Okular – How to Make Okular Follow the System Theme

okularthemes

Since I upgraded to Ubuntu 18.04, Okular doesn't follow the Adwaita-dark or Arc themes when I set them with the Gnome tweak tool. Is there any way to fix this? All I really want is for Okular to use dark colors for its menus and toolbars.

Edit: When I try

GTK2_RC_FILES=Adwaita:dark okular

from the terminal, I get a bunch of errors like

(okular:16699): Gtk-WARNING **: 22:58:15.581: Theme parsing error: gtk.css:137:54: Using one color stop with linear-gradient() is deprecated.
(okular:16699): Gtk-WARNING **: 22:58:15.587: Theme parsing error: gtk.css:1839:9: Expected a string.
(okular:16699): Gtk-WARNING **: 22:58:15.590: Theme parsing error: gtk.css:2913:17: Using Pango syntax for the font: style property is deprecated; please use CSS syntax

I've also tried downloading systemsettings and kde-config-gtk-style and activating the themes there, with no response.

Best Answer

What worked for me was:

sudo apt-get install qt5-style-plugins

This is taken from the ArchLinux documentation. It also recommends setting the QT_QPA_PLATFORMTHEME=gtk2 environment variable, but I did not need that.

See also this other AskUbuntu question, this solution applies to all KDE applications.

Related Solutions

Ubuntu – How to install the latest version of okular

To have the latest version of Okular you have 3 options:

Easy Option - Install the latest Kubuntu. Either 11.10 or wait for 12.04. The reason for this will be explained in the other Options.

Intermediate Option - Download the DEB Package of Okular and all of it's dependencies and the dependencies of those dependencies until you have literally downloaded KDE in pieces just to install that since the latest Okular depends on libraries and other packages that also depend on others that need to be a specific version or newer. This versions are not compatible with an older Ubuntu so you would have to start downloading a lot of packages. This in most cases will not work and waste your time since at some point a package might say "Hey I need a newer kernel version of autotool, autoconf, make... and so on." So your chances of having it work there are very difficult.

Difficult Option - Compile the whole thing from scratch. This option will take more experience and a heck of more time to do and at the end it will not guarantee that it will work on the kernel used in Ubuntu 10.10 with the versions of the tools provided in 10.10.

To make matters worse, 10.10 has been discontinued. So try the option everyone has suggested (Install 12.04). If you do not want a heavy system then install Lubuntu or Xubuntu and then install Okular from there but just so you know, you can install Okular very easy and with less download time in Ubuntu 12.04 since it already comes with the QT libraries for it. No need to download them when trying to download Okular.

Ubuntu – How to make Okular play embedded video

The following worked for me:

Change the backend of Phonon (which is used by Okular to play videos) to the VLC one. For me it sufficed to install the respective package:
```
sudo apt install phonon-backend-vlc
```
On newer versions of Ubuntu, the crucial package is phonon4qt5-backend-vlc.

Use multimedia instead of movie15:

\documentclass{beamer}
\usepackage{multimedia}

\begin{document}
    \begin{frame}
        \movie[poster, height=6.5cm, width=6.5cm]{}{/figures/Video.avi}
    \end{frame}
\end{document}

Best Answer

Related Solutions

Ubuntu – How to install the latest version of okular

Ubuntu – How to make Okular play embedded video

Related Question