Hello there, lonely wanderer and welcome to the magical land of Google Drive!
$ git clone git://anongit.kde.org/kio-gdrive.git $ cd kio-gdrive $ mkdir build && cd build $ cmake -DCMAKE_INSTALL_PREFIX=`qtpaths --install-prefix` .. $ sudo make install $ kdeinit5 # or just re-login
Now you are ready to use the slave. Either click the "Network" button in Dolphin or run:
$ kioclient5 exec gdrive:/
GDocs file don't have file size Not our fault, Google Drive API simply does not return filesize of these files. I think it's because they are in the Google Docs format, so the size is irrelevant, since only GDocs can open them, and if we convert the files into .ODT or .DOCX or whatever else, the size is different (so we would have to measure it manually)
Folders have "Unknown" size We cannot provide size information on folders, so I guess this is actually implemented in KIO/Dolphin by simply listing each folder and showing the number of files. This is probably not done on remote filesystems to save bandwidth and improve performance, hence the size is "unknown".
Open tasks are tracked here: https://phabricator.kde.org/tag/kio_gdrive/