Connor,
Everyone here wants to help, but you are a hard case because you adamantly refuse to credit the experience of others who have acquired the knowledge you crave
. Please allow me to provide a (constructive) critique of your views, as I understand them.
It seems to me a chicken and egg situation: you ask for implausible means of getting control of GUI code because you have an incorrect view of the relationship between these matters, but reject the one means that would clear up the misconceptions, namely acquiring some Java basics.
You want a special manual, containing no extraneous matter, to tell you how to construct a GUI under NetRexx. David has explained on more than one occasion that a GUI is absolutely the wrong thing to attack first, because it has tricky aspects that are unrelated to Java or NetRexx, and implies lots of invisible infrastructure. But let us take GUI programming to be the goal.
You show a GUI program fragment and remark "The comment is fine for the block of code. But it does not explain what the function JMenu is doing or why." Correct, but that is because JMenu is a complicated entity. Since you are OO-aware, you know that objects have associated methods (functions). A quick check of JMenu's javadoc shows 54 methods. Also, JMenu has to mesh with a complicated framework involving other Java classes. There is no way we could provide you with an account boiling them down to "just the ones you need to know," because all are needed in some context or other.
There have been several well intentioned efforts here to help you and others "kick start" GUI programming by providing small annotated examples that purportedly demystify it. But IMO they all have the drawback of inevitably leaving out more than they explain, with the result that your efforts to extend them will fail for no obvious reason and require further explanations, seemingly
ad infinitum.
I know you have been pointed at more comprehensive efforts at this, but they are beyond my competence to evaluate. Perhaps one will answer your prayers.
Even if I knew how to write your manual, I would be disinclined to do so, because it seems a fool's errand. My labors would simply produce an inferior version of information already available on the web.
However, that need for a more methodical way to acquire the requisite Java knowledge is real, and there may be a way out. That is to construct your manual as links to available resources, ordered logically, and with a running commentary putting them in context.
I think, but have not explored the issue in any detail, that the main component of these links, at least the early ones, should be selected elements of Sun's Java Tutorial. Sun has a pecuniary interest in promoting Java, and this concentrates minds. They have been working at attempting to convert the programming world for a long time (with resounding success), and I suspect their tutorial has received a lot of feedback which they have taken under advisement. So this strikes me as the most promising avenue. We cannot provide a printable version because Sun/Oracle does not allow redistribution, but you can print anything you like for your own use.
We could try to construct such a "virtual manual" on our own, but it would suffer from our lack of a fresh perspective. The result would be much better if it had feedback from its target audience as it is constructed in real time. I think you and Bob Hamilton have an opportunity to make a valuable contribution to NetRexx 3.0
But this can't be sugar coated. To reach the point of writing GUI code you must acquire specific knowledge and skills. All we can do is reduce the noise level as you do so. Pace Euclid, there is no royal road to GUI.
Do you want to proceed?
On Wed, Oct 6, 2010 at 6:34 AM, Connor Birch
<[hidden email]> wrote:
On 5 Oct 2010, at 16:53, George Hovey wrote:
Connor, David
David wrote:
When it comes to the java library, I think it's just a matter of overseeing what is available in there and how is it broken into different "functional domains" (packages). Then, when you need something in particular, you just look it up and use it. I don't think anyone is going to hold the whole 2700+ classes thing in his head!
Connor wrote:
Yep, you are right, getting to grips with existing java objects is a great starting point, especially where I'm not intending to leverage the OO aspect, and just want to write portable programs. So just how do I do that? Where/which is the guide that tells me how to use the more useful objects in a NetRexx centred way, that doesn't expect me to read Java programs?
-------------------------------------------------------------
This seems to me to focus on a core issue in making NetRexx new user-friendly. Connor, trying to get his arms around Java, wants to know "how to use the more useful objects". David replies, correctly, that " it's just a matter of overseeing what is available in there and how is it broken into different "functional domains" (packages)". I suspect that Connor doesn't find this answer totally satisfactory.
That's right. I once saw a Marx Brothers film where one of the brothers sells a manual to a punter. The brothers show him how to look up the information he needs. It then transpires that the punter needs to look up a value in another manual that the brothers duly sell him. Minutes later they are using a wheelbarrow to deliver more manuals. I wonder why this came to mind....
The answer, briefly, is that we can't tell you what are the more useful objects, because only you know what interests you.
