Creating my own gui block on GRC

Hi list,

I am using grc to create my flow and at the end my final block outputs
a constant signal like 1, 2, 3, 4, or 5.

What i want to do is to create a gui on grc and show some textes
according to these values. For ex if output is 1, i want to show A, or
if it is 3, i want to show B.
Something like this.

I checked if i can use the existing grc blocks to use for this issue
but i can not find the solution.

Can you give any suggestions about it.