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{{Related articles start}}
{{Article summary start}}
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{{Related|Desktop environment}}
{{Article summary text|This article covers installation, configuration, and troubleshooting of KDE.}}
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{{Related|Display manager}}
{{Article summary heading|Overview}}
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{{Related|Window manager}}
{{Article summary text|{{Graphical user interface overview}}}}
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{{Related|Qt}}
{{Article summary heading|Related}}
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{{Related|SDDM}}
{{Article summary wiki|Plasma}}
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{{Related|Dolphin}}
{{Article summary wiki|Qt}} - KDE uses the Qt toolkit
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{{Related|KDE Wallet}}
{{Article summary wiki|KDM}}
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{{Related|KDevelop}}
{{Article summary wiki|KDevelop 4}}
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{{Related|Trinity}}
{{Article summary wiki|Uniform Look for Qt and GTK Applications}}
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{{Related|Uniform Look for Qt and GTK Applications}}
{{Article summary end}}
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{{Related articles end}}
  
From [http://www.kde.org/community/whatiskde/softwarecompilation.php KDE Software Compilation] and [http://www.kde.org/download/ Getting KDE Software]:
+
KDE is a software project currently comprising of a [[desktop environment]] known as Plasma, a collection of libraries and frameworks (KDE Frameworks) and several applications (KDE Applications) as well. KDE upstream has a well maintained [https://userbase.kde.org/ UserBase wiki]. Detailed information about most KDE applications can be found there.
 
 
:''The KDE Software Compilation is the set of frameworks, workspaces, and applications produced by KDE to create a beautiful, functional and free desktop computing environment for Linux and similar operating systems. It consists of a large number of individual applications and a desktop workspace as a shell to run these applications. ''
 
 
 
The KDE upstream has a well maintained [http://userbase.kde.org/ UserBase wiki]. Users can get detailed information about most KDE applications there.
 
  
 
== Installation ==
 
== Installation ==
  
KDE 4.x is '''modular'''. You can install an entire set of packages or only install your preferred KDE applications.
+
=== Plasma ===
  
{{Note|If you do not have [[Xorg#Installation|Xorg]] installed on your system, be sure to install it before KDE.}}
+
Before installing Plasma, make sure you have a working [[Xorg]] installation on your system.
  
=== Full install ===
+
[[Install]] the {{Pkg|plasma-meta}} meta-package or the {{Grp|plasma}} group. For differences between {{Pkg|plasma-meta}} and {{Grp|plasma}} reference [[Creating packages#Meta packages and groups]]. Alternatively, for a more minimal Plasma installation, install the {{Pkg|plasma-desktop}} package.
  
[[pacman|Install]] {{Grp|kde}} or {{Grp|kde-meta}} available in the [[official repositories]]. For differences between {{Grp|kde}} and {{Grp|kde-meta}} see the [[KDE Packages]] article.
+
To enable support for [[Wayland]] in Plasma, also install the {{Pkg|plasma-wayland-session}} package.
  
=== Minimal install ===
+
=== KDE applications ===
  
If you want to have a minimal installation of the KDE SC, install:
+
To install the full set of KDE Applications, install the {{Grp|kde-applications}} group or the {{Pkg|kde-applications-meta}} meta-package. Note that this will only install applications, it will not install any version of Plasma.
* {{Grp|kdebase}}
 
* {{Pkg|phonon-vlc}} or {{Pkg|phonon-gstreamer}} as phonon backend
 
  
=== Language pack ===
+
=== Unstable releases ===
  
If you need language files, install {{ic|kde-l10n-yourlanguagehere}} (e.g. {{Pkg|kde-l10n-de}} for the German language).
+
See [[Official repositories#kde-unstable]]
  
For a full list of available languages see [https://www.archlinux.org/packages/extra/any/kde-l10n/ this link].
+
== Starting Plasma ==
 +
{{Note|Although it is possible to launch Plasma under [[Wayland]], there are some missing features and known problems as of Plasma 5.13. See the [https://community.kde.org/Plasma/5.13_Errata#Wayland Plasma 5.13 Errata] for a list of issues and the [https://phabricator.kde.org/project/board/99/ Plasma on Wayland workboard] for the current state of development. Use [[Xorg]] for the most complete and stable experience.}}
  
== Upgrading ==
+
Plasma can be started either using a [[display manager]], or from the console.
  
'''KDE 4.11''' Software Compilation is the current major [http://kde.org/announcements/ release of KDE]. Important hints for upgraders:
+
=== Using a display manager ===
* Always check if your mirror is '''up to date'''.
 
* '''Do not force an update using pacman --force'''. If pacman complains about conflicts please '''file a bug report'''.
 
* You can remove the meta packages and the sub packages you do not need after the update.
 
* If you do not like split packages just keep using the kde-meta packages.
 
  
== Starting KDE ==
+
* Select ''Plasma'' to launch a new session in [[Xorg]].
 +
* [[Install]] {{Pkg|plasma-wayland-session}} and select ''Plasma (Wayland)'' to launch a new session in [[Wayland]].
  
Starting KDE depends on your preferences. Basically there are two ways of starting KDE. Using '''KDM''' or '''xinitrc'''.
+
{{Note|The [[NVIDIA]] proprietary driver implementation for Wayland requires EGLStreams. KDE have not implemented EGLStreams in their Wayland [https://blog.martin-graesslin.com/blog/2016/09/to-eglstream-or-not implementation]. The following workarounds are available:
 +
*Using the [[Nouveau]] driver.
 +
*Using the (default) Xorg session.
 +
}}
  
=== Using KDM (KDE Display Manager)===
+
=== From the console ===
  
''It is highly recommended to get familiar with the [[Display Manager|full article]] concerning display managers, before you make any changes. See also [[KDM]] Wiki page.''
+
To start Plasma with [[xinit|xinit/startx]], append {{ic|exec startkde}} to your {{ic|.xinitrc}} file. If you want to start Xorg at login, please see [[Start X at login]]. To start a Plasma on Wayland session from a console, run {{ic|1=export XDG_SESSION_TYPE=wayland && export $(dbus-launch) && startplasmacompositor}}.[https://community.kde.org/KWin/Wayland#Start_a_Plasma_session_on_Wayland]
  
[[Daemons|Enable/start]] {{ic|kdm.service}}.
+
== Configuration ==
  
=== Using xinitrc ===
+
Most settings for KDE applications are stored in {{ic|~/.config/}}. However, configuring KDE is primarily done through the '''System Settings''' application. It can be started from a terminal by executing {{ic|systemsettings5}}.
''The meaning and usage of '''xinitrc''' is very well described [[Xinitrc|here]].
 
  
{{Pkg|kdebase-workspace}} provides startkde. Make sure it is installed. Then edit {{ic|~/.xinitrc}}, uncomment:
+
=== Personalization ===
exec startkde
 
  
After a reboot and/or log-in, each execution of Xorg ('''startx''' or '''xinit''') will start KDE automatically.
+
==== Plasma desktop ====
  
{{Note|If you want to start Xorg at boot, please read [[Start X at Login]] article.}}
+
===== Themes =====
  
== Configuration ==
+
[https://store.kde.org/browse/cat/104/ Plasma themes] define the look of panels and plasmoids. For easy system-wide installation, some themes are available in both the official repositories and the [https://aur.archlinux.org/packages.php?K=plasma+theme AUR].
  
All KDE configuration is saved in the {{ic|~/.kde4}} folder. If your KDE is giving you a lot of trouble or if you ever want a fresh installation of KDE, just back this folder up and restart your X session. KDE will re-create this folder with all the default config files. If you want very fine-grained control over your KDE programs, then you may want to edit the files in this folder.
+
Plasma themes can also be installed through ''System Settings > Workspace Theme > Desktop Theme > Get new Themes''.
  
However, configuring KDE is primarily done in ''''System Settings''''. There are also a few other options available for the desktop with ''''Default Desktop Settings'''' when you right click the desktop.
+
The [https://store.kde.org/ KDE-Store] offers more Plasma customization's, like [[SDDM]] themes and splash-screens.
  
For other personalization options not covered below such as activities, different wallpapers on one cube, etc please refer to the [[Plasma]] wiki page.
+
====== Qt and GTK+ Applications Appearance ======
  
=== Personalization ===
+
{{Tip|For Qt and GTK theme consistency, see [[Uniform look for Qt and GTK applications]].}}
  
How to set up the KDE desktop to your personal style; use different Plasma themes, window decorations and icon themes.  
+
; Qt4
 +
Breeze is not directly available for Qt4 since it cannot be built without KDE 4 packages, which have been dropped from the extra repository in August 2018 ({{Bug|59784}}). However you can install {{Pkg|breeze-gtk}} and pick GTK+ as GUI Style by running {{ic|qtconfig-qt4}}.
  
==== Plasma desktop ====
+
; GTK+
  
[[Plasma]] is a desktop integration technology that provides many functions from displaying the wallpaper, adding widgets to the desktop, and handling the panels or "taskbar".
+
The recommended theme for a pleasant appearance in GTK+ applications is {{Pkg|breeze-gtk}} or {{AUR|gnome-breeze-git}}, a GTK+ theme designed to mimic the appearance of Plasma's Breeze theme.
 +
Install {{Pkg|kde-gtk-config}} (part of the {{grp|plasma}} group) and select the installed GTK-theme for GTK2/GTK3-Theme in ''System Settings > Application Style > GNOME Application Style''.
  
===== Themes =====
+
In some themes, tooltips in GTK+ applications have white text on white backgrounds making it difficult to read. To change the colors in GTK2 applications, find the section for tooltips in the {{ic|.gtkrc-2.0}} file and change it. For GTK3 application two files need to be changed, {{ic|gtk.css}} and {{ic|settings.ini}}.
 +
It might also help to uncheck the option to ''Apply colors to non-Qt applications'' under ''System Settings'' > ''Colors''.
  
[http://kde-look.org/index.php?xcontentmode=76 Plasma themes] can be installed through the Desktop Settings control panel. Plasma themes define how your panels and plasmoids look like. If you like to have them installed system-wide, themes can be found in both the official repositories and [https://aur.archlinux.org/packages.php?O=0&K=plasmatheme&do_Search=Go AUR].
+
Some GTK2 programs like {{AUR|vuescan-bin}} still look hardly usable due to invisible checkboxes with the Breeze or Adwaita skin in a Plasma session. To workaround this, install and select e.g. the Numix-Frost-Light skin of the {{AUR|numix-frost-themes}} under ''System Settings'' > ''Application Style'' > ''GNOME Application Style (GTK)'' > ''Select a GTK2 Theme:''. Numix-Frost-Light looks similar to Breeze.
  
 
===== Widgets =====
 
===== Widgets =====
  
Plasmoids are little scripted or coded KDE apps that enhance the functionality of your desktop.  There are two kinds, plasmoid scripts and plasmoid binaries.
+
Plasmoids are little scripted (plasmoid scripts) or coded (plasmoid binaries) KDE applications designed to enhance the functionality of your desktop.
  
Plasmoid binaries must be installed using PKGBUILDS from [https://aur.archlinux.org/packages.php?O=0&K=plasmoid&do_Search=Go&PP=25&SO=d&SB=v AUR].  Or write your own PKGBUILD.
+
The easiest way to install plasmoid scripts is by right-clicking onto a panel or the desktop and choosing ''Add Widgets > Get new widgets > Download New Plasma Widgets''. This will present a nice frontend for https://store.kde.org/ that allows you to install, uninstall, or update third-party plasmoid scripts with literally just one click.
  
The easiest way to install plasmoid scripts is by right-clicking onto a panel or the desktop:
+
Many Plasmoid binaries are available from the [https://aur.archlinux.org/packages.php?K=plasmoid AUR].
  
Add Widgets > Get new Widgets > Download Widgets
+
===== Sound applet in the system tray =====
  
This will present a nice frontend for [http://www.kde-look.org/ kde-look.org] and allows you to (un)install or update third-party plasmoid scripts with just one click.
+
[[Install]] {{Pkg|plasma-pa}} or {{Pkg|kmix}} (start Kmix from the Application Launcher). {{Pkg|plasma-pa}} is now installed by default with {{Grp|plasma}}, no further configuration needed.
  
Most plasmoids are not created officially by KDE developers. You can also try installing Mac OS X widgets, Microsoft Windows Vista/7 widgets, Google Widgets, and even SuperKaramba widgets.
+
{{Note|1=To adjust the [https://bugs.kde.org/show_bug.cgi?id=313579#c28 step size of volume increments/decrements], add e.g. {{ic|1=VolumePercentageStep=1}} in the {{ic|[Global]}} section of {{ic|~/.config/kmixrc}}.}}
  
===== Sound applet in the system tray =====
+
===== Disable panel shadow =====
  
Install Kmix ({{Pkg|kdemultimedia-kmix}}) from the official repositories and start it from the application launcher. Since KDE autostarts programs from the previous session, the program need not be started manually every time one logs in.
+
As the Plasma panel is on top of other windows, its shadow is drawn over them. [https://bbs.archlinux.org/viewtopic.php?pid=1228394#p1228394] To disable this behaviour without impacting other shadows, [[install]] {{Pkg|xorg-xprop}} and run:
  
==== Window decorations ====
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$ xprop -remove _KDE_NET_WM_SHADOW
  
[http://kde-look.org/index.php?xcontentmode=75 Window decorations] can be changed in
+
then select the panel with the plus-sized cursor. [https://forum.kde.org/viewtopic.php?f=285&t=121592] For automation, install {{Pkg|xorg-xwininfo}} and create the following script:
System Settings > Workspace Appearance > Window Decorations
 
There you can also directly download and install more themes with one click and some are available on [https://aur.archlinux.org/packages.php?O=0&K=kdestyle&do_Search=Go&PP=25&SO=d&SB=v AUR].
 
