+ <!--
+ surfaceVisibilityChanged:
+ @surfaceId: The surface that changed.
+ @visible: True, if the surface is visible.
+
+ This is emitted when the visible property of the surfaces changes.
+ -->
+ <signal name="surfaceVisibilityChanged">
+ <arg name="surfaceId" type="i"/>
+ <arg name="visible" type="b"/>
+ </signal>