i am making a plugin style app..but i am facing a dilema...i have the plugins which will implement an interface(or maybe an abstract class i dont really know) so the mother class will know that every plugin have that given functions...but i want interaction between the plugins and the main class(Form)..for example, i want that my plugins give the url to the mother form and that form will do the download and in the end say to the plugin that the download has finished..but how the plugin will know the which function to call? will i have to make a interface that the form will have to implement too, so the plugin knows what are the form's functions?

..
if i wasnt explicit enough say it..i am almost asleep