Struct input_pipeline::input_pipeline::InputPipelineAssembly

pub struct InputPipelineAssembly { /* private fields */ }

An input pipeline assembly.

Represents a partial stage of the input pipeline which accepts inputs through an asynchronous sender channel, and emits outputs through an asynchronous receiver channel. Use [new] to create a new assembly. Use [add_handler], or [add_all_handlers] to add the input pipeline handlers to use. When done, InputPipeline::new can be used to make a new input pipeline.

Implementation notes

Internally, when a new InputPipelineAssembly is created with multiple [InputHandler]s, the handlers are connected together using async queues. This allows fully streamed processing of input events, and also allows some pipeline stages to generate events spontaneously, i.e. without an external stimulus.

Implementations

impl InputPipelineAssembly

pub fn new(metrics_logger: MetricsLogger) -> Self

Create a new but empty InputPipelineAssembly. Use [add_handler] or similar to add new handlers to it.

pub fn add_handler(self, handler: Rc<dyn InputHandler>) -> Self

Adds another input_handler::InputHandler into the InputPipelineAssembly. The handlers are invoked in the order they are added, and successive handlers are glued together using unbounded queues. Returns Self for chaining.

pub fn add_all_handlers(self, handlers: Vec<Rc<dyn InputHandler>>) -> Self

Adds all handlers into the assembly in the order they appear in handlers.

pub fn add_display_ownership( self, display_ownership_event: Event, input_handlers_node: &Node ) -> InputPipelineAssembly

Adds the DisplayOwnership to the input pipeline. The display_ownership_event is assumed to be the Scenic event used to report changes in display ownership, obtained by fuchsia.ui.scenic/Scenic.GetDisplayOwnershipEvent. This code has no way to check whether that invariant is upheld, so this is something that the user will need to ensure.

pub fn add_autorepeater(self, input_handlers_node: &Node) -> Self

Adds the autorepeater into the input pipeline assembly. The autorepeater is installed after any handlers that have been already added to the assembly.

pub fn add_focus_listener( self, focus_chain_publisher: FocusChainProviderPublisher ) -> Self

Adds a focus listener task into the input pipeline assembly. The focus listener forwards focus chain changes to fuchsia.ui.keyboard.focus.Controller and watchers of fuchsia.ui.focus.FocusChainProvider. It is required for the correct operation of the implementors of those protocols, e.g. text_manager.

Arguments:

• focus_chain_publisher: to forward to other downstream watchers.

Requires:

• fuchsia.ui.views.FocusChainListenerRegistry: to register for updates.
• fuchsia.ui.keyboard.focus.Controller: to forward to text_manager.