[gtk+/wip/xdg-shell-props: 2/2] xdg-shell: Update to latest state change mechanism

[Jasper St. Pierre <jstpierre src gnome org>]

commit 0f1944c66f8acace4f7eee9d83734b50df42889e
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Sun Feb 9 11:39:01 2014 -0500

    xdg-shell: Update to latest state change mechanism

 gdk/wayland/gdkwindow-wayland.c    |   84 +++++++++-----------
 gdk/wayland/protocol/xdg-shell.xml |  156 +++++++++++++++---------------------
 2 files changed, 103 insertions(+), 137 deletions(-)
---
diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index b0772b5..f1156c3 100644
--- a/gdk/wayland/gdkwindow-wayland.c
+++ b/gdk/wayland/gdkwindow-wayland.c
@@ -107,7 +107,6 @@ struct _GdkWindowImplWayland
   struct gtk_surface *gtk_surface;
 
   unsigned int mapped : 1;
-  unsigned int fullscreen : 1;
   unsigned int use_custom_surface : 1;
   unsigned int pending_commit : 1;
   GdkWindowTypeHint hint;
@@ -943,35 +942,31 @@ xdg_surface_configure (void               *data,
 }
 
 static void
-xdg_surface_request_set_fullscreen (void *data,
-                                    struct xdg_surface *xdg_surface)
+xdg_surface_change_state (void *data,
+                          struct xdg_surface *xdg_surface,
+                          uint32_t state_type,
+                          uint32_t value,
+                          uint32_t serial)
 {
   GdkWindow *window = GDK_WINDOW (data);
-  gdk_window_fullscreen (window);
-}
-
-static void
-xdg_surface_request_unset_fullscreen (void *data,
-                                      struct xdg_surface *xdg_surface)
-{
-  GdkWindow *window = GDK_WINDOW (data);
-  gdk_window_unfullscreen (window);
-}
 
-static void
-xdg_surface_request_set_maximized (void *data,
-                                   struct xdg_surface *xdg_surface)
-{
-  GdkWindow *window = GDK_WINDOW (data);
-  gdk_window_maximize (window);
-}
+  switch (state_type)
+    {
+    case XDG_SURFACE_STATE_TYPE_MAXIMIZED:
+      if (value)
+        gdk_synthesize_window_state (window, 0, GDK_WINDOW_STATE_MAXIMIZED);
+      else
+        gdk_synthesize_window_state (window, GDK_WINDOW_STATE_MAXIMIZED, 0);
+      break;
+    case XDG_SURFACE_STATE_TYPE_FULLSCREEN:
+      if (value)
+        gdk_synthesize_window_state (window, 0, GDK_WINDOW_STATE_FULLSCREEN);
+      else
+        gdk_synthesize_window_state (window, GDK_WINDOW_STATE_FULLSCREEN, 0);
+      break;
+    }
 
-static void
-xdg_surface_request_unset_maximized (void *data,
-                                     struct xdg_surface *xdg_surface)
-{
-  GdkWindow *window = GDK_WINDOW (data);
-  gdk_window_unmaximize (window);
+  xdg_surface_ack_change_state (xdg_surface, state_type, value, serial);
 }
 
 static void
@@ -1010,10 +1005,7 @@ xdg_surface_delete (void *data,
 
 static const struct xdg_surface_listener xdg_surface_listener = {
   xdg_surface_configure,
-  xdg_surface_request_set_fullscreen,
-  xdg_surface_request_unset_fullscreen,
-  xdg_surface_request_set_maximized,
-  xdg_surface_request_unset_maximized,
+  xdg_surface_change_state,
   xdg_surface_activated,
   xdg_surface_deactivated,
   xdg_surface_delete,
@@ -1732,8 +1724,10 @@ gdk_wayland_window_maximize (GdkWindow *window)
   if (!impl->xdg_surface)
     return;
 
-  xdg_surface_set_maximized (impl->xdg_surface);
-  gdk_synthesize_window_state (window, 0, GDK_WINDOW_STATE_MAXIMIZED);
+  xdg_surface_request_change_state (impl->xdg_surface,
+                                    XDG_SURFACE_STATE_TYPE_MAXIMIZED,
+                                    TRUE,
+                                    0 /* serial, unused */);
 }
 
 static void
@@ -1747,8 +1741,10 @@ gdk_wayland_window_unmaximize (GdkWindow *window)
   if (!impl->xdg_surface)
     return;
 
