ENH: Add TestXdmfVisitorValueCounter to demonstrate how to write visitor...

ENH: Add TestXdmfVisitorValueCounter to demonstrate how to write visitor operations over the Xdmf graph that do something other than write to disk.  Separate hexahedron grid example into a header file so that other test cases can use it for testing.

tests/Cxx/CMakeLists.txt

@@ -6,6 +6,7 @@ set(XdmfCxxTests
 	TestXdmfGrid
 	TestXdmfTopology
 	TestXdmfVisitor
+	TestXdmfVisitorValueCounter
 )
 
 foreach(test ${XdmfCxxTests})

tests/Cxx/TestXdmfVisitor.cpp

-#include "XdmfAttribute.hpp"
-#include "XdmfArray.hpp"
-#include "XdmfDomain.hpp"
-#include "XdmfGeometry.hpp"
-#include "XdmfGrid.hpp"
-#include "XdmfTopology.hpp"
 #include "XdmfVisitor.hpp"
 
+#include "XdmfTestDataGenerator.hpp"
+
 int main(int argc, char* argv[])
 {
 	boost::shared_ptr<XdmfVisitor> visitor = XdmfVisitor::New();
 	visitor->setLightDataLimit(10);
-	boost::shared_ptr<XdmfGrid> grid = XdmfGrid::New();
-
-	grid->setName("test");
-
-	// Set Geometry
-	double points[] = {0.1, 0.1, 1.1, 1.1, 0.1, 1.1, 3.1, 0.1, 2.1, 0.1, 1.1, 1.1, 1.1, 1.1, 1.1, 3.1, 2.1, 2.1,
-			0.1, 0.1, -1.1, 1.1, 0.1, -1.1, 3.1, 0.1, -2.1, 0.1, 1.1, -1.1, 1.1, 1.1, -1.1, 3.1, 2.1, -2.1};
-	grid->getGeometry()->setGeometryType(XdmfGeometryType::XYZ());
-	grid->getGeometry()->getArray()->copyValues(0, &points[0], 36);
-
-	// Set Topology
-	int connectivity[] = {0, 1, 7, 6, 3, 4, 10, 9, 1, 2, 8, 7, 4, 5, 11, 10};
-	grid->getTopology()->setTopologyType(XdmfTopologyType::Hexahedron());
-	grid->getTopology()->getArray()->copyValues(0, &connectivity[0], 16);
-
-	// Add Node Attribute
-	boost::shared_ptr<XdmfAttribute> nodalAttribute = XdmfAttribute::New();
-	int nodeValues[] = {100, 200, 300, 300, 400, 500, 300, 400, 500, 500, 600, 700};
-	nodalAttribute->setName("Nodal Attribute");
-	nodalAttribute->setAttributeType(XdmfAttributeType::Scalar());
-	nodalAttribute->setAttributeCenter(XdmfAttributeCenter::Node());
-	nodalAttribute->getArray()->copyValues(0, &nodeValues[0], 12);
-
-	// Add Cell Attribute
-	boost::shared_ptr<XdmfAttribute> cellAttribute = XdmfAttribute::New();
-	int cellValues[] = {100, 200};
-	cellAttribute->setName("Cell Attribute");
-	cellAttribute->setAttributeType(XdmfAttributeType::Scalar());
-	cellAttribute->setAttributeCenter(XdmfAttributeCenter::Cell());
-	cellAttribute->getArray()->copyValues(0, &cellValues[0], 2);
 
-	grid->insert(nodalAttribute);
-	grid->insert(cellAttribute);
+	boost::shared_ptr<XdmfGrid> grid = XdmfTestDataGenerator::createHexahedron();
 
 	boost::shared_ptr<XdmfDomain> domain = XdmfDomain::New();
 	domain->insert(grid);

