New Host

I've decided to leave blogger and move to blogs.scienceforums.net. The change is almost entirely simply due to the fact that the blogging community (and larger forum community) at ScienceForums is more fitting my subject matter, and it's an easier way to have people find my site.

The new link is http://blogs.scienceforums.net/GlitchHound/ and my new posts will all go there. For the moment it's under construction, but it's still fully functional.

For my one regular reader out there, be sure to update your link!

Weekend Plans

So, this coming week is the last week of classes before Easter break, and also the only week standing between me and US soil for a little time at home.

That means that this week is the final week for a lot of projects. Pro/E was one of them, but that's done. I have one assignment due Wednesday, and technically two due Friday (one of those being MATLAB, which will probably be pushed back). Incidentally, I have a friend coming to visit on Wednesday.

So that puts me in a predicament. I'd like to not be doing any sort of (boring) work while my friend's here, so I need to get at least the second project which is due on Friday done by Wednesday. Obviously the other assignment needs to be done by Wednesday. MATLAB, therefore, is technically my last priority. Expect to see that reflected in this weekend's turnout. I want to get at least a bare minimum done each day, with an arbitrary goal being something like one class/object per day. But the main priority is other work. And that means, little news on this front.

See you tomorrow.

Unplanned, Yet Foreseen Hiatus

What's that? No MATLAB code today? Who's surprised by that? *Looks out over the crowd* I'm not seeing any hands. Oh, I'm not seeing any crowd, either.

Regardless, I'm still posting. Aren't I a trooper? Today I did absolutely nothing. Not even gonna talk about some decision I made. I have not discussed any code aside from talking about the idiocy of MATLAB's ridiculously expensive compiler.

I /did/ play a good game of L4D2 versus. I /did/ get a hell of a lot done with CAD in school today. But nothing code-related. And that means that this post, while short, is done.

30 Posts! Consecutive, no less!

Considering the average number of days in a month (in a non-leap year), rounded to the nearest integer (just truncated in a leap year. Yes, I did the math on this) is 30, I'm considering myself one full month of daily blog posts into this. For me, that's pretty impressive, as I'm usually the kind of guy who commits himself to something and then gets bored of it.

That said, I have literally accomplished NOTHING else today. Programming-wise, at least. I did get a new best answer for actual Java-related help on Y! A, but otherwise, nada. Zippo. Zilch. Get the picture? And here I thought I'd have time to do something today.

I did make one decision. In order to practice my object-oriented programming in this upcoming MATLAB assignment, I'm going to strive to achieve well-isolated code. I intend to program the essential workings first, getting the calculations encapsulated and finished, and then work on integrating them into the GUI and everything else. With Java, this is how I program already. With MATLAB, I programmed everything last time top-down. I built the GUI, then made the callbacks, then made the functions. It was actually ridiculous, in hindsight.

Doing things this way will give me the two-fold advantage of having the opportunity to play around with different arrangements and also allowing me to throw together a basic version if I find the optional stuff is taking too long.

And... that's all I've done today. Well, better than nothing. And still, a milestone! I'm happy.

Overcomplication, and How it Simplifies My Life

Did some thinking on MATLAB today. Not content with just doing a GUI, I figure I'm going to implement a simple sort of file I/O system whereby when a user enters constant values it can save them, and then reload them on a later start of the program. The inputs required include some that will be different on each logon, but things like the wingspan, chord length, and (empty) mass (and weight) will always be the same. As a result, it would save time in the long run, assuming, of course, that this program is usable beyond the marks it earns me, to be able to save an aircraft configuration to reference by name at a later point. It should also save time.

I looked over the functions today and, while not simple, they certainly look possible. Since my Java program has yet to actually produce output, and that output is going to be database-oriented, I figured it'd be a good idea to learn the basic .txt input/output procedures. MATLAB is object-oriented, so I should be able to manage stretching the assignment into a learning experience for Java, even if it isn't exact.

Depending on how much time we have (the lecturer suggested he may be pushing the deadline back on account of the actually massive workload we have between his assigning the project and the due date, including this being a solid week of CAD training), I was considering doing a bit more optimization work on the first assignment and packaging both assignments together into an "Aerospace Tools" package, with a central launcher accessing both. But that's entirely optional and will only happen if I do have an extra three weeks (given the holidays starting the day after the current due date, this is possible).

