package horstmann.ch10_command;
import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JTextArea;

/**
   This action places a greeting into a text field
   and afterwards disables itself and enables its
   opposite action.
 */
@SuppressWarnings("serial")
public class GreetingAction extends AbstractAction
{
	/**
      Constructs a greeting action.
      @param greeting the string to add to the text area
      @param textArea the text area to which to add the greeting
	 */
	public GreetingAction(String greeting, JTextArea textArea)
	{
		this.greeting = greeting;
		this.textArea = textArea;
	}

	/**
      Sets the opposite action.
      @param action the action to be enabled after this action was
      carried out
	 */
	public void setOpposite(Action action)
	{
		oppositeAction = action;
	}

	public void actionPerformed(ActionEvent event)
	{
		textArea.append(greeting);
		textArea.append("\n");
		if (oppositeAction != null)
		{
			setEnabled(false);
			oppositeAction.setEnabled(true);
		}
	}

	private String greeting;
	private JTextArea textArea;
	private Action oppositeAction;
}