Switching compositing on systemwide per default

[Lars Behrens]

Hi there,

what is the correct way to enable compositing (border shadows) per
default for all users in Xfce4?

I thought I found out that the properties

<property name="use_compositing" type="bool" value="true"/>
<property name="show_frame_shadow" type="bool" value="true"/>
<property name="show_popup_shadow" type="bool" value="true"/>
<property name="shadow_delta_height" type="int" value="0"/>
<property name="shadow_delta_width" type="int" value="0"/>
<property name="shadow_delta_x" type="int" value="0"/>
<property name="shadow_delta_y" type="int" value="-3"/>
<property name="shadow_opacity" type="int" value="50"/>
<property name="show_dock_shadow" type="bool" value="true"/>
<property name="title_shadow_active" type="string" value="false"/>
<property name="title_shadow_inactive" type="string" value="false"/

are the ones in question in my
~/.config/xfce4/xfconf/xfce-perchannel-xml/xfwm4.xml

So I copied that file to
/etc/xdg/xfce4/xfconf/xfce-perchannel-xml/
and removed all other options, hoping it would work like in the good old
days where existing system files set the default but it doesn't have any
effect.

So am I doing something wrong? How to set defaults with that xfconf
mechanism?

TIA for ideas!

Cheerz,
Lars