I'm still reading through Yahoo! Answers, having a good time of it. I actually got chosen as a best answer, and the best part of it is that it was the only question I answered half-heartedly. It was someone asking for a good free place to make a blog, and I simply recommended blogspot // blogger here. I like to think I've helped some people out with their code, but I know I won't get some best answers simply because I refuse to actually do people's homework for them, instead choosing to try to explain how they can do it.

That's all for today, though. Tomorrow's the only short day we have this week, so maybe I'll get some coding done.

General Thoughts on MATLAB

MATLAB is a nice program. It's great for doing what it does, expandable, pretty easy to program, overall a very handy tool. Seriously, though, they haven't thought much about usability so far as I can tell. This isn't a rant about the program being hard to use for built-in functions. In fact, that's all pretty easy and, more importantly, well-documented.

This is a rant about development problems. Like any progamming language, you can code MATLAB programs in whatever text editor you feel like using. Unlike most, however, there are no third-party IDEs. Compiling code requires that MATLAB be installed (and in most, if not all, cases running), and if not MATLAB then a very expensive compiler. There's no such thing as a third-party compiler.

Compiling code is important as it's how you test it. Hopefully you don't get compilation errors, but if you do they'll tell you what's wrong. But you can't test for run-time errors without first compiling the code. In other words, I can't possibly develop efficiently on any machine that doesn't have their very expensive software on it. Nor can anyone else, of course.

I find this to be a major flaw with MATLAB. As great of a platform as it may be, it's such a hassle to program that most people prefer to program in a more accessible language. And it's not like those languages can't be manipulated to allow for the programs that MATLAB can support. In my opinion it was a seriously poor decision on their part.

I don't think Mathworks minds, however. They have a very strong hold on the academic and scientific markets. Their customers, mostly, make due with what they have. In other words, I don't expect anything to be changing on these fronts.

All I can do is post a mini-rant on my blog and suffer though the little inconveniences that these problems cause me. Or theoretically fork over $5,000 (no joke, I made an account on Mathworks to confirm this) to get the compiler for personal use. Can you guess which solution I chose?

Old MATLAB Improvements, Java Data Objects Primer

Matlab m-file (Download and run) 

Matlab Source Code (to view online)

For the most part I haven't changed the workings of this code. I did change one error dialog that told you the height needed to be between 0 and 20,000 meters when inputting an incorrect value for the height increments. Just a copy-paste situation where I forgot to edit the message. The big changes here are comments. It's quite thoroughly commented now and should be a bit easier to follow. I also commented-out the "Standards Selection" box, which was unusable, and centered the title information to make it look more natural. Finally I cleaned up a function call that was passing the constants array despite the fact that the other function had full view of the same array. Basically, unnecessary transferring of variables. Theoretically should have sped up the code. Considering the ambiguity of some of this code and the amount of time that passed between writing it last and doing this editing, I'm quite pleased with my ability to understand what was performing which actions throughout.

After finishing that I decided not to start the new assignment yet. Instead I started reading my book on JDO. The more I read, the more excited I get about the system. It really seems quite easy to work with and I'm excited for the implementation of it all.

I'm not sure I've talked much about JDO and why it's important to my application and Java in general, so here goes. Java code is run in a Java Virtual Machine. This is what enables it to be so universal... once the JVM is started up, one computer "appears" to be exactly like any other. At least in terms of executing the code. Unfortunately, every action the code performs is done in this Virtual Machine, and this means that everything that's been done is deleted when the code finishes, as the code finishing results in the JVM being closed. Saving in Java is done by file output during the execution of the code, by Serialization, or by storing the values of a class's variables in a database.

The first, file output, is mostly for saving a text file or similar. It's simple and useful sometimes, but it's simple and therefore not useful other times. In the case of my simulation, it's impractical due to the methods of parsing a text file back in (it would take AGES) and due to the ease of editing that text file between sessions to hack the game. Besides that, saving the file on your computer makes it tough to have an exciting multiplayer experience.

The second, Serialization, is complex. Essentially it converts the state of an object into a stream of bits and bytes, then on loading deserializes it back into its object form. These bytestreams can be large, but more importantly it's a bit unwieldy to program a class to be Serializable and program the Serialization and Deserialization across a full application like the simulation. There's also, again, the problem of things being stored on a client computer and making multiplayer a bit lackluster.