-  xdg_surface_unset_maximized (impl->xdg_surface);
-  gdk_synthesize_window_state (window, GDK_WINDOW_STATE_MAXIMIZED, 0);
+  xdg_surface_request_change_state (impl->xdg_surface,
+                                    XDG_SURFACE_STATE_TYPE_MAXIMIZED,
+                                    FALSE,
+                                    0 /* serial, unused */);
 }
 
 static void
@@ -1759,15 +1755,13 @@ gdk_wayland_window_fullscreen (GdkWindow *window)
   if (GDK_WINDOW_DESTROYED (window))
     return;
 
-  if (impl->fullscreen)
-    return;
-
   if (!impl->xdg_surface)
     return;
 
-  xdg_surface_set_fullscreen (impl->xdg_surface);
-  impl->fullscreen = TRUE;
-  gdk_synthesize_window_state (window, 0, GDK_WINDOW_STATE_FULLSCREEN);
+  xdg_surface_request_change_state (impl->xdg_surface,
+                                    XDG_SURFACE_STATE_TYPE_FULLSCREEN,
+                                    TRUE,
+                                    0 /* serial, unused */);
 }
 
 static void
@@ -1778,15 +1772,13 @@ gdk_wayland_window_unfullscreen (GdkWindow *window)
   if (GDK_WINDOW_DESTROYED (window))
     return;
 
-  if (!impl->fullscreen)
-    return;
-
   if (!impl->xdg_surface)
     return;
 
-  xdg_surface_unset_fullscreen (impl->xdg_surface);
-  impl->fullscreen = FALSE;
-  gdk_synthesize_window_state (window, GDK_WINDOW_STATE_FULLSCREEN, 0);
+  xdg_surface_request_change_state (impl->xdg_surface,
+                                    XDG_SURFACE_STATE_TYPE_FULLSCREEN,
+                                    FALSE,
+                                    0 /* serial, unused */);
 }
 
 static void
diff --git a/gdk/wayland/protocol/xdg-shell.xml b/gdk/wayland/protocol/xdg-shell.xml
index 4a1d08a..ad525af 100644
--- a/gdk/wayland/protocol/xdg-shell.xml
+++ b/gdk/wayland/protocol/xdg-shell.xml
@@ -275,113 +275,87 @@
       <arg name="output" type="object" interface="wl_output" allow-null="true"/>
     </request>
 
-    <event name="request_set_fullscreen">
-      <description summary="server requests that the client set fullscreen">
-       Event sent from the compositor to the client requesting that the client
-       goes to a fullscreen state. It's the client job to call set_fullscreen
-       and really trigger the fullscreen state.
+    <enum name="state_type">
+      <description summary="types of state on the surface">
+        The different state values used on the surface. This is designed for
+        state values like maximized, fullscreen. It is paired with the
+        request_change_state event to ensure that both the client and the
+        compositor setting the state can be synchronized.
+
+        States set in this way are double-buffered. They will get applied on
+        the next commit.
+
+        Desktop environments may extend this enum by taking up a range of
+        values and documenting the range they chose in this description.
+        They are not required to document the values for the range that they
+        chose. Ideally, any good extensions from a desktop environment should
+        make its way into standardization into this enum.
+
+        The current reserved ranges are:
+
+        0x0000 - 0x0FFF: xdg-shell core values, documented below.
+        0x1000 - 0x1FFF: GNOME
       </description>
-    </event>
-
-    <event name="request_unset_fullscreen">
-      <description summary="server requests that the client unset fullscreen">
-       Event sent from the compositor to the client requesting that the client
-       leaves the fullscreen state. It's the client job to call
-       unset_fullscreen and really leave the fullscreen state.
-      </description>
-    </event>
-
-    <request name="set_fullscreen">
-      <description summary="set the surface state as fullscreen">
-       Set the surface as fullscreen.
-
-       After this request, the compositor should send a configure event
-       informing the output size.
-
-       This request informs the compositor that the next attached buffer
-       committed will be in a fullscreen state. The buffer size should be the
-       same size as the size informed in the configure event, if the client
-       doesn't want to leave any empty area.
-
-       In other words: the next attached buffer after set_maximized is the new
-       maximized buffer. And the surface will be positioned at the maximized
-       position on commit.
-
-       A simple way to synchronize and wait for the correct configure event is
-       to use a wl_display.sync request right after the set_fullscreen
-       request. When the sync callback returns, the last configure event
-       received just before it will be the correct one, and should contain the
-       right size for the surface to maximize.
-
-       Setting one state won't unset another state. Use
-       xdg_surface.unset_fullscreen for unsetting it.
-      </description>
-    </request>
+      <entry name="maximized" value="1" summary="the surface is maximized">
+        A non-zero value indicates the surface is maximized. Otherwise,
+        the surface is unmaximized.
+      </entry>
+      <entry name="fullscreen" value="2" summary="the surface is fullscreen">
+        A non-zero value indicates the surface is fullscreen. Otherwise,
+        the surface is not fullscreen.
+      </entry>
+    </enum>
 
