/*
 *  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.viewer;

import automata.State;
import automata.Transition;
import java.awt.Rectangle;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

/**
 * This variant of automaton pane is meant to draw the automaton only with a
 * <CODE>SelectionDrawer</CODE> that restricts the display to what is selected
 * (plus a little extra for padding).
 * 
 * @author Thomas Finley
 */

public class ZoomPane extends AutomatonPane {
	/**
	 * Instantiates a <CODE>ZoomPane</CODE> for a given <CODE>SelectionDrawer</CODE>.
	 * 
	 * @param drawer
	 *            the selection drawer
	 */
	public ZoomPane(SelectionDrawer drawer) {
		super(drawer);
		drawer.addChangeListener(new ChangeListener() {
			public void stateChanged(ChangeEvent e) {
				transform = null;
			}
		});
	}

	/**
	 * Returns the bounds for the section of the automaton that should be drawn.
	 * In the case of this object this will be restricted to those objects which
	 * are restricted. If no objects are selected, then the default superclass
	 * bounds are returned
	 * 
	 * @return the bounds for this zoom pane
	 */
	protected Rectangle getAutomatonBounds() {
		SelectionDrawer d = (SelectionDrawer) drawer;
		State[] s = d.getSelected();
		Transition[] t = d.getSelectedTransitions();
		// What if nothing is selected?
		if (s.length + t.length == 0)
			return super.getAutomatonBounds();

		Rectangle rect = null;
		if (s.length != 0) {
			rect = d.getBounds(s[0]);
			for (int i = 1; i < s.length; i++)
				rect.add(d.getBounds(s[i]));
		} else
			rect = d.getBounds(t[0]);
		for (int i = 0; i < t.length; i++)
			rect.add(d.getBounds(t[i]));
		return rect;
	}
}