  
==== Icon themes ====
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{{hc|/usr/local/bin/kde-no-shadow|<nowiki>
 +
#!/bin/bash
 +
for WID in $(xwininfo -root -tree | sed '/"Plasma": ("plasmashell" "plasmashell")/!d; s/^  *\([^ ]*\) .*/\1/g'); do
 +
  xprop -id $WID -remove _KDE_NET_WM_SHADOW
 +
done
 +
</nowiki>}}
  
Not many full system icons themes are available for KDE 4.  You can open up '''System Settings > Application Appearance > Icons''' and browse for new ones or install them manually. Many of them can be found on [http://www.kde-look.org/ kde-look.org].
+
Set execution permissions for the script:
  
Official logos, icons, CD labels and other artwork for Arch Linux are provided in the {{Pkg|archlinux-artwork}} package. After installing you can find such artwork at {{ic|/usr/share/archlinux/}}.
+
  # chmod 755 /usr/local/bin/kde-no-shadow
  
==== Fonts ====
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The script can be run on login with ''Add Script'' in ''Autostart'':
  
===== Fonts in KDE look poor =====
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$ kcmshell5 autostart
Try installing the {{Pkg|ttf-dejavu}} and {{Pkg|ttf-liberation}} packages.
 
  
After the installation, be sure to log out and back in. You should not have to modify any settings in the "Fonts" panel of the KDE System Settings application.
+
==== Window decorations ====
  
If you have personally set up how your [[Fonts]] render, be aware that System Settings may alter their appearance.  When you go ''System Settings > Appearance > Fonts'', System Settings will likely alter your font configuration file ({{ic|fonts.conf}}).  
+
[https://store.kde.org/browse/cat/114/ Window decorations] can be changed in ''System Settings > Application Style > Window Decorations''.
  
There is no way to prevent this but if you set the values to match your {{ic|fonts.conf}} file the expected font rendering will return (it will require you to restart your application or in a few cases for you to have to restart your desktop).  
+
There you can also directly download and install more themes with one click, and some are available in the [https://aur.archlinux.org/packages.php?K=kde+window+decoration AUR].
  
Note too that Gnomes' Font Preferences will also do this if you use both desktop environments.
+
==== Icon themes ====
  
===== Fonts are huge or seems disproportional =====
+
Icon themes can be installed and changed on ''System Settings > Icons''.
  
Try to force fonts DPI to '''96''' on ''System Settings > Application Appearance > Fonts.''
+
{{Note|Although all modern Linux desktops share the same icon theme format, desktops like [[GNOME]] use fewer icons (esp. in menus and toolbars). Themes developed for such desktops usually lack icons required by Plasma and KDE apps. It is recommended to install Plasma compatible icon themes instead.}}
  
If it does not work try set DPI directly on Xorg configuration [[Xorg#Setting_DPI_manually|here]].
+
{{Tip|Since some icon themes do not inherit from the default icon theme, some icons may be missing.
 +
To inherit from the Breeze, add {{ic|breeze}} to the {{ic|1=Inherits=}} array in {{ic|/usr/share/icon/''theme-name''/index.theme}}, for example: {{ic|1=Inherits=breeze,hicolor}}. You need to reapply this patch after every update to the icon theme, consider using [[Pacman hooks]] to automate the process.}}
  
 
==== Space efficiency ====
 
==== Space efficiency ====
  
Users with small screens (eg Netbooks) can change some setting to make KDE more space efficient. See [http://userbase.kde.org/KWin#Using_with_small_screens_(eg_Netbooks) upstream wiki] for more info. Also you can use [http://www.kde.org/workspaces/plasmanetbook/ KDE's Plasma Netbook] which is a workspace made specifically for small, lightweight netbook devices.
+
The Plasma Netbook shell has been dropped from Plasma 5, see the following [https://forum.kde.org/viewtopic.php?f=289&t=126631&p=335947&hilit=plasma+netbook#p335899 KDE forum post]. However, you can achieve something similar by editing the file {{ic|~/.config/kwinrc}} adding  {{ic|1=BorderlessMaximizedWindows=true}} in the {{ic|[Windows]}} section.
  
=== Networking ===
+
==== Thumbnail generation ====
  
You can choose from the following tools:
+
To allow thumbnail generation for media or document files on the desktop and in Dolphin, install {{Pkg|kdegraphics-thumbnailers}}, {{Pkg|ffmpegthumbs}} and {{AUR|kde-thumbnailer-odf}}.
* NetworkManager.  See [[NetworkManager#KDE4|NetworkManager]] for more information.
 
* Wicd and its KDE front end {{AUR|wicd-kde}}. See [[Wicd]] for more information.
 
  
=== Printing ===
+
Then enable the thumbnail categories for the desktop via ''right click'' on the ''desktop background'' > ''Configure Desktop'' > ''Icons'' > ''More Preview Options...''.
  
{{Tip|Use the [[CUPS]] web interface for faster configuration.}}
+
In ''Dolphin'', navigate to ''Control'' > ''General'' > ''Previews''.
  
The printers are configured in this way can be found in applications KDE.
+
=== Printing ===
  
You can also choose the printer configuration through ''System Settings > Printer Configuration''. To use this method, you must first install the packages {{Pkg|kdeutils-print-manager}} and {{Pkg|cups}}.
+
{{Tip|Use the [[CUPS]] web interface for faster configuration. Printers configured in this way can be used in KDE applications. }}
  
You need to start the avahi-daemon and cupsd daemons first or you will get the following error:
+
You can also configure printers in ''System Settings > Printers''. To use this method, you must first install {{Pkg|print-manager}} and {{Pkg|cups}}. See [[CUPS#Configuration]].
{{bc|The service 'Printer Configuration' does not provide an interface 'KCModule'
 
with keyword 'system-config- printer-kde/system-config-printer-kde.py'
 
The factory does not support creating components of the specified type.
 
}}
 
  
If you are getting the following error, you need to give the user rights to manage printers:
+
=== Samba/Windows support ===
There was an error during CUPS operation: 'cups-authorization-canceled'
 
  
For CUPS, this is set in {{ic|/etc/cups/cupsd.conf}}.
+
If you want to have access to Windows services, install [[Samba]] (package {{Pkg|samba}}).
  
Adding {{ic|lp}} to {{ic|SystemGroup}} allows anyone who can print to configure printers. You can, of course, add another group instead of {{ic|lp}}.
+
The Dolphin share functionality requires the package {{Pkg|kdenetwork-filesharing}} and usershares, which the stock {{ic|smb.conf}} does not have enabled. Instructions to add them are in [[Samba#Enable usershares]], after which sharing in Dolphin should work out of the box after restarting Samba.
{{hc|/etc/cups/cupsd.conf|# Administrator user group...
 
SystemGroup sys root lp}}
 
  
=== Samba/Windows support ===
+
{{Tip|Use {{ic|*}} (asterisk) for both username and password when accessing a Windows share without authentification in Dolphin's prompt.}}
  
If you want to have access to Windows services install [[Samba]] (package {{Pkg|samba}}).
+
Unlike GTK file browsers which utilize GVfs also for the launched program, opening files from Samba shares in Dolphin via KIO makes Plasma copy the whole file to the local system first with most programs (VLC is an exception).
 +
To workaround this, you can use a GTK based file browser like {{Pkg|thunar}} with {{Pkg|gvfs}} and {{Pkg|gvfs-smb}} (and {{Pkg|gnome-keyring}} for saving login credentials) to access SMB shares in a more able way.
  
You may then configure your Samba shares through
+
Another possibility is to [[mount]] a Samba share via {{Pkg|cifs-utils}} to make it look to Plasma like if the SMB share was just a normal local folder and thus can be accessed normally.
 +
See [[Samba#Manual mounting]] and [[Samba#Automatic mounting]].
  
  System Settings > Sharing > Samba
+
An GUI solution is available with {{AUR|samba-mounter-git}}, which offers basically the same functionality via an easy to use option located at ''System Settings'' > ''Network Drivers''. However, it might break with new KDE Plasma versions.
  
 
=== KDE Desktop activities ===
 
=== KDE Desktop activities ===
  
KDE Desktop Activities are Plasma based "virtual desktop"-like set of Plasma Widgets where you can independently configure widgets as if you had more than one screens/desktops.  
+
[https://userbase.kde.org/Plasma#Activities KDE Desktop Activities] are special workspaces where you can select specific settings for each activity that apply only when you are using said activity.
  
On your desktop, click the Cashew Plasmoid and on the pop-up window press "Activities".
+
=== Power saving ===
 
 
A plasma bar will appear at the bottom of the screen which presents you the current Plasma Desktop Activities which exist. You can then navigate between them by pressing their correspondent icon.
 
  
=== Power saving ===
+
[[Install]] {{Pkg|powerdevil}} for an integrated power saving service called "'''Powerdevil Power Management'''", that may adjust the power saving profile of the system and/or the brightness of the screen (if supported).
  
KDE has an integrated power saving service called "'''Powerdevil Power Management'''" that may adjust the power saving profile of the system and/or the brightness of the screen (if supported).
+
{{Accuracy|Regarding the note below, it might be that the problem is the logind setting ''LidSwitchIgnoreInhibited'' which defaults to ''yes''. [https://bbs.archlinux.org/viewtopic.php?pid&#61;1649022#p1649022]}}
  
==== How to enable Cpufreq based power saving ====
+
{{Note|Powerdevil may not [[Power management#Power managers|inhibit]] all logind settings (such as the lid close action for laptops). In these cases, the logind setting itself will need to be changed - see [[Power management#Power management with systemd]].}}
  
{{Note|Cpufreq seems have been dropped from arch linux in favour of [[cpupower]] ([https://github.com/mate-desktop/mate-applets/issues/11 reference]).}}
+
=== Autostart ===
  
Since KDE 4.6, CPU frequency scaling is no longer managed by KDE.  Instead it is assumed to be handled automatically by the the hardware and/or kernel. Arch uses {{ic|ondemand}} as default cpufreq governor from kernel vesion 3.3. See [[cpufreq|wiki article on cpufreq]].
+
Plasma can autostart applications and run scripts on startup and shutdown. To autostart an application, navigate to ''System Settings > Startup and Shutdown > Autostart'' and add the program or shell script of your choice. For applications, a ''.desktop'' file will be created, for shell scripts, a symlink will be created.
  
If you are happy with setting your governor once at boot (with the {{ic|cpufreq}} daemon script, for example) then this section is not relevant and can be skipped.
+
{{Note|
 +
* Programs can be autostarted on login only, whilst shell scripts can also be run on shutdown or even before Plasma itself starts.
 +
* Shell scripts will only be run if they are marked [[executable]].
 +
}}
  
# If you have not already done so, install the {{Pkg|cpufrequtils}} package (for the {{ic|cpufreq-set}} utility).
+
* Place [[Desktop entries]] (i.e. ''.desktop'' files) in the appropriate [[XDG Autostart]] directory.
  
# Next, you will need to grant access to '''cpufreq-set''' for the appropriate users by configuring [[sudo]].  For example, if you are part of the ''wheel'' group, you could use {{ic|visudo}} to add:
+
* Place or symlink shell scripts in one of the following directories:
%wheel ALL = (ALL) NOPASSWD: /usr/bin/cpufreq-set
 
to your {{ic|sudoers}} file.
 
  
3. From ''System Settings > Power Management > Power Profiles'' select a profile to edit or create a new one. Check the ''Run Script'' option and add an appropriate {{ic|cpufreq-set}} command for the selected power profile. For example, your "Powersave" profile might have:
+
:; {{ic|~/.config/plasma-workspace/env/}}: for executing scripts at login before launching Plasma.
sudo cpufreq-set -r -g ondemand
+
:; {{ic|~/.config/autostart-scripts/}}: for executing scripts at login.
Your "Performance" profile might have
+
:; {{ic|~/.config/plasma-workspace/shutdown/}}: for executing scripts on shutdown.
sudo cpufreq-set -r -g performance
 
  
{{Note|* The ''cpufreq-set'' examples above may be insufficient for setting the governor for all processors/cores.
+
=== Phonon ===
For some CPU families the {{ic|-r}} switch may not set the governor for all cores/cpus and instead only set the governor for CPU 0.  In this case you will need to write a script to iterate through all your cores.  A simple script for a four core system could look like:
 
#!/bin/bash
 
for i in {0..3}; do
 
  sudo /usr/bin/cpufreq-set -c${i} -gondemand
 
done
 
* You can check which governors are active with {{ic|cpufreq-info -o}} or less intuitively by inspecting {{ic|/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor}}.
 