tests/Cxx/TestXdmfVisitorValueCounter.cpp

+#include "XdmfVisitor.hpp"
+
+#include "XdmfTestDataGenerator.hpp"
+
+// Make a new XdmfVisitor that simply counts number of values
+class XdmfVisitorValueCounter : public XdmfVisitor {
+public:
+
+	XdmfNewMacro(XdmfVisitorValueCounter);
+
+	int getCount()
+	{
+		return mCount;
+	}
+
+	virtual void visit(const XdmfArray * const array, boost::shared_ptr<XdmfVisitor> visitor)
+	{
+		mCount += array->getSize();
+	}
+
+protected:
+
+	XdmfVisitorValueCounter() :
+		mCount(0)
+	{
+	}
+
+	~XdmfVisitorValueCounter()
+	{
+	};
+
+private:
+
+	int mCount;
+};
+
+int main(int argc, char* argv[])
+{
+	boost::shared_ptr<XdmfVisitorValueCounter> visitor = XdmfVisitorValueCounter::New();
+	boost::shared_ptr<XdmfGrid> grid = XdmfTestDataGenerator::createHexahedron();
+
+	grid->write(visitor);
+
+	assert(visitor->getCount() == 66);
+
+	return 0;
+}

tests/Cxx/XdmfTestDataGenerator.hpp

+#include "XdmfAttribute.hpp"
+#include "XdmfArray.hpp"
+#include "XdmfDomain.hpp"
+#include "XdmfGeometry.hpp"
+#include "XdmfGrid.hpp"
+#include "XdmfTopology.hpp"
+
+class XdmfTestDataGenerator {
+public:
+
+	/**
+	 * Number of Cells = 2
+	 * Number of Points = 12
+	 * Number of Attributes = 2
+	 * 	Cell Attributes = 1
+	 * 	Nodal Attributes = 1
+	 * Total Number of Values = 66
+	 *
+	 */
+	//
+	//
+
+	static boost::shared_ptr<XdmfGrid> createHexahedron()
+	{
+		boost::shared_ptr<XdmfGrid> grid = XdmfGrid::New();
+		grid->setName("Hexahedron");
+
+		// Set Geometry
+		double points[] = {0.1, 0.1, 1.1, 1.1, 0.1, 1.1, 3.1, 0.1, 2.1, 0.1, 1.1, 1.1, 1.1, 1.1, 1.1, 3.1, 2.1, 2.1,
+				0.1, 0.1, -1.1, 1.1, 0.1, -1.1, 3.1, 0.1, -2.1, 0.1, 1.1, -1.1, 1.1, 1.1, -1.1, 3.1, 2.1, -2.1};
+		grid->getGeometry()->setGeometryType(XdmfGeometryType::XYZ());
+		grid->getGeometry()->getArray()->copyValues(0, &points[0], 36);
+
+		// Set Topology
+		int connectivity[] = {0, 1, 7, 6, 3, 4, 10, 9, 1, 2, 8, 7, 4, 5, 11, 10};
+		grid->getTopology()->setTopologyType(XdmfTopologyType::Hexahedron());
+		grid->getTopology()->getArray()->copyValues(0, &connectivity[0], 16);
+
+		// Add Node Attribute
+		boost::shared_ptr<XdmfAttribute> nodalAttribute = XdmfAttribute::New();
+		int nodeValues[] = {100, 200, 300, 300, 400, 500, 300, 400, 500, 500, 600, 700};
+		nodalAttribute->setName("Nodal Attribute");
+		nodalAttribute->setAttributeType(XdmfAttributeType::Scalar());
+		nodalAttribute->setAttributeCenter(XdmfAttributeCenter::Node());
+		nodalAttribute->getArray()->copyValues(0, &nodeValues[0], 12);
+
+		// Add Cell Attribute
+		boost::shared_ptr<XdmfAttribute> cellAttribute = XdmfAttribute::New();
+		int cellValues[] = {100, 200};
+		cellAttribute->setName("Cell Attribute");
+		cellAttribute->setAttributeType(XdmfAttributeType::Scalar());
+		cellAttribute->setAttributeCenter(XdmfAttributeCenter::Cell());
+		cellAttribute->getArray()->copyValues(0, &cellValues[0], 2);
+
+		grid->insert(nodalAttribute);
+		grid->insert(cellAttribute);
+		return grid;
+	}
+
+};
+