Commit 6b281e8f authored by Jehan's avatar Jehan

plug-ins: add progression to PDF exporting.

PDF exporting had no progression. In particular when exporting a PDF
with more a hundred pages today, it took maybe 20 secs without any
progression status, which is annoying.

Limitations:
1. When exporting as multi-images, we reset to 0 at each image. I am
   actually not sure if this is the expected behavior.
2. I am updating the progression per top layer, not doing finer grained
   progression steps. An extreme case would be a single top layer group
   with many children layers inside. Yet I wanted to avoid too much
   progression updates for the normal cases.
parent a4a9e17b
Pipeline #257053 failed with stages
in 65 minutes and 24 seconds