}}
 
  
=== Monitoring changes on local files and directories ===
+
From [[Wikipedia:Phonon (software)|Wikipedia]]:
  
KDE now uses '''inotify''' directly from the kernel with '''kdirwatch''' (included in kdelibs), so Gamin or FAM are no longer needed. You may want to install this {{AUR|kdirwatch}} from AUR which is a GUI frontend for kdirwatch.
+
:Phonon is the multimedia API provided by KDE and is the standard abstraction for handling multimedia streams within KDE software and also used by several Qt applications.
  
== System administration ==
+
:Phonon was originally created to allow KDE and Qt software to be independent of any single multimedia framework such as GStreamer or xine and to provide a stable API for a major version's lifetime.
  
=== Set keyboard layout in order switch language inputs ===
+
Phonon is being widely used within KDE, for both audio (e.g., the System notifications or KDE audio apps) and video (e.g., the [[Dolphin]] video thumbnails).
  
In order to do that, navigate to
+
==== Which backend should I choose? ====
    System Settings > Hardware > Input Devices > Keyboard
 
There you may choose your keyboard model at first.
 
{{Note| It is preferable that, if you use Evdev, that means Xorg automatic configuration for keyboards, you should choose "Evdev-managed keyboard".}}
 
In the "'''Layouts'''" tab, you choose the languages you may want to use by pressing the "Add Layout" button and therefore the variant and the language.
 
In the "'''Advanced'''" tab, you can choose the keyboard combination you want in order to change the layouts in the "Key(s) to change layout" sub-menu.
 
  
=== Terminate Xorg-server through KDE system settings ===
+
You can choose between backends based on [[GStreamer]] and [[VLC]] – each available in versions for Qt4 applications and Qt5 applications ({{AUR|phonon-qt4-gstreamer}}, {{Pkg|phonon-qt5-gstreamer}} – {{AUR|phonon-qt4-vlc}}, {{Pkg|phonon-qt5-vlc}}).
  
Navigate to:
+
[https://www.phoronix.com/scan.php?page=news_item&px=MTUwNDM Upstream prefers VLC] but prominent Linux distributions (Kubuntu and Fedora-KDE for example) prefer GStreamer because that allows them to easily leave out patented MPEG codecs from the default installation. Both backends have a slightly different [https://community.kde.org/Phonon/FeatureMatrix features set]. The Gstreamer backend has some optional codec dependency, install them as needed:
System Settings > Input Devices > Keyboard > Advanced (tab) > "Key Sequence to kill the X server" submenu
 
and tick the checkbox.
 
  
=== Useful KCM ===
+
* {{Pkg|gst-libav}} — Libav codecs.
 +
* {{Pkg|gst-plugins-good}} — PulseAudio support and additional codecs.
 +
* {{Pkg|gst-plugins-ugly}} — additional codecs.
 +
* {{Pkg|gst-plugins-bad}} — additional codecs.
  
KCM means KConfig Module. This modules help you to configure you system providing a interface on System Settings.
+
In the past other backends were developed as well but are no longer maintained and their AUR packages have been deleted.
  
'''Configuration for look&feel of your GTK apps.'''
+
{{Note|1=<br>
* {{Pkg|kde-gtk-config}}
+
* Multiple backends can be installed at once and prioritized at ''System Settings > Multimedia > Audio and Video > Backend''.
* {{AUR|kcm-gtk}}
+
* According to the [https://forum.kde.org/viewtopic.php?f=250&t=126476&p=335080 KDE forums], the VLC backend lacks support for [[wikipedia:ReplayGain|ReplayGain]].
* {{AUR|kcm-qt-graphicssystem}}
+
* If using the VLC backend, you may experience crashes every time Plasma wants to send you an audible warning and in quite a number of other cases as well [https://forum.kde.org/viewtopic.php?f=289&t=135956]. A possible fix is to rebuild the VLC plugins cache:
 +
{{bc|# /usr/lib/vlc/vlc-cache-gen /usr/lib/vlc/plugins}}
 +
}}
  
'''Configuration for the GRUB2 bootloader.'''
+
== Applications ==
* {{AUR|grub2-editor}}
 
* {{AUR|kcm-grub2}}
 
  
'''Configuration for Synaptics driver based touchpads.'''
+
The KDE project provides a suite of applications that integrate with the Plasma desktop. See the {{Grp|kde-applications}} group for a full listing of the available applications. Also see [[:Category:KDE]] for related KDE application pages.
* {{Pkg|synaptiks}}
 
* {{AUR|kcm_touchpad}}
 
  
'''Configuration for [[Firewalls#ufw|UFW]]'''
+
Aside from the programs provided in KDE Applications, there are many other applications available that can complement the Plasma desktop. Some of these are discussed below.
* {{AUR|kcm-ufw}}
 
  
'''Configuration for [[PolicyKit]]'''
+
=== System administration ===
* {{AUR|kcm-polkit-kde-git}}
 
  
'''Configuration for Wacom Tablet'''
+
==== Terminate Xorg server through KDE System Settings ====
* {{AUR|kcm-wacomtablet}}
 
  
More KCM can be found [http://kde-apps.org/index.php?xcontentmode=273 here].
+
Navigate to the submenu ''System Settings > Input Devices > Keyboard > Advanced (tab) > "Key Sequence to kill the X server"'' and ensure that the checkbox is ticked.
  
== Desktop search and semantic desktop ==
+
==== KCM ====
  
According to [https://en.wikipedia.org/wiki/Semantic_desktop Wikipedia], ''"the Semantic Desktop is a collective term for ideas related to changing a computer's user interface and data handling capabilities so that data is more easily shared between different applications or tasks and so that data that once could not be automatically processed by a computer can be (automatically processed)."''
+
KCM stands for '''KC'''onfig '''M'''odule. KCMs can help you configure your system by providing interfaces in System Settings, or through the command line with ''kcmshell5''.
  
The KDE implementation of this concept is tied to (as of KDE 4.10) two major pieces of software, Akonadi and Nepomuk. Between the two of them, these programs look at your data and make an easily searchable index of it. The idea behind these pieces of software is to make your system "aware" of your data and give it context using meta-data and user-supplied tags.
+
* {{App|kde-gtk-config|GTK2 and GTK3 Configurator for KDE.|https://cgit.kde.org/kde-gtk-config.git|{{Pkg|kde-gtk-config}}}}
 +
* {{App|System policies|Set of configuration modules which allows administrator to change [[PolicyKit]] settings.|https://cgit.kde.org/polkit-kde-kcmodules-1.git|{{AUR|kcm-polkit-kde-git}}}}
 +
* {{App|wacom tablet|KDE GUI for the Wacom Linux Drivers.|https://www.linux-apps.com/p/1127862/|{{Pkg|kcm-wacomtablet}}}}
 +
* {{App|Kcmsystemd|systemd control module for KDE.|https://github.com/rthomsen/kcmsystemd|{{AUR|systemd-kcm}}}}
  
Soprano and Virtuoso are two dependencies of the Nepomuk Semantic Desktop. Since the relationship between the two major components and their dependencies is not very clear, the following sections try to shed some light on their inner workings.
+
More KCMs can be found at [https://www.linux-apps.com/search?projectSearchText=KCM linux-apps.com].
  
=== Virtuoso and Soprano ===
+
=== Desktop search ===
  
The database used to store all the metadata used by the semantic desktop is a ''[https://en.wikipedia.org/wiki/Resource_Description_Framework Resource Description Framework (RDF)]'' database called Virtuoso. Internally, Virtuoso may be looked as a relational database. (A [https://en.wikipedia.org/wiki/Relational_model relational database] is different from a traditional single-table based database in the sense that it uses multiple tables related by a single key in order to store data.) It is currently controlled by OpenLink, and is available under commercial and an open source license.
+
KDE implements desktop search with a software called [[Baloo]], a file indexing and searching solution.
  
From the [http://techbase.kde.org/Projects/Nepomuk/ComponentOverview#Soprano KDE Techbase], ''Soprano is a Qt abstraction over databases. It provides a friendly Qt-based API for accessing different RDF stores. It currently supports 3 database backends - Sesame, Redland and Virtuoso. The KDE Semantic Stack only works with Virtuoso. Soprano also provides additional features such as serializing, parsing RDF data, and a client server architecture that is heavily used in Nepomuk.''
+
=== Web browsers ===
  
=== Nepomuk ===
+
The following web browsers can integrate with Plasma:
  
Nepomuk stands for "Networked Environment for Personal, Ontology-based Management of Unified Knowledge". It is what allows all the tagging and labeling of files as well to take place and also serves as the way to actually read the Virtuoso databases. It provides an API to application developers which allows them to read the data collected by it.
+
* {{App|[[Wikipedia:Konqueror|Konqueror]]|Part of the KDE project, supports two rendering engines – KHTML and the [[Chromium]]-based Qt WebEngine.|https://konqueror.org/|{{Pkg|konqueror}}}}
 +
* {{App|[[Wikipedia:Falkon|Falkon]]|A Qt web browser with Plasma integration features, previously known as Qupzilla. It uses Qt WebEngine.|https://userbase.kde.org/Falkon/|{{Pkg|falkon}}}}
 +
* {{App|[[Chromium]]|Chromium and its proprietary variant Google Chrome have limited Plasma integration. [[KDE Wallet#KDE Wallet for Chrome and Chromium|They can use KWallet]] and KDE Open/Save windows.|https://www.chromium.org/|{{Pkg|chromium}}}}
 +
* {{App|[[Firefox]]|Firefox can be configured to better integrate with Plasma. See [[Firefox#KDE/GNOME integration|Firefox KDE integration]] for details.|https://mozilla.org/firefox|{{Pkg|firefox}}}}
  
In the past, the "Strigi" service was used to collect data about the various files present on the system. However, due to many reasons, the most important of them being CPU and Memory usage, Strigi was replaced by a homegrown indexing service which is integrated with Nepomuk-Core.
+
{{Tip|Starting from Plasma 5.13, one can integrate [[Firefox]] or [[Chrome]] with Plasma: providing media playback control from the Plasma tray, download notifications and find open tabs in KRunner. [[Install]] {{pkg|plasma-browser-integration}} and the corresponding browser add-on. Chrome/Chromium support should already be included, for Firefox add-on see [[Firefox#KDE/GNOME integration]].}}
  
For further information about Nepomuk, [http://techbase.kde.org/Projects/Nepomuk/ComponentOverview#Nepomuk_Components this page] is a good resource. However, some of the information in the previous page has been rendered outdated according to [http://vhanda.in/blog/2012/11/nepomuk-without-strigi/ this blog post].
+
=== PIM ===
  
==== Using and configuring Nepomuk ====
+
KDE offers its own stack for personal information management. This includes emails, contacts, calendar, etc. To install all the PIM packages, you could use the meta-package {{Pkg|kdepim-meta}}.
  
In order to search using Nepouk on the KDE desktop, press {{ic|ALT+F2}} and type in your query. Nepomuk is enabled by default. It can be turned on and off in
+
==== Akonadi ====
System Settings > Desktop Search
 
  
Nepomuk has to keep track of a lot of files. It is for this reason that it is recommended to increase the number of files that can be watched with inotify. In order to do that this command is a good option.
+
Akonadi is a system meant to act as a local cache for PIM data, regardless of its origin, which can be then used by other applications. This includes the user's emails, contacts, calendars, events, journals, alarms, notes, and so on. Akonadi does not store any data by itself: the storage format depends on the nature of the data (for example, contacts may be stored in vCard format).
sysctl fs.inotify.max_user_watches=524288
 
  
To do it persistently:
+
Install {{Pkg|akonadi}}. For additional addons, install {{Pkg|kdepim-addons}}.
echo "fs.inotify.max_user_watches = 524288" >> /etc/sysctl.conf
 
  
Restart Nepomuk to see the changes.
+
{{Note|If you wish to use a database engine other than [[MySQL]], then when installing the {{Pkg|akonadi}} package, use the following command to skip installing the {{Pkg|mariadb}} dependencies:
  
====KDE without Nepomuk====
+
# pacman -S akonadi --assume-installed mariadb
  
If you wish to run KDE without Nepomuk, there exists a {{AUR|nepomuk-core-fake}} package in the AUR.
+
See also {{Bug|32878}}.
{{Warning|As of now, Dolphin depends on {{Pkg|nepomuk-widgets}} and hence will break if used with the fake Nepomuk package}}
+
}}
  
=== Akonadi ===
+
===== PostgreSQL =====
  
Akonadi is a system meant to act as a local cache for PIM data, regardless of its origin, which can be then used by other applications. This includes the user's emails, contacts, calendars, events, journals, alarms, notes, and so on. It interfaces with the Nepomuk libraries to provide searching capabilities.
+
[[Install]] {{Pkg|postgresql}}.
  
