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    <p>Just some thoughts. </p> <p>When thinking in object oriented way, thinking about real-life objects lays out the view, what you should describe in program. And what is object in real-life? It is a "thing" which has certain features and exposes some functionality.</p> <p>For example ShipTemplate is a blue-print of the ship. It should define size, layout, part <strong>types</strong> and quantities (DieselEngine, SteamEngine, AntiAircraftGun, UnderwaterMines, etc), and how they are connected with each other. </p> <p>Ship on the other had is constructed according to blueprint - it should have all part <strong>instances</strong>. For example it might have two DieselEngines and three AntiAircraftGuns. And it is correct, that ship does not inherit from blueprint. Blueprint is only a description of ship, not it's parent. </p> <p>Now, each type of the object (blueprint, part, ship) has it's own properties and functionality. For example, each engine consumes some amount of fuel and can increase speed of the ship to some value. Why not have base class for Engine, which has these features? (inheritance). The same goes for the guns (lets call it ShipWeapon). There is of course a big difference between mine-gun and anti-aircraft gun, but they are both guns, they are both mountable on the ship, they both have weight, ammo type, reload time, ammo capacity, whether gun is operating. </p> <p>So these are some properties of the objects. What about functionality? Other important concept of OO design is that each object has (encapsulated) some functions which can be done with it (and it may or may not alter objects state). For example ShipWeapon should have method Fire(), which maybe should decrees amount of ammo in it. Or try to target at first with Aim(sometarget). Engine on the other hand would have Start(), Stop(), SetSpeed(speed). Note that these would work internally on the object and it's state. Ship might have SetCourse(direction, speed), which would start it's engines at required power and orient its rudder. Also ship might have Colide(ship). And Hit(typeofattackinggun), which would iterate through all parts of ship and damage some randomly (and set IsOperating for a gun, or turn off one of the engines, etc.)</p> <p>As you can see you can go into a lot of detail while designing OO approach. Its also very good to know when to stop - just how much detail (or accuracy) you really need for you program to work.</p> <p>Also, there could be a global World, which would hold all ships. And so on..</p> <p>There is other part of program, the infrastructure. How you data objects (ships, worlds, players) are managed, how they know and interact with each other. For example each ship as an object can be observed by global map and each ship would notify it about movement (observer pattern). Or global world would query state of each ship at some time intervals, based on global clock. Or...</p> <p>I guess what I was trying to say is to stick to main OO principles - encapsulation, inheritance, polymorphism. And there is a lot of literature out there for object-oriented design, design patterns, etc., which is useful. <a href="http://en.wikipedia.org/wiki/Object-oriented_programming" rel="nofollow">Wiki entry</a> is a bit "academic" but has main definitions, which make you think :) Also look at <a href="http://en.wikipedia.org/wiki/SOLID_%28object-oriented_design%29" rel="nofollow">SOLID</a></p> <p>PS. And it is usually a sign of a bad design to do everything in a single class.</p>
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    1. POWhat is the best way to arrange this classes?
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    1. COI'm trying to stick as much as possible to OO principles, that's basically the whole point of this project. However, the part I'm usually troubled with is exactly with the infrastructure. Usually is easy coming up with basic method, but as soon as relationships become complicated I don't know where to put my hands. In this case my problem relies mostly in the updating of costs related to some Ship change.
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    2. COIf you have some view of the ship, which displays cost, it might be the observer of ships cost, which is a sum of all ships parts costs. Cost is a property of ship part and adding/removing part from the ship would trigger notification (through event or observer) to single (or multiple) view. [Observer pattern](http://en.wikipedia.org/wiki/Observer_pattern). Selecting a ship and opening some window (view) should start observing the ship's cost (attach to event or as observer), and any updates to the ship cost would reflect in the view.
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    3. COI thought about this. Do you think such a solution is warranted for a small problem like this? It does sound overkill in some way, but maybe I'm just imagining it.
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