The third is storing values in a database. To start with, we'll ignore JDO. Storing values in the database means building a database (using SQL, most likely), linking the Java code up with it through the JDBC API, and programming in all the possible commands for editing the database that the client will ever use. While it sounds daunting, it's certainly doable and it had my vote for a while. Every time the client-side application is run, the user would log into the database and it would load all of his/her details, initializing all the objects necessary and setting the values back to what they are in the database.

Then comes JDO. JDO is a standard that allows me, as a Java developer, to program everything in Java code. I don't need to build my database with SQL to start with, I don't need to include ridiculous amounts of SQL hidden among the Java I'm writing, I don't need to specially format my classes. All I do is write the class as normal, enhance it with an automated tool (which builds into the class all of the methods necessary to view and edit it, automatically), initiate my database with a similar automated tool, and tell my program to make an object persistent whenever I need it to. Loading that object isn't always done per se, more often you just access the values in the database. It's just that those values are set within the Java application and without any complicated translation are plopped into the database in a Java-accessible structure.

It's really the easiest of the bunch I've seen so far. I can't wait to actually use it.

But first... I have more MATLAB to code.

Java Hiatus

Alright, I'm officially putting my Java development on hold from this point until... well, when I change my mind (probably no more than a couple of weeks, possibly much shorter). The reasons for this are twofold:

1. While I enjoy Java more, I'm actually required to do my MATLAB assignments, so I need to get to work on them.
2. Before going on with serious development, I need to know what exactly is required for creating a Java Data Object database.

If I continue without researching JDO more thoroughly, I may well find myself stuck deep in the mud when suddenly it turns out I needed to implement specific classes for each of my classes, or I needed to ensure certain formats matched up or whatever.

I managed to find a book on JDO online in PDF form for free download. If you search Java Data Objects on Yahoo! Groups, the first result should be a site for the book, and if you become a member you can download it as a PDF. I haven't read it yet but it should be more useful than nothing by a long shot. That's what I'll be doing when I'm not thrilled with the idea of MATLAB and I need to progress on my Java developing.

Also, I've started scrolling through Yahoo! Answers, trying to provide help to people looking for Java//Generic Programming help. I refuse to outright code people's homework (or midterms, like one person asked) but hopefully the information I give is useful for those who want to learn what they're doing. It's also a little bit of publicity for the blog, by having it linked from my profile. We'll see if it gets anywhere, I'm not holding my breath.

Contract for the Material class

Today's post is mostly organization for me, setting down guidelines for the Material class I'm working on. Still, this could also serve as an informative post as I'm using strategies set out in some of my books.

A contract is essentially what the name implies: a list of terms and conditions. In these particular circumstances, it's a list of things that the class is expected to be able to do. In the professional world, a contract is often what a programmer will receive. How the person works out the inner dealings of the code is unimportant, so long as they accept inputs defined by the contract and return outputs defined by the contract.

So, without further ado, the Material contract:
The Material class must be able to:
-Create a new instance, with String inputs name and matcode.
   -Verify the formatting of the input (11 characters, a-z only).
   -Convert the characters of the matcode to integer values 0-25.
-Include classes to set individual attributes with int 0-25 input.
-[OPTIONAL] Include classes to set/get attributes by name.
-Include a class to get the current matcode of the material.
-Include all classes to produce a GUI to view and modify the material.
   -Construct input panel.
   -Construct edit panel.
   -Construct output panel (display graphic).
-Include a list of market prices for the past 12 weeks (or more).
   -Method to set current price (saving old price as above)
   -Method to archive prices when they're removed from above list.
   -Method to get current price
   -Method to display a graph of past prices
   -[OPTIONAL] Display graph including archive.


I'm pretty sure that's all, at least for now. I think it's safe to say that everything except the market prices has been coded, though it hasn't all been migrated to be within the Material class.

Remember I said that it's up to the programmer to decide how to then code the inner workings? That's how I think I've come up with another class. And then from the fact that I'm also developing the whole thing, I decided on another still. Internally, the Material class will also host the MatCode class. This class will make it easy for a Material method to alter a specific attribute by calling methods within that class. It will allow for error checking, editing materials by supplying integer OR character values, and overall serve to be a convenience class for making the Material class look cleaner. That said, it won't be needed outside of the Material class and serves as a good internal class.