Akonadi does not store any data by itself: the storage format depends on the nature of the data (for example, contacts may be stored in vcard format).
+
To use [[PostgreSQL]] edit Akonadi configuration file so that it has the following contents:
  
For more information on Akonadi and its relationship with Nepomuk, see [http://blogs.kde.org/node/4503] and [http://cmollekopf.wordpress.com/2013/02/13/kontact-nepomuk-integration-why-data-from-akonadi-is-indexed-in-nepomuk/].
+
{{hc|~/.config/akonadi/akonadiserverrc|<nowiki>
 +
[%General]
 +
Driver=QPSQL
  
==== Disabling Akonadi ====
+
[QPSQL]
 +
Host=
 +
InitDbPath=/usr/bin/initdb
 +
Name=akonadi
 +
ServerPath=/usr/bin/pg_ctl
 +
StartServer=true
 +
</nowiki>}}
  
See this [http://userbase.kde.org/Akonadi#Disabling_the_Akonadi_subsystem section in the KDE userbase].
+
{{Note|The value for {{ic|1=Host=}} will get set by Akonadi when it starts for the first time.}}
  
==== Database configuration ====
+
Start Akonadi with {{ic|akonadictl start}}, and check its status: {{ic|akonadictl status}}.
  
Start {{ic|akonaditray}} from package {{Pkg|kdepim-runtime}}. Right click on it and select '''configure'''. In the Akonadi server configure tab, you can:
+
===== SQLite =====
* Configuring Akonadi to use MySQL Server running on the System
 
* Configuring Akonadi to use sqlite
 
  
==== Running KDE without Akonadi ====
+
To use [[SQLite]] edit Akonadi configuration file to match the configuration below:
  
The package {{AUR|akonadi-fake}} is a good option for those who wish to run KDE without Akonadi.
+
{{hc|~/.config/akonadi/akonadiserverrc|2=
 +
[%General]
 +
Driver=QSQLITE3
  
== Phonon ==
+
[QSQLITE3]
 +
Name=/home/''username''/.local/share/akonadi/akonadi.db
 +
}}
  
=== What is Phonon? ===
+
===== Disabling Akonadi =====
  
From [[Wikipedia:Phonon|Wikipedia]]:
+
See this [https://userbase.kde.org/Akonadi#Disabling_the_Akonadi_subsystem section in the KDE userbase].
''Phonon is the multimedia API for KDE 4. Phonon was created to allow KDE 4 to be independent of any single multimedia framework such as GStreamer or xine and to provide a stable API for KDE 4's lifetime. It was done for various reasons: to create a simple KDE/Qt style multimedia API, to better support native multimedia frameworks on Windows and Mac OS X, and to fix problems of frameworks becoming unmaintained or having API or ABI instability.
 
''
 
  
'''Phonon''' is being widely used within KDE, for both audio (e.g., the System notifications or KDE audio apps) and video (e.g., the Dolphin video thumbnails).
+
=== KDE Telepathy ===
  
=== Which backend should I choose? ===
+
[https://community.kde.org/KTp KDE Telepathy] is a project with the goal to closely integrate Instant Messaging with the KDE desktop. It utilizes the Telepathy framework as a backend and is intended to replace Kopete.
  
You can choose between various backends, like GStreamer ({{Pkg|phonon-gstreamer}}) or VLC ({{Pkg|phonon-vlc}}) available in the [[official repositories]], Xine ({{AUR|phonon-xine}}) or  MPlayer ({{AUR|phonon-mplayer-git}}) available on [[AUR]].  Most users will want GStreamer or VLC which have the best upstream support. Note that multiple backends can be installed at once and you can switch between them via ''System Settings > Multimedia > Phonon > Backend''.
+
To install all Telepathy protocols, install the {{Grp|telepathy}} group.
 +
To use the KDE Telepathy client, install the {{Pkg|telepathy-kde-meta}} package that includes all the packages contained in the {{Grp|telepathy-kde}} group.
  
{{Note|According to the [http://userbase.kde.org/Phonon#Backend_libraries KDE UserBase], Phonon-MPlayer and Phonon-Xine are currently unmaintained}}
+
==== Use Telegram with KDE Telepathy ====
  
According to [https://www.archlinux.org/news/kde-sc-46-to-extra/ announcement of KDE 4.6 in Arch] and [http://mail.kde.org/pipermail/phonon-backends/2011-February/000500.html mail in Phonon dev list], users should prefer GStreamer over VLC due to the feature difference.
+
[[Telegram]] protocol is available using {{pkg|telepathy-haze}}, installing {{aur|telegram-purple}} or {{aur|telegram-purple-git}} and {{aur|telepathy-morse-git}}. The username is the Telegram account telephone number (complete with the national prefix {{ic|+''xx''}}, e.g. {{ic|+49}} for Germany).
  
== Useful applications ==
+
The configuration through the GUI may be tricky: if the phone number is not accepted when configuring a new account in the KDE Telepathy client (with an error message complaining about an invalid parameter which prevents the account creation), insert it between single quotes and then remove the quotes manually from the configuration file ({{ic|~/.local/share/telepathy/mission-control/accounts.cfg}}) after the account creation (if the quotes are not removed after, an authentication error should rise).
  
The official set of KDE applications may be found [http://www.kde.org/applications/ here].
+
{{Note|The configuration file should be edited manually when KDE Telepathy is not running, e.g. when there is no KDE desktop session active, otherwise manual changes may be overwritten by the software.}}
  
=== Yakuake ===
+
=== KDE Connect ===
  
[http://yakuake.kde.org/ This] application provides a Quake-like terminal emulator, which is toggled visible using the F12 key. It also has support for multiple tabs. Yakuake can be installed by package {{Pkg|yakuake}}.
+
[https://community.kde.org/KDEConnect KDE Connect] provides several features to connect your [[Android]] phone with your Linux desktop:
  
===  KDE Telepathy ===
+
* Share files and URLs to/from KDE from/to any app, without wires.
 +
* Touchpad emulation: Use your phone screen as your computer's touchpad.
 +
* Notifications sync (4.3+): Read your Android notifications from the desktop.
 +
* Shared clipboard: copy and paste between your phone and your computer.
 +
* Multimedia remote control: Use your phone as a remote for Linux media players.
 +
* WiFi connection: no usb wire or bluetooth needed.
 +
* RSA Encryption: your information is safe.
  
[http://community.kde.org/KTp KDE Telepathy] is a project with the goal to closely integrate Instant Messaging with the KDE desktop. It utilizes the Telepathy framework as a backend, and is intended to replace Kopete.
+
You will need to install KDE Connect both on your computer and on your Android. For PC side, [[install]] {{Pkg|kdeconnect}} package. For Android side, install KDE Connect from [https://play.google.com/store/apps/details?id=org.kde.kdeconnect_tp Google Play] or from [https://f-droid.org/packages/org.kde.kdeconnect_tp/ F-Droid].
  
To install all Telepathy protocols install the {{Grp|telepathy}} group.
+
It is possible to use KDE Connect even if you do not use the Plasma desktop. For desktop environments that use AppIndicators, such as Unity, install {{AUR|indicator-kdeconnect}} package as well. For GNOME users, better integration can be achieved by installing {{AUR|gnome-shell-extension-gsconnect}} instead of {{Pkg|kdeconnect}}.
To use the KDE Telepathy client, install the {{Pkg|kde-telepathy-meta}} package that includes all the packages contained in the {{Grp|kde-telepathy}} group .
 
  
 
== Tips and tricks ==
 
== Tips and tricks ==
  
=== Configure KWin to use OpenGL ES ===
+
=== Use a different window manager ===
  
Beginning with KWin version 4.8 it is possible to use the separately built binary '''kwin_gles''' as a replacement for kwin. It behaves almost the same as the kwin executable in OpenGL2 mode with the slight difference that it uses ''egl'' instead of ''glx'' as the native platform interface. To test kwin_gles you just have to run {{ic|kwin_gles --replace}} in Konsole.
+
The component chooser settings in Plasma does not allow changing the window manager anymore. [https://github.com/KDE/plasma-desktop/commit/2f83a4434a888cd17b03af1f9925cbb054256ade]
If you want to make this change permanent you have to create a script in {{ic|$(kde4-config --localprefix)/env/}} which exports {{ic|1=KDEWM=kwin_gles}}.
+
In order to change the window manager used you need to set the {{ic|KDEWM}} [[environment variable]] before KDE startup. [https://wiki.haskell.org/Xmonad/Using_xmonad_in_KDE] To do that you can create a script called {{ic|set_window_manager.sh}} in {{ic|~/.config/plasma-workspace/env/}} and export the {{ic|KDEWM}} variable there. For example to use the i3 window manager :
  
=== Enabling audio thumbnails under Konqueror/Dolphin file managers ===
+
{{hc|~/.config/plasma-workspace/env/set_window_manager.sh|2=
 +
export KDEWM=/usr/bin/i3
 +
}}
  
For thumbnails of audio files in Konqueror and Dolphin install {{AUR|audiothumbs}} from AUR.
+
And then make it executable :
  
=== Enabling video thumbnails under Konqueror/Dolphin file managers ===
+
{{bc|$ chmod +x ~/.config/plasma-workspace/env/set_window_manager.sh}}
  
For thumbnails of videos in konqueror and dolphin install {{Pkg|kdemultimedia-mplayerthumbs}} or {{Pkg|kdemultimedia-ffmpegthumbs}}.
+
==== KDE/Openbox session ====
  
=== Speed up application startup ===
+
The {{Pkg|openbox}} package provides a session for using KDE with [[Openbox]]. To make use of this session, select ''KDE/Openbox'' from the [[display manager]] menu.
  
User Rob wrote on his blog this "[http://kdemonkey.blogspot.nl/2008/04/magic-trick.html magic trick]" to improve applications start up by 50-150ms.
+
For those starting the session manually, add the following line to your [[xinit]] configuration:
To enable it, create this folder in your home:
 
$ mkdir -p ~/.compose-cache
 
  
''For those curious about what is going on here, this enables an optimization which Lubos (of general KDE speediness fame) came up with some time ago and was then rewritten and integrated into libx11. Ordinarily on startup applications read input method information from {{ic|/usr/share/X11/locale/<your locale>/Compose}}. This Compose file is quite long (>5000 lines for the en_US.UTF-8 one) and takes some time to process. libX11 can create a cache of the parsed information which is much quicker to read subsequently, but it will only re-use an existing cache or create a new one in {{ic|~/.compose-cache}} if the directory already exists.'' [Cit. Rob]
+
{{hc|~/.xinitrc|
 +
exec openbox-kde-session
 +
}}
  
=== Hiding partitions ===
+
==== Re-enabling compositing effects ====
  
In Dolphin, it is as simple as right-clicking on the partition in the 'Places' sidebar and selecting 'Hide <partition>'. Otherwise...
+
When replacing Kwin with a window manager which does not provide a Compositor (such as Openbox), any desktop compositing effects e.g. transparency will be lost. In this case, install and run a separate Composite manager to provide the effects such as [[Xcompmgr]] or [[Compton]].
  
If you wish to prevent your internal partitions from appearing in your file manager, you can create an udev rule, for example {{ic|/etc/udev/rules.d/10-local.rules}}:
+
=== Configuring monitor resolution / multiple monitors ===
  
KERNEL=="sda[0-9]", ENV{UDISKS_IGNORE}="1"
+
To enable display resolution management and multiple monitors in Plasma, install {{Pkg|kscreen}}. This adds the additional options to ''System Settings > Display and Monitor''.
  
The same thing for a certain partition:
+
=== Disable opening application launcher with Super key (Windows key) ===
  
KERNEL=="sda1", ENV{UDISKS_IGNORE}="1"
+
To disable this feature you currently can run the following command:
KERNEL=="sda2", ENV{UDISKS_IGNORE}="1"
 
  
=== Konqueror tips ===
+
$ kwriteconfig5 --file kwinrc --group ModifierOnlyShortcuts --key Meta ""
  
==== Disabling smart key tooltips (browser) ====
+
== Troubleshooting ==
 
 
To disable those smart key tooltips in Konqueror (pressing {{ic|Ctrl}} on a web page), open {{ic|~/.kde4/share/config/konquerorrc}} and add this section:
 
 
 
[Access Keys]
 
Enabled=false
 
  
==== Disabling the sidebar tab (filemanager) ====
+
=== Fonts ===
  
To disable this small sidebar tab on the left side, open {{ic|~/.kde4/share/config/konqsidebartng.rc}} and set {{ic|HideTabs}} to {{ic|true}}.
+
==== Fonts in a Plasma session look poor ====
  
==== Using WebKit ====
+
Try installing the {{Pkg|ttf-dejavu}} and {{Pkg|ttf-liberation}} packages.
  
WebKit is an open source browser engine developed by Apple Inc. It is a derivative from the KHTML and KJS libraries and contains many improvements. WebKit is used by Safari, Google Chrome and rekonq.
+
After the installation, be sure to log out and back in. You should not have to modify anything in ''System Settings > Fonts''. If you are using {{Pkg|qt5ct}}, the settings in Qt5 Configuration Tool may override the font settings in System Settings.
  
It is possible to use WebKit in Konqueror instead of KHTML. First install the {{Pkg|kwebkitpart}} package.
+
If you have personally set up how your [[Fonts]] render, be aware that System Settings may alter their appearance. When you go ''System Settings > Fonts'' System Settings will likely alter your font configuration file ({{ic|fonts.conf}}).
  
