exo: Implement notification surface support

components/exo/wayland/server.cc

Index: components/exo/wayland/server.cc
diff --git a/components/exo/wayland/server.cc b/components/exo/wayland/server.cc
index 5ba8ee4496989fe48d99864c4126dafeef57a06e..888d19cce847c35112b06dd20b2abb544a8ea5fe 100644
--- a/components/exo/wayland/server.cc
+++ b/components/exo/wayland/server.cc
@@ -42,6 +42,8 @@
 #include "components/exo/display.h"
 #include "components/exo/keyboard.h"
 #include "components/exo/keyboard_delegate.h"
+#include "components/exo/notification_surface.h"
+#include "components/exo/notification_surface_registry.h"
 #include "components/exo/pointer.h"
 #include "components/exo/pointer_delegate.h"
 #include "components/exo/shared_memory.h"
@@ -1485,6 +1487,16 @@ const struct zwp_remote_surface_v1_interface remote_surface_implementation = {
     remote_surface_unfullscreen};
 
 ////////////////////////////////////////////////////////////////////////////////
+// notification_surface_interface:
+
+void notification_surface_destroy(wl_client* client, wl_resource* resource) {
+  wl_resource_destroy(resource);
+}
+
+const struct zwp_notification_surface_v1_interface
+    notification_surface_implementation = {notification_surface_destroy};
+
+////////////////////////////////////////////////////////////////////////////////
 // remote_shell_interface:
 
 // Implements remote shell interface and monitors workspace state needed
@@ -1517,6 +1529,17 @@ class WaylandRemoteShell : public ash::ShellObserver,
     return display_->CreateRemoteShellSurface(surface, container);
   }
 
+  bool IsValidNotificationId(const std::string& notification_id) const {

[reveman, 2016/06/22 16:44:30]

Would be nice if this could instead be validated when inserting the surface so
we can avoid two lookups. Maybe just have a null return value from
CreateNotificationSurface mean generate this error. I think that should work
after changing how ERROR_ROLE messages are generated as suggested below.

[xiyuan, 2016/06/23 14:46:43]

Done.

+    return display_->notification_surface_registry()->GetSurface(
+               notification_id) == nullptr;
+  }
+
+  std::unique_ptr<NotificationSurface> CreateNotificationSurface(
+      Surface* surface,
+      const std::string& notification_id) {
+    return display_->CreateNotificationSurface(surface, notification_id);
+  }
+
   // Overridden from display::DisplayObserver:
   void OnDisplayAdded(const display::Display& new_display) override {}
   void OnDisplayRemoved(const display::Display& new_display) override {}
@@ -1692,10 +1715,42 @@ void remote_shell_get_remote_surface(wl_client* client,
                     std::move(shell_surface));
 }
 
+void remote_shell_get_notification_surface(wl_client* client,
+                                           wl_resource* resource,
+                                           uint32_t id,
+                                           wl_resource* surface,
+                                           const char* notification_id) {
+  WaylandRemoteShell* remote_shell =
+      GetUserDataAs<WaylandRemoteShell>(resource);
+  if (!remote_shell->IsValidNotificationId(notification_id)) {
+    wl_resource_post_error(resource,
+                           ZWP_REMOTE_SHELL_V1_ERROR_INVALID_NOTIFICATION_ID,
+                           "invalid notification id");
+    return;
+  }
+
+  std::unique_ptr<NotificationSurface> notification_surface =
+      remote_shell->CreateNotificationSurface(GetUserDataAs<Surface>(surface),
+                                              std::string(notification_id));
+  if (!notification_surface) {

[reveman, 2016/06/22 16:44:31]

Instead of using a null return value here. Can you check this earlier by calling
Surface::HasSurfaceDelegate()?

[xiyuan, 2016/06/23 14:46:43]

Done.

+    wl_resource_post_error(resource, ZWP_REMOTE_SHELL_V1_ERROR_ROLE,
+                           "surface has already been assigned a role");
+    return;
+  }
+
+  wl_resource* notification_surface_resource =
+      wl_resource_create(client, &zwp_notification_surface_v1_interface,
+                         wl_resource_get_version(resource), id);
+  SetImplementation(notification_surface_resource,
+                    &notification_surface_implementation,
+                    std::move(notification_surface));
+}
+
 const struct zwp_remote_shell_v1_interface remote_shell_implementation = {
-    remote_shell_destroy, remote_shell_get_remote_surface};
+    remote_shell_destroy, remote_shell_get_remote_surface,
+    remote_shell_get_notification_surface};
 
-const uint32_t remote_shell_version = 3;
+const uint32_t remote_shell_version = 4;
 
 void bind_remote_shell(wl_client* client,
                        void* data,