[isabelle-dev] Missing letters in jEdit

[Jasmin Blanchette]

Hi Makarius,

> This looks really bad, and needs to be investigated further.  I've not seen such a bad visual drop-out in the past 1-2 years, despite many minor mistakes in the painting of Java on many different platforms.
> 
> I might be also responsible myself, potentially doing some text painting too ambitously or improperly according to Java 2D standards.  (All text that you see in Isabelle/jEdit is painted by the Isabelle plugin, not the standard painter of jEdit.)

A few more observations. When a letter is missing, it's missing everywhere. For example, b, e, r, t, L, and N are missing wherever they appear on the screenshot.

> We should start looking there, and pin down fonts that tend to cause problems vs. fonts that work.
> 
> Which is the font used in the screenshot?  Is this a standard font by Apple, or from somewhere else?

It's called Consolas. I believe it's included with Mac OS X 10.8 -- I don't remember installing any special fonts. I had the same issue with Monaco, which is definitely a standard Mac font.

I'll let you know if I run into the issue with IsabelleText, since this would presumably point to something strange with my machine.

Since the problem is nondetermistic, it's a bit hard to test. But it seems to affect only the very first font loaded. All the other fonts, of different sizes or from different families, are fine, but when I revert back to the initial font (the font that was set as the default when I launched jEdit), it's just as broken as initially.

Jasmin