Initial native keyboard proof of concept.

examples/keyboard_client/keyboard_client.cc

+// Copyright 2015 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 "base/macros.h"
+#include "mojo/public/cpp/application/application_delegate.h"
+#include "mojo/public/cpp/application/application_impl.h"
+#include "mojo/public/cpp/application/application_runner.h"
+#include "mojo/services/keyboard/public/interfaces/keyboard.mojom.h"
+
+namespace examples {
+
+class KeyboardDelegate : public mojo::ApplicationDelegate,
+                         public keyboard::KeyboardClient {
+ public:
+  KeyboardDelegate() : binding_(this) {}
+
+  ~KeyboardDelegate() override {}
+
+  // mojo::ApplicationDelegate implementation.
+  void Initialize(mojo::ApplicationImpl* app) override {
+    app->ConnectToService("mojo:keyboard_native", &keyboard_);
+    keyboard_->ShowByRequest();
+    keyboard_->Hide();
+
+    keyboard::KeyboardClientPtr keyboard_client;
+    mojo::InterfaceRequest<keyboard::KeyboardClient> request =
+        mojo::GetProxy(&keyboard_client);

[jamesr, 2015/05/11 17:50:56]

two tips (you don't have to change the code but FYI):

(1) auto is really useful for this call
(2) you don't have to say the "mojo::" part in "mojo::GetProxy" as that function
is designed to work with ADL
(http://en.wikipedia.org/wiki/Argument-dependent_name_lookup)

so you can write this

auto request = GetProxy(&keyboard_client);

+    binding_.Bind(request.Pass());
+    keyboard_->Show(keyboard_client.Pass());
+  }
+
+  // keyboard::KeyboardClient implementation.
+  void CommitCompletion(keyboard::CompletionDataPtr completion) override {}
+
+  void CommitCorrection(keyboard::CorrectionDataPtr correction) override {}
+
+  void CommitText(const mojo::String& text,
+                  int32_t new_cursor_position) override {}
+
+  void DeleteSurroundingText(int32_t before_length,
+                             int32_t after_length) override {}
+
+  void SetComposingRegion(int32_t start, int32_t end) override {}
+
+  void SetComposingText(const mojo::String& text,
+                        int32_t new_cursor_position) override {}
+
+  void SetSelection(int32_t start, int32_t end) override {}
+
+ private:
+  mojo::Binding<keyboard::KeyboardClient> binding_;
+  keyboard::KeyboardServicePtr keyboard_;
+
+  DISALLOW_COPY_AND_ASSIGN(KeyboardDelegate);
+};
+
+}  // namespace examples
+
+MojoResult MojoMain(MojoHandle application_request) {
+  mojo::ApplicationRunner runner(new examples::KeyboardDelegate);
+  return runner.Run(application_request);
+}