PROTOCOLS
Registry
Defined in fuchsia.ui.annotation/annotation.fidl
Annotation allows a privileged client service to create an "annotation"
ViewHolder, linked with an annotation View drawn within the View-space
of the existing client View.
CreateAnnotationViewHolder
Creates a new annotation ViewHolder. The created ViewHolder holds an
annotation View which renders within the existing client's View-space
without that client's knowledge.
The client should create a ViewToken / ViewHolderToken pair, pass
the ViewHolderToken as an argument to this function to create the
annotation ViewHolder, and create an annotation View in its own
Session using the corresponding ViewToken.
The annotation View has the following properties:
+ It is a descendent of client_view's ViewNode in the scene graph
but it's not visible by the Session of client_view.
+ It does not receive or intercept any hit event.
+ It always has the same rendering state as client_view and always
match the size and metrics.
When client_view's Session receives the following Events, all its
annotation Views' Sessions will receive the corresponding Events of
the annotation Views:
+ ViewAttachedToSceneEvent
+ ViewDetachedFromSceneEvent
+ ViewPropertiesChangedEvent
+ ViewStateChangedEvent
Since creating a ViewHolder modifies the SceneGraph, this function won't take effect until we schedule a new frame by calling Present() on any Session.
EPITAPH
There are a few erroneous conditions where the annotation ViewHolder
will not be created and the the FIDL binding will be disconnected.
Clients should remove the annotation View and Session they create.
It may return the following epitaphs:
- ZX_ERR_INVALID_ARGS, if the provided
ViewRefis invalid. - ZX_ERR_PEER_CLOSED, if Scenic fails creating the annotation
ViewHolder.
Request
| Name | Type |
|---|---|
client_view |
fuchsia.ui.views/ViewRef
|
view_holder_token |
fuchsia.ui.views/ViewHolderToken
|
Response
| Name | Type |
|---|