[PATCH wayland-protocols] xdg-output: make xdg_output.description mutable

[Simon Ser]

The output description is a human-readable text describing the output. Unlike
the name which uniquely identifies the output, it's intended to be displayed to
the user.

It might be desirable for a compositor to update an output's description. For
instance, when only one output is plugged in, it's not necessary to dump make,
model, serial and connector to the description, something like "Dell U2717D" is
enough. However when two identical outputs are plugged in it's necessary to add
e.g. the connector type to tell them apart ("Dell U2717D on HDMI"). See [1] for
a discussion about this.

This commit bumps xdg_output's version to allow compositors to update the
property.

[1]: https://github.com/swaywm/wlroots/issues/1623

Signed-off-by: Simon Ser <contact at emersion.fr>
---
 unstable/xdg-output/xdg-output-unstable-v1.xml | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/unstable/xdg-output/xdg-output-unstable-v1.xml b/unstable/xdg-output/xdg-output-unstable-v1.xml
index ccbfe1c..86216a7 100644
--- a/unstable/xdg-output/xdg-output-unstable-v1.xml
+++ b/unstable/xdg-output/xdg-output-unstable-v1.xml
@@ -54,7 +54,7 @@
     reset.
   </description>

-  <interface name="zxdg_output_manager_v1" version="2">
+  <interface name="zxdg_output_manager_v1" version="3">
     <description summary="manage xdg_output objects">
       A global factory interface for xdg_output objects.
     </description>
@@ -77,7 +77,7 @@
     </request>
   </interface>

-  <interface name="zxdg_output_v1" version="2">
+  <interface name="zxdg_output_v1" version="3">
     <description summary="compositor logical output region">
       An xdg_output describes part of the compositor geometry.

@@ -197,10 +197,12 @@
 	output via :1'.

 	The description event is sent after creating an xdg_output (see
-	xdg_output_manager.get_xdg_output). This event is only sent once per
+	xdg_output_manager.get_xdg_output) and whenever the description
+	changes. The description is optional, and may not be sent at all.
+
+	For objects of version 2 and lower, this event is only sent once per
 	xdg_output, and the description does not change over the lifetime of
-	the wl_output global. The description is optional, and may not be sent
-	at all.
+	the wl_output global.
       </description>
       <arg name="description" type="string" summary="output description"/>
     </event>
--
2.21.0