Tutorial Exercise $-$ VT$100$ Simulation

Not to be submitted but MUST BE shown to your lab TA

VT$100$ is a video terminal which was among the first to support ANSI escape characters. As you may

including text colour, ANSI escape characters allow you to change the format of your program output

This tutorial will walk you through how to create a basic terminal$-$based simulation of some VT$100$

functionality.

To begin, create a Python file. We vill

which will be used throughot this

function you may decide to implement$).$ Begin by importing os to your program and copying the

Python

Each of these codes begins with and are followed by the command to be executed. If you wish to

add or change the colors or formats in this dictionary, you can refer to this Wikipedia article for a full lis

code is used to reset display attributes to their default, so color and other custom formatting which you

prepend or append them to the text you want to display.

Let's start by displaying the text $"$VT$100$ SIMULATOR" underlined at the top of the terminal in blue.

Python os$.$system$("")$ # Enables ANSI escape codes in terminal

if

os$.$name $=="$nt$"$: # for Windows

em$("$clear

for Mac$/$Linux

ANSI$["$BLUE$"]+"$VT$100$ SIMULATOR" $+$ ANSI$["$RESET$"])$

$!!$ You should always use the RESET code after displaying any formatted text to ensure anything displayed

after does not unintentionally take on its formatting.

Note: Just like in Lab $5$ you must run your program directly from the terminal, not within Wing IDE

beginning of your program before displaying any ANSI characters to ensure their compatibility on al

operating systems.

Now, let's write a short script that allows the user to change the colour of the text. Firstly, print the

Enter a text colour:

Enter a background colour: $(Print$ this line $onx=3,y=0)$

$(Print$ this line $onx=4,y=0)$

You can refer back to Lab $5$ on how to print in a specific position based on $x($row$),y($column$)$ inputs.

Next, let's move our cursor so that it is positioned right after the first prompt. It should look something

like this, where the $|$ is the cursor location.

Enter a text colour: $|$

Enter a background colour:

The cursor here is placed on $x=3,y=21.$ But why $y=21?$ Why not $y=10?$ Test this out for yoursel

and see what happens. Afterwards, you will take the user input, where the valid inputs will be $1$ of $4$

Be sure to check for whitespaces before and after the input, as well as the casing $($greEEN is considered

valid input!$).$ If the user does not enter a valid input, set the cursor to the start of the input $(x=3,y=21,$

print ANSI $[$ "CLEARLINE"$]$ which will clear all the characters from the cursor to the end of the line. T

places the cursor at the start of the next line, so we need to move the cursor back to the start of the input and ask user input. The cursor should not move to the next line until valid input has been inputted.

Repeat the previous part for the background text prompt. However, the cursor will be placed in a different

location. Place the cursor in the correct location after the prompt, then take in the user's input. The user input will be $1$ of $5$ inputs $($RED$,$ GREEN, BLUE, NONE, exit$).$ NONE indicates that no background

colour should be applied. Valid inputs and error handling remain the same as previously mentioned.

Take the user's input and its corresponding entries in the ANSI dictionary and apply the desired

background colour. Note

Take your two user inputs and change the text of the title to match the text style desired by the user. The

change. The program will continue taking input from the user until 'exit' is inputted.

This is a sample VT$100$ SIMULATOB

Enter a text colour: REd Enter a background colour: black

$\backslash$table$[[(2$nd input gets cleared$)],[$VT$100$ SIMULATOR$]]$

Enter a text colour: REd Enter a background colour: Green

$($screen gets cleared$)$ VT$100$ SIMULATO

Enter a text colour: green Enter a background colour: none

Enter a text colour: exit Enter a background colour: $($program exis fofer ser inpus exi