// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module chromeos.ime.mojom;

// Manages access to a set of IME engines.
interface InputEngineManager {
  // Sets up the connection by binding the |to_engine_request| to the input
  // engine identified by the |ime_spec|. The |extra| is an optional serialized
  // protobuf data for setting up the IME engine. On success, return |success|
  // as true, and the input data can be sent to the engine by the channel using
  // the interface of |to_engine_request|. The channel interface |from_engine|
  // is implmented on the client and used to receive data sent from the engine.
  // On failure (e.g. input engine is not found), |success| is false.
  ConnectToImeEngine(string ime_spec,
                     InputChannel& to_engine_request,
                     InputChannel from_engine,
                     array<uint8> extra)
                     => (bool success);
};

// A message channel is a paired message sender and receiver, representing
// the communication channel between an client and the input engine connected.
// In order to encapsulate all the communication, (e.g. access to some
// closed-sourced input engine with decoders), implement the method that takes
// a serialized protobuf message (instead of a plaintext) as its argument.
interface InputChannel {
  // Returns a plaintext result after processing a plaintext message.
  ProcessText(string message) => (string result);

  // Returns a serialized protobuf result after processing a serialized
  // protobuf message.
  ProcessMessage(array<uint8> message) => (array<uint8> result);
};