Okular supports opening multiple files at the same time on the command line by specifying multiple PDF files as arguments. However, if one wants to open multiple PDFs within the Okular QT GUI, one must open each one one at a time through the Open dialog since it is a single-file open dialog. I suggest this Open dialog be changed to support multiple files so that users can quickly open a set of PDFs in a directory without having to run okular from the terminal.
Interesting. The code actually loops over all selected files, but the dialog is not executed in a mode where multiple files are allowed. This might just be a porting regression, and should be easy to fix. See https://cgit.kde.org/okular.git/tree/shell/shell.cpp#n476
It is easy to fix: https://phabricator.kde.org/D13667
https://phabricator.kde.org/D13667 works for me
Git commit 862b2ab6647e49b141ea7e9197f295bc5e220720 by Oliver Sander. Committed on 25/06/2018 at 15:11. Pushed by sander into branch 'master'. Allow to select more than one file in the 'open file' dialog Differential Revision: https://phabricator.kde.org/D13667 M +1 -0 shell/shell.cpp https://commits.kde.org/okular/862b2ab6647e49b141ea7e9197f295bc5e220720