KDE

KDE & Qt Applications

• kdesvn, when used with KDE < 3.5.6 can cause an error message with the context menu (although this is inoffensive), telling about DCOP errors. The fix is in KDE 3.5.6.

• Some applications are much better opened only once if they support tabs. For example, Quanta and Kate. Generally, they have a command-line option to tell them to use an existing instance. Open the KDE control panel and change the file association, so that the application is launched with this option. For Kate it is -u.

• By default, KDE uses all key shortcuts control+F5, control+F6, etc... for virtual desktop switching. This prevents these keys from working in Firefox for example. The best is to disable these key shortcuts. KDE Control Center -> Regional & Accessibility -> Keyboard Shortcuts -> Shortcut Sequences.

Advanced KDE configuration

• First, using the KDE control center should *never* mess up with the KDE base installation/configuration, except when it asks for administration rights.

• The user directories used by KDE 4 under Gentoo:

~/.kde4/
~/.local/
~/.config/

The last directory (.config) seems more related to Qt stuff and themes. It also contains data about the Kmenu, but that's not the only place.

• UPDATE: Not sure .config is still used by KDE (only by Qt).

KMenu Entries

• The KMenu is built unfortunately from a number of different places. System-wide, /usr/share/applications for example. For one user, it is in config/menus/applications-kmenuedit.menu (probably deprecated place), as well as .local/share/applications.

• The KMenu entries in a user home directory will override the system ones. So using the user ones is dangerous as you may override Portage's data.

• If an entry does not appear in the KMenu, try to delete all the stuff in /var/tmp/kde-cache (and in /tmp). You can also run kbuildsycoca4 with various options. If nothing works, try to run the menu editor and to reset the menu to the system one. It will rebuild correctly everything but will remove user defined stuff.

• If an application still does not appear, check that the binary is present on the system and the user can actually execute it (eg, no permission problems).

• If a .desktop file has no categories, the icon will probably appear in Lost+Found in the KDE menu.

Wallet Subsystem

• You can disable the subsystem entirely.
• In order for Kopete not to keep asking you for the wallet password, you can deny Kopete any access to the wallet subsystem. This will force it to use the unsafe password storing option (in the configuration file). Edit the file ~/.kde/share/config/kwalletrc.

Brightness

• The default brightness (restored when KDE starts up) depends on your power management profile. Thus you can change that by configuring your power management profile.

Volume keys

• These will work in KDE if you install kmix.

Screen Locking & Screen Saving

• Chromium can prevent the screen from locking when some sites are opened. This seems to happen on Youtube for instance. Not sure how to prevent this yet.

Input Actions

• In KDE 4, you can configure those in System Settings -> Computer Administration -> Input Actions. You can associate hotkeys to KMenu entries (eg, launch applications this way).

Issues

• In KDE-4.2, if you uncheck the "Confirm Logout" checkbox in Session Manager, the computer reboots when you simply choose to logout.

KDE Frameworks

Baloo

• Baloo is the new indexing framework replacing nepomuk. You can configure it (exclude some paths from indexing) in System Settings -> Desktop Search.

• Useful commands:

balooctl status # shows how many files are indexed and indexing process
balooshow /path/to/file # shows if file is indexed
baloosearch ExampleWord
balooctl check # checks for any unindexed file (this should normally not happen, but I had to manually issue this one time)
balooctl monitor # prints what the indexer is currently doing (indexing). If nothing happens, it means the indexer is stuck / idle

• Sometimes the database is not up to date and contain wrong, old entries. The easiest way is to remove it at ~/.local/share/baloo/, logout then relog, Baloo will build a new one.

Nepomuk

• Nepomuk is obsolete and no longer used, you can remove its database at ~/.kde4/share/apps/nepomuk if it is still present.