As an external class, I need Price. Basically all it does is store a price and the date that price was set. It will be used for a number of different objects and needs to be outside of the Material class. Mostly, it makes the eventual database more useful when the price is its own object storing pertinent information.

With these done in a day or two, I'll be able to move on to the next class, probably Planet. But also expect some work done on both my old MATLAB project (ISA Calculator) mostly in the form of adding comments, and my new MATLAB project.

Mobile Solution, and (Re?)inventing the Wheel

I've settled on an IDE called tIDE. It doesn't seem to be very popular, but I find it to be amazingly quick when set up on a flash drive, it's remarkably small, and it works quite well for everything I need. It's not Netbeans in terms of some convenience features, but it's actually survivable to use it for programming on the go. Compiling and running take a little bit of time, but that's because I'm running the JDK and JRE off of the same flash drive, which is not an inherently quick method for it.

Overall I'm quite pleased with the result, but I'll keep you posted if something happens to change my mind.

Now, I know, I was almost done, right? But no, I've decided to go back and play with the Matcode Interpeter I've nearly finished. In terms of hard stuff, I'm not doing too much. I've decided, however, to use a Material class rather than a string for the Matcode it edits. What's this mean? Well, a number of things:

• Editing a single character in the MatCode is a bit easier and mostly more accessible, as the method is stored within the Material class.
• The eventual creation of Materials will be easily managed through just the MatCode Interpreter (/editor), as the new Material object will be made and then uploaded to the database.
• The graphic panel displaying a material's stats will be accessible by any and all objects that need to reference it, quite easily.
• By moving all the buttons and panels I've been making to within the Material class, any panel throughout the entire simulation that needs to view or modify a Material can easily access all the tools that can be used for it.

In all, it's a more thorough form of isolation and encapsulation. It's also the general strategy I'll be following for all of the objects in the game from this point forth. In hindsight, it's blaringly obvious, but, well, hindsight's always 20/20.

Mobility and Programming (also: New Assignment)

Two major things today.

First, I'm working on getting a programming thumb-drive set up. Until I have a netbook, or, better yet in terms of performance, a laptop for my programming endeavors, I need some solution for mobility. My desktop and the PS3 are both set up on the same screen, which makes developing tough while my girlfriend slogs her way through Final Fantasy XIII, Tom Clancy, or whatever else she happens to be playing. I've tried a wide range of solutions to this but none have worked out. I haven't been able to get remote desktop working reliably, my first attempt at a thumb drive failed horribly (my second attempt is currently copying over), and I can't really think of much else.

When it comes to using my girlfriend's laptop, I could certainly install my tools on it and just worry about having the code on the thumb drive. But when I'm in school or anywhere else, that doesn't work so well. I'm now trying combinations of installing the IDE I normally use (Netbeans 6.8) on the flash drive as well as the JDK necessary for coding, installing just a text editor with some programming features (like highlighting code and suggesting auto-completion), and everything in between.

So, that said, I've also got a new MATLAB assignment. It's basically along the lines of the last one, accepting user input values for an aircraft and its flight, and working out things like cruising thrust and drag coefficients. No plotting this time but a few more complicated output values. We've got two weeks at this point, but given next week being a full-time (9-5 Monday through Friday) intensive CAD week, he's agreed to probably push the deadline back. Seeing as Easter holidays start the day after the current date, that would mean we have at least an extra three weeks.

I'll be getting started on it by the end of this weekend. I'd rather not take my chances. Besides, I like this stuff.

Another Link in the Chain

So I've linked all of the characters to their own characters. In other words, I'm nearly done with the matcode piece for now.

I think next step after this is work on some of my data-storing classes. I'm working on thinking out the different things that will go into the management of an empire. A lot of what's to come isn't very graphical in nature, but, hey, it needs to be done for progress to be made.

I'm thinking an interface for sim-based objects, abstract classes for spatial bodies, for military values, for whatever else I can come up with. Non-abstract classes will then flesh out the specifics. I'm also trying to decide how best to organize the data within the classes. For now, though, I've still  got a while to go before I get to that having an effect.

Did I mention L4D 2 is a lot of fun? Oh, and FFXIII too. Lack of significant progression can certainly be attributed to the presence of these distractions. Fun times, these.