Then, after executing Konqueror, press ''Settings > Configure Konqueror''.  
+
There is no way to prevent this, but, if you set the values to match your {{ic|fonts.conf}} file, the expected font rendering will return (it will require you to restart your application or in a few cases restart your desktop). Note that Gnome's Font Preferences also does this.
  
On the ''General'' submenu, select ''WebKit'' as the ''Default web browser engine''.
+
==== Fonts are huge or seem disproportional ====
  
=== Firefox integration ===
+
Try to force font DPI to {{ic|'''96'''}} in ''System Settings > Fonts''.
  
See [[Firefox#KDE_integration]].
+
If that does not work, try setting the DPI directly in your Xorg configuration as documented in [[Xorg#Setting DPI manually]].
  
== Troubleshooting ==
 
 
=== Configuration related ===
 
=== Configuration related ===
Many issues in KDE are related to configuration. One way to resolve upgrade problems is to start over with a fresh KDE config.
 
  
==== Reset all KDE configuration ====
+
Many problems in KDE are related to its configuration.
 
 
To test whether your config is the problem try quitting your KDE session by logging out and, in a tty, run
 
$ mv ~/.kde4 ~/.kde4.safekeeping
 
$ rm .kde4/{cache,socket,tmp}-$(hostname)
 
 
 
The rm command just removes symbolic links which will be recreated by KDE automatically. Now start a new KDE session to see the results.
 
 
 
If the problem is resolved, you will have a fresh, problem-free ~/.kde4. You can gradually move parts of your saved configuration back, restarting your session regularly to test, to identify the problematic parts of your config. Some files here are named after applications so you will probably be able to test these without needing to restart KDE.
 
 
 
==== File Indexer Service not working even after enabling everything properly ====
 
 
 
This is caused due to a corrupted Nepomuk database. It may be remedied by moving the database or deleting it all together. Log out of KDE and issue this command from a virtual console:
 
 
 
$ mv ~/.kde4/share/apps/nepomuk ~/.kde4/share/apps/nepomuk_backup
 
 
 
to move your existing (and corrupt) nepomuk database. It will be recreated when you log in again.
 
  
 
==== Plasma desktop behaves strangely ====
 
==== Plasma desktop behaves strangely ====
  
Plasma issues are usually caused by unstable '''plasmoids''' or '''plasma themes'''. First, find which was the last plasmoid or plasma theme you had installed and disable it or uninstall it.  
+
Plasma problems are usually caused by unstable ''Plasma widgets'' (colloquially called ''plasmoids''or ''Plasma themes''. First, find which was the last widget or theme you had installed and disable or uninstall it.
  
So, if your desktop suddenly exhibits "locking up", this is likely caused by a faulty installed widget. If you cannot remember which widget you installed before the problem began(sometimes it can be an irregular problem), try to track it down by removing each widget until the problem ceases. Then you can uninstall the widget, and file a bug report (bugs.kde.org) '''only if it is an official widget'''. If it is not, I recommend you find the entry on kde-look.org and inform the developer of that widget about the issue (detailing steps to reproduce, etc).
+
So, if your desktop suddenly exhibits "locking up", this is likely caused by a faulty installed widget. If you cannot remember which widget you installed before the problem began (sometimes it can be an irregular problem), try to track it down by removing each widget until the problem ceases. Then you can uninstall the widget, and file a bug report on the [https://bugs.kde.org/ KDE bug tracker] '''only if it is an official widget'''. If it is not, it is recommended to find the entry on the [https://store.kde.org/ KDE Store] and inform the developer of that widget about the problem (detailing steps to reproduce, etc.).
  
If you cannot find the problem, but you do not want ''all'' the KDE settings to be lost, do:
+
If you cannot find the problem, but you do not want ''all'' the settings to be lost, navigate to {{ic|~/.config/}} and run the following command:
  
  rm -r ~/.kde4/share/config/plasma*
+
$ for j in plasma*; do mv -- "$j" "${j%}.bak"; done
  
This command will '''delete all plasma related configs''' of your user and when you will relogin into KDE, you will have the '''default''' settings back. You should know that this action '''cannot be undone'''. You ought to create a backup folder and copy all the plasma related configs in it.
+
This command will rename '''all''' Plasma related configuration files to ''*.bak'' (e.g. {{ic|plasmarc.bak}}) of your user and when you will relogin into Plasma, you will have the default settings back. To undo that action, remove the ''.bak'' file extension. If you already have ''*.bak'' files, rename, move, or delete them first. It is highly recommended that you create regular backups anyway. See [[Synchronization and backup programs]] for a list of possible solutions.
  
 
==== Clean cache to resolve upgrade problems ====
 
==== Clean cache to resolve upgrade problems ====
  
The problem may be caused by old cache. Sometimes after an upgrade, the old cache might introduce strange, hard to debug behaviour such as unkillable shells, hangs when changing various settings and several other problems such as ark being unable to unrar or unzip or amarok not recognizing any of your musics. This solution can also resolve problems with KDE and QT programmes looking bad following upgrade.
+
The [https://bbs.archlinux.org/viewtopic.php?id=135301 problem] may be caused by old cache. Sometimes, after an upgrade, the old cache might introduce strange, hard to debug behaviour such as unkillable shells, hangs when changing various settings, Ark being unable to extract archives or Amarok not recognizing any of your music. This solution can also resolve problems with KDE and Qt applications looking bad after an update.
 
 
Rebuild your cache with the following commands:
 
 
 
  $ rm ~/.config/Trolltech.conf
 
  $ kbuildsycoca4 --noincremental
 
 
 
Hopefully, your problems are now fixed.
 
 
 
[https://bbs.archlinux.org/viewtopic.php?id=135301 Reference].
 
 
 
=== Clean akonadi configuration to fix kmail ===
 
First, make sure that KMail is not running.  Then backup configuration:
 
$ mv ~/.local/share/akonadi  ~/.local/share/akonadi-old
 
$ mv ~/.config/akonadi ~/.config/akonadi-old
 
 
 
Start {{ic|SystemSettings -> Personal}} and remove all the resources. Go back to Dolphin and remove the original {{ic|~/.local/share/akonadi}} and
 
{{ic|~/.config/akonadi}} - the copies you made ensure that you can back-track if necessary.
 
 
 
Now go back to the SystemSettings page and carefully add the necessary resources.  You should see the resource reading in your mail folders. Then start Kontact/KMail to see if it work properly.
 
 
 
=== Getting current state of KWin for support and debug purposes ===
 
 
 
This command prints out a wonderful summary of the current state of KWin including used options, used compositing backend and relevant OpenGL driver capabilities. [http://blog.martin-graesslin.com/blog/2012/03/on-getting-help-for-kwin-and-helping-kwin/ See more at Martin's blog]
 
 
 
qdbus org.kde.kwin /KWin supportInformation
 
 
 
=== KDE4 does not finish loading ===
 
 
 
There might be a situation in which the graphic driver might create a conflict when starting KDE4. This situation happens after the login but before finishing loading the desktop, making the user wait indefinitely at the loading screen. Until now the only users confirmed to be affected by this are the ones that use Nvidia drivers and KDE4.
 
 
 
A solution for Nvidia users is to edit the file at {{ic|/home/user/.kde4/share/config/kwinrc}} and change the option '''Enabled=true''' to '''false''' in the '''[Compositing]''' section. For more information look at this [https://bbs.archlinux.org/viewtopic.php?pid=932598 thread].
 
 
 
If a minimal install was done, make sure you installed the required font by your phonon backend listed here: [[KDE#Minimal_install]]
 
 
 
=== KDE and Qt programs look bad when in a different window manager ===
 
 
 
If you are using KDE or Qt programs but not in a full KDE session (specifically, you did not run "startkde"), then as of KDE 4.6.1 you will need to tell Qt how to find KDE's styles (Oxygen, QtCurve etc.)
 
 
 
You just need to set the environment variable QT_PLUGIN_PATH. E.g. put:
 
 
 
export QT_PLUGIN_PATH=$HOME/.kde4/lib/kde4/plugins/:/usr/lib/kde4/plugins/
 
 
 
into your {{ic|/etc/profile}} (or {{ic|~/.profile}} if you do not have root access). qtconfig should then be able to find your kde styles and everything should look nice again!
 
 
 
Alternatively, you can symlink the Qt styles directory to the KDE styles one:
 
# ln -s /usr/lib/kde4/plugins/styles/ /usr/lib/qt/plugins/styles
 
  
Under Gnome you can try to install the package libgnomeui.
+
Rebuild the cache using the following commands:
  
=== Graphical related issues ===
+
$ rm ~/.config/Trolltech.conf
 +
$ kbuildsycoca5 --noincremental
  
==== Low 2D desktop performance (or) artifacts appear when on 2D ====
+
Optionally, empty the {{ic|~/.cache/}} folder contents, however, this will also clear the cache of other applications:
 +
 +
$ rm -rf ~/.cache/*
  
===== GPU driver problem =====
+
=== Graphical problems ===
  
Make sure you have the proper driver for your card installed, so that your desktop is at least 2D accelerated. Follow these articles for more information: [[ATI]], [[NVIDIA]], [[Intel]] for more information, in order to make sure that everything is all right.
+
Make sure you have the proper driver for your GPU installed. See [[Xorg#Driver installation]] for more information. If you have an older card, it might help to [[#Disable desktop effects manually or automatically for defined applications]] or [[#Disable compositing]].
The open-source ATI and Intel drivers and the proprietary (binary) Nvidia driver should theoretically provide the best 2D and 3D acceleration.
 
  
===== The Raster engine workaround =====
+
==== Getting current state of KWin for support and debug purposes ====
  
If this does not solve your problems, maybe your driver does not provide a good '''XRender''' acceleration which the current Qt painter engine relies on by default.  
+
This command prints out a summary of the current state of KWin including used options, used compositing backend and relevant OpenGL driver capabilities. See more on [https://blog.martin-graesslin.com/blog/2012/03/on-getting-help-for-kwin-and-helping-kwin/ Martin's blog].
  
You can change the painter engine to software based only by invoking the application with the "'''-graphicssystem raster'''" command line. This rendering engine can be set as the default one by recompiling Qt with the same as configure option, "'''-graphicssystem raster'''".  
+
$ qdbus org.kde.KWin /KWin supportInformation
  
The raster paint engine enables the CPU to do the majority of the painting, as opposed to the GPU. You may get better performance, depending on your system. This is basically a work-around for the terrible Linux driver stack, since the CPU should obviously not be doing graphical computations since it is designed for fewer threads of greater complexity, as opposed to the GPU which is many threads but lesser computational strength. So, only use Raster engine if you are having problems or your GPU is much slower than you CPU, otherwise is better to use XRender.
+
==== Disable desktop effects manually or automatically for defined applications ====
  
Since Qt 4.7+, recompiling Qt is not needed. Simply export '''QT_GRAPHICSSYSTEM=raster''', or "opengl", or "native" (for the default). Raster depends on the CPU, OpenGL depends on the GPU and high driver support, and Native is just using the X11 rendering (mixture, usually).
+
Plasma has desktop effects enabled by default and e.g. not every game will disable them automatically. You can disable desktop effects in ''System Settings > Desktop Behavior > Desktop Effects'' and you can toggle desktop effects with {{ic|Alt+Shift+F12}}.  
  
'''The best and automatic way to do that''' is to install {{AUR|kcm-qt-graphicssystem}} from AUR and configure this particular Qt setting through
+
Additionally, you can create custom KWin rules to automatically disable/enable compositing when a certain application/window starts under ''System Settings > Window Management > Window Rules''.
  
  System Settings > Qt Graphics System
+
==== Disable compositing ====
  
For more information, consult this [http://apachelog.wordpress.com/2010/09/05/qt-graphics-system-kcm/ KDE Developer blog entry] and/or this [http://labs.trolltech.com/blogs/2009/12/18/qt-graphics-and-performance-the-raster-engine/ Qt Developer blog entry].
+
In ''System Settings > Display and Monitor'', uncheck ''Enable compositor on startup'' and restart Plasma.
 
 
==== Low 3D desktop performance====
 
 
 
KDE begins with desktop effects enabled.  Older cards may be insufficient for 3D desktop acceleration.  You can disable desktop effects in
 
System Settings > Desktop Effects
 
or you can toggle desktop effects with {{ic|Alt+Shift+F12}}.
 
 
 
{{Note| You may encounter such problems with 3D desktop performance even when using a more powerful graphics card, especially the catalyst proprietary driver (fglrx). This driver is known for having issues with 3D acceleration. Visit [[ATI|the ATi Wiki page]] for more troubleshooting.}}
 
 
 
==== Desktop compositing is disabled on my system with a modern Nvidia GPU ====
 
 
 
Sometimes, KWin may have settings in its configuration file ('''kwinrc''') that ''may'' cause a problem on re-activating the 3D desktop '''OpenGL''' compositing. That could be caused randomly (for example, due to a sudden Xorg crash or restart, and it gets corrupted), so, in case that happens, delete your {{ic|~/.kde4/share/config/kwinrc}} file and relogin. The KWin settings will turn to the KDE default ones and the problem should be probably gone.
 
