ProgressBar objects provide support for modeless progress-bar
dialogs. Both determinate (thermometer style) and indeterminate
(barber-pole style) progress bars are supported. The bar will be
determinate if its maximum value is greater than zero; otherwise it
will be indeterminate.
Changed in version 2.2:
Support for indeterminate-style progress bars was
added.
The dialog is displayed immediately after creation. If the dialog's
``Cancel'' button is pressed, or if Cmd-. or ESC is typed,
the dialog window is hidden and KeyboardInterrupt is
raised (but note that this response does not occur until the progress
bar is next updated, typically via a call to inc() or
set()). Otherwise, the bar remains visible until the
ProgressBar object is discarded.
ProgressBar objects possess the following attributes and
methods:
The current value (of type integer or long integer) of the progress
bar. The normal access methods coerce curval between
0 and maxval. This attribute should not be altered
directly.
The maximum value (of type integer or long integer) of the progress
bar; the progress bar (thermometer style) is full when curval
equals maxval. If maxval is 0, the bar will
be indeterminate (barber-pole). This attribute should not be altered
directly.
Sets the progress bar's curval to value, and also
maxval to max if the latter is provided. value
is first coerced between 0 and maxval. The thermometer bar
is updated to reflect the changes, including a change from
indeterminate to determinate or vice versa.
Increments the progress bar's curval by n, or by 1
if n is not provided. (Note that n may be negative, in
which case the effect is a decrement.) The progress bar is updated to
reflect the change. If the bar is indeterminate, this causes one
``spin'' of the barber pole. The resulting curval is coerced
between 0 and maxval if incrementing causes it to fall
outside this range.
