Release Notes for Jcon

The Git version of Jcon includes several changes since the last public release of version 2.1 in 1999.

• The source code is now compatible with Java 8 (Java v1.8).
• For consistency with v9, reads() no longer translates line terminators.
• &time now properly reports CPU time instead of wall-clock time.
• The linewidth graphics attribute is now implemented.
• Some minor bugs have been fixed.

Tested Platforms

Jcon has been successfully tested on:

Mac OS 10.9.4 (Mavericks) / Oracle Java 1.8.0_20
Ubuntu 12.04.5 LTS / Java 1.7.0_05
Ubuntu 12.04.4 LTS / Java 1.6.0_26

We would be interested to learn of either successes or failures on other platforms.

Problems seen recently

• Graphics windows are often incorrect when first opened. This seems to be a timing problem (race condition) of some sort.

Older unverified problems (nongraphical)

• Some JIT compilers fail to execute Jcon programs correctly. Disabling the JIT compiler produces correct execution.
• The -S option of jcont does not work for programs that link other files.
• &clock and &dateline may be off by one hour (Java bug #4059431).
• On Solaris systems, &host may return "localhost" (Java bug #4073539).
• Extremely large procedures (thousands of lines long) can generate code that is too large for Java to handle.

Older graphics problems

Some problems are universal:

• When an obscured part of a window is exposed, it may not be repaired (redrawn) until the program pauses to await an event.
• WOpen("image=file.gif") does not load an image if presented with a multi-part (animated) GIF image.
• A java exception may occur during program termination.

Other problems are seen only on some platforms and are attributed to Java bugs:

• Fonts can be poor when one vendor's Java system displays on another vendor's X server.
• Different fonts may be written to the window and to and its backup image, leading to bizarre effects from CopyArea() and window repair.
• On one older system, nothing appears in a window until it is dragged to a different location.
• The initial window size may not be as specified:
  • It is one pixel too wide, or
  • It is always the default size, or
  • Its height is correct but its width is the default.
• Intermittently, drawop=reverse draws the wrong color.
• GIF images have a yellowish tint.
• The CopyArea() section of the gpxtest program shows a minor glitch.