Down to Business

Er... Left 4 Dead 2 is business, isn't it? And Final Fantasy XIII?

Yeah, having acquired these two games in the past 12 hours, my free time today was not very code-producing. I read a bit of my book during downtime in school, but the only snippet I've managed to add to my code was connecting the MatEditLine (previously described, still lacking the appropriate button sizing (in my opinion)) to a specified character in the material code. And heck, even that's not complete because it's a one-time linkup rather than a constantly-updating link (for the moment--that's a small thing to change).

I imagine tomorrow will be similarly... unproductive, but should have some sort of progress, like usual. It won't take me more than a few days to get back to programming as much as I have been up to now. Oh well, for now, it's bed-time (or maybe time to observe Final Fantasy... I'm not quite sure.)

The Little Things

I got hung up today on the stupidest thing. My buttons.

They work great, do exactly what they're supposed to do. But my buttons bug the bejeezus out of me. Why? Because they're huge. I just want a nice little square button with a plus sign on it, maybe a minus sign, maybe two. They just do "fill," "add," "subtract," or "empty" on the value they're editing.

It's the "little" and "square" requirements that are annoying me. For some reason or other, the button truncates the string to "..." when it's smaller than 40 pixels wide. The plus sign is THINNER than the ellipsis, by my approximation, but is apparently too large to display. If I want the "+ +" label to display I need to extend it to 60 pixels.

Simple math says each character is 10 pixels wide, and the string needs to be a minimum of 15 pixels from each side. That's what Java is deciding. I can't figure out how to change this. I've asked in some forums and will keep searching, but this is what is currently holding up my development. I hate being obsessive-compulsive sometimes.

Theoretically progress is proceeding nicely. I added the functionality of showing the current matcode in the text input, a small feature mostly useful for changing your mind and therefore leaving the input with an empty string when you decide to play with a different setting. It also prepares the link-up of the value-editing MatEditLines that I've created to the matcode being displayed.

Still, this little tiny problem has bugged me enough to cause me not to progress too far forward. It's really a shame. Oh well, there's always tomorrow.

Where There's a Will There's a Way

I'm starting to realize more and more that, however convoluted it may be, there is always a method to get my program to do what I want it to. Sometimes the method is messy. Most times, I just assume it's messy and skim over the really easy answer for a few hours.

So far I've completed compartmentalizing the input panel (and successfully). Now I'm working on the editing panel, which consists simply of a fill button, an add button, an identifier of the current value, a subtract button, and an empty button. Repeated 11 times, once for each character in the Matcode, of course. I've gotten the edit line finalized (just did that now), so that I can simply repeat that 11 times. I still need to code it to accept those 11 values, in order, as a Matcode and make the appropriate graphic. Also, as this is a tool mostly for myself as the eventual administrator of the simulation, I'll have a points system set up so that every time I add or subtract a value I see where I stand versus the average number of points I'd like for a material to have. Just as a guideline.

The final product will link the current code in the text input to the code being manipulated with the +/- buttons in order to make a more intuitive interface.

The work I've been doing the past couple of days has been frustrating. It took a long time to make something that still isn't actually very useful. Still, not all was lost. I finally understand how to make a subclass constructor actually do what I want it to. I had been programming a stupid little setup where the constructor simply set instance variables, then constructed a version of the superclass. It then returned this superclass in a separate method, making the class I defined essentially useless except as an instance variable holder. Turns out, and I've finally stumbled across this factoid, that the first line of a constructor's code is supposed to be a call to the constructor being used. Worse yet, all the times I didn't place this call, the program calls it anyway and I simply don't make use of it.

Ah, well, live and learn. Have to go back and edit a couple of constructors, but for the most part that won't take much at all. Time for bed, now. I'll be back tomorrow.

Efficient Algorithms and Abstract Data Types

These are the things I've learned the most about today. I've read through roughly a quarter of my new book so far and I'm liking what it's teaching me. It started with algorithms.

Algorithms are basically just set methods to achieve some sort of goal. A majorly important aspect of them is that they're broken down into pieces, and set up in such a way that a machine (computer, mechanical, or whatever) can perform them step-by-step. You increase an algorithm's efficiency by reducing the number of "characteristic operations" done to complete the task.

