001 /*
002 * Calculator Interface
003 *
004 * Developed for "Rethinking CS101", a project of Lynn Andrea Stein's.
005 * For more information, see <a href="http://www.cs101.org/">the
006 * CS101 homepage</a> or email <las@olin.edu>.
007 *
008 * Copyright (C) 1996 Massachusetts Institute of Technology.
009 * Please do not redistribute without obtaining permission.
010 */
011 package calculator;
012
013 /**
014 * This is the interface for a basic four-function calculator, as seen
015 * from the perspective of its logic.
016 *
017 * This interface defines an enumerated type, buttonIDs (including
018 * 0...9, which represent themselves), an array of ButtonLabels
019 * suitable for displaying on the GUI, and the three access functions
020 * by which the logic can manipulate the Calculator: getButton,
021 * getText, and setText.
022 *
023 *
024 * @see CalculatorGUI
025 */
026 public interface Calculator {
027 // buttonID constants.
028 // The numbers 0 through 9 should serve as buttonIDs for the respective buttons.
029 /**
030 * No operation in progress.
031 */
032 public static final int NO_OP = -1;
033
034 /**
035 * Calculator division.
036 */
037 public static final int OP_DIV = 10;
038
039 /**
040 * Calculator multiplication.
041 */
042 public static final int OP_MUL = 11;
043
044 /**
045 * Calculator addition.
046 */
047 public static final int OP_ADD = 12;
048
049 /**
050 * Calculator subtraction.
051 */
052 public static final int OP_SUB = 13;
053
054 /**
055 * Calculator decimal point.
056 */
057 public static final int DOT = 14;
058
059 /**
060 * Calculator = button.
061 */
062 public static final int EQUALS = 15;
063
064 /**
065 * Calculator clear button.
066 */
067 public static final int CLEAR = 16;
068
069 /**
070 * One more than the biggest button index.
071 */
072 public static final int LAST = 17;
073
074
075 /**
076 * An array for the button's labels to deal with dispatch cleanly.
077 * You can use this to get the name of the button (i.e., a String).
078 */
079 public static String[] ButtonLabels = new String[Calculator.LAST];
080
081 /**
082 * Get the next Button pressed. The return value will be an int
083 * between 0 and 9 (if the button was a number) or one of the
084 * Calculator constants.
085 *
086 * @return the next button to be handled.
087 */
088 public int getButton();
089
090 /**
091 * Get the text currently displayed on the Calculator.
092 *
093 * @return the text as a String.
094 */
095 public String getText();
096
097 /**
098 * Set the text currently displayed on the Calculator.
099 *
100 * @param newText the text to be displayed.
101 */
102 public void setText( String newText );
103
104 }
105
106 /* Comments:
107 *
108 * History:
109 * $Log: Calculator.java,v $
110 * Revision 1.2 2004/03/26 21:04:11 gus
111 * take ownership
112 *
113 * Revision 1.1 2003/07/10 21:14:43 jon
114 * Initial commit of spring03 calculator source.
115 *
116 * Revision 1.1.1.1 2002/06/05 21:56:24 root
117 * CS101 comes to Olin finally.
118 *
119 * Revision 1.3 1997/10/05 21:11:19 shong
120 * Updated for fall97, to Java 1.1
121 * changed GUI, using 1.1 Event Model
122 *
123 * Revision 1.2 1997/07/16 14:15:20 tparnell
124 * *** empty log message ***
125 *
126 * Revision 1.2 1996/10/04 16:20:20 las
127 * Transformed Calculator into an application and made it a package. See
128 * STAFF_SETUP for which files are public. To run, use Calculator.Main.
129 *
130 * Specifics:
131 * Added Main.java, which starts the calculator program (both
132 * CalculatorGUI and ButtonHandler);
133 * Made Calculator an interface;
134 * Moved GUI implementation (previously in Calculator) to
135 * CalculatorGUI.
136 * Added clear button, which looks pretty gross right now. (It can
137 * be deleted in a single line, though.)
138 *
139 * Revision 1.1.1.1 1996/07/18 17:26:12 sit
140 * Import from summer 6.80s web tree
141 *
142 *
143 */
144
145