  
 
==== Flickering in fullscreen when compositing is enabled ====
 
==== Flickering in fullscreen when compositing is enabled ====
  
As of KDE SC 4.6.0, there is an option in systemsettings > Desktop Effect > Advanced > "Suspend desktop effects for fullscreen windows" Uncheck it would tell kwin to disable unredirect fullscren.
+
In ''System Settings > Display and Monitor > Compositor'', uncheck ''Allow applications to block compositing''. This may harm performance.
  
==== Screen Tearing with desktop compositing enabled ====
+
==== Screen tearing with NVIDIA ====
{{Note|With the recent update of KDE to 4.11, several new Vsync options have been added, which may help with screen tearing.}}
 
  
 +
See [[NVIDIA/Troubleshooting#Avoid screen tearing in KDE (KWin)]].
  
KWin may suffer from screen tearing while desktop effects are enabled. Uncheck the VSync option under System Settings > Desktop Effects > Advanced > "Use Vsync".
+
==== Plasma cursor sometimes shown incorrectly ====
  
For proprietary driver users, ensure that the driver's VSync option is enabled (amdccle for [[amd_catalyst|Catalyst]] users, and nvidia-settings for [[Nvidia]] users).
+
Create the directory {{ic|~/.icons/default}} and inside a file named {{ic|index.theme}} with the following contents:
  
=== Sound problems under KDE ===
+
{{hc|~/.icons/default/index.theme|2=
 +
[Icon Theme]
 +
Inherits=breeze_cursors
 +
}}
  
==== ALSA related problems ====
+
Execute the following command:
  
{{Note|First make sure you have {{Pkg|alsa-lib}} and {{Pkg|alsa-utils}} installed.}}
+
$ ln -s /usr/share/icons/breeze_cursors/cursors ~/.icons/default/cursors
  
===== "Falling back to default" messages when trying to listen to any sound in KDE =====
+
=== Sound problems ===
  
When you encounter such messages:
+
{{Note|First make sure you have {{Pkg|alsa-utils}} installed.}}
:The audio playback device ''<name-of-the-sound-device>'' does not work.
 
:Falling back to default
 
Go to
 
System Settings > Multimedia > Phonon
 
and set the device named "'''default'''" above all the other devices in each box you see.
 
  
===== I cannot play MP3 files when using the GStreamer Phonon backend =====
+
==== No sound after suspend ====
  
That can be solved by installing the GStreamer plugins (package {{Pkg|gstreamer0.10-plugins}}. If you still encounter problems, you can try changing the Phonon backend used by installing another such as {{Pkg|phonon-vlc}}.
+
If there is no sound after suspending and if KMix does not show audio devices which should be there, restarting plasmashell and pulseaudio may help:
Then make sure the backend is preferred via:
 
  System Settings > Multimedia > Phonon > Backend (tab)
 
  
=== Konsole does not save commands' history ===
+
$ killall plasmashell
 +
$ systemctl --user restart pulseaudio.service
 +
$ plasmashell
  
By default console commands' history is saved only when you type 'exit' in console. When you close Konsole with 'x' in the corner it does not happen.
+
Some applications may also need to be restarted in order for sound to play from them again.
To enable autosaving after every command execution you should add following lines into your .bashrc
 
shopt -s histappend
 
[[ "${PROMPT_COMMAND}" ]] && PROMPT_COMMAND="$PROMPT_COMMAND;history -a" || PROMPT_COMMAND="history -a"
 
  
=== KDE password prompts display three bullets per char ===
+
==== MP3 files cannot be played when using the GStreamer Phonon backend ====
  
You can change it under ''System Settings > Account Details''. At ''Password & User Account'' the options are:
+
This can be solved by installing the GStreamer libav plugin (package {{Pkg|gst-libav}}). If you still encounter problems, you can try changing the Phonon backend used by installing another such as {{AUR|phonon-qt4-vlc}} or {{Pkg|phonon-qt5-vlc}}.
* Show one bullet for each letter
 
* Show three bullets for each letter
 
* Show nothing
 
  
=== Nepomukserver process still autostart even with semantic desktop disabled ===
+
Then, make sure the backend is preferred via ''System Settings > Multimedia > Audio and Video > Backend''.
Go to ''' System Settings > Startup and Shutdown > Service Manager > Startup Services''' and uncheck the Nepomuk Search Module.
 
  
=== Desktop does not respond for several seconds at startup ===
+
=== Power management ===
  
There is a bug in either [https://bugs.freedesktop.org/show_bug.cgi?id=58758 pulseaudio] or [https://bugs.kde.org/show_bug.cgi?id=312560 kde] that makes the desktop not being usable for a few seconds after it has showed up (for example if you click on the K-menu it does not appears until that waiting time has elapsed).
+
==== No Suspend/Hibernate options ====
  
The workaround is to disable {{ic|/etc/xdg/autostart/pulseaudio.desktop}} by adding the following line at the end (do not omit the semicolon):
+
If your system is able to suspend or hibernate using [[systemd]] but do not have these options shown in KDE, make sure {{Pkg|powerdevil}} is installed.
  
NotShowIn=KDE;
+
=== KMail ===
  
Note that you could also remove that file, or renaming it (to pulseaudio.desktop.disable or the like) but then it will not load in other Desktop Managers, and will be restored by a package update.
+
==== Clean akonadi configuration to fix KMail ====
  
[http://linuxadvantage.blogspot.fr/2013/01/kde-rather-slow-to-start-pulseaudio.html Reference].
+
First, make sure that KMail is not running. Then backup configuration:
  
=== Dolphin and File Dialogs are extremely slow to start everytime ===
+
$ cp -a ~/.local/share/akonadi ~/.local/share/akonadi-old
 +
$ cp -a ~/.config/akonadi ~/.config/akonadi-old
  
May be caused by the upower service. If the upower service is not needed on your system, it can be disabled :
+
Start ''SystemSettings > Personal'' and remove all the resources. Go back to Dolphin and remove the original {{ic|~/.local/share/akonadi/}} and
 +
{{ic|~/.config/akonadi/}} - the copies you made ensure that you can back-track if necessary.
  
  systemctl disable upower
+
Now go back to the System Settings page and carefully add the necessary resources. You should see the resource reading in your mail folders. Then start Kontact/KMail to see if it works properly.
  systemctl mask upower
 
  
Obviously this will not have any side effect on a desktop system.
+
==== Empty IMAP inbox in KMail ====
  
=== Default PDF viewer in GTK applications under KDE ===
+
For some IMAP accounts KMail will show the inbox as a top-level container (so it will not be possible to read messages there) with all other folders of this account inside.[https://bugs.kde.org/show_bug.cgi?id=284172]. To solve this problem simply disable the server-side subscriptions in the KMail account settings.
  
In some cases when you have installed [[Inkscape]], [[Gimp]] or other graphic programs, GTK applications ([[Firefox]] among all) might not select Okular as the default PDF application, and they are not going to follow the KDE settings on default applications. You can use the following user command to make Okular the default application again.
+
=== Networking ===
 
 
xdg-mime default kde4-okularApplication_pdf.desktop application/pdf
 
  
If you are using a different PDF viewer application, or a different mime-type is misbehaving, you should change {{ic|kde4-okularApplication_pdf.desktop}} and {{ic|application/pdf}} respectively according to your needs.
+
==== Freezes when using Automount on a NFS volume  ====
  
For more information, consult [[Default Applications]] wiki page.
+
Using [[Fstab#Automount with systemd]] on a [[NFS]] volume may cause freezes, see [https://bugs.kde.org/show_bug.cgi?id=354137 bug report upstream].
  
=== Problems following updates to KDE packages ===
+
=== Aggressive QXcbConnection journal logging ===
  
If you reboot to problems following a system update involving KDE packages, try rebooting a second time. For some reason, problems often magically resolve themselves following a second reboot.
+
See [[Qt#Disable/Change Qt journal logging behaviour]].
  
== Other KDE projects ==
+
=== KF5/Qt 5 applications do not display icons in i3/FVWM/awesome ===
  
=== Official kde-unstable ===
+
See [[Qt#Configuration of Qt5 apps under environments other than KDE Plasma]].
  
When KDE is reaching beta or RC milestone, KDE "unstable" packages are uploaded to the [kde-unstable] repo. They stay there until KDE is declared stable and passes to [extra].
+
=== Problems with saving credentials and persistently occurring KWallet dialogs ===
  
You may add it by adding:
+
It is not recommended to turn off the [[KWallet]] password saving system in the user settings as it is required to save encrypted credentials like WiFi passphrases for each user. Persistently occuring KWallet dialogs can be the consequence of turning it off.
  
[kde-unstable]
+
In case you find the dialogs to unlock the wallet annoying when applications want to access it, you can let the [[Display manager|display managers]] [[SDDM]] and [[LightDM]] unlock the wallet at login automatically, see [[KDE Wallet#Unlock KDE Wallet automatically on login]]. The first wallet needs to be generated by KWallet (and not user-generated) in order to be usable for system program credentials.
SigLevel = PackageRequired
 
Include = /etc/pacman.d/mirrorlist
 
  
to {{ic|/etc/pacman.conf}}
+
In case you want the wallet credentials not to be opened in memory for every application, you can restrict applications from accessing it with {{Pkg|kwalletmanager}} in the KWallet settings.
  
# kde-unstable is based upon testing. Therefore, you need to enable the repositories in the following order: '''kde-unstable, testing, core, extra, community-testing, community'''.  
+
If you do not care for credential encryption at all, you can simply leave the password forms blank when KWallet asks for the password while creating a wallet. In this case, applications can access passwords without having to unlock the wallet first.
# To update from a previous KDE installation, run: <code>pacman -Syu</code> or <code>pacman -S kde-unstable/kde</code>
 
# If you don't have KDE installed, you might have difficulties to install it by using groups (limitation of pacman)
 
# '''Subscribe and read the arch-dev-public mailing list'''
 
# Make sure [[#Distro_and_Upstream_bug_report|you make bug reports]] if you find any issues.
 
  
=== Trinity ===
+
=== Discover does not show any applications ===
  
From the release of KDE 4.x, the developers dropped support for KDE 3.5.x. Trinity Desktop Environment is a fork of KDE3 developed by Timothy Pearson ([http://trinitydesktop.org/ trinitydesktop.org]). This project aims to keep the KDE3.5 computing style alive, as well as polish off any rough edges that were present as of KDE 3.5.10. See [[Trinity]] for more info.
+
This can be solved by installing {{Pkg|packagekit-qt5}}.
  
{{Warning|KDE 3 is no longer maintained and supported by the KDE developers. The "Trinity KDE" is maintained by the Trinity project commmunity. Use KDE 3 on your own risk, regarding any bugs, performance issues or security risks.}}
+
=== High CPU usage of kscreenlocker_greet with NVIDIA drivers ===
  
==Bugs==
+
As described in [https://bugs.kde.org/show_bug.cgi?id=347772 KDE Bug 347772] NVIDIA OpenGL drivers and QML may not play well together with Qt 5. This may lead {{ic|kscreenlocker_greet}} to high CPU usage after unlocking the session. To work around this issue, set the {{ic|QSG_RENDERER_LOOP}} [[environment variable]] to {{ic|basic}}.
  
===Distro and Upstream bug report===
+
Then kill previous instances of the greeter with {{ic|killall kscreenlocker_greet}}.
  
It is preferrable that if you find a minor or serious bug, you should visit [https://bugs.archlinux.org the Arch Bug Tracker] or/and [http://bugs.kde.org KDE Bug Tracker] in order to report that. Make sure that you be clear on what you want to report.
+
=== OS error 22 when running Akonadi on ZFS ===
  
If you have any issue and you write about in on the Arch forums, first make sure that you have '''FULLY''' updated your system using a good sync mirror (check [https://www.archlinux.de/?page=MirrorStatus here]) or try [[Reflector]].
+
If your home directory is on a [[ZFS]] pool, create a {{ic|~/.config/akonadi/mysql-local.conf}} file with the following contents:
  
KDE 4 config files are usually located at
+
[mysqld]
 +
innodb_use_native_aio = 0
  
~/.kde4/share/config/
+
See [[MySQL#OS error 22 when running on ZFS]].
  
and for app-specific configs
+
=== Some programs are unable to scroll when their windows are inactive ===
  
~/.kde4/share/apps/
+
This is caused by the problematic way of GTK3 handling mouse scroll events. A workaround for this is to set [[environment variable]] {{ic|1=GDK_CORE_DEVICE_EVENTS=1}}. However, this workaround also breaks touchpad smooth scrolling and touchscreen scrolling.
  
 
== See also ==
 
== See also ==
  
* [http://www.kde.org KDE Homepage]
+
* [https://www.kde.org/ KDE homepage]
* [http://bugs.kde.org KDE Bug Tracker]
+
* [https://bugs.kde.org/ KDE bug tracker]
* [https://bugs.archlinux.org Arch Linux Bug Tracker]
+
* [https://blog.martin-graesslin.com/blog/kategorien/kde/ Martin Graesslin's blog]
* [http://websvn.kde.org KDE WebSVN]
 

Latest revision as of 21:05, 22 October 2018

KDE is a software project currently comprising of a desktop environment known as Plasma, a collection of libraries and frameworks (KDE Frameworks) and several applications (KDE Applications) as well. KDE upstream has a well maintained UserBase wiki. Detailed information about most KDE applications can be found there.

