Objectives

Work with your partner and read the handout carefully as you go along. Make sure you EACH try every exercise.

Getting your account

1. Make sure that you have filled out, signed, and returned an account policy sheet.

2. Our System Administrator will lead you through the steps to establish your account for this class. These steps are summarized in the prelab reading, as well.

There are 6 checkpoints in this lab. If you need help with any problem, raise your hand.

Getting Started

1. Log in to the computer by entering your name and password. If your login is successful, there will be a short delay followed by the display of some startup Gnome windows (Gnome is your Desktop Manager Program.) Close any windows that show up by clicking on the X in the upper right-hand corner of the window.

2. Look for the Applications menu in the top left corner of the screen. Click it to see Favorites, then click Terminal. panel at the top of the screen with several icons on it. Click on the terminal icon. You should get a terminal window titled with your login name, machine and current directory location. The cursor should appear to the right of the prompt "[login-name@vegetable-name~]$".

3. Log out by clicking on your name in the top right corner of the screen and selecting the option, "Log Out". Another dialog box will then appear from which you can confirm that you want to log out.

4. At this point you would normally walk away from the machine, but today we want you and your partner to practice logging on and off. Do so now.

Getting Lab Materials

Before we start, it would be a good idea to try to be somewhat organized! There is nothing worse that completing an assignment or lab and not being able to find it. So, your instructors suggest creating a directory hierarchy that organizes your files. Let's start by creating some directories.

1. Open a terminal window. When you first open your terminal window, you are placed in your home directory.
2. Create a new folder for CSCI 241. To do this, execute the following command:

         mkdir Cs241 

3. Make the new directory your current directory. To do this, execute the following command:

         cd Cs241 

4. Make the new directory your Cs241 directory. To do this, execute the following command:

         mkdir Labs 

5. Make the new directory your current directory. To do this, execute the following command:

         cd Labs 

Your instructors suggest using this directory hierarchy to stay organized. Now that you are in your Labs directory, you can copy the files you need for today's lab. Again, remember that you should use this procedure each time we have lab.

• Copy the files you need for today's lab. Following the "$" prompt, enter

        cp -r /home/student/Classes/Cs241/Labs/Lab01 .     

  Don't forget to leave one space between Lab01 and the dot . at the end of the command. Refer to the prelab reading for more details about cp, the copy command.

Continuing with UNIX Commands

1. Get a long listing of your home directory by entering ls -l (remember that this command uses lowercase L's, not number 1's). Notice that there is now a subdirectory called Lab01.

2. Get a long listing of what is contained in Lab01 (that's a zero-one at the end of Lab) by entering

         ls -l Lab01     

3. Change the current directory to Lab01 by entering

         cd Lab01     

   Perform another ls once you get there.

4. View the contents of a file, LabOne.java by entering

         more LabOne.java     

   To advance to the next page of the file, press the space bar.

1. Tell us why it is important to log off when done working.
2. Tell us what the -r, / and . mean in the copy command you entered.

Sending a Program to a Second Account

2: Be prepared to answer the following questions:

1. Why can't lab partners copy directly from one account to another account?
2. Show us that the copy has been obtained by your partner.

Your partner may now log off, and partners should now go back to working together in one account.

Running the Firefox Web Browser

1. Start running the Firefox web browser from Applications-Favorites-Firefox Web Browser in the top desktop display panel.

2. Go to the CSCI-241 course website

         http://www.cs.uwp.edu/Classes/Cs241     

3. Log on to Canvas by clicking the link from the course web page. Type your RangerMail id and password. Choose the CSCI-241 course and read the information at the top of the Announcements area. This page may be updated at any time! An email message to your RangerMail address will tell you when to check it.

Working with BlueJ

• Make sure you are in your home directory by entering cd and pressing Enter at the terminal window command line.
• Running BlueJ
  Start running BlueJ by entering (after the $ prompt) the command

  	bluej&     

  Don't forget to type the ampersand (&).

• Open project Lab01
  
  • Choose Project -> Open Project
  • In the file dialog window that appears, double click on the Lab01 icon.