Consider, as a metaphor, rabbits. You start off with two rabbits. Each set of two rabbits produces two offspring, and so on and so on. (Note: this is, indeed, a vague shroud covering the exponential equations used as a model in the book, and would be plagiarism if I didn't acknowledge the fact). Presuming we're not considering bunny lifespans in our scenario, the number of rabbits around at generation 1 is 2, at 2 it's 4, at 3 it's 8, 4 it's 16, and so on where n = 2^n rabbits. If you're in generation 1, it only takes n = 2 to calculate the answer. At generation 2, n = 2*2 for anything to determine the proper value, which is one characteristic operation (multiplication is done one time).  At three it's n = 2*2*2 (two characteristic operations), and so on to infinity.

In other words, it takes (n-1) characteristic calculations to determine the number of bunnies we've got running around our backyard.

Instead, you can consider the fact that for n = 1, it's simply 1*2 bunnies. For n = 2, it's 2*2 bunnies. For n = 3, it's (2*2)*2. This looks sloppy. Instead take n to be 100. For the first case, it takes 99 multiplications to get the proper answer. For the second, however, n = (2^50) * (2^50), which can also be broken down to simplify. When programmed properly (the value of 2^25 gets stored in a variable, then multiplied by itself to get the value of 2^50 which is stored into that variable, for example), this then only takes 6 iterations to calculate the number of bunnies at generation 100. And yes, it's possible to arrange this to apply to any value of n. And for any base (not just 2), for that matter.

It's really an amazing improvement, and in terms of code (the examples are provided in the book, I won't copy them here) you're looking at 1, maybe 2 extra lines to achieve that speed increase. Eventually I'll look over the equations I used for the MATLAB ISA Calculator assignment and try to figure out a quicker algorithm for that work. I'm sure something exists.

So, what are Abstract Data Types then? These are simply user-defined (where user- means programmer-) classes that serve to provide a structure and appropriate manipulation tools for the data stored within them. Technically pretty much every type of data in Java (or most any programming language) is an ADT, though most are defined by the language. Generally an ADT fulfills a specific role known as a contract, which states explicitly what the inputs to the class will be, what kinds of manipulation and output one can expect to get from the class, and what data must be stored within it. It's then the programmer's role to decide how to accomplish those goals most efficiently, without methods that are uncalled for (unless they serve to ease the processes that are required). I've been aware of the basic concept for a long time now, but the specifics of planning the type and implementing it as code is becoming more and more clear as time progresses.

I expect a lot of progress this weekend, as well as documentation of that progress.Wish me luck!

Computer Issues, More Code, and Toast

My girlfriend's laptop is on the fritz. I think there's a virus on it given how it's acting, though I admit she's usually more cautious about them than I am. That said, I spent a while working on it today and it left me with limited time.

Still, I finished the builder pattern. It works perfectly for the text box I used before, and I imagine it won't have any problems with any other text boxes I make. In the end I had a nasty if/else structure in the processing of the input text, but I spent a long time trying to come up with a better way and couldn't find one. That said I did reduce the redundancy of it by creating method calls to do any repetetive tasks, so while the structure is a bit messy it isn't very wordy.

Tomorrow will see the finalization of the interpreter with the last internalization of the input panels. Aside from that, I got a new book to read from the library. This one is actually one that I'll probably read cover-to-cover rather than as a reference book to pick and choose sections from. It's called "Java Collections: An Introduction to Abstract Data Types, Data Structures, and Algorithms" by David A. Wyatt and Deryck F. Brown. I'm hoping to find the best way of making my JDO classes by reading through it.

In all, a nice and short post, expect more tomorrow.

"Bob" the Builder (pattern)

So, I've heard of Java constructors. These friendly little guys make an instance of an object when the program calls them, setting variables if necessary, making everything work the way you need to. Today, however, was the first time I'd heard of Builders.

Constructors can, sometimes, get really messy. "Setting variables if necessary" can get to the point where you have 20 variables to set and 18 of those are optional. It's nasty to program a constructor to properly handle optional variables and it's nasty to call a constructor with all of those variables. And who wants to print out a list of which variable comes when in the call to the constructor?

