/*
 * NumButtonObj Class
 *
 * 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) 1997 Massachusetts Institute of Technology.
 * Please do not redistribute without obtaining permission.
 */
package Calculator;

/**
 *  This class is a smart button object that handles the Calculator's
 *  numeric buttons.  Every ButtonHandler should have ten ( 0 - 9 ).
 *
 * @author:  Lynn Andrea Stein, las@ai.mit.edu
 * @author:  Luis F. G. Sarmenta, lfgs@mit.edu
 * @version: $$
 *
 * @see Calculator, ButtonHandler, ButtonObj
 */
public class NumButtonObj extends ButtonObj 
{
    /**
     * Which number am I?  buttonVal remembers. <p>
     *
     * Initialized by constructor, doesn't change.
     */
  private int buttonVal;

    /**
     * How to make one: Make a ButtonObj (i.e., my superclass) and
     * also remember my number.
     *
     * @param num         Which numbered button am I?  ( 0 - 9 )
     * @param gui         The CalcTextGUI to keep track of.
     * @param stateObj    The CalculatorState to keep track of.
     */
  public NumButtonObj( int num, CalcTextGUI gui, CalculatorState stateObj ) 
  {
    super( gui, stateObj );
    this.buttonVal = num;      // remember my number.
  }

    /**
     * This method is called by the ButtonHandler whenever the
     * decimal point button is pressed.  <p>
     *
     * How to handle (my button) being pressed?  Make sure that we're
     * reading a number (tell the stateObj if it doesn't know) and
     * then either use this number as the current display or append it
     * to it if there's already a partial number.
     */
  public void handleButton() 
  {
    String whatToPrint = Calculator.ButtonLabels[this.buttonVal];
    if ( this.stateObj.notReadingNumber() )   // if no number yet,
    {
      this.stateObj.startReadingNumber();
      this.gui.setText( whatToPrint );        // this is it
    } else 
    {
      this.gui.appendText( whatToPrint );     // else just add my num to end.
    }
  }

}


/*
 * $Log: NumButtonObj.java,v $
 * Revision 1.1.1.1  2002/06/05 21:56:25  root
 * CS101 comes to Olin finally.
 *
 * Revision 1.3  1997/10/30 03:28:36  lfgs
 * Added overview and fixed "* /" commenting typo in code.
 *
 * Revision 1.2  1997/10/24 22:20:41  las
 * Documented all of the code files, but didn't write the user manual (yet).
 *
 */