/*
 * CalcTextGUI.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;
import cs101.util.Coerce;

/**
 * This class is a text-only adapter for the Calculator GUI.  Each
 * ButtonHandler should have exactly one instance of CalcTextGUI.
 * This provides the basic text functionality present in the
 * Calculator interface (though not the getButton() method) as well as
 * some additional utility functions.
 *
 * @author:  Lynn Andrea Stein, las@ai.mit.edu
 * @version: $$
 *
 * @see Calculator, ButtonHandler
 */
public class CalcTextGUI 
{
    /**
     * The Calculator that this provides the textual interface to.
     * Should really be private (or at least protected)! <p>
     * Initialized by constructor.   Shouldn't change.
     */
  Calculator gui; 

    /**
     * A CalcTextGUI is an adapter for a Calculator, so we'll need a
     * Calculator to adapt on behalf of.  Otherwise, vanilla
     * construction.
     *
     * @param realGUI  the Calculator to adapt.
     */
  public CalcTextGUI( Calculator realGUI ) 
  {
    this.gui = realGUI;
  }

    /**
     *  How to display a String on the Calculator.
     *
     *  @param s   The string to be displayed.
     */
  public void setText( String s ) 
  {
      this.gui.setText( s );         // just do it.
  }

    /**
     *  How to find out what String is displayed on the Calculator.
     *
     *  @returns   The string currently being displayed.
     */
  public String getText()
  {
      return this.gui.getText();    // just do it.
  }

    /**
     *  How to find out what number is displayed on the Calculator.
     *
     *  @returns   A double representing the currently displayed value.
     */
  public double getValue() 
  {                    // Get the String, then turn it into a double.
    return Coerce.StringTodouble( this.gui.getText() );
  }

    /**
     *  How to append something to the String currently displayed on
     *  the Calculator.
     *
     *  @param s The string to be appended.  */
  public void appendText( String s ) 
  {                   // add s to what's already there.
    this.gui.setText( this.gui.getText() + s );
  }

    /**
     *  How to clear the Calculator's screen.
     */
  public void clearScreen() 
  {                   // New text is no text.
	this.gui.setText( "" );
  }

}


/*
 * $Log: CalcTextGUI.java,v $
 * Revision 1.1.1.1  2002/06/05 21:56:25  root
 * CS101 comes to Olin finally.
 *
 * Revision 1.2  1997/10/24 22:20:41  las
 * Documented all of the code files, but didn't write the user manual (yet).
 *
 */