Added network components for blimp text input feature

blimp/client/feature/ime_feature.cc

+// 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.
+
+#include <blimp/client/feature/ime_feature.h>
+#include <string>
+
+#include "blimp/common/create_blimp_message.h"
+#include "blimp/common/proto/blimp_message.pb.h"
+#include "blimp/net/input_message_converter.h"
+#include "net/base/net_errors.h"
+
+namespace blimp {
+namespace client {
+
+ImeFeature::ImeFeature()
+    : delegate_(nullptr), tab_id_(-1), render_widget_id_(0) {}
+
+ImeFeature::~ImeFeature() {}
+
+void ImeFeature::OnImeTextEntered(const std::string& text) {
+  DCHECK(tab_id_ >= 0 && render_widget_id_ > 0);

[Wez, 2016/03/22 21:43:38]

nit: Replace these w/ separate:

DCHECK_LE(0, tab_id_);
DCHECK_LT(0, render_widget_id_);

which will print out the actual value if they fire - your current check will
print the expression that failed, but not explain which parameter was bad.

[shaktisahu, 2016/03/22 23:45:42]

Done.

+
+  ImeMessage* ime_message;
+  scoped_ptr<BlimpMessage> blimp_message =
+      CreateBlimpMessage(&ime_message, tab_id_);
+  ime_message->set_render_widget_id(render_widget_id_);
+  ime_message->set_type(ImeMessage::SET_TEXT);
+  ime_message->set_ime_text(text);
+
+  outgoing_message_processor_->ProcessMessage(std::move(blimp_message),
+                                              net::CompletionCallback());
+}
+
+void ImeFeature::ProcessMessage(scoped_ptr<BlimpMessage> message,
+                                const net::CompletionCallback& callback) {
+  DCHECK(!callback.is_null());
+  DCHECK(message->type() == BlimpMessage::IME);
+
+  DCHECK(delegate_);
+
+  const ImeMessage& ime_message = message->ime();
+
+  switch (ime_message.type()) {

[Wez, 2016/03/22 21:43:38]

You haven't checked whether |ime_message| actually has a |type| field yet, so
you may get the default value - IIUC that will be the first value listed in the
enum, so it'll actually work, but for clarity you should either check has_type()
explicitly here, and reject the message if it's missing, or update the ime.proto
to have a [ default = ... ] tag on the field, so it's explicit that it'll be
UNKNOWN if not present.

[shaktisahu, 2016/03/22 23:45:42]

Ok. I will explicitly add a [default = UNKNOWN] tag in the ime.proto

+    case ImeMessage::SHOW_IME:
+      if (message->target_tab_id() < 0 || ime_message.render_widget_id() <= 0) {

[Wez, 2016/03/22 21:43:38]

Similarly, you haven't checked whether the sender actually provided values at
all; integer fields will default to zero so if they only failed to provide
target_tab_id then this test could still pass.

[shaktisahu, 2016/03/22 23:45:42]

Done.

+        callback.Run(net::ERR_INVALID_ARGUMENT);
+        return;
+      }
+
+      tab_id_ = message->target_tab_id();
+      render_widget_id_ = ime_message.render_widget_id();
+
+      delegate_->OnShowImeRequested(
+          InputMessageConverter::TextInputTypeFromProto(
+              ime_message.text_input_type()),
+          ime_message.ime_text());
+      break;
+    case ImeMessage::HIDE_IME:
+      tab_id_ = -1;
+      render_widget_id_ = 0;
+      delegate_->OnHideImeRequested();
+      break;
+    case ImeMessage::SET_TEXT:
+    case ImeMessage::UNKNOWN:
+      NOTREACHED();
+      callback.Run(net::ERR_UNEXPECTED);
+      return;
+  }
+
+  callback.Run(net::OK);
+}
+
+}  // namespace client
+}  // namespace blimp