refactor of VtkCallbackCommand to be its' own class

vtk/src/commands/TimerCallbackCommand.h

@@ -0,0 +1,22 @@
+#ifndef TIMERCALLBACKCOMMAND_H
+#define TIMERCALLBACKCOMMAND_H
+
+#include <vtkCallbackCommand.h>
+#include "../helperClasses/Program.h"
+
+class TimerCallbackCommand : public vtkCallbackCommand {
+public:
+  TimerCallbackCommand();
+  static TimerCallbackCommand* New(Program *program);
+  void Execute(vtkObject* caller, unsigned long eventId, void* vtkNotUsed(callData)) override;
+
+  void setProgram(Program *program);
+
+private:
+  int time;
+  int dt;
+  int maxTime;
+  Program *program;
+};
+
+#endif