package BoxTools;
/**
*	a <code> DataIterator </code> object is used to iterate through the local
*	boxed data contained in a <code>BoxLayoutData</code> object.
*	a <code> DataIterator </code> object actually iterates through the layout
*	of a <code>BoxLayoutData</code> object. It returns a <code>DataIndex</code>
*	object each time. This <code>DataIndex</code> object is used to get the 
*	corresponding <code>BoxedArray</code> from the <code>BoxLayoutData</code>.
*	<p> Usage: a <code> DataIterator </code> object must be declared local. A typical
*	way to use a  <code> DataIterator </code> is 
*		<code>	DataIterator local DIT = new DataIterator(a_BoxLayoutData.boxLayout());
*			DataIndex local DI;
*			template BoxedArray<double > local boxedArray;
*			while (!DIT.isEnded()){
*				DI=LIT.access();
*			boxedArray=a_BoxLayoutData.getLocalBoxedArray(DI);	
*				 ...
*				DIT.advance();
*			}
*		</code>
*	@see DataIndex, BoxLayout
*	@see <a href="http://davis.lbl.gov/NASA/chombomanual/classDataIterator.html">Chombo Specification</a>
*	@version 1.0
*	@author Tong Wen, LBNL
*	@since 1.0
*/  
public  class DataIterator{
	private int m_index=0;
	private int m_procID=Ti.thisProc();
	private BoxLayout local m_layout;
	private int m_numOfBoxes;

	private DataIterator(){}
	/*a_BL must be closed*/
	public inline DataIterator(BoxLayout local a_BL){
		if (!a_BL.isClosed()) Util.printErrMsg("DataIterator::DataIterator(): BoxLayout must be closed!");
		m_layout=a_BL;
		m_numOfBoxes=m_layout.numBoxesAt(m_procID);
	}
/*	public inline DataIterator(BoxLayoutData local a_BLD){
		m_layout=a_BLD.boxLayout();
		if (!m_layout.isClosed()) Util.printErrMsg("DataIterator::DataIterator(): BoxLayout must be closed!");
		m_numOfBoxes=m_layout.numBoxesAt(m_procID);
	}*/
	public final inline local void reset(){
		m_index=0;
	}
	public final inline local  void advance(){
		if (m_index < m_numOfBoxes) m_index++;
	}

	public final inline local DataIndex local getIndex(){
		if (m_index < m_numOfBoxes)
			return new DataIndex(m_index,m_layout.getRoot(),m_procID);
		else
			return new DataIndex(m_numOfBoxes-1,m_layout.getRoot(),m_procID);	
	}
	public final inline local DataIndex local access(){
		if (m_index < m_numOfBoxes)
			return new DataIndex(m_index,m_layout.getRoot(),m_procID);
		else
			return new DataIndex(m_numOfBoxes-1,m_layout.getRoot(),m_procID);	
	}
	public final inline local boolean isEnded(){
		return (m_index>=m_numOfBoxes);
	}
}