Keep app responsive during long task

Question

A certain form in our application displays a graphical view of a model. The user can, amongst loads of other stuff, initiate a transformation of the model that can take quit

Answer 1

While I don't completely understand what your trying to do, what I can offer is my view on a possible solution. My understanding is that you have a series of n things to do, and along the way decisions on one could cause one or more different things to be added to the "transformation". If this is the case, then I would attempt to separate (as much as possible) the GUI and decisions from the actual work that needs to be done. When the user kicks off the "transformation" I would (not in a thread yet) loop through each of the necessary decisions but not performing any work...just asking the questions required to do the work and then pushing the step along with the parameters into a list.

When the last question is done, spawn your thread passing it the list of steps to run along with the parameters. The advantage of this method is you can show a progress bar of 1 of n items to give the user an idea of how long it might take when they come back after getting their coffee.