Contents

Installation

Plasma

Before installing Plasma, make sure you have a working Xorg installation on your system.

Install the plasma-meta meta-package or the plasma group. For differences between plasma-meta and plasma reference Creating packages#Meta packages and groups. Alternatively, for a more minimal Plasma installation, install the plasma-desktop package.

To enable support for Wayland in Plasma, also install the plasma-wayland-session package.

KDE applications

To install the full set of KDE Applications, install the kde-applications group or the kde-applications-meta meta-package. Note that this will only install applications, it will not install any version of Plasma.

Unstable releases

See Official repositories#kde-unstable

Starting Plasma

Note: Although it is possible to launch Plasma under Wayland, there are some missing features and known problems as of Plasma 5.13. See the Plasma 5.13 Errata for a list of issues and the Plasma on Wayland workboard for the current state of development. Use Xorg for the most complete and stable experience.

Plasma can be started either using a display manager, or from the console.

Using a display manager

Note: The NVIDIA proprietary driver implementation for Wayland requires EGLStreams. KDE have not implemented EGLStreams in their Wayland implementation. The following workarounds are available:
  • Using the Nouveau driver.
  • Using the (default) Xorg session.

From the console

To start Plasma with xinit/startx, append exec startkde to your .xinitrc file. If you want to start Xorg at login, please see Start X at login. To start a Plasma on Wayland session from a console, run export XDG_SESSION_TYPE=wayland && export $(dbus-launch) && startplasmacompositor.[1]

Configuration

Most settings for KDE applications are stored in ~/.config/. However, configuring KDE is primarily done through the System Settings application. It can be started from a terminal by executing systemsettings5.

Personalization

Plasma desktop

Themes

Plasma themes define the look of panels and plasmoids. For easy system-wide installation, some themes are available in both the official repositories and the AUR.

Plasma themes can also be installed through System Settings > Workspace Theme > Desktop Theme > Get new Themes.

The KDE-Store offers more Plasma customization's, like SDDM themes and splash-screens.

Qt and GTK+ Applications Appearance
Tip: For Qt and GTK theme consistency, see Uniform look for Qt and GTK applications.
Qt4

Breeze is not directly available for Qt4 since it cannot be built without KDE 4 packages, which have been dropped from the extra repository in August 2018 (FS#59784). However you can install breeze-gtk and pick GTK+ as GUI Style by running qtconfig-qt4.

GTK+

The recommended theme for a pleasant appearance in GTK+ applications is breeze-gtk or gnome-breeze-gitAUR, a GTK+ theme designed to mimic the appearance of Plasma's Breeze theme. Install kde-gtk-config (part of the plasma group) and select the installed GTK-theme for GTK2/GTK3-Theme in System Settings > Application Style > GNOME Application Style.

In some themes, tooltips in GTK+ applications have white text on white backgrounds making it difficult to read. To change the colors in GTK2 applications, find the section for tooltips in the .gtkrc-2.0 file and change it. For GTK3 application two files need to be changed, gtk.css and settings.ini. It might also help to uncheck the option to Apply colors to non-Qt applications under System Settings > Colors.

Some GTK2 programs like vuescan-binAUR still look hardly usable due to invisible checkboxes with the Breeze or Adwaita skin in a Plasma session. To workaround this, install and select e.g. the Numix-Frost-Light skin of the numix-frost-themesAUR under System Settings > Application Style > GNOME Application Style (GTK) > Select a GTK2 Theme:. Numix-Frost-Light looks similar to Breeze.

Widgets

Plasmoids are little scripted (plasmoid scripts) or coded (plasmoid binaries) KDE applications designed to enhance the functionality of your desktop.

The easiest way to install plasmoid scripts is by right-clicking onto a panel or the desktop and choosing Add Widgets > Get new widgets > Download New Plasma Widgets. This will present a nice frontend for https://store.kde.org/ that allows you to install, uninstall, or update third-party plasmoid scripts with literally just one click.

Many Plasmoid binaries are available from the AUR.

Sound applet in the system tray

Install plasma-pa or kmix (start Kmix from the Application Launcher). plasma-pa is now installed by default with plasma, no further configuration needed.

Note: To adjust the step size of volume increments/decrements, add e.g. VolumePercentageStep=1 in the [Global] section of ~/.config/kmixrc.
Disable panel shadow

As the Plasma panel is on top of other windows, its shadow is drawn over them. [2] To disable this behaviour without impacting other shadows, install xorg-xprop and run:

$ xprop -remove _KDE_NET_WM_SHADOW

then select the panel with the plus-sized cursor. [3] For automation, install xorg-xwininfo and create the following script:

/usr/local/bin/kde-no-shadow
#!/bin/bash
for WID in $(xwininfo -root -tree | sed '/"Plasma": ("plasmashell" "plasmashell")/!d; s/^  *\([^ ]*\) .*/\1/g'); do
   xprop -id $WID -remove _KDE_NET_WM_SHADOW
done

Set execution permissions for the script:

# chmod 755 /usr/local/bin/kde-no-shadow

The script can be run on login with Add Script in Autostart:

$ kcmshell5 autostart

Window decorations

Window decorations can be changed in System Settings > Application Style > Window Decorations.

There you can also directly download and install more themes with one click, and some are available in the AUR.

Icon themes

Icon themes can be installed and changed on System Settings > Icons.

Note: Although all modern Linux desktops share the same icon theme format, desktops like GNOME use fewer icons (esp. in menus and toolbars). Themes developed for such desktops usually lack icons required by Plasma and KDE apps. It is recommended to install Plasma compatible icon themes instead.
Tip: Since some icon themes do not inherit from the default icon theme, some icons may be missing. To inherit from the Breeze, add breeze to the Inherits= array in /usr/share/icon/theme-name/index.theme, for example: Inherits=breeze,hicolor. You need to reapply this patch after every update to the icon theme, consider using Pacman hooks to automate the process.

Space efficiency

The Plasma Netbook shell has been dropped from Plasma 5, see the following KDE forum post. However, you can achieve something similar by editing the file ~/.config/kwinrc adding BorderlessMaximizedWindows=true in the [Windows] section.

Thumbnail generation

To allow thumbnail generation for media or document files on the desktop and in Dolphin, install kdegraphics-thumbnailers, ffmpegthumbs and kde-thumbnailer-odfAUR.

Then enable the thumbnail categories for the desktop via right click on the desktop background > Configure Desktop > Icons > More Preview Options....

In Dolphin, navigate to Control > General > Previews.

Printing

Tip: Use the CUPS web interface for faster configuration. Printers configured in this way can be used in KDE applications.

You can also configure printers in System Settings > Printers. To use this method, you must first install print-manager and cups. See CUPS#Configuration.

Samba/Windows support

If you want to have access to Windows services, install Samba (package samba).

The Dolphin share functionality requires the package kdenetwork-filesharing and usershares, which the stock smb.conf does not have enabled. Instructions to add them are in Samba#Enable usershares, after which sharing in Dolphin should work out of the box after restarting Samba.

Tip: Use * (asterisk) for both username and password when accessing a Windows share without authentification in Dolphin's prompt.

Unlike GTK file browsers which utilize GVfs also for the launched program, opening files from Samba shares in Dolphin via KIO makes Plasma copy the whole file to the local system first with most programs (VLC is an exception). To workaround this, you can use a GTK based file browser like thunar with gvfs and gvfs-smb (and gnome-keyring for saving login credentials) to access SMB shares in a more able way.

Another possibility is to mount a Samba share via cifs-utils to make it look to Plasma like if the SMB share was just a normal local folder and thus can be accessed normally. See Samba#Manual mounting and Samba#Automatic mounting.

An GUI solution is available with samba-mounter-gitAUR, which offers basically the same functionality via an easy to use option located at System Settings > Network Drivers. However, it might break with new KDE Plasma versions.

KDE Desktop activities

KDE Desktop Activities are special workspaces where you can select specific settings for each activity that apply only when you are using said activity.

Power saving

Install powerdevil for an integrated power saving service called "Powerdevil Power Management", that may adjust the power saving profile of the system and/or the brightness of the screen (if supported).

Tango-inaccurate.pngThe factual accuracy of this article or section is disputed.Tango-inaccurate.png

Reason: Regarding the note below, it might be that the problem is the logind setting LidSwitchIgnoreInhibited which defaults to yes. [4] (Discuss in Talk:KDE#)
Note: Powerdevil may not inhibit all logind settings (such as the lid close action for laptops). In these cases, the logind setting itself will need to be changed - see Power management#Power management with systemd.

Autostart

Plasma can autostart applications and run scripts on startup and shutdown. To autostart an application, navigate to System Settings > Startup and Shutdown > Autostart and add the program or shell script of your choice. For applications, a .desktop file will be created, for shell scripts, a symlink will be created.

Note:
  • Programs can be autostarted on login only, whilst shell scripts can also be run on shutdown or even before Plasma itself starts.
  • Shell scripts will only be run if they are marked executable.
  • Place or symlink shell scripts in one of the following directories:
~/.config/plasma-workspace/env/
for executing scripts at login before launching Plasma.
~/.config/autostart-scripts/
for executing scripts at login.
~/.config/plasma-workspace/shutdown/
for executing scripts on shutdown.

Phonon

From Wikipedia:

Phonon is the multimedia API provided by KDE and is the standard abstraction for handling multimedia streams within KDE software and also used by several Qt applications.
Phonon was originally created to allow KDE and Qt software to be independent of any single multimedia framework such as GStreamer or xine and to provide a stable API for a major version's lifetime.

Phonon is being widely used within KDE, for both audio (e.g., the System notifications or KDE audio apps) and video (e.g., the Dolphin video thumbnails).

Which backend should I choose?

You can choose between backends based on GStreamer and VLC – each available in versions for Qt4 applications and Qt5 applications (phonon-qt4-gstreamerAUR, phonon-qt5-gstreamerphonon-qt4-vlcAUR, phonon-qt5-vlc).

Upstream prefers VLC but prominent Linux distributions (Kubuntu and Fedora-KDE for example) prefer GStreamer because that allows them to easily leave out patented MPEG codecs from the default installation. Both backends have a slightly different features set. The Gstreamer backend has some optional codec dependency, install them as needed:

In the past other backends were developed as well but are no longer maintained and their AUR packages have been deleted.

Note:
  • Multiple backends can be installed at once and prioritized at System Settings > Multimedia > Audio and Video > Backend.
  • According to the KDE forums, the VLC backend lacks support for ReplayGain.
  • If using the VLC backend, you may experience crashes every time Plasma wants to send you an audible warning and in quite a number of other cases as well [5]. A possible fix is to rebuild the VLC plugins cache:
# /usr/lib/vlc/vlc-cache-gen /usr/lib/vlc/plugins

Applications

The KDE project provides a suite of applications that integrate with the Plasma desktop. See the kde-applications group for a full listing of the available applications. Also see Category:KDE for related KDE application pages.

Aside from the programs provided in KDE Applications, there are many other applications available that can complement the Plasma desktop. Some of these are discussed below.

System administration

Terminate Xorg server through KDE System Settings

Navigate to the submenu System Settings > Input Devices > Keyboard > Advanced (tab) > "Key Sequence to kill the X server" and ensure that the checkbox is ticked.

KCM

KCM stands for KConfig Module. KCMs can help you configure your system by providing interfaces in System Settings, or through the command line with kcmshell5.

  • kde-gtk-config — GTK2 and GTK3 Configurator for KDE.
https://cgit.kde.org/kde-gtk-config.git || kde-gtk-config
  • System policies — Set of configuration modules which allows administrator to change PolicyKit settings.
https://cgit.kde.org/polkit-kde-kcmodules-1.git || kcm-polkit-kde-gitAUR
  • wacom tablet — KDE GUI for the Wacom Linux Drivers.
https://www.linux-apps.com/p/1127862/ || kcm-wacomtablet
  • Kcmsystemd — systemd control module for KDE.
https://github.com/rthomsen/kcmsystemd || systemd-kcmAUR

More KCMs can be found at linux-apps.com.

Desktop search

KDE implements desktop search with a software called Baloo, a file indexing and searching solution.

Web browsers

The following web browsers can integrate with Plasma:

  • Konqueror — Part of the KDE project, supports two rendering engines – KHTML and the Chromium-based Qt WebEngine.
https://konqueror.org/ || konqueror
  • Falkon — A Qt web browser with Plasma integration features, previously known as Qupzilla. It uses Qt WebEngine.
https://userbase.kde.org/Falkon/ || falkon
  • Chromium — Chromium and its proprietary variant Google Chrome have limited Plasma integration. They can use KWallet and KDE Open/Save windows.
https://www.chromium.org/ || chromium
https://mozilla.org/firefox || firefox
Tip: Starting from Plasma 5.13, one can integrate Firefox or Chrome with Plasma: providing media playback control from the Plasma tray, download notifications and find open tabs in KRunner. Install plasma-browser-integration and the corresponding browser add-on. Chrome/Chromium support should already be included, for Firefox add-on see Firefox#KDE/GNOME integration.

