Adds ash::MaterialDesignController

ash/material_design/material_design_controller.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 ASH_MATERIAL_DESIGN_MATERIAL_DESIGN_CONTROLLER_H_
+#define ASH_MATERIAL_DESIGN_MATERIAL_DESIGN_CONTROLLER_H_
+
+#include "ash/ash_export.h"
+#include "base/macros.h"
+
+namespace ash {
+
+namespace test {
+class MaterialDesignControllerTestAPI;
+}  // namespace test
+
+// Central controller to handle material design modes.
+class ASH_EXPORT MaterialDesignController {
+ public:
+  // The different material design modes for Chrome OS system UI.
+  enum Mode {
+    // Not initialized.
+    UNINITIALIZED = -1,
+    // Classic, non-material design.
+    NON_MATERIAL = 0,
+    // Basic material design.
+    MATERIAL_NORMAL = 1,
+    // Material design with experimental features.
+    MATERIAL_EXPERIMENTAL = 2
+  };
+
+  // Initializes |mode_|. Must be called before calling IsMaterial().
+  static void Initialize();
+
+  // Returns true if Material Design is enabled in Chrome OS system UI.
+  // Maps to "ash-md" flag "enabled" or "experimental" values.
+  static bool IsMaterial();
+
+  // Returns true if Material Design experimental features are enabled in
+  // Chrome OS system UI.
+  // Maps to "--ash-md=experimental" command line switch value.
+  static bool IsMaterialExperimental();
+
+ private:
+  friend class test::MaterialDesignControllerTestAPI;
+
+  // Declarations only. Do not allow construction of an object.
+  MaterialDesignController();
+  ~MaterialDesignController();
+
+  // Material Design |Mode| for Chrome OS system UI. Used by tests.
+  static Mode mode();
+
+  // Returns the per-platform default material design variant.
+  static Mode DefaultMode();
+
+  // Sets |mode_| to |mode|. Can be used by tests to directly set the mode.
+  static void SetMode(Mode mode);
+
+  // Resets the initialization state to uninitialized. To be used by tests to
+  // allow calling Initialize() more than once.
+  static void Uninitialize();
+
+  DISALLOW_COPY_AND_ASSIGN(MaterialDesignController);
+};
+
+}  // namespace ash
+
+#endif  // ASH_MATERIAL_DESIGN_MATERIAL_DESIGN_CONTROLLER_H_