static void Main(string[] args)
{
/*
* More info: https://en.wikipedia.org/wiki/Mediator_pattern
* What problems can the Mediator design pattern solve?
* Tight coupling between a set of interacting objects should be avoided.
* It should be possible to change the interaction between a set of objects independently.
*
* Defining a set of interacting objects by accessing and updating each other directly is inflexible because it tightly couples the objects to each other and makes
* it impossible to change the interaction independently from (without having to change) the objects.
*
* And it stops the objects from being reusable and makes them hard to test.
* Tightly coupled objects are hard to implement, change, test, and reuse because they refer to and know about many different objects.
*/
IChatMediator mediator = new ChatMediator();
IUser user1 = new User(mediator, "Hamid");
IUser user2 = new User(mediator, "Lisa");
IUser user3 = new User(mediator, "Saurabh");
IUser user4 = new User(mediator, "David");
IUser vipUser = new VipUser(mediator, "Hans");
mediator.AddUser(user1);
mediator.AddUser(user2);
mediator.AddUser(user3);
mediator.AddUser(user4);
mediator.AddUser(vipUser);
user1.Send("Hi All");
}
private static void Main(string[] args)
{
/*
* In this example we have a simple decorator which extends StringBuilder
* type of .Net and add it the functionality of string concatenation by += operator
* and implicit conversion from string to it's type.
*/
var assignableSb = new AssignableStringBuilder();
assignableSb = "Hello";
assignableSb += " World";
WriteLine(assignableSb);
/*
* Decorator pattern is used to add or extend functionality of an
* existing type. In this example we decorate the basic User class
* to have a last name when it becomes a VipUser.
*/
var user = new User("John", 24);
var vipUser = new VipUser(user, "Doe");
WriteLine(user);
WriteLine(vipUser);
/*
* Demonstration of C# extension methods to apply decorator pattern.
*/
var user2 = new User("Jane", 17);
var ageInfo = user2.IsAdult() ? "an adult" : "not an adult";
WriteLine($"{user2} is {ageInfo}");
var vipUser2 = user2.ConvertToVip("Doe");
WriteLine($"{vipUser2} is a VIP user now.");
/*
* Course exercise
*/
var dragon = new Dragon()
{
Age = 0
};
WriteLine(dragon.Fly());
WriteLine(dragon.Crawl());
}
/// <summary>
/// Get Users on VipList.
/// </summary>
/// <param name="online">If online.</param>
/// <returns></returns>
private List<VipUser> GetUsers(bool? online)
{
List<VipUser> users = new List<VipUser>();
uint begin = Memory.Addresses.VipList.VipBegin;
uint distc = Memory.Addresses.VipList.VipDist;
for (uint i = 0; i < Memory.Addresses.VipList.VipMaxD; i++) {
VipUser user = new VipUser(Memory, begin + (i * distc));
if (user.Id > 0) {
if (online.HasValue) {
if (online.Value && user.IsOnline) { users.Add(user); }
else if (!online.Value && !user.IsOnline) { users.Add(user); }
}
else { users.Add(user); }
}
else { break; }
}
return users;
}
