[PATCH wayland 3/4] protocol: wl_surface.frame needs wl_surface.commit

Pekka Paalanen ppaalanen at gmail.com
Wed Oct 10 02:47:49 PDT 2012

Clarify, when frame request takes effect.
Explain when to send/receive the callback.

Signed-off-by: Pekka Paalanen <ppaalanen at gmail.com>
 protocol/wayland.xml |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index 6293f56..740fb43 100644
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -700,10 +700,20 @@
     <request name="frame">
       <description summary="request repaint feedback">
-	Request notification when the next frame is displayed.  Useful
+	Request notification when the next frame is displayed. Useful
 	for throttling redrawing operations, and driving animations.
+	The frame request will take effect on the next wl_surface.commit.
 	The notification will only be posted for one frame unless
 	requested again.
+	A server should avoid signalling the frame callbacks if the
+	surface is not visible in any way, e.g. the surface is off-screen,
+	or completely obscured by other opaque surfaces.
+	A client can request a frame callback even without an attach,
+	damage, or any other state changes. wl_surface.commit triggers a
+	repaint, so the callback event will arrive after the next output
+	refresh where the surface is visible.
       <arg name="callback" type="new_id" interface="wl_callback"/>

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