Enum fidl_examples_canvas_clientrequesteddraw::InstanceRequest

pub enum InstanceRequest {
    AddLines {
        lines: Vec<[Point; 2]>,
        control_handle: InstanceControlHandle,
    },
    Ready {
        responder: InstanceReadyResponder,
    },
    _UnknownMethod {
        ordinal: u64,
        control_handle: InstanceControlHandle,
        method_type: MethodType,
    },
}

Manages a single instance of a canvas. Each session of this protocol is responsible for a new canvas.

Variants

AddLines

Add multiple lines to the canvas. We are able to reduce protocol chatter and the number of requests needed by batching instead of calling the simpler AddLine(...) one line at a time.

Fields

lines: Vec<[Point; 2]>

control_handle: InstanceControlHandle

Ready

Rather than the server randomly performing draws, or trying to guess when to do so, the client must explicitly ask for them. This creates a bit of extra chatter with the additional method invocation, but allows much greater client-side control of when the canvas is “ready” for a view update, thereby eliminating unnecessary draws.

This method also has the benefit of “throttling” the -> OnDrawn(...) event - rather than allowing a potentially unlimited flood of -> OnDrawn(...) calls, we now have the runtime enforced semantic that each -> OnDrawn(...) call must follow a unique Ready() -> () call from the client. An unprompted -> OnDrawn(...) is invalid, and should cause the channel to immediately close.

Fields

responder: InstanceReadyResponder

_UnknownMethod

An interaction was received which does not match any known method.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

ordinal: u64

Ordinal of the method that was called.

control_handle: InstanceControlHandle

method_type: MethodType

Implementations

impl InstanceRequest

pub fn into_add_lines(self) -> Option<(Vec<[Point; 2]>, InstanceControlHandle)>

pub fn into_ready(self) -> Option<InstanceReadyResponder>

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

Name of the method defined in FIDL

Trait Implementations

impl Debug for InstanceRequest

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

Formats the value using the given formatter.