Enum ParentViewportWatcherRequest

pub enum ParentViewportWatcherRequest {
    GetLayout {
        responder: ParentViewportWatcherGetLayoutResponder,
    },
    GetStatus {
        responder: ParentViewportWatcherGetStatusResponder,
    },
}

A protocol that provides information about the parent Viewport attached to a Flatland instance’s sole View. Although Flatland instances can have at most one view, it is possible to have multiple ParentViewportWatchers during the brief transition period when replacing the instance’s View with another, e.g. via [CreateView]. During this period, certain updates may be duplicated and sent to each ParentViewportWatcher connection.

A ParentViewportWatcher will remain connected as long as the corresponding parent Viewport exists; the connection will also be closed if the parents’s ViewportCreationToken is dropped without using it to create a Viewport.

Variants

GetLayout

A hanging get for receiving layout information. Clients may receive layout information before the ParentViewportWatcher operation has been presented. This allows children to layout their content before their first call to [Present]. In transition cases where two ParentViewportWatcher channels exist at the same time, both protocol instances will be receiving different layout information.

This hanging get will only fire when the LayoutInfo is different than the previously returned LayoutInfo. Note that, since LayoutInfo is a table, only some fields may have changed.

It is invalid to call GetLayout while a previous call is still pending. Doing so will cause both this channel and the Flatland channel that handed out ParentViewportWatcher to be closed.

Fields

responder: ParentViewportWatcherGetLayoutResponder

GetStatus

A hanging get for receiving the status of the parent Viewport. This provides global connectivity information to the child.

This hanging get will only fire when the ParentViewportStatus is different than the previously returned ParentViewportStatus.

It is invalid to call GetStatus while a previous call is still pending. Doing so will cause both this channel and the Flatland channel that handed out ParentViewportWatcher to be closed.

Fields

responder: ParentViewportWatcherGetStatusResponder

Implementations

impl ParentViewportWatcherRequest

pub fn into_get_layout(self) -> Option<ParentViewportWatcherGetLayoutResponder>

pub fn into_get_status(self) -> Option<ParentViewportWatcherGetStatusResponder>

pub fn method_name(&self) -> &'static str

Name of the method defined in FIDL

Trait Implementations

impl Debug for ParentViewportWatcherRequest

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.