*note: .as files must be placed in the same folder as the .fla file for
everything to work properly
This tutorial covers an Object-Oriented
approach to creating an inventory system for your games. If you are interested
in making a basic inventory, check out AS:
Inventory 1 by Inglor. Also, this tutorial will not teach you
Object-Oriented Programming. This tutorial assumes you understand basic OOP
concepts such as objects, classes, constructors, encapsulation, etc. If you need
an OOP lesson try AS:Basic OOP by Inglor.
I also suggest senocular tutorial on OOP
for actionscript 2.0 if you really want to learn more. Now, let move
on
Why OOP?
Look, I wont lie to you. There a lot of code here.
In fact youl probably look at it and say 憌ow, I could code that in a quarter of
the lines.?And you would be right. But OOP isn about conserving code. Reasons I
have chosen to do this in OOP:
-Portability- ideally you should be able
to drop this code in place into any flash with a few minimal changes to the
graphics. Also, it allows flexibility during the design process. If partway
through your game you decide you want your inventory to have six slots in two
rows instead of four slots in three rows, you can change it with no
hassle.
-Dynamic behavior- this is not a static system. Items are added into
the first available slots, not into predetermined places. This lets you fill
your inventory in a more realistic manner
-Encapsulation- Most of the dirty
work is done by the inventory class. You as the programmer have a set of methods
at your disposal. Instead of rewriting lines and lines of code you can simple
create an inventory object and call methods such as Inventory.Add(),
Inventory.Remove, and Inventory.ToggleVisibility()
Please also note that
I am in no way, shape, or form an OOP expert. I only know what I know. In fact
I抦 anxious to see other programmers?take on my code
Starting The
Inventory
First, we need a movie clip to act as a generic lot.?This
is what each item in your inventory will be placed into. I just used a 75x75
black outline square. Make whatever you like, just make sure it is square.
Convert it to a movieclip and set its linkage identifier to 揑box.?Make sure its
registration point is set to the top left. THIS IS IMPORTANT.
Next, you
need to draw your inventory items. In my example I drew three simple objects.
Whatever you draw make sure they fit within the size of your inventory slot.
Convert them to movieclips and give each one a linkage name to remember them by.
IE a hammer should be named 揾ammer,?a knife 搆nife,?etc. Make sure to set their
registration points back to the center. ALSO IMPORTANT.
Now, wel jump
into our first class, the Item class. Create a new .as file and paste the
following code into it:
class Item {
var itemName:String =
'';
function Item(inName:String)
{
itemName =
inName;
}
}
Remember that .as files must be named the same as the
class they represent. The above file MUST be named Item.as or it will simply not
work. This is a very basic class and only serves to help us visually see our
inventory as a collection of Item objects. This is a class that will be applied
to all items, but right now it will remain by itself.
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