This first tutorial 186 function checks for inside bars and outside bars and then draws the high and the low of the pattern until either line is breached by price. The other line continues to be drawn (i.e. if the price goes below the low line, it is stopped but the high line continues to be drawn.)
The lines are drawn using drawing objects (as opposed to the legacy drawing tools.)
See the program page here: https://markplex.com/free-tutorials/tutorial-186-inside-and-outside-bar-lines/
