// Selection  (Model of a filtered list of students)
// Modified: Carsten Schuermann
// Date: Sat Mar 25 22:02:34 2006

import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.AbstractListModel;


// Interface for Event driven SelectionListener
interface SelectionListener {
    // Non-trival event:  needs to communicate the selected OOPStudent
    public static class Event{
	private OOPStudent selection;
	public Event( OOPStudent selection){
	    this.selection=selection;
	}
	public OOPStudent getSelection(){ return selection; }
    }	
    void selectionChanged(Event e);
}
  

class Selection extends AbstractListModel {
    // Listener functionality announced to the outside.
    private ArrayList<SelectionListener> listeners = new ArrayList <SelectionListener> ();
    public void addListener(SelectionListener l){listeners.add(l);}
    public void removeListener(SelectionListener l){listeners.remove(l);}

    // Listener functionality connecting the inside to the outside.
    private void notifyListeners() {
	SelectionListener.Event ev = new SelectionListener.Event(this.getSelected ());
	Iterator itr = listeners.iterator();
	while ( itr.hasNext() ){
	    SelectionListener l = (SelectionListener)itr.next();
	    l.selectionChanged(ev);
	}
    }

    // Model of a selection
    private final OOPStudent[] rawData;
    private ArrayList<OOPStudent> filteredData = new ArrayList<OOPStudent>();
    private String filter;
    private OOPStudent selectedStudent;

    public void setSelected (OOPStudent student) {
	if (selectedStudent != null) {selectedStudent.removeListener ();}
	selectedStudent = student;
	if (selectedStudent != null) {
	    // Listener Relationship 5
	    selectedStudent.addListener (new OOPStudentListener () {
		    public void nameChanged () {
			Selection.this.fireContentsChanged( this, 0 , filteredData.size() );
		    }
		});
	}
	notifyListeners ();
    }
    
    public OOPStudent getSelected () {
	return selectedStudent;
    }

    Selection(OOPStudent[] raw){
	rawData = raw;
	updateFilter("");
    }
    
    private boolean checkAgainstFilter(Object o){
	String data = o.toString().toLowerCase();
	String filter = this.filter.toLowerCase();
	return data.indexOf(filter) >=0;
    }
    
    void updateFilter(String newFilter){
	filter = newFilter;
	
	    filteredData.clear();
	    for (int i = 0; i<rawData.length; i++)
		if ( checkAgainstFilter( rawData[i] ) ){
		    filteredData.add(rawData[i]);
		}
	    
	    this.fireContentsChanged( this, 0, filteredData.size() );
    }
    
    public int getSize(){
	return filteredData.size();
	}
    
    public OOPStudent getElementAt(int index){
	return filteredData.get(index);
    }
}