I'm sure that some objects are used more than others and that a few are used particularly often. Someone somewhere ought to have an idea on the 2% top used java objects.
You don't need to read Java code.
You do need to explore the Java API by reading it's Javadoc documentation. You don't use the Javadoc program itself, you just look at its HTML output files describing the API, which can be downloaded from Sun/Oracle, with your browser.
Ah, another one of those 'manuals'
This requires that you know how the find you way around the browser display to locate packages, classes, properties and methods. You also have to understand the nature of Java's data types, both native and Object.
Here we go again. It's all very well telling me that I have to understand something. But where is the straight to the point piece of documentation that tells me just what I need to know without all the platitudes, adverts for how wonderful everything Java is, masses of irrelevant info, and java programs?
Then you are ready to invoke any Java class that strikes your fancy
None of them 'strike my fancy'. I need an easy method of identifying which ones do what I need.
from NetRexx and without the use of Java code (you are using only NetRexx objects which are, with a few weasel words, identical to Java's).
Connor wrote: In short, is there a NetRexx Cookbook?
No, but there must be if we are to succeed
Absolutely!!!!!! If success of NetRexx is what we want to achieve we need to create a relatively painless way to use java's objects, not just a painless language that invokes Java's objects.
Re-read the last three paragraphs a few times, and then some more times, and do the same tomorrow. This is the important issue. If we don't get this right, we may as well accept the inevitable demise of NetRexx.
(although the old IBM Red Book could be so described). The information in the previous paragraph should be there but in much expanded form, with screen shots etc. If you would be willing to contribute time to advancing this cause, I am available, and I think others, certainly David, will contribute. I propose that we find out what is require to "bootstrap" you into Java API awareness by doing it step by step. This will give us the information to produce a fair stab at the article "Using the Java Class Library in NetRexx" in "The NetRexx Cookbook". I would be glad to act as recording secretary in collecting materials. I also have Adobe Acrobat (writer) to produce a PDF.
We might start a new thread and ask people to use it solely for contributions to this experiment.
What do you think?
That is the most positive statement I have heard on this forum. I don't really have the time, but I am good at critiquing books, and this is an important and worthwhile activity. So yes, I'll do it in byte sized pieces. A gui equivalent of the Hello World program (okay with a bit more functionality) might be the place to start.
On 5 Oct 2010, at 17:19, Quique Britto wrote:
I ended up purchasing a Java Book as I find the Javadoc too much for my eyes.
I have started writing a tutorial for writing Netrexx programs using Java Swing, it's basically a shortcut for people who wish to use Swing and Netrexx.
http://www.esimplesoft.es/
Looks useful. However we handle this, I think that we need ONE Guide that contains everything the new user needs, rather than a whole bunch of documents and tutorials that partly overlap each other, and leave gaps between them. That guide could be online if we need online functionality, but my preference would be for a printable guide that is not competing for screen real estate when we are trying to work, and allows
the user to see how much material there is (rather than it seeming as if there is no end in sight as with online tutorials). Also, one can write notes on printed guides.
I would suggest that we use some form of online document that allows multiple people to edit so that it can be a collaborative effort, eg if I see an easy change or addition, I can make it myself, if something is not clear enough, I can say so (perhaps in another colour). Any contributor could add clarity where necessary. I think that Google Documents is supposed to be a bit like that, but there may be a better mechanism (one that tells everyone what has changed, when it has changed).
In a way, we are in a good starting position. Since I last downloaded NetRexx, jEdit etc, I have purchased a new laptop. So there is nothing to do with NetRexx installed. The Guide can therefore start from scratch and I can test whether it takes me painlessly form zero to everything working. Last time I suffered pain to do with classpaths. Perhaps the guide can ensure that the pain is removed. My laptop is a Mac, I also have a PC running XP and one running Windows7, so I can test the system setup on three common environments.
We should seek permission to use whatever existing materials (eg red book) there are.
In the guide, we should not leave the newbie thinking "what the h*** does that do" eg:
-- define menu headers (use loop)
menubar_he = [ "File", "Edit", "Info" ]
loop i=0 to 2
menubar[i] = JMenu( menubar_he[i] )
mb.add( menubar[i] )
end
The comment is fine for the block of code. But is does not explain what the function JMenu is doing or why.
Lets make this happen,
Connor.
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