• Open class LabOne in the editor by right clicking on the icon and choosing Open Editor.
  So ... you may not have ever seen Java before, but this class is simple enough that you should be able to figure out what it does. Examine the code in the file, but do not change it. What do you think this program does?

• Compile this class.
  Refer back to the prelab reading if you need a hint.

• Use your mouse to return to the black terminal window, and enter the UNIX command

        ls -l Lab01     

  See the two additional files in the Lab01 subdirectory? LabOne.class holds the compiled version of the class (translated into bytecode). LabOne.ctxt holds information used by BlueJ.

• To run your compiled program, return to the main BlueJ window and right-click on the class icon for LabOne. Choose the line that says 'Run Main Method'.

• While running, the program will prompt you to enter two integer values. Enter one value at a time by typing it at the end of the line, then pressing Enter. After the program collects the two integers it will display the result of dividing the first by the second. Follow the directions and press Enter after each value. Close the output and editing windows when you are done.

Electronically Submitting and Printing a Programming Assignment

For practice, submit your BlueJ project named Lab01:

1. Open a terminal (command) window and navigate (cd) inside the Lab01 folder.
2. Perform an ls to make sure your LabOne.java file is here. If not, navigate to the project folder and check again.
3. Once you are in the correct Lab01 directory, type submit LabOne.java and hit enter. A success message will be printed.
4. Open a browser window and submit the LabOne.java file to Canvas for Grading.
5. Close the window(s) when you are finished.

     more /home/student/Submit/Cs241/smith/Lab01/LabOne.java

1. What does a BlueJ project hold?
2. What are the basic differences between source code and byte code?
3. Show your lab instructor or assistant that you have compiled this program and can run it.
4. Show us your printout. Tell us how you will find out how many pages your account has in it before you need to buy more paper.

Now is a good time to trade keyboard and/or mouse control with your partner.

Creating your own Class

1. Add a new class named Doodle to the project.

2. Edit the class so that it appears almost exactly like that below (but with your own names, etc).

   /**
    *  Name: ____________ (login)
    *  Course: CSCI 241 - Computer Science I
    *  Section: ____
    *  Assignment: 0
    */
   
   import acm.program.*;
   import acm.graphics.*;
   import java.awt.*;
   import java.awt.event.*;
       
   public class Doodle extends GraphicsProgram
   {
       // instance variables
       private Point last;   // The previous position of the mouse
       private Color color;  // The color used for the drawing
       
       /**
        * Constructor for objects of class Doodle
        */
       public Doodle()
       {
            start();
            addMouseListeners();
            color = Color.BLACK;
       }
       
       /** 
        *  Called when the mouse is first pressed.
        */
       public void mousePressed(MouseEvent e) {
           last = e.getPoint();
       }
   
      /** 
       *  Called when the mouse is dragged.
       *  It creates a short line segment from the previous position to 
       *  this position.
       */
       public void mouseDragged(MouseEvent e) {
           Point pt = e.getPoint();
           GLine gline = new GLine(pt.x, pt.y, last.x, last.y);
           gline.setColor(color);
           add(gline);
           last = e.getPoint();
       }
       
       /** 
        *  Change the color for the next line drawn.
        */
       public void setColorBlue()
       {
           color = Color.BLUE;
       }
   }            
               

3. Save this class by selecting "Class" and "Save". Note that there is a keystroke that you can use to do this instead (Ctrl-S). Your class is saved every time you use Ctrl-S.

4. Compile the class, removing any errors that are detected.

5. Create an instance of the class.
   To do this, right-click on the Doodle class and choose new Doodle(). Click OK on the next window that appears. WAIT for the newly created Doodle object will be displayed as a red icon on BlueJ's object bench.

6. Draw a multi-colored picture. To draw, hold the left mouse button down while you move the mouse. It is up to you to figure out how to change colors.

5: Show your lab instructor or assistant that you have entered and compiled this program and can run it.

End of lab

Each time you leave the lab, be sure to do the following:

1. Log out of Firefox (if logged in).
2. Log out of your account.
3. Turn your monitor off.
4. Push in your chair.
5. Clean up any food, drink or other materials left on the wooden table near the printer.