << "UseImageSpacing: " << ( m_UseImageSpacing ? "On" : "Off" ) << std::endl;
-    os << indent << "State: " << m_State << std::endl;
-    os << std::endl;
-    if ( m_DifferenceFunction )
-      {
-      os << indent << "DifferenceFunction: " << std::endl;
-      m_DifferenceFunction->Print( os, indent.GetNextIndent() );
-      }
-    else
-      {
-      os << indent << "DifferenceFunction: " << "(None)" << std::endl;
-      }
-    os << std::endl;
-  */
+
+  os << indent << "InitTime: " << static_cast<typename NumericTraits<TimeProbe>::PrintType>(m_InitTime) << std::endl;
+  os << indent
+     << "ComputeUpdateTime: " << static_cast<typename NumericTraits<TimeProbe>::PrintType>(m_ComputeUpdateTime)
+     << std::endl;
+  os << indent << "ApplyUpdateTime: " << static_cast<typename NumericTraits<TimeProbe>::PrintType>(m_ApplyUpdateTime)
+     << std::endl;
+  os << indent << "SmoothFieldTime: " << static_cast<typename NumericTraits<TimeProbe>::PrintType>(m_SmoothFieldTime)
+     << std::endl;
+
+  itkPrintSelfObjectMacro(DifferenceFunction);
+
+  os << indent << "UseImageSpacing: " << (m_UseImageSpacing ? "On" : "Off") << std::endl;
+  os << indent << "State: " << m_State << std::endl;
 }
 
 } // end namespace itk