<chapter xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-x11">
 <title>X Window System</title>
 <para>
  The X Window System (X11) provides the basis of NixOS’ graphical user
  interface. It can be enabled as follows:
<programlisting>
<xref linkend="opt-services.xserver.enable"/> = true;
</programlisting>
  The X server will automatically detect and use the appropriate video driver
  from a set of X.org drivers (such as <literal>vesa</literal> and
  <literal>intel</literal>). You can also specify a driver manually, e.g.
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "r128" ];
</programlisting>
  to enable X.org’s <literal>xf86-video-r128</literal> driver.
 </para>
 <para>
  You also need to enable at least one desktop or window manager. Otherwise,
  you can only log into a plain undecorated <command>xterm</command> window.
  Thus you should pick one or more of the following lines:
<programlisting>
<xref linkend="opt-services.xserver.desktopManager.plasma5.enable"/> = true;
<xref linkend="opt-services.xserver.desktopManager.xfce.enable"/> = true;
<xref linkend="opt-services.xserver.desktopManager.gnome3.enable"/> = true;
<xref linkend="opt-services.xserver.desktopManager.mate.enable"/> = true;
<xref linkend="opt-services.xserver.windowManager.xmonad.enable"/> = true;
<xref linkend="opt-services.xserver.windowManager.twm.enable"/> = true;
<xref linkend="opt-services.xserver.windowManager.icewm.enable"/> = true;
<xref linkend="opt-services.xserver.windowManager.i3.enable"/> = true;
</programlisting>
 </para>
 <para>
  NixOS’s default <emphasis>display manager</emphasis> (the program that
  provides a graphical login prompt and manages the X server) is LightDM. You can
  select an alternative one by picking one of the following lines:
<programlisting>
<xref linkend="opt-services.xserver.displayManager.sddm.enable"/> = true;
<xref linkend="opt-services.xserver.displayManager.slim.enable"/> = true;
</programlisting>
 </para>
 <para>
  You can set the keyboard layout (and optionally the layout variant):
<programlisting>
<xref linkend="opt-services.xserver.layout"/> = "de";
<xref linkend="opt-services.xserver.xkbVariant"/> = "neo";
</programlisting>
 </para>
 <para>
  The X server is started automatically at boot time. If you don’t want this
  to happen, you can set:
<programlisting>
<xref linkend="opt-services.xserver.autorun"/> = false;
</programlisting>
  The X server can then be started manually:
<screen>
# systemctl start display-manager.service
</screen>
 </para>
 <simplesect xml:id="sec-x11-graphics-cards-nvidia">
  <title>NVIDIA Graphics Cards</title>
  <para>
   NVIDIA provides a proprietary driver for its graphics cards that has better
   3D performance than the X.org drivers. It is not enabled by default because
   it’s not free software. You can enable it as follows:
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidia" ];
</programlisting>
   Or if you have an older card, you may have to use one of the legacy drivers:
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidiaLegacy340" ];
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidiaLegacy304" ];
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidiaLegacy173" ];
</programlisting>
   You may need to reboot after enabling this driver to prevent a clash with
   other kernel modules.
  </para>
  <para>
   On 64-bit systems, if you want full acceleration for 32-bit programs such as
   Wine, you should also set the following:
<programlisting>
<xref linkend="opt-hardware.opengl.driSupport32Bit"/> = true;
</programlisting>
  </para>
 </simplesect>
 <simplesect xml:id="sec-x11--graphics-cards-amd">
  <title>AMD Graphics Cards</title>
  <para>
   AMD provides a proprietary driver for its graphics cards that has better 3D
   performance than the X.org drivers. It is not enabled by default because
   it’s not free software. You can enable it as follows:
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "ati_unfree" ];
</programlisting>
   You will need to reboot after enabling this driver to prevent a clash with
   other kernel modules.
  </para>
  <para>
   On 64-bit systems, if you want full acceleration for 32-bit programs such as
   Wine, you should also set the following:
<programlisting>
<xref linkend="opt-hardware.opengl.driSupport32Bit"/> = true;
</programlisting>
  </para>
 </simplesect>
 <simplesect xml:id="sec-x11-touchpads">
  <title>Touchpads</title>
  <para>
   Support for Synaptics touchpads (found in many laptops such as the Dell
   Latitude series) can be enabled as follows:
<programlisting>
<xref linkend="opt-services.xserver.libinput.enable"/> = true;
</programlisting>
   The driver has many options (see <xref linkend="ch-options"/>). For
   instance, the following disables tap-to-click behavior:
<programlisting>
<xref linkend="opt-services.xserver.libinput.tapping"/> = false;
</programlisting>
   Note: the use of <literal>services.xserver.synaptics</literal> is deprecated
   since NixOS 17.09.
  </para>
 </simplesect>
 <simplesect xml:id="sec-x11-gtk-and-qt-themes">
  <title>GTK/Qt themes</title>
  <para>
   GTK themes can be installed either to user profile or system-wide (via
   <literal>environment.systemPackages</literal>). To make Qt 5 applications
   look similar to GTK2 ones, you can install <literal>qt5.qtbase.gtk</literal>
   package into your system environment. It should work for all Qt 5 library
   versions.
  </para>
 </simplesect>
</chapter>
