Added network components for blimp text input feature

blimp/client/feature/ime_feature.h

+// Copyright 2016 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.
+
+#ifndef BLIMP_CLIENT_FEATURE_IME_FEATURE_H_
+#define BLIMP_CLIENT_FEATURE_IME_FEATURE_H_
+
+#include <map>
+#include <string>
+
+#include "base/macros.h"
+#include "blimp/client/blimp_client_export.h"
+#include "blimp/net/blimp_message_processor.h"
+#include "ui/base/ime/text_input_type.h"
+
+namespace blimp {
+namespace client {
+
+// Handles all incoming and outgoing protobuf messages for text input of type
+// BlimpMessage::IME for blimp client.
+// Upon receiving a text input request from the engine, the ImeFeature caches
+// the |tab_id_| and |render_widget_id_| for the request and
+// delegates the request to the Delegate which then opens up the IME.
+// After user is done typing, the text is passed back to ImeFeature, which then
+// sends the text to the engine over network along with the same |tab_id_| and
+// |render_widget_id_|.
+// Any time user taps on an input text, ImeMessage::SHOW_IME message will be
+// sent to client. Similarly, any time the text input is out of focus (e.g. if
+// user navigates away from the currently page or the page loads for the first
+// time), ImeMessage::HIDE_IME will be sent.
+
+class BLIMP_CLIENT_EXPORT ImeFeature : public BlimpMessageProcessor {
+ public:
+  // A delegate to be notified of text input requests.
+  class Delegate {
+   public:
+    virtual void OnShowImeRequested(ui::TextInputType input_type,
+                                    const std::string& text) = 0;
+    virtual void OnHideImeRequested() = 0;
+  };
+
+  ImeFeature();
+  ~ImeFeature() override;
+
+  // Set the BlimpMessageProcessor that will be used to send BlimpMessage::IME
+  // messages to the engine.
+  void set_outgoing_message_processor(
+      scoped_ptr<BlimpMessageProcessor> processor) {
+    outgoing_message_processor_ = std::move(processor);
+  }
+
+  // Sets a Delegate to be notified of all text input messages.
+  // Passing a null |delegate| causes IME messages to be ignored.
+  void set_delegate(Delegate* delegate) { delegate_ = delegate; }
+
+  // Sends text from IME to the blimp engine.
+  void OnImeTextEntered(const std::string& text);
+
+ private:
+  // BlimpMessageProcessor implementation.
+  void ProcessMessage(scoped_ptr<BlimpMessage> message,
+                      const net::CompletionCallback& callback) override;
+
+  // Delegate for processing the text input related messages. |delegate_| must
+  // remain valid until the last message has been passed to ImeFeature.
+  Delegate* delegate_ = nullptr;
+
+  // Tab id and render widget id for the input field for which user input is
+  // being requested.
+  // The values are cached from the ImeMessage::SHOW_IME message and sent back
+  // to engine in the subsequent ImeMessage::SET_TEXT message.
+  // The cached values are cleared on receiving ImeMessage::HIDE_IME request.
+  int tab_id_ = -1;
+  int render_widget_id_ = 0;
+
+  // Used to send BlimpMessage::IME messages to the engine.
+  scoped_ptr<BlimpMessageProcessor> outgoing_message_processor_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImeFeature);
+};
+
+}  // namespace client
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_FEATURE_IME_FEATURE_H_