PIM

KDE offers its own stack for personal information management. This includes emails, contacts, calendar, etc. To install all the PIM packages, you could use the meta-package kdepim-meta.

Akonadi

Akonadi is a system meant to act as a local cache for PIM data, regardless of its origin, which can be then used by other applications. This includes the user's emails, contacts, calendars, events, journals, alarms, notes, and so on. Akonadi does not store any data by itself: the storage format depends on the nature of the data (for example, contacts may be stored in vCard format).

Install akonadi. For additional addons, install kdepim-addons.

Note: If you wish to use a database engine other than MySQL, then when installing the akonadi package, use the following command to skip installing the mariadb dependencies:
# pacman -S akonadi --assume-installed mariadb

See also FS#32878.

PostgreSQL

Install postgresql.

To use PostgreSQL edit Akonadi configuration file so that it has the following contents:

~/.config/akonadi/akonadiserverrc
[%General]
Driver=QPSQL

[QPSQL]
Host=
InitDbPath=/usr/bin/initdb
Name=akonadi
ServerPath=/usr/bin/pg_ctl
StartServer=true
Note: The value for Host= will get set by Akonadi when it starts for the first time.

Start Akonadi with akonadictl start, and check its status: akonadictl status.

SQLite

To use SQLite edit Akonadi configuration file to match the configuration below:

~/.config/akonadi/akonadiserverrc
[%General]
Driver=QSQLITE3

[QSQLITE3]
Name=/home/username/.local/share/akonadi/akonadi.db
Disabling Akonadi

See this section in the KDE userbase.

KDE Telepathy

KDE Telepathy is a project with the goal to closely integrate Instant Messaging with the KDE desktop. It utilizes the Telepathy framework as a backend and is intended to replace Kopete.

To install all Telepathy protocols, install the telepathy group. To use the KDE Telepathy client, install the telepathy-kde-meta package that includes all the packages contained in the telepathy-kde group.

Use Telegram with KDE Telepathy

Telegram protocol is available using telepathy-haze, installing telegram-purpleAUR or telegram-purple-gitAUR and telepathy-morse-gitAUR. The username is the Telegram account telephone number (complete with the national prefix +xx, e.g. +49 for Germany).

The configuration through the GUI may be tricky: if the phone number is not accepted when configuring a new account in the KDE Telepathy client (with an error message complaining about an invalid parameter which prevents the account creation), insert it between single quotes and then remove the quotes manually from the configuration file (~/.local/share/telepathy/mission-control/accounts.cfg) after the account creation (if the quotes are not removed after, an authentication error should rise).

Note: The configuration file should be edited manually when KDE Telepathy is not running, e.g. when there is no KDE desktop session active, otherwise manual changes may be overwritten by the software.

KDE Connect

KDE Connect provides several features to connect your Android phone with your Linux desktop:

  • Share files and URLs to/from KDE from/to any app, without wires.
  • Touchpad emulation: Use your phone screen as your computer's touchpad.
  • Notifications sync (4.3+): Read your Android notifications from the desktop.
  • Shared clipboard: copy and paste between your phone and your computer.
  • Multimedia remote control: Use your phone as a remote for Linux media players.
  • WiFi connection: no usb wire or bluetooth needed.
  • RSA Encryption: your information is safe.

You will need to install KDE Connect both on your computer and on your Android. For PC side, install kdeconnect package. For Android side, install KDE Connect from Google Play or from F-Droid.

It is possible to use KDE Connect even if you do not use the Plasma desktop. For desktop environments that use AppIndicators, such as Unity, install indicator-kdeconnectAUR package as well. For GNOME users, better integration can be achieved by installing gnome-shell-extension-gsconnectAUR instead of kdeconnect.

Tips and tricks

Use a different window manager

The component chooser settings in Plasma does not allow changing the window manager anymore. [6] In order to change the window manager used you need to set the KDEWM environment variable before KDE startup. [7] To do that you can create a script called set_window_manager.sh in ~/.config/plasma-workspace/env/ and export the KDEWM variable there. For example to use the i3 window manager :

~/.config/plasma-workspace/env/set_window_manager.sh
export KDEWM=/usr/bin/i3

And then make it executable :

$ chmod +x ~/.config/plasma-workspace/env/set_window_manager.sh

KDE/Openbox session

The openbox package provides a session for using KDE with Openbox. To make use of this session, select KDE/Openbox from the display manager menu.

For those starting the session manually, add the following line to your xinit configuration:

~/.xinitrc
exec openbox-kde-session

Re-enabling compositing effects

When replacing Kwin with a window manager which does not provide a Compositor (such as Openbox), any desktop compositing effects e.g. transparency will be lost. In this case, install and run a separate Composite manager to provide the effects such as Xcompmgr or Compton.

Configuring monitor resolution / multiple monitors

To enable display resolution management and multiple monitors in Plasma, install kscreen. This adds the additional options to System Settings > Display and Monitor.

Disable opening application launcher with Super key (Windows key)

To disable this feature you currently can run the following command:

$ kwriteconfig5 --file kwinrc --group ModifierOnlyShortcuts --key Meta ""

Troubleshooting

Fonts

Fonts in a Plasma session look poor

Try installing the ttf-dejavu and ttf-liberation packages.

After the installation, be sure to log out and back in. You should not have to modify anything in System Settings > Fonts. If you are using qt5ct, the settings in Qt5 Configuration Tool may override the font settings in System Settings.

If you have personally set up how your Fonts render, be aware that System Settings may alter their appearance. When you go System Settings > Fonts System Settings will likely alter your font configuration file (fonts.conf).

There is no way to prevent this, but, if you set the values to match your fonts.conf file, the expected font rendering will return (it will require you to restart your application or in a few cases restart your desktop). Note that Gnome's Font Preferences also does this.

Fonts are huge or seem disproportional

Try to force font DPI to 96 in System Settings > Fonts.

If that does not work, try setting the DPI directly in your Xorg configuration as documented in Xorg#Setting DPI manually.

Configuration related

Many problems in KDE are related to its configuration.

Plasma desktop behaves strangely

Plasma problems are usually caused by unstable Plasma widgets (colloquially called plasmoids) or Plasma themes. First, find which was the last widget or theme you had installed and disable or uninstall it.

So, if your desktop suddenly exhibits "locking up", this is likely caused by a faulty installed widget. If you cannot remember which widget you installed before the problem began (sometimes it can be an irregular problem), try to track it down by removing each widget until the problem ceases. Then you can uninstall the widget, and file a bug report on the KDE bug tracker only if it is an official widget. If it is not, it is recommended to find the entry on the KDE Store and inform the developer of that widget about the problem (detailing steps to reproduce, etc.).

If you cannot find the problem, but you do not want all the settings to be lost, navigate to ~/.config/ and run the following command:

$ for j in plasma*; do mv -- "$j" "${j%}.bak"; done

This command will rename all Plasma related configuration files to *.bak (e.g. plasmarc.bak) of your user and when you will relogin into Plasma, you will have the default settings back. To undo that action, remove the .bak file extension. If you already have *.bak files, rename, move, or delete them first. It is highly recommended that you create regular backups anyway. See Synchronization and backup programs for a list of possible solutions.

Clean cache to resolve upgrade problems

The problem may be caused by old cache. Sometimes, after an upgrade, the old cache might introduce strange, hard to debug behaviour such as unkillable shells, hangs when changing various settings, Ark being unable to extract archives or Amarok not recognizing any of your music. This solution can also resolve problems with KDE and Qt applications looking bad after an update.

Rebuild the cache using the following commands:

$ rm ~/.config/Trolltech.conf
$ kbuildsycoca5 --noincremental

Optionally, empty the ~/.cache/ folder contents, however, this will also clear the cache of other applications:

$ rm -rf ~/.cache/*

Graphical problems

Make sure you have the proper driver for your GPU installed. See Xorg#Driver installation for more information. If you have an older card, it might help to #Disable desktop effects manually or automatically for defined applications or #Disable compositing.

Getting current state of KWin for support and debug purposes

This command prints out a summary of the current state of KWin including used options, used compositing backend and relevant OpenGL driver capabilities. See more on Martin's blog.

$ qdbus org.kde.KWin /KWin supportInformation

Disable desktop effects manually or automatically for defined applications

Plasma has desktop effects enabled by default and e.g. not every game will disable them automatically. You can disable desktop effects in System Settings > Desktop Behavior > Desktop Effects and you can toggle desktop effects with Alt+Shift+F12.

Additionally, you can create custom KWin rules to automatically disable/enable compositing when a certain application/window starts under System Settings > Window Management > Window Rules.

Disable compositing

In System Settings > Display and Monitor, uncheck Enable compositor on startup and restart Plasma.

Flickering in fullscreen when compositing is enabled

In System Settings > Display and Monitor > Compositor, uncheck Allow applications to block compositing. This may harm performance.

Screen tearing with NVIDIA

See NVIDIA/Troubleshooting#Avoid screen tearing in KDE (KWin).

Plasma cursor sometimes shown incorrectly

Create the directory ~/.icons/default and inside a file named index.theme with the following contents:

~/.icons/default/index.theme
[Icon Theme]
Inherits=breeze_cursors

Execute the following command:

$ ln -s /usr/share/icons/breeze_cursors/cursors ~/.icons/default/cursors

Sound problems

Note: First make sure you have alsa-utils installed.

No sound after suspend

If there is no sound after suspending and if KMix does not show audio devices which should be there, restarting plasmashell and pulseaudio may help:

$ killall plasmashell
$ systemctl --user restart pulseaudio.service
$ plasmashell

Some applications may also need to be restarted in order for sound to play from them again.

MP3 files cannot be played when using the GStreamer Phonon backend

This can be solved by installing the GStreamer libav plugin (package gst-libav). If you still encounter problems, you can try changing the Phonon backend used by installing another such as phonon-qt4-vlcAUR or phonon-qt5-vlc.

Then, make sure the backend is preferred via System Settings > Multimedia > Audio and Video > Backend.

Power management

No Suspend/Hibernate options

If your system is able to suspend or hibernate using systemd but do not have these options shown in KDE, make sure powerdevil is installed.

KMail

Clean akonadi configuration to fix KMail

First, make sure that KMail is not running. Then backup configuration:

$ cp -a ~/.local/share/akonadi ~/.local/share/akonadi-old
$ cp -a ~/.config/akonadi ~/.config/akonadi-old

Start SystemSettings > Personal and remove all the resources. Go back to Dolphin and remove the original ~/.local/share/akonadi/ and ~/.config/akonadi/ - the copies you made ensure that you can back-track if necessary.

Now go back to the System Settings page and carefully add the necessary resources. You should see the resource reading in your mail folders. Then start Kontact/KMail to see if it works properly.

Empty IMAP inbox in KMail

For some IMAP accounts KMail will show the inbox as a top-level container (so it will not be possible to read messages there) with all other folders of this account inside.[8]. To solve this problem simply disable the server-side subscriptions in the KMail account settings.

Networking

Freezes when using Automount on a NFS volume

Using Fstab#Automount with systemd on a NFS volume may cause freezes, see bug report upstream.

Aggressive QXcbConnection journal logging

See Qt#Disable/Change Qt journal logging behaviour.

KF5/Qt 5 applications do not display icons in i3/FVWM/awesome

See Qt#Configuration of Qt5 apps under environments other than KDE Plasma.

Problems with saving credentials and persistently occurring KWallet dialogs

It is not recommended to turn off the KWallet password saving system in the user settings as it is required to save encrypted credentials like WiFi passphrases for each user. Persistently occuring KWallet dialogs can be the consequence of turning it off.

In case you find the dialogs to unlock the wallet annoying when applications want to access it, you can let the display managers SDDM and LightDM unlock the wallet at login automatically, see KDE Wallet#Unlock KDE Wallet automatically on login. The first wallet needs to be generated by KWallet (and not user-generated) in order to be usable for system program credentials.

In case you want the wallet credentials not to be opened in memory for every application, you can restrict applications from accessing it with kwalletmanager in the KWallet settings.

If you do not care for credential encryption at all, you can simply leave the password forms blank when KWallet asks for the password while creating a wallet. In this case, applications can access passwords without having to unlock the wallet first.

Discover does not show any applications

This can be solved by installing packagekit-qt5.

High CPU usage of kscreenlocker_greet with NVIDIA drivers

As described in KDE Bug 347772 NVIDIA OpenGL drivers and QML may not play well together with Qt 5. This may lead kscreenlocker_greet to high CPU usage after unlocking the session. To work around this issue, set the QSG_RENDERER_LOOP environment variable to basic.

Then kill previous instances of the greeter with killall kscreenlocker_greet.

OS error 22 when running Akonadi on ZFS

If your home directory is on a ZFS pool, create a ~/.config/akonadi/mysql-local.conf file with the following contents:

[mysqld]
innodb_use_native_aio = 0

See MySQL#OS error 22 when running on ZFS.

Some programs are unable to scroll when their windows are inactive

This is caused by the problematic way of GTK3 handling mouse scroll events. A workaround for this is to set environment variable GDK_CORE_DEVICE_EVENTS=1. However, this workaround also breaks touchpad smooth scrolling and touchscreen scrolling.

See also