/*
 *  JFLAP - Formal Languages and Automata Package
 * 
 * 
 *  Susan H. Rodger
 *  Computer Science Department
 *  Duke University
 *  August 27, 2009

 *  Copyright (c) 2002-2009
 *  All rights reserved.

 *  JFLAP is open source software. Please see the LICENSE for terms.
 *
 */





package gui.regular;

import automata.Transition;
import javax.swing.table.AbstractTableModel;

/**
 * The <CODE>TransitionTableModel</CODE> is a model for displaying a table of
 * transitions. This will display one transition per row with, in order, the
 * from state ID number, the to state ID number, and the transition description.
 * 
 * @author Thomas Finley
 */

public class TransitionTableModel extends AbstractTableModel {
	/**
	 * Instantiates a new <CODE>TransitionTableModel</CODE>.
	 * 
	 * @param transitions
	 *            the array of transitions to create the table for
	 */
	public TransitionTableModel(Transition[] transitions) {
		this.transitions = transitions;
	}

	/**
	 * Instantiates a new <CODE>TransitionTableModel</CODE> with no contents.
	 */
	public TransitionTableModel() {
		this(new Transition[0]);
	}

	/**
	 * This table model has three columns.
	 * 
	 * @return the number 3!
	 */
	public int getColumnCount() {
		return 3;
	}

	/**
	 * This table model has as many rows are there are transitions.
	 * 
	 * @return the number of transitions
	 */
	public int getRowCount() {
		return transitions.length;
	}

	/**
	 * Returns the transition for a row. This method will fail if there isn't a
	 * transition for this index.
	 * 
	 * @param row
	 *            the row to get the transition for
	 * @return the transition for this row
	 */
	public Transition getTransition(int row) {
		return transitions[row];
	}

	/**
	 * Returns the contents of a cell.
	 * 
	 * @param row
	 *            the number of the transition to display
	 * @param column
	 *            controls which parameter of the transition shall be displayed,
	 *            for 0 through 2, this is from, to, and description, in that
	 *            order
	 * @return the string description for the appropriate part of a transition
	 */
	public Object getValueAt(int row, int column) {
		switch (column) {
		case 0:
			return "" + transitions[row].getFromState().getID();
		case 1:
			return "" + transitions[row].getToState().getID();
		case 2:
			return transitions[row].getDescription();
		default:
			return null;
		}
	}

	/**
	 * Returns the name for a column.
	 * 
	 * @param column
	 *            the index of the column to get the name for
	 * @return the name for the indicated column
	 */
	public String getColumnName(int column) {
		return COLUMN_NAMES[column];
	}

	/** The list of transitions displayed in the table. */
	private Transition[] transitions;

	/** The column names. */
	private static final String[] COLUMN_NAMES = { "From", "To", "Label" };
}