Ubuntu – PDF thumbnails are missing in Dolphin

Slower than other file browsers ?

What other ? Konqueror ? Krusader ?

The Dolphin is the default KDE file manager but you don't need to use it. System Settings > Default Applications > File Manager.

Thunbnails ?

Package: kdegraphics-thumbnailers

:~$ apt-cache show kdegraphics-thumbnailers
Description: graphics file format thumbnailers for KDE SC
 These plugins allow KDE software to create thumbnails for several
 advanced graphic file formats (PS, RAW).
Homepage: http://www.kde.org/

Commandline install:

sudo apt-get install kdegraphics-thumbnailers

Dolphin > Settings > Configure Dolphin > General > Previews: Show previews for PostScript, PDF and DVI Files

You may need to rise the "Do not create previews for" limit !

--- EDIT ----

Comment:

Slower than Nautilus, its GNOME brother.

I have not used the Nautilus but the developer /1/, /2/ is promising improved performance with the KDE 4.8 & Dolphin 2.0.

Comment:

...Though I don't get why I have to hit the "preview" button on toolbar for every directory I enter in. How can I make it the default behavior?

One way: Dolphin > View > Adjust View Properties. Press the F1 key, when the Dolphin is active, to get the Dolphin Handbook.

Another way /3/: Open the Dolphin in the ~/.kde/share/apps/dolphin/view_properties/global/ (*1) and turn the Icons/Details/Columns/Preview/... on/off. The settings are saved to the ~/.kde/share/apps/dolphin/view_properties/global/.directory file and used as the global defaults - IF the local folder does not have own .directory file with the overriding settings.

KDE .directory file:

The .directory file is a KDE folder view properties file. It contains the folder viewing settings for a directory in KDE. It includes settings such as icon positions and view mode (icon, list, etc.). Automatically created when the view settings of a folder are modified. Hidden by default.

(*1) If the ~/.kde/share/apps/dolphin/view_properties/global/ directory does not exist, you could make it.

More of the Dolphin: KDE UserBase /4/ and the Dolphin KDE Home /5/.

Links

1. http://ppenz.blogspot.com/
2. http://ppenz.blogspot.com/2011/08/introducing-dolphin-20.html
3. http://www.kubuntuforums.net/showthread.php?55954-Solved-Dolphin-settings&s=3b900a05916fdf62051c6acedb4d9e7c
4. http://userbase.kde.org/Dolphin
5. http://dolphin.kde.org/index.html

Solved this problem by adding repository ppa:gnome3-team/gnome3 and upgrading the system. Totem was updated: I think that was "it". Hope it'll help.