cros: Simple password view for lock. Adds test support.

ash/login/ui/login_password_view.h

+// Copyright 2017 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 ASH_LOGIN_UI_LOGIN_PASSWORD_VIEW_H_
+#define ASH_LOGIN_UI_LOGIN_PASSWORD_VIEW_H_
+
+#include "ash/ash_export.h"
+#include "base/strings/string16.h"
+#include "ui/views/controls/button/button.h"
+#include "ui/views/view.h"
+
+namespace views {
+class ButtonListener;
+class Textfield;
+}  // namespace views
+
+namespace ash {
+
+// Contains a textfield instance with a submit button. The user can type a
+// password into the textfield and hit enter to submit.
+//
+// The password view looks like this:
+//
+//   * * * * * *   =>
+//  ------------------
+class ASH_EXPORT LoginPasswordView : public views::View,
+                                     public views::ButtonListener {
+ public:
+  // TestApi is used for tests to get internal implementation details.
+  class ASH_EXPORT TestApi {
+   public:
+    explicit TestApi(LoginPasswordView* view);
+    ~TestApi();
+
+    views::View* textfield() const;
+    views::View* submit_button() const;
+
+   private:
+    LoginPasswordView* view_;
+  };
+
+  using OnPasswordSubmit =
+      base::RepeatingCallback<void(const base::string16& password)>;
+
+  // |on_submit| is called when the user hits enter or pressed the submit arrow.
+  // Must not be null.
+  explicit LoginPasswordView(const OnPasswordSubmit& on_submit);
+  ~LoginPasswordView() override;
+
+  // views::View:
+  const char* GetClassName() const override;
+  gfx::Size CalculatePreferredSize() const override;
+  bool OnKeyPressed(const ui::KeyEvent& event) override;
+
+  // views::ButtonListener:
+  void ButtonPressed(views::Button* sender, const ui::Event& event) override;
+
+ private:
+  friend class TestApi;
+
+  // Submits the current password field text to mojo call and resets the text
+  // field.
+  void SubmitPassword();
+
+  OnPasswordSubmit on_submit_;
+  views::Textfield* textfield_;
+  views::View* submit_button_;
+
+  DISALLOW_COPY_AND_ASSIGN(LoginPasswordView);
+};
+
+}  // namespace ash
+
+#endif  // ASH_LOGIN_UI_LOGIN_PASSWORD_VIEW_H_