Hello, builders. Builders are like flexible constructors, but they require a bit more manipulation to set up properly. Basically a builder is a class placed inside the class you want to construct, and no constructor is made available for that class. Instead, you call the constructor for the builder (in Java syntax this means you call something like endgoal.builder() where endgoal is the thing being built), with any required values included in the () after builder. Then you continue calling optional values by adding .option1(), .option2(), and so on until the object is fully set up for you. All of the values that eventually go into your endgoal object are stored privately inside the builder class so as not to cause any funny business on the part of your outer class.

When you're all done, you call the endgoal.build() class to put it all together for you, as necessary.

What am I using this for? At the moment, validation on the text box used to enter Material Codes. Matcodes must be 11 characters long, consisting only of english alphabet letters. I convert the input to uppercase inside the material code interpreter's method, so it's not a big deal what case you use externally, but internally it does make a difference.

I realize that the matcode input is not the only text field I'm going to use, and in searching for the way to limit the maximum number of characters in a text field I've come to the conclusion that it requires making a so-called "Document" that tells the input box how to behave. This is easy enough, but why code a separate document for each text input when I can just create a builder?

For now I'm coding in the options to change the input to Upper/Lowercase depending on needs, to force the input to be alphabetical, numerical, or both, to set a maximum length onto the input, and finally to allow or disallow spaces in the input. In the case of my matcode text box, I'll call something like:

input.setDocument( new JTextFieldLimits.LimitBuilder()

.charLimit(11).toUpperCase().forceLetter()

.forceNoSpace().build() );

It looks a little nasty but for my sanity it's better than something more like:

input.setDocument( new JTextFieldLimits(true, 11,

true, false, true, false, false, true));

where I have to remember which position responds to which value every time I make a new input box. And that would be even longer if I come up with more options to throw in here. Don't forget that if all I want to do is disallow spaces, with the builder I can just do LimitBuilder().forceNoSpace().build() whereas with the other one I have to include all of the "false" values until the very end. And Java forbid I forget how many false values that adds up to.

The JTextFieldLimits class isn't quite finished yet, but it's progressing smoothly and I don't think I'll run into too many problems with it. Once that's done I'll get back to work on isolating the MatPolygonDraw class by having it build its own panels. I think I'll have both of those done before my next post.

Reference: http://rwhansen.blogspot.com/2007/07/theres-builder-pattern-that-joshua.html Thanks for the help!

MatPolygonDraw: LF More Responsibility, Better Name.

So, naming scheme aside, my "MatPolygonDraw" function is quite a capable function. It defines the vector of colors used to determine the fill color of the polygon in question, it draws the labels for each point, the bounds of the full shape, and the lines connecting each point to the maximum value for that point. In achieving these goals, it takes an input string, checks it for validity, determines its numerical value, converts the numerical value combined with its string position to work out the variable the value applies to and then determine X,Y coordinates of where that point is.

I'm sure it does more, but, meh, I'm still working on it so there's no need to keep explaining it. I updated it today to contain a nested class entitled matButton, a subclass of the JButton. Now, rather than creating a new JButton and assigning it an actionListener to make everything work as it should, the frame that hosts the MatPolygonDraw instance simply calls the getButton class, passes any pertinent information over, and receives a new JButton appropriately configured for the task.

Tomorrow will see the expansion of this concept. Rather than just the the JButton, I'll include the JTextField component and place both of them on a panel. This way I'll just call getInputPane or whatever I decide to name it and I'll receive both of these, properly configured. I'll do the same to create a getEditPane for manipulating the material's properties, and any other panes I may need to accomplish any task I can imagine that requires a material graphic interpretation.

Then I just make the structure for any other objects that need manipulation, I go ahead and follow the same process for getting the necessary interfaces, and voila, simple finished product.

In other words, I think I'm getting this, because suddenly I'm realizing just how little  work I'll have to put into the final assembly of everything compared to the creation of the manipulating classes.

In all, I'm content. It's time for bed though, and that leaves this post open for discussion. Any recommendations for a better name for this class? Preferably something that defines what it does, very concisely. Best name gets immortalized in my code! And... a cyber cookie?

P.S: I'm going to stop going ridiculously overboard on the tags for my posts. They're all about computing, no need to continue labelling that.

Compartmentalization, Encapsulation, and Isolation, oh my!

I've been focusing a lot on these inheritance features today. I know, for instance, that I can create a class Planet, and that I can also create a class Moon extends Planet, so that the two are differentiated in name but don't need repetitive coding. I've been considering the pros and cons of making all of the attributes I've taken to calling low-level attributes (a planet's name, for exmaple... the things that the object stores that don't reference other objects) implement a custom interface.

