interface

Does coding towards an interface rather then an implementation imply a performance hit?

In day to day programs I wouldn't even bother thinking about the possible performance hit for coding against interfaces rather than implementations. The advantages largely outweigh the cost. So please no generic advice on good OOP. Nevertheless in this post, the designer of the XNA (game) platform gives as his main argument to not hav...

C# Plugin Architecture with interfaces share between plugins

Hi all, I divided my problem into a short and a long version for the people with little time at hand. Short version: I need some architecture for a system with provider and consumer plugins. Providers should implement intereface IProvider and consumers should implement IConsumer. The executing application should only be aware of IProv...

hibernate annotations, hql query by interfaces?

The hibernate (I'm using version 3.4) documentation for hql says that it supports interfaces, and I'm having trouble getting it to work. I have some persistent classes (not inherited from eachother, but sharing many functions) that all share an interfaces (CategorizableEntity). I can use it with instanceof in my java code, but I cannot...

How do you work around the need to cast an interfaced object back to its base class?

This question is meant to apply to interfaces in general, but I'll use AS3/Flex for my language. It should be [mostly] obvious how to apply it in different languages. If I create a base class, and it extends an interface, there is an explicit contract defined: for every method in the interface, the base class must implement said method...

How does this "Programming to Interfaces" thing work?

I like the idea of "programming to interfaces" and avoiding the use of the "new" keyword. However, what do I do when I have two classes that have the same interface but are fundamentally different to set up. Without going into detail about my specific code, I have an interface with a method, "DoStuff". Two classes implement this interfa...

How can I write a generic container class that implements a given interface in C#?

Context: .NET 3.5, VS2008. I'm not sure about the title of this question, so feel free to comment about the title, too :-) Here's the scenario: I have several classes, say Foo and Bar, all of them implement the following interface: public interface IStartable { void Start(); void Stop(); } And now I'd like to have a contai...

Fluent nhibernate: How do I map an entity with a property who's type is an interface?

I have an entity like: public class Employee { public int ID { get; set; } public IAccountManager AccountManager { get; set; } ... } I also have a mapping defined for "DefaultAccountManager" - a concrete implementation of IAccountManager. When mapping the above "Employee" entity, how do I tell NHibernate to persist/load th...

Interface design using C# Generics

Hi, I am currently designing a class library that will provide data to a web application graph rendering engine in C#. I am currently defining the interfaces of this library. I have a IGraphData interface which I would like to cache using a service that accesses the cache, this is called IGraphDataCacheService and has set and get met...

Using polymorphism on member of interface

Okay this is a bit of a noobish question, but I ran across this today and it somewhat puzzles me WHY it would be this way. Consider the following structure Public Class Employee Implements IPerson Private _MyManager As Manager Public Property MyManager() As Manager Implements IPerson.TheirLeader Get Return _...

Challenges in writing wrappers for C++ functions so that they can be used from C code

I am now writing wrappers for C++ functions, such that they can be used from C code. The idea is to compile the cpp files using g++ and the c files using gcc, then link them together (!), but exposing ONLY those functions that are needed, to the C programs, by making them available in a header file 'test.h' (or maybe test.hpp?), like so...

Recommendations on HTML Form Input Field Lengths (e.g. username, e-mail)

Are there any guidelines/recommendations on how long the input fields should be on HTML forms. Specifically: Viewable length (the length of the input field the user can see on the screen - without having to scroll horizontally. i.e. SIZE, not MAXLENGTH) Capture length (the number of characters the HTML form will save to the database) ...

Implementing IPagedList<T> on my models using NHibernate

I have found when using NHibernate and creating a one to many relationship on an object that when the many grows very large it can slow down dramatically. Now I do have methods in my repository for collecting a paged IList of that type, however I would prefer to have these methods on the model as well because that is often where other de...

Java Interface: Inheriting, Overriding, and Overloading Methods

Hi All, In "THE Java™ Programming Language, Fourth Edition" By Ken Arnold, James Gosling, David Holmes, its mentioned that: paragraph: (4.3.2) "Similarly, if an interface inherits more than one method with the same signature, or if a class implements different interfaces containing a method with the same signature, there is only one su...

Interface inheritance - a good thing?

I've just used it for the first time - consider: IGameObject void Update() IDrawableGameObject : IGameObject void Draw() I had a level class which used DrawableGameObjects - I switched this to be IDrawableGameObject's instead to reduce coupling and aid in TDD. However I of course lose the ability to call Update(..) without c...

C++ Interface Compiling

EDIT: I figured out the solution. I was not adding -combine to my compile instructions and that was generating the errors. I'm in the process of working through the Deitel and Deitel book C++ How to Program and have hit a problem with building and compiling a C++ interface using g++. The problem is, I've declared the class in the .h...

How to build a top-like UI in Ruby

I want to build an application with a text based UI that is similar to the Linux command 'top', in Ruby. What toolkits and/or techniques can I use to build the UI? In particular I want an area of the console window that is constantly updating, and the ability to press keys to manipulate the display. ...

Sending an Interface definition over the wire (WCF service)

I have a WCF service that generates loads Entity Framework objects (as well as some other structs and simple classes used to lighten the load) and sends them over to a client application. I have changed 2 of the classes to implement an interface so that I can reference them in my application as a single object type. Much like this examp...

Visual Studio - automatically implement all inherited methods from an interface

Let's say we have a class called MyClass. public class MyClass We also have an interface like so: public interface MyInterface{ public string SomeFunction(int foo, string bar, short baz){} } We want this class to inherit from MyInterface. public class MyClass: MyInterface MyInterface has n properties, and i methods. How can I g...

Is there an idiom in Java for empty methods which exist to satisfy an interface?

Let's say I have a class Foo implementing an interface such as MouseListener. The MouseListener interface consists of five methods but I only wish to override one of them (mouseClicked()). Is there a standard, idiomatic way of formatting the other methods? My inclination was to write the following: @Override public void mouseClicked(...

Interfaces declaring methods with abstracts as parameters

I have this question about best practices in following examples: interface Request; interface Service { void process(Request request) } class MyService implements Service; class YourService implements Service; class MyRequest implements Request; class YourRequest implements Request; But how to ensure that MyService will always rec...