logind-session-dbus: allow to set display name via dbus

Currently, the only way to set display name of a graphical session is to
pass it to CreateSession(). But modern display managers like gdm start
the display server as part of the user session, which means that the
display name isn't known yet when the session is being created. Hence,
let's make it possible to set it later.

1 files changed, 8 insertions, 0 deletions

diff --git a/man/org.freedesktop.login1.xml b/man/org.freedesktop.login1.xml
index 108a47a38d..4cc9f27891 100644
--- a/man/org.freedesktop.login1.xml
+++ b/man/org.freedesktop.login1.xml
@@ -1075,6 +1075,7 @@ node /org/freedesktop/login1/session/1 {
       TakeControl(in  b force);
       ReleaseControl();
       SetType(in  s type);
+      SetDisplay(in  s display);
       TakeDevice(in  u major,
                  in  u minor,
                  out h fd,
@@ -1172,6 +1173,8 @@ node /org/freedesktop/login1/session/1 {
 
     <variablelist class="dbus-method" generated="True" extra-ref="SetType()"/>
 
+    <variablelist class="dbus-method" generated="True" extra-ref="SetDisplay()"/>
+
     <variablelist class="dbus-method" generated="True" extra-ref="TakeDevice()"/>
 
     <variablelist class="dbus-method" generated="True" extra-ref="ReleaseDevice()"/>
@@ -1268,6 +1271,11 @@ node /org/freedesktop/login1/session/1 {
       connection. This should help prevent a session from entering an inconsistent state, for example if the
       controller crashes. The only argument <varname>type</varname> is the new session type.</para>
 
+      <para><function>SetDisplay()</function> allows the display name of the graphical session to be changed. This is
+      useful if the display server is started as part of the session. It can only be called by session's current
+      controller. If <function>TakeControl()</function> has not been called, this method will fail. The only argument
+      <varname>display</varname> is the new display name.</para>
+
       <para><function>TakeDevice()</function> allows a session controller to get a file descriptor for a
       specific device. Pass in the major and minor numbers of the character device and
       <filename>systemd-logind</filename> will return a file descriptor for the device. Only a limited set of