-    <request name="unset_fullscreen">
-      <description summary="unset the surface state as fullscreen">
-       Unset the surface fullscreen state.
+    <request name="request_change_state">
+      <description summary="client requests to change a surface's state">
+        This asks the compositor to change the state. If the compositor wants
+        to change the state, it will send a change_state event with the same
+        state_type, value, and serial, and the event flow continues as if it
+        it was initiated by the compositor.
 
-       Same negotiation as set_fullscreen must be used.
+        If the compositor does not want to change the state, it will send a
+        change_state to the client with the old value of the state.
       </description>
+      <arg name="state_type" type="uint" summary="the state to set"/>
+      <arg name="value" type="uint" summary="the value to change the state to"/>
+      <arg name="serial" type="uint" summary="an event serial">
+        This serial is so the client can know which change_state event corresponds
+        to which request_change_state request it sent out.
+      </arg>
     </request>
 
-    <event name="request_set_maximized">
-      <description summary="server requests that the client set maximized">
-       Event sent from the compositor to the client requesting that the client
-       goes to a maximized state. It's the client job to call set_maximized
-       and really trigger the maximized state.
+    <event name="change_state">
+      <description summary="compositor wants to change a surface's state">
+        This event tells the client to change a surface's state. The client
+        should respond with an ack_change_state request to the compositor to
+        guarantee that the compositor knows that the client has seen it.
       </description>
-    </event>
 
-    <event name="request_unset_maximized">
-      <description summary="server requests that the client unset maximized">
-       Event sent from the compositor to the client requesting that the client
-       leaves the maximized state. It's the client job to call unset_maximized
-       and really leave the maximized state.
-      </description>
+      <arg name="state_type" type="uint" summary="the state to set"/>
+      <arg name="value" type="uint" summary="the value to change the state to"/>
+      <arg name="serial" type="uint" summary="a serial for the compositor's own tracking"/>
     </event>
 
-    <request name="set_maximized">
-      <description summary="set the surface state as maximized">
-       Set the surface as maximized.
-
-       After this request, the compositor will send a configure event
-       informing the output size minus panel and other MW decorations.
-
-       This request informs the compositor that the next attached buffer
-       committed will be in a maximized state. The buffer size should be the
-       same size as the size informed in the configure event, if the client
-       doesn't want to leave any empty area.
-
-       In other words: the next attached buffer after set_maximized is the new
-       maximized buffer. And the surface will be positioned at the maximized
-       position on commit.
+    <request name="ack_change_state">
+      <description summary="ack a change_state event">
+        When a change_state event is received, a client should then ack it
+        using the ack_change_state request to ensure that the compositor
+        knows the client has seen the event.
 
-       A simple way to synchronize and wait for the correct configure event is
-       to use a wl_display.sync request right after the set_maximized request.
-       When the sync callback returns, the last configure event received just
-       before it will be the correct one, and should contain the right size
-       for the surface to maximize.
+        By this point, the state is confirmed, and the next attach should
+        contain the buffer drawn for the new state value.
 
-       Setting one state won't unset another state. Use
-       xdg_surface.unset_maximized for unsetting it.
-      </description>
-    </request>
-
-    <request name="unset_maximized">
-      <description summary="unset the surface state as maximized">
-       Unset the surface maximized state.
-
-       Same negotiation as set_maximized must be used.
+        The values here need to be the same as the values in the cooresponding
+        change_state event.
       </description>
+      <arg name="state_type" type="uint" summary="the state to set"/>
+      <arg name="value" type="uint" summary="the value to change the state to"/>
+      <arg name="serial" type="uint" summary="a serial to pass to change_state"/>
     </request>
 
     <request name="set_minimized">
-      <description summary="set the surface state as minimized">
-       Set the surface minimized state.
-
-       Setting one state won't unset another state.
+      <description summary="minimize the surface">
+        Minimize the surface.
       </description>
     </request>