During the last week I have been working on some further
low-level classes. The following ones are new:
- Certificate / CertificateI (public company share papers).
- Portfolio, discussed before. Certificates are held in
a ListArray per company, accessed via a HashMap.
This works easiest. There still also is an overall ArrayList
of certificates, but I think that one is redundant.
- CashHolder: an interface implemented by all money holders,
to allow cash transfer. This is done via a static method
Bank.transferCash (CashHolder from, CashHolder to, int amount).
To avoid the need to have a Bank instance everywhere I have added
the shortcut, that either 'from' or 'to' may be null,
in which case it is the Bank.
- Log: to log the proceeds (currently to System.out) and make
the increments after each action available for display (see below).
I have also created a new test servlet (GameTestServlet).
On my website (http://home.hccnet.nl/erik.vos/18xx.html) I have
added 6 screenshots of HTML output from this servlet, which shows,
that most of the simple actions during a game already can be done.
Also the Log output is shown.
Below more on this servlet.
Currently implemented features (partly in the servlet, but all
using underlying code in the base classes):
- Share buying and selling (but no presidency change yet).
All done via a Portfolio method
buyCertificate (CertificateI certificate, Portfolio from, int price)
[which calls transferCash for the monetary part of the transaction).
- Correct dividend payout and withholding.
- Private buying and payout, also by and to companies.
- Correct stock marker movements, including when sold out.
Not covered yet are:
- Trains, tokens and tiles (but the servlet allows a company
to spend any amount on whatever).
- Private special properties, i.e. B&O does not come with the
president's share (so better subtract $200 from the private price!)
and does not close when B&O operates (buys a train).
- Player order, operating order, priority.
- Money amount limit checking (e.g. when buying privates).
Also negative cash still allowed.
I have not done much to the XML files yet. Only addition is
the definition of Certificates per company type and/or per company
(see the 1830 Company.Manager.xml file).
Many details (like the bank size and player initial cash)
are now hardcoded the 1830 way, but that will be changed soon.
If Certificates are defined per CompanyType, these will be cloned
into each company which has not itself defined a certificate array.
I plan to change this so, that a <CompanyType> can contain
a whole dummy company with all possible features,
all of which will be cloned into the <Company> if not overridden.
How does this all fit into our project's architecture?
I see it like this:
+------------------------------------+
| Upper layer = View (UI) |
| display, produce events |
+------------------------------------+
| Middle layer = Model (game logic) |
| catch events, call data objects |
+------------------------------------+
| Lower layer = Model (data objects) |
| file interfaces, object states |
+------------------------------------+
The game classes I have developed so far cover part of the lowest layer.
The test servlet replaces the top 2 layers, and already
contains code fragments that I think will end up
in the middle layer classes. But I have no idea yet
on how this middle layer will actually look like.
Unfortunately, UI development seems to be lagging behind.
All I can contribute right now is in defining the lower layer
components and their interfaces (APIs) with the middle layer.
In this respect, what I have done so far looks pretty good,
taking into account the things that can already be done
(see the screen shots). Hopefully the upper/middle layer
development will get a boost now....
It turns out Brett does not want the servlet code in the project repository
(or maybe just not below the game package). If it does not get another
place, so be it; I'm happy to send this code to anyone who is interested
in how I'm using the base classes developed so far.
Anyhow, I'll continue this way, which is the only one that works
for me right now.
Erik.
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