How to make an if condition based on text (TextView) display

I'm planning to make an image that change depends on certain text displayed in an activity. For example:

if ("1st Floor" text displayed)
 {
  "shows 1st Floor Images"
 }

else()
 {
  "shows 2nd Floor Images"
 }

Something like that. Thank you kindly for those who answers my question. And much appreciated it if you offer me some advice since I'm new in this type of programming. Thank you once again.