Oberon-2 Episode 2
One thing that has cooled somewhat my desire to learn Oberon-2 is the fact that I still want to program for Windows-styled environments. Command lines and line-by-line data entry just doesn’t cut it. To do that, I will need to go to Blackbox, a programming environment that allows you to generate programs with a Windows feel (or Gnome/KDE, if you are a Windows hater).
To that end, I wanted to find a quality way to produce such a program. I was already aware that there are a number of GUI environments available for Python, so I decided to give Python another try. The GUI package I selected, after some research, was WxPython. I downloaded Python, WxPython, even Eclipse for a good editor and Python compatibility.
After I downloaded these things, though, I became aware of one thing I should have thought of before, something I was aware of even from my IBM midrange experience.
From the very beginning, Screen Design Aid (SDA) was part of the programming experience. DDS was the language used to generate the midrange screen displays, and SDA was what you used to generate the appropriate DDS specifications, which were (and are) compiled. If you wanted a heading on your screen, you typed it where you wanted it. If you wanted a field on the screen, you prefixed a set of special characters with a + in front. For example, putting a +6666666 on the screen indicated a 7-character numeric field; +BBBB, a 4-character alphanumeric input-output field; +99999999, an 8-digit input-output numeric field. When you pressed enter, the + disappeared and the field remained. Since you would no doubt want to give the field a name so you could use it when interacting with the program the screen was associated with, you would put a ? in front of the field and press enter and a prompt screen would pop up and allow you to give the field a name and even change its length if desired. To change other field characteristics, you would put an * in front of the field; this would pop up a series of prompts that would allow you to specify such characteristics as high-intensity, blink, reverse-image (from white on black to black on white), and so on. When done, you ended SDA and it would generate DDS specifications, which you then compile as a “file” for use by your RPG program.
Now, Visual Basic it wasn’t; but it protected you from having to key in those DDS specifications line by line. You did not have to get a deep understanding of DDS to produce acceptable screen output. Of course, once you got a good understanding of DDS, you could often make changes directly to ths DDS faster than you could do it by opening up SDA; the point is, you didn’t have to.
With this in mind, you may imagine how disillusioned I was when I opened up the tutorial, and what did I see in the first lesson for WxPython? Being able to size and resize radio buttons, list boxes and pushbuttons and text boxes? No. Source code. To get a box, you type in code. To get a window, you type in code. To get any widget, you type in code, with lots of lovely parameters to enhance your programming experience.
This was not enthralling. I found that WxPython doesn’t act like Visual Basic; neither does V(isual) Python, for that matter. For every little widget, you have to grind out parameter-laden code. The result, judging from the illustrations, is very nice, but it don’t come easy. (Note: There is apparently a plugin for .NET called IronPython that allows Python to be used in the .NET environment; but I’m not sure of the details about it, particularly whether or not it is free. )
Now, whether it’s RPG, Python, or Visual Basic, there is still code to write; but it is not screen code. In fact, you have to work hard to even find the actual source code generated by VB. You are shielded from the details, even as you are (or can be) using SDA in association with the RPG program.
So I will likely shy away from learning Python and WxPython. So what will I do? An experienced Oberon-2 programmer recommended I try the POW! Oberon development environment before I tried Blackbox; but even with POW!, I will still not have the GUI widgets to work with. Since I already have a good feel, I believe, for the semantics of Oberon-2 based upon my study up to now, I may just dive into BlackBox. I am an experienced programmer, so I don’t see that I’ll need to start at “Hello World”.