From dstein@marmot Thu Oct 12 18:53:50 1995
From: dstein@marmot (Doug Stein)
To: sami.shaio@Eng, vbo@marmot
Subject: GridBag layout for awt
Cc: arthur.vanhoff@Eng


I finished porting GridBag to awt. It sure is easy to port C-code to Java!
(At least it is if you don't have lots of pointers everywhere).

I ran some tests and it seems to work fine. The included tar file has
two classes for gridbag layout (GridBagLayout and GridBagConstraints).
It also includes 9 silly little applets that lay out bunches of buttons.

The only new stuff I added that wasn't in the Tk version was handling
the preferredSize vs. minimumSize stuff. The way I am doing it to
first try preferredSize for everything. If that doesn't fit, then I
revert to using minimumSize for everything. Using a combination of
preferredSize and minimumSize for the case where some components fit
with preferredSize (but not all components) doesn't seem worth it.

I'm also wondering if I should use insets instead of pads, since the
Container class uses insets already. Insets seem more useful than pads,
so I'll likely change it to use insets.

I noticed that sometimes the first components to be layed out don't get
painted until a subsequent refresh is performed. I noticed this
behavior using some of the other layout classes as well as gridbag, so
I don't think this bug is specific to gridbag.

Try it out and let me know what you think. The documentation I've
included is for the Tk version. Check out the GridBagConstraints class
and the demos to get an idea of how to use it for awt.

If you find any bugs, please let me know. I am using the Pre-Beta 1
release of the Java Developers Kit.


- Doug