CS111 Lab 4:

Inheritance and Interfaces

Part I: Graphical User Interface This application will contain a graphical window as the top-level container. It will measure 700 pixels in height and width. The user interface components placed on this top-level container will include: JPanel container: This is lightweight container for components. For example, a button and a label component can be placed into a panel component. JLabel: Label for the input textfield component. JTextField: Input textbox for the user to specify a C-curve level. Note: For numeric input, this string must parsed into a number value. JButton : To activate the drawing of a C-curve fractal. Note: This button will be assigned an ActionListener. JComponent container: The drawing canvas for the C-curve fractal. Note: JComponent includes an infrastructure for painting.

    import java.awt.Graphics;

    public class Fractal {


      public void drawCCurve(Graphics g, int x1, int y1, int x2, int y2, int level) {
        //PRIMITIVE STATE: DRAWS A STRAIGHT LINE FROM X1,Y1 TO X2,Y2
        if (level == 1){
          g.drawLine(x1, y1, x2, y2);
        }
        //RECURSIVE ELEMENT: TWO LINES WILL BE PRODUCED FOR EVERY SINGLE LINE
        else {
          int xn = (x1 + x2) / 2 + (y1 - y2) / 2;
          int yn = (x2 - x1) / 2 + (y1 + y2) / 2;

          drawCCurve(g, x1, y1, xn, yn, level - 1);
          drawCCurve(g, xn, yn, x2, y2, level - 1);
        }
      }

    }

  

    import java.awt.Graphics;
    import javax.swing.JComponent;


    //**************************************************************************
    //FractalCanvas class is derived from the JComponent: This is the canvas.
    //**************************************************************************
    public class FractalCanvas extends JComponent {

    	// DATA MEMBERS: THE DRAWING COMPONENT
    	private Fractal fractal;
    	private int level;
    	private int x1, y1, x2, y2;

    	public FractalCanvas() {
    		level = 2;
    		fractal = new Fractal();
    	}

    	public void setXY(int x1, int y1, int x2, int y2) {
    		this.x1 = x1;
    		this.y1 = y1;
    		this.x2 = x2;
    		this.y2 = y2;
    	}
    	public void setLevel(int level){
    		this.level = level;
    	}

    	public void createCcurve() {
    		repaint();
    	}

    	public void paintComponent(Graphics g) {
            fractal.drawCCurve(g, x1, y1, x2, y2, level);
    	}
    }


  

    import java.awt.Dimension;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;

    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    import javax.swing.JTextField;

    //****************************************************************
    // AppWindow class is derived from the JFrame
    // Programmer: T. Cornez
    //****************************************************************

    public class AppWindow extends JFrame {


      // TASK 1: DECLARE DATA MEMBERS
      //      NOTE: THESE WILL BE GUI ELEMENTS AND JPANEL THAT WILL BE PLACED
      //      IN THE WINDOW FRAME. JPANEL WILL BE USED TO HOLD THE GUI ELEMENTS.
      private JPanel panel;
      private JLabel levelLabel;
      private JTextField levelTextField;
      private JButton button;
      private FractalCanvas fractalCanvas;

      private final int WIDTH = 700;
      private final int HEIGHT = 700;

      // DEFAULT CONSTRUCTOR
      public AppWindow() {
        // TASK 1: SET THE WIDTH AND HEIGHT OF THE WINDOW FRAME TO 700
        this.setSize(700, 700);

        // TASK 2: INSTANTIATE THE JPANEL CONTAINER TO HOLD THE GUI ELEMENTS
        panel = new JPanel();

        // TASK 3: BUILD EACH GUI ELEMENT AND ADD THEM TO THE JPANEL

        levelLabel = new JLabel("Level: ");
        levelTextField = new JTextField(10); //FIELD WIDTH OF 10
        levelTextField.setText("" + 2);		 //INITIALIZE THE TEXT FIELD TO 2
        button = new JButton("Create C-curve");

        // TASK 4: ADD EACH GUI ELEMENT TO THE PANEL
        panel.add(levelLabel);
        panel.add(levelTextField);
        panel.add(button);

        // TASK 5: INSTANTIATE THE DRAWING COMPONENT AND ADD IT TO THE JPANEL
        fractalCanvas = new FractalCanvas();
        fractalCanvas.setPreferredSize(new Dimension(WIDTH,HEIGHT));
        fractalCanvas.setLevel(2); //The default level
        panel.add(fractalCanvas);

        // TASK 7: ADD THE COMPLETED PANEL TO THE FRAME WINDOW
        this.add(panel);

        // TASK 6: REGISTER AN ACTION LISTENER FOR THE BUTTON
        ActionListener listener = new FractalActionListener();
        button.addActionListener(listener);
      }



      class FractalActionListener implements ActionListener {

        //Code this class.

      }

    }


  

1. MultipleChoice inherits from Question
2. TrueFalse inherits from MultipleChoice
3. A MultipleChoice object stores the various choices for the answer. A method will be used for adding answer choices.
4. When a MultipleChoice question is displayed to the user, the choices must appear so that the user can choose one of them.
5. TrueFalse objects are MultipleChoice questions with only two options.

    import java.util.ArrayList;
    import java.util.Scanner;

    public class MyMain {
      public static void main(String[] args) {
        // TASK 1: INSTANTIATE THREE QUESTIONS, ONE FOR EACH TYPE.

        // TYPE: GENERIC QUESTION
        Question q1 = new Question("Who invented Java?", "James Gosling");

        // TYPE: MULTIPLE CHOICE QUESTION
        MultipleChoice q2 = new MultipleChoice("Year was Java born?", "");
        q2.addChoice("1994", false);
        q2.addChoice("1993", false);
        q2.addChoice("1992", false);
        q2.addChoice("1991", true);

        // TYPE: TRUE OR FALSE QUESTION
        Question q3 = new TrueFalse("Java is popular language.", "true");

        // TASK 2: INSTANTIATE A QUIZ ENGINE AND POPULATE IT WITH QUESTIONS
        QuizEngine quizEngine = new QuizEngine();
        quizEngine.addQuestion(q1);
        quizEngine.addQuestion(q2);
        quizEngine.addQuestion(q3);

        // TASK 3: SHUFFLE THE QUESTIONS AND START THE QUIZ
        quizEngine.shuffleQuestions();
        quizEngine.start();
        quizEngine.getResults();
      }
    }
  

1. Define a Java interface called Nameable
2. Classes that implement this interface must provide the following:
   • setName() method that requires a single String parameter and returns nothing
   • getName() method that has no parameters and returns a String