[PATCH v4 xdg-shell-unstable-v6] xdg-shell: add preferred min/max size requests

[Olivier Fourdan]

Some application may wish to restrict their window in size, but
xdg-shell has no mechanism for the client to advertise such a maximum
or minimum preferred size the compositor can use.

As a result, the compositor may try to maximize or fullscreen a window
while the client would not allow for the requested size.

Add new requests "set_preferred_max_size" and "set_preferred_min_size"
to xdg-shell so that the client can tell the compositor which would be
its preferred smallest/largest acceptable size, so that he compositor
can decide if maximize or fullscreen makes sense, draw an accurate
animation, etc.

Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
Bugzilla: https://bugzilla.gnome.org/show_bug.cgi?id=764413
---
 v2: Rename the request to "set_preferred_max_size",
     add "set_preferred_min_size" as well
 v3: Rebase above patch 72427 in branch xdg-shell-unstable-v6
     Rephrase description to clarify the unscaled size and using 0 to
     reset back the preferred size to an unspecified state
 v4: Patch the correct xml file (v6, not v5 <facepalm>)
     Fix mutliple mismatch of min/max in the description
     Remove mention of "unscaled", specify window geometry coordinates
     and refer to set_window_geometry.

 unstable/xdg-shell/xdg-shell-unstable-v6.xml | 60 ++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/unstable/xdg-shell/xdg-shell-unstable-v6.xml b/unstable/xdg-shell/xdg-shell-unstable-v6.xml
index 3fc7d42..05f28f6 100644
--- a/unstable/xdg-shell/xdg-shell-unstable-v6.xml
+++ b/unstable/xdg-shell/xdg-shell-unstable-v6.xml
@@ -489,6 +489,66 @@
       <arg name="states" type="array"/>
     </event>
 
+    <request name="set_preferred_max_size">
+      <description summary="set the preferred maximum size">
+	Set a preferred maximum size for the window.
+
+	The client can specify a preferred maximum size to tell the
+	compositor that a window should not be resized beyond this
+	size.
+
+	The width and height arguments are in window geometry coordinates.
+	See set_window_geometry.
+
+	The compositor may use this information from the client to allow
+	or disallow different states like maximixe or fullscreen and
+	draw accurate animations.
+
+	Similarily, a tiling window manager can use this information to
+	place and resize client windows in a more effective way.
+
+	If never set, the size of the window is not limited by the client.
+
+	A value of zero in the request for either width, height or both
+	means that the client has no preference regarding the maximum size
+	in the given dimension. As a result, a client wishing to reset the
+	preferred maximum size to an unspecified state can use zero for
+	width and height in the request.
+      </description>
+      <arg name="width" type="int"/>
+      <arg name="height" type="int"/>
+    </request>
+
+    <request name="set_preferred_min_size">
+      <description summary="set the preferred minimum size">
+	Set a preferred minimum size for the window.
+
+	The client can specify a preferred minimum size to tell the
+	compositor that a window should not be resized below this
+	size.
+
+	The width and height arguments are in window geometry coordinates.
+	See set_window_geometry.
+
+	The compositor may use this information from the client to allow
+	or disallow different states like maximixe or fullscreen and
+	draw accurate animations.
+
+	Similarily, a tiling window manager can use this information to
+	place and resize client windows in a more effective way.
+
+	If never set, the size of the window is not limited by the client.
+
+	A value of zero in the request for either width, height or both
+	means that the client has no preference regarding the minimum size
+	in the given dimension. As a result, a client wishing to reset the
+	preferred minimum size to an unspecified state can use zero for
+	width and height in the request.
+      </description>
+      <arg name="width" type="int"/>
+      <arg name="height" type="int"/>
+    </request>
+
     <request name="set_maximized">
       <description summary="maximize the window">
 	Maximize the surface.
-- 
2.5.5