Alternative JCP architecture

Soooo. I have been messing around with what I've optimistically been thinking of as an 'alternative' JChemPaint renderer rather than just a botched refactoring. I started with the code by Niels Out (blog) and messed around with it a bit. Here is a diagram of part of where it is at:

This is meant to be valid UML, but the message is the same : "Overly. Complex." The basic idea is that the parent SymbolTreeFactory handles the logic of what bonds to create, and the child factory creates a tree suitable for AWT.

There's a name problem here, as "AWT" is not right for Java2D; also I'm not sure why I decided on "SymbolTree" as it's not really a tree as such. It could be, using a Composition pattern perhaps, but that seems unnecessary.

Anyway, the point of this is to make separate AWT and SWT renderers, while sharing as much code as possible. This may not be the way to do it, but it is a way to do it.

Comments

Egon Willighagen said…

Arvid implemented this basic design yesterday...

2 October 2008 at 09:23

gilleain said…

Oh, I should have said, this diagram was made from the implementation, not the other way round!

So, I have a version. There are still problems with the design; mainly due to having to render text (font sizes are always the problem).

Not sure where to put the code...

2 October 2008 at 10:13

chalky

I wanted to show something that hints at the things that the new architecture can afford us: This is using a Java2D graphics Paint object to make it look like chalk...kindof. It's a very simplistic way of doing it by making a small image with a random number of white, gray, lightgray, and black pixels. edit: it doesn't look so good at small scales some tweaking of stroke widths and so on is essential.

The Gale-Ryser Theorem

This is a small aside. While reading a paper by Grüner, Laue, and Meringer on generation by homomorphism they mentioned the Gale-Ryser (GR) theorem. As it turns out, this is a nice small theorem closely related to the better known Erdős-Gallai (EG). So, GR says that given two partitions of an integer ( p and q) there exists a (0, 1) matrix A iff p* dominates q such that the row sum vector r(A) = p and the column sum vector c(A) = q . As with most mathematics, that's quite terse and full of terminology like 'dominates' : but it's relatively simple. Here is an example: The partitions p and q are at the top left, they both sum to 10. Next, p is transposed to get p* = [5, 4, 1] and this is compared to q at the bottom left. Since the sum at each point in the sequence is greater (or equal) for p* than q , the former dominates. One possible matrix is at the top left with the row sum vector to the right, and th...

1,2-dichlorocyclopropane and a spiran

As I am reading a book called "Symmetry in Chemistry" (H. H. Jaffé and M. Orchin) I thought I would try out a couple of examples that they use. One is 1,2-dichlorocylopropane : which is, apparently, dissymmetric because it has a symmetry element (a C2 axis) but is optically active. Incidentally, wedges can look horrible in small structures - this is why: The box around the hydrogen is shaded in grey, to show the effect of overlap. A possible fix might be to shorten the wedge, but sadly this would require working out the bounds of the text when calculating the wedge, which has to be done at render time. Oh well. Another interesting example is this 'spiran', which I can't find on ChEBI or ChemSpider: Image again courtesy of JChempaint . I guess the problem marker (the red line) on the N suggests that it is not a real compound? In any case, some simple code to determine potential chiral centres (using signatures) finds 2 in the cyclopropane structure, and 4 in the ...

Some Stuff

Search This Blog