CS100A, Fall Lecture, 4 Nov. 1 CS100A, Fall 1997 Lecture 4 November: OTHELLO Goals: Introduce you to assignment 8. Let you have fun with the game Othello. Introduce you to graphical user interfaces (GUIs) and the Java abstract window toolkit (awt). You don’t have to write code that effects the GUI, but you should understand fully what is going on in the Othello program. Discuss two-dimensional arrays (which are used in this assignment 8; you will write code that deals with the arrays and plays the game). There is a lot to read, a lot to learn. But it’s worthwhile! Start Early!!!!!

CS100A, Fall Lecture, 4 Nov. 2 Here is the game board of the game Othello. It’s an 8x8 board of green squares onto which pieces can be placed. The pieces are black on one side and white on the other. Help You can play Othello on the web. Access the CS100A home page, find assignment 8, and click on the appropriate link to play the game. Click the HELP button for help.

CS100A, Fall Lecture, 4 Nov. 3 Basic play for white (black is similar). Place a white piece in an empty square that is at one end of a sequence of black pieces and that has a white piece at the other end. Turn over the black pieces just described, in all 8 directions. Play here and turn these over (make them white).

CS100A, Fall Lecture, 4 Nov. 4 The Java Abstract Window Toolkit (awt): A collection of classes that provides facilities for writing graphical user interfaces (GUIs) Each square is an instance of class Canvas instances of class Button instances of class Label The area that comes here when you press Help The whole window is an is an instance instance of class Frame of TextArea.

CS100A, Fall Lecture, 4 Nov. 5 The next four slides contain a class, an extension of Frame, that can be used to illustrate many of the features of the awt. The class places an Othello square (a Canvas), a Label, a TextField, a TextArea, and two titles in the Frame. We use this class in the lecture to illustrate: How layout manager GridBagLayout is used to place components in its rectangular grid. How to say that the Frame should not be resized. How gbc.fill is used to indicate how a component should be resized when the Frame is resized. How weights are used to guide resizing of components. That a component use more than one element of the grid. Events: How the pressing of a mouse button is communicated to the program. (See method action.) Events: How a mouse-up event (and other mouse events) and a click in the window-destroy box are communicated to the program. (See method handleEvent.) This class will be in file Experiment.java on our home page, so you can try it yourself. Add it to your project and place the following statement in method main: Experiment ex= new Experiment ( );

CS100A, Fall Lecture, 4 Nov. 6 import java.awt.*; // Frame to illustrate the awt. public class Experiment extends Frame { // Components that go in the frame OthelloSquare sq; Label lab; TextField textf; TextArea texta; // Titles for buttons String[ ] buttons= {"new game", "quit"}; // The layout and constraint variables for this frame GridBagLayout gbl; GridBagConstraints gbc; final int xweight= 100; // Weights for all components final int yweight= 100; // when they are resized

CS100A, Fall Lecture, 4 Nov. 7 // Constructor: a frame with the above components public Experiment() { super(”Experiment"); gbl= new GridBagLayout(); gbc= new GridBagConstraints(); setFont(new Font("Dialog", Font.PLAIN, 10)); setLayout(gbl); gbc.fill= gbc.BOTH; sq= new OthelloSquare(0,0); add(sq,gbl,gbc,0,0,1,1,xweight,yweight); lab= new Label("A label at (1,1)"); add(lab, gbl,gbc,1,1,1,1,xweight,yweight); textf= new TextField("A TextField at (1,2)"); add(textf,gbl,gbc,1,2,1,1,xweight,yweight); texta= new TextArea("A TextArea at (1,3)"); add(texta,gbl,gbc,1,3,1,1,xweight,yweight); add(new Button(buttons[0]),gbl,gbc, 2,0, 1,1, xweight,yweight); add(new Button(buttons[1]),gbl,gbc, 3,0, 1,1, xweight,yweight); pack(); move(150,50); show(); //setResizable(false); }

CS100A, Fall Lecture, 4 Nov. 8 // Add c to gbl with constraints gbc at position (x,y). // c takes w cols and r rows, and is weighted (wx, wy). private void add(Component c, GridBagLayout gbl, GridBagConstraints gbc, int x, int y, int w, int h, int wx, int wy){ gbc.gridx= x; gbc.gridy= y; gbc.gridwidth= w; gbc.gridheight= h; gbc.weightx= wx; gbc.weighty= wy; gbl.setConstraints(c, gbc); add(c); } // If a button was pressed, process it; else, return false public boolean action(Event e, Object arg) { if (arg.equals(buttons[0])) { System.out.println("\"new game\" pressed"); return true; } if (arg.equals(buttons[1])) { System.out.println("\"Quit\" pressed"); System.out.println("TextField is: \"" + textf.getText() + "\""); System.out.println("selection is: \"" + textf.getSelectedText() + "\""); return true; } return false; }

CS100A, Fall Lecture, 4 Nov. 9 // Process press of WINDOW_DESTROY or // mouse up in an Othello square --return super.handleEvent(e) // if the even is not one of those. public boolean handleEvent(Event e) { //System.out.println("" + e); if (e.id == Event.WINDOW_DESTROY) { System.out.println("Window destroy clicked"); //dispose(); return true; } if (e.id == Event.MOUSE_UP && e.target instanceof OthelloSquare) { System.out.println("Mouse up in Othello square"); return true; } return super.handleEvent(e); }

CS100A, Fall Lecture, 4 Nov. 10 On to Othello! Variable b[ ] [ ] will be an 8 x 8 array of elements of class OthelloSquare. Each element of class OthelloSquare maintains (0) its column and row number in the square. (1) whether it is empty, contains a white piece, or contains a black piece. The OthelloSquare constructor saves the col and row number, makes the square empty, and gives it a “preferred” size of 42 x 42 pixels. Since it is an extension of Canvas, it contains method paint(graphics g), which paints the square. It also has three methods: (0) Contents, which returns what piece it contains (or EMPTY). (1) pickUpPiece, which makes the square empty. (2) placePiece(p), which puts piece p on the square (if thesquare is empty).

CS100A, Fall Lecture, 4 Nov. 11 Mapping the Othello Board onto the Frame (0,0) (1,0) (7,0) 2 3 (0,1) (1,1) (7,10) Button Label

CS100A, Fall Lecture, 4 Nov. 12 Section this week Section this week will deal with two-dimensional arrays and the way they are used in this game. Don’t miss section.

CS100A, Fall Lecture, 4 Nov. 13

CS100A, Fall Lecture, 4 Nov. 14 From: Jeffrey HarradineFrom: Hector Yee A team of cornell students have set up a distributed computing effort to coordinate participation in projects such as breaking the rc5 64-bit encryption (RSA sponsored competition) and a distributed computing initiative to scan 2 KHz chunks of the radio spectrum for intelligent signals from elsewhere.If you have spare cycles on your home machine to spare, please do join us in the rc 5 competition. More information can be found at: Instructions to join our mailing list are included. Our team, Big Red, is ranked eleventh in the world as of now in the RC5-64 competition. If you do join us, we are team ID 38. Team Stats: RC5 competition: Please use personal computers for these projects as the lab administrators do not think it is an appropriate use of lab facilities. The programs use only idle time and can even be run offline. We might embark on our own distributed computing programs in the future if we gather enough programming talent and interest. Thanks for your time and interest!