A StringBuilder is a mutable data structure to create a String.
When the String is created, the new String does not share any
storage with the StringBuilder. Thus, we can keep a same
StringBuilder, and reuse its internal storage between different
iterations.
I incorrectly included the DeleteLine in the progress line length and
this could cause certain progress lines to be incorrectly reported as
multi line when they actually fit on a single terminal line.
On the off chance that in some configurations the terminal width is set
to zero, avoid an exception by returning 0 for terminal lines. It is
likely that supershell will not work well if terminal width is zero, but
that's better than a potential crash (I think the crash would be in the
progress background thread, so I'm not sure how bad it would be, but
still its good to avoid).
Sometimes if the progress lines are wider than the terminal width,
the supershell blank zone can expand indefinitely because be do not move
the cursor far enough up to properly re-fill the blank zone.
It takes about a second to load scala.reflect.runtime.universe. If we
lazy load here, we can load scala.relect.runtime.universe in the
background to speed up the sbt start up time. See
0ebb7a5662.
The previous implementation of supershell log line interlacing with
regular line interlacing relied on state in a global object. A somewhat
better approach is for each appender to hold a reference to a state
object. Every time tasks run, new appenders are created, so the state
should always reflect the current progress state.
Supershell actually works quite well in no color mode. On the sbt side,
we still want to disable supershell automatically if the output is not a
terminal or no color is set, but this commit allows the user to force
supershell through -Dsbt.supershell or the useSuperShell setting even
when no color is set.
With this commit, I improved the padding management so that padding is
now added above the progress report. Whenever a line is logged at the
info or greater level, we can reduce the padding level by one since that
line has effectively filled in the padding.
With the current supershell implementation, the progress display
flickers when there is heavy console logging during task evaluation.
This is because the console appender clears out the task progress and it
isn't restored until the next periodic super shell report (which
runs every 100ms by default). To remove the flickering, I reworked the
implementation to interlace the log lines with progress reports. In
order to ensure that the log lines remained contiguous, I had to apply
padding at the bottom of the supershell region whenever the new report
contained fewer lines than the old report. The report shifts down as new
log lines are appended. This isn't optimal, but I think removing
the flickering while preserving contiguous log lines is worth it.
We discovered in the community build that 1.3.0-RC4 breaks the
lucidchart scalafmt plugins. We can unbreak binary compatibility by
adding alternative classes.