Like so many things in application design..the end result may seem simple (you click an area and it gets filled with colour) but the means to accomplish it are not.
Read through the article and figure out what you can, if you need us to clarify parts of it then tell us which parts you dont understand and we'll try to explain them.
There isnt a simple, pre-written method that you can use for this. You need to write code that will figure out the area you want filled, determine the edges of the area, etc.
I am working creating a fully encapsulated, homogeneous singly linked data structure. The Listing class and SinglyLinkedList class that are part of the whole application compile fine, but the problem ...