/*
 * Calculator Default ButtonHandler
 *
 * Developed for "Rethinking CS101", a project of Lynn Andrea Stein's AP Group.
 * For more information, see <a href="http://www.ai.mit.edu/projects/cs101/">the
 * CS101 homepage</a> or email <las@ai.mit.edu>.
 *
 * Copyright (C) 1999 Massachusetts Institute of Technology.
 * Please do not redistribute without obtaining permission.
 */
package calculator;
import cs101.io.Console;
import cs101.lang.Animate;
import cs101.lang.AnimatorThread;

/**
 * This class provides the smarts for a basic four-function 
 * calculator.  It repeatedly calls its Calculator(GUI)'s getButton()
 * to consume the buttonIDs that the Calculator object produces. <p>
 *
 * <P>Copyright (c) 1999 Massachusetts Institute of Technology
 *
 * @author  Todd C. Parnell, tparnell@ai.mit.edu
 * @author  Emil Sit, sit@mit.edu
 * @author  Lynn Andrea Stein, las@ai.mit.edu
 * @version $Id: ButtonHandler.java,v 1.1.1.1 2002/06/05 21:56:28 root Exp $
 *
 * @see Calculator
 * @see cs101.util.IntBuffer
 */

public class ButtonHandler implements Animate 
{

  protected Calculator gui;
  protected CalculatorState brains;
  protected AnimatorThread spirit;

  /**
   * Build a ButtonHandler object from a Calculator gui passed in as
   * an argument.
   */
  protected ButtonHandler( CalculatorGUI myGUI ) 
  {
    this.gui = myGUI;
    this.brains = new CalculatorState( this.gui );
    this.brains.resetCalc();
    this.spirit = new AnimatorThread(this);
    this.spirit.start();
  }

  protected ButtonHandler( )
    {
	this( new CalculatorGUI() );
    }

  /**
   * Provides the interactive control loop of this animate object.
   * @see java.lang.Animate
   */
  public void act () 
  {
      int buttonID = this.gui.getButton();

      // Deal with number buttons -- add to display text
      if ( buttonID < 10 && buttonID >= 0) 
      {
	  this.brains.handleNumKey( buttonID );
	  return;
      }

      // deal with everything else
      switch ( buttonID ) 
      {
	  case Calculator.DOT:
	    this.brains.handleDecimal();
	    break;

	  case Calculator.OP_MUL:
	  case Calculator.OP_DIV:
	  case Calculator.OP_ADD:
	  case Calculator.OP_SUB:
	    this.brains.handleOperation( buttonID );
	    break;

	  case Calculator.EQUALS:
	    this.brains.handleEquals();
	    break;

	  case Calculator.CLEAR:
	    this.brains.resetCalc();
	    break;

	  default:
	    Console.println("ERROR:  unmatched buttonID.");
	    Console.println( this.brains.toString() );
      }
  }
}


/* Comments:
 *
 * History:
 *     $Log: ButtonHandler.java,v $
 *     Revision 1.1.1.1  2002/06/05 21:56:28  root
 *     CS101 comes to Olin finally.
 *
 *     Revision 1.2  1999/10/17 05:40:59  jsmthng
 *     Created constructor which took in CalculatorGUI (because it was
 *     complaining that there wasn't one, before) -- no-parameters
 *     constructor still exists.
 *
 *     Revision 1.1  1999/10/08 15:09:23  las
 *     This pset replaces the old Calculator pset.  However, not everything
 *     has been transferred.  At the moment, it's just java, doc, and index.
 *     The rest are still in the repository under Calculator-Old.
 *
 *     Revision 1.5  1998/07/24 16:37:13  tparnell
 *     Placate new javadoc behavior
 *
 *     Revision 1.4  1998/07/23 14:28:26  tparnell
 *     made class public
 *
 *     Revision 1.3  1998/07/06 20:22:56  tparnell
 *     changed from while (true)... to while (!this.stopped)... in support of
 *     JDK1.2 deprecation of Thread.stop()
 *
 *     Revision 1.2  1998/06/05 05:19:26  craigh
 *     added getButtonLabel() to Calculator interface.  Implemented the
 *     method in CalculatorGUI, and made use of it in ButtonHandler.
 *
 *     Revision 1.1  1998/02/26 17:25:43  tparnell
 *     Reconstruction from hard drive failure.  Everything appears intact.
 *
 *     Revision 1.3  1997/10/05 21:11:18  shong
 *     Updated for fall97, to Java 1.1
 *     changed GUI, using 1.1 Event Model
 *
 *     Revision 1.2  1997/07/16 14:15:19  tparnell
 *     *** empty log message ***
 *
 *     Revision 1.2  1996/10/04 16:20:17  las
 *     Transformed Calculator into an application and made it a package.  See
 *     STAFF_SETUP for which files are public.  To run, use Calculator.Main.
 *
 *     Specifics:
 *         Added Main.java, which starts the calculator program (both
 *     CalculatorGUI and ButtonHandler);
 *         Made Calculator an interface;
 *         Moved GUI implementation (previously in Calculator) to
 *     CalculatorGUI.
 *         Added clear button, which looks pretty gross right now.  (It can
 *     be deleted in a single line, though.)
 *
 *
 */