Time for some explaining? I think so. In Java, a class (known as a child or a subclass) can extend another class (known as a parent or a superclass). This means that, unless an underlying method in the child overrides the parent's method (this is done simply by creating a method in the child with the same name as the parent's method), the methods defined in the parent are equally as applicable to the child. In the case of class Planet and class Moon extends Planet, as above, the method getSize() would return a number representing the planet's diameter, and would do the same for a Moon even without explicitly rewriting the code.

Now on to implementing interfaces. An interface is an abstract class, which means that it cannot be used directly. Instead, when a class implements an interface, everything written into that interface MUST be overridden by the new class. If I have attributes, to use the example above, which all have different variables within them (say, a description attribute holds text describing the object, an armor attribute holds a value representing the armor's strength), I can create an interface that defines getType() and getValue() as methods that MUST be overridden, therefore making the attributes universal in structure.

A Java class can extend only one parent lass, but can be extended by infinitely many children. A Java class can implement as many interfaces as it wishes, so long as all of the underlying methods are overridden. Because of the way these two aspects of "inheritance" work, they are known as two related but separate pathways of defining a new class. By making a new class a child of a parent class, you are inheriting behavior. That is to say, all of the 'hows' in the class are defined by the parent class, except for the occasional overriding method or additional method. By having a new class implement an interface, you are inheriting structure, because the layout of the new class must match the interface, but the specific algorithms used are specific to the new class.

There's my brief lecture on Java's inheritance. That out of the way, I haven't done coding work today, seeing as I instead attended a showing of "Willy Wonka and the Chocolate Factory" (that's right, the original) at the University. I did get a lot of (additional) thinking in and I realized one of the shortcomings in the current embodiment of the interpreter I showed yesterday. I have a button that is specialized for the window I showed you, not one I can place into just any window I place the graphic into. This also means that when I go to make a more capable "administrator" version that allows me to generate material codes on-the-fly, I'll have to completely reprogram that button.

Instead I can use some nifty features of Java's by including a specialized button subclass into the class that creates the material graphic. This subclass would be inherently tied to the material graphic that the button updates, and wouldn't require any coding except placement in the larger window.

Overall this would greatly increase the capabilities of the materials panel I've made, as well as the capabilities of any future classes I make. I consider this Compartmentalization (and I think the textbooks agree with me) because it means that any frame that uses the MatCodeInterpreter will, without extra work, be able to add the necessary buttons and fields to manipulate it.

I think tomorrow will see me working on making that a reality.

Mission Accomplished!

For the first time in my blogging career of nearly two weeks, I have something to show you that I've been promising in relation to my Simulation. That's right, I have finished my material decoder. Well, at least functionally, certainly it needs work to be implemented.

That, my reader(s), is my new MatCode Interpreter in action. Type in 11 characters, hit evaluate, and a new shape will be made for you. I admit, it has limited practical use as it doesn't supply exact values (it could, just doesn't), but it gives a good representation of approximate values. The color of the figure shows an interpretation of the material's "Workability Factor," a fancy name for cost modifier. The interpretation is that the darker/redder the color, the more expensive it is to work with. This random material apparently is very cheap to work with. The ten named values are (clockwise from right (3 o'clock)) integrity, conductivity, combustibility, heat resistance [index], transparency, elasticity, magnetism, nuclear value [index], decay resistance [index], and [intrinsic] value. Bear in mind that mid-range values are assumed to be average. In other words, the only places this material is above-average are magnetism, elasticity, heat resistance, and perhaps combustibility.

Above average isn't always better, though.

Anyway, this is my first actually vaguely complex Java program, and my first go with Java graphics aside from JFrames (basically, windows and buttons). I had made the text layout in photoshop, but I decided instead to render it using Java's graphics, in part to better acquaint myself with the system and in part because for a long time I was having trouble figuring out how to get the image into the program. I've since figured it out, but that was after setting Java up to do it.

So... what's my next step? I have no freaking clue. But I have plenty of other classes to work on. Some should be pretty easy, just the structural classes for my JDO database. Others are more involved, making frames and panels for managing different pieces. I have a lot of work to go, but I've made the first sizeable step.