Avoid redrawing GimpCanvasProgress items upon
GimpProgress::set_value() if a minimal amount of time hasn't passed
since the last call. This notably improves performance of
frequently-updated GimpCanvasProgress items.
- change start() and set_text() to use "format" and "..." instead of
"message", allowing to format progress messages in place
- s/cancelable/cancellable/
- move "cancellable" to be the second argument of start()
and get the shell from gimp_canvas_item_get_shell() if needed. Remove
some cairo_translate() that didn't have any effect and were leftovers
from a very early canvas item code.
Ell