Jeanne Boyarsky wrote:Yes. Unit you submit your answers, you can switch between them as often as you like. I did what you are asking about - read through all the questions.
It's not that the questions are duplicate per se. It's that some facts fit well in multiple questions. And it also helps you to not over-answer an earlier question by accidentally answering a similar later one.
You are currently designing your own Desktop Publishing application as you have not found any existing application that does exactly what you want. As part of the design, you are using a Controller to which you send all GUI requests. Not all objects can process the same commands.
For example, you cannot select the spell check tool when an image has the focus. To stop any possible errors, you would like to filter out some of the messages as they are passed from these objects to the Controller object. What pattern could you use?
Choices:
Firewall
Proxy
Adapter
Observer
Chain of Responsibility
Filter