package edu.neu.ccs.eclipse.LoDChecker;

import org.eclipse.jface.viewers.ISelection;

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.jface.viewers.SelectionChangedEvent;

import org.eclipse.jface.viewers.ISelectionChangedListener;

import org.eclipse.ui.ISelectionListener;

import org.eclipse.ui.IWorkbenchPart;

import org.eclipse.core.resources.IFile;

import java.util.Iterator;

import java.util.Vector;

import java.util.Observable;



/*

 * Input for the viewer.

 */                                                       

public class ViewerInput extends Observable implements ISelectionListener{



  Vector elements=new Vector();

  

  public ViewerInput(ISelection selection) {

    if (selection!=null && selection instanceof IStructuredSelection) 

     setSelection((IStructuredSelection)selection);

  }

  

  public Object[] getElements() {

    return elements.toArray();

  }





 /** Executes whenever we make new selection in the Workbench

   */

  public void selectionChanged(IWorkbenchPart part, ISelection selection) {

    if (selection!=null && selection instanceof IStructuredSelection) {

     IStructuredSelection sel=(IStructuredSelection)selection;

     setSelection((IStructuredSelection)selection);

    }

  } 





 /** Convert selection into model objects and notifys listeners if

   */

  protected void setSelection(IStructuredSelection selection) {

    Vector newElements=new Vector();

    Vector removed=new Vector();

    Vector inserted=new Vector();

    Iterator iter=selection.iterator();



    while (iter.hasNext()) {

      Object el=iter.next();

      if (el instanceof IFile && 

          ((IFile)el).getFileExtension()!=null &&

          ((IFile)el).getFileExtension().equals("java")

       ) {

        if (!elements.contains(el)) 

          inserted.add(el);

        newElements.add(el);

      }

    }     



    for (int i=0;i<elements.size();i++) {

      Object el=elements.get(i);

      if (!newElements.contains(el)) removed.add(el);

    }      

                

    if (removed.size()>0) {

      setChanged();

      notifyObservers(new removeElementsEvent(removed));

      clearChanged();       

    }

    if (inserted.size()>0) {

      setChanged();

      notifyObservers(new insertElementsEvent(inserted));

      clearChanged();       

    }



    elements=newElements;

  }



}





//Event classes

class elementsEvent {

   private Vector elements;



   public elementsEvent(Vector elements)  {

    this.elements=elements;

   }

   public Vector getElements() {return elements;}

}



class insertElementsEvent extends elementsEvent {

   public insertElementsEvent(Vector elements)  {

    super(elements);

   }



}



class removeElementsEvent extends elementsEvent {

   public removeElementsEvent(Vector elements)  {

    super(elements);

   }

}