IUP Computer Science
COSC 300 Spring 2001

Assignment #4
(Due 28 March 2001)

You are to write a very simple type of editor program in which the user of the user of the program can control the color of the text on the screen.

The program should begin by clearing the screen (to black) and displaying on the top line a color menu using green letters on a white background. The menu should look like this: 

0 Black  |1 Blue   |2 Green  |3 Cyan   |4 Red    |5 Magenta|6 Brown |7 White  |
The cursor should then be placed at the beginning of line 3 on the screen and the user should be allowed to type characters. Initially, the input characters should be displayed in white on the black background. In addition to entering regular characters (which the program should display in the current color at the cursor position), the program should respond to the entry of several special characters. These are the special characters and the reactions the program must provide:

Carriage return (Enter)
Move the cursor to the beginning of the next line

Backspace
Move the cursor to the left one position - this should cause the next regular character entered to replace the character the cursor is under. Do NOT try to "erase" the character the cursor is under.

~ (tilde) Move the cursor to the beginning of line 23 and terminate the program. Do not clear the screen when doing this; leave the entered text on the screen.

\ (backslash)
Tells editor to get ready for change to the current color. The next character that is entered must be in the range 0 - 7 to indicate one of the 8 possible display colors. Neither the \ nor the color number should be echoed to the screen; however, subsequently entered regular characters should appear in the newly specified color (until another color is specified).

Hand in a well-commented printout of your program - you may print the .asm file for this printout. Also, hand in a floppy disk on which you have placed the executable program (the .exe file). Name this file after yourself as yourinitials-p4.exe




HARDER EXTRA CREDIT:

Replace the \ character interaction with mouse interaction. That is, allow the user to choose the color for the text by left clicking on the appropriate color name area on the top line of the screen. Be sure to display the menu so that the color name area on which the mouse can click is 10 characters long for each color. The user would then change colors to the entered characters by clicking with the left mouse button on the appropriate color at any time. Once the color is selected with mouse action, subsequent characters must be displayed in the chosen color, until the color is changed again.

Notes:
  1. Other character interactions (for enter, backspace, and ~) must work the same as before.

  2. Occasionally, when a small programming mistake is made with the mouse, you may get strange behavior from the mouse pointer. It is best to execute in full-screen mode to lessen this behavior and to see the mouse pointer as it is intended for text operations.
If you choose to do this extra credit version, be sure to make a note of it on the top of the printout for your program.


EASIER EXTRA CREDIT:

If the cursor reaches the bottom line of the screen and Enter is pressed, scroll the text area (lines 3 through 24) up one line and put the cursor at the beginning of line 24. Also, when the cursor needs to move beyond column 79 on a line, move it to the beginning of the next line. If column 79 of line 24 is reached, do scrolling and cursor movement to put the cursor at the start of line 24. Do NOT remove or redisplay the color menu during any of this manipulation - it should remain on the screen at all times.

If you choose to do this extra credit version, be sure to make a note of it on the top of the printout for your program.