Add palette tool/manager.

ash/common/system/chromeos/palette/palette_tool_manager.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_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_TOOL_MANAGER_H_
+#define ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_TOOL_MANAGER_H_
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "ash/ash_export.h"
+#include "ash/common/system/chromeos/palette/palette_ids.h"
+#include "base/callback.h"
+#include "base/macros.h"
+
+namespace views {
+class View;
+}
+
+namespace ash {
+
+class PaletteTool;
+enum class PaletteGroup;
+enum class PaletteToolId;
+class WmWindow;
+
+struct ASH_EXPORT PaletteToolView {
+  PaletteGroup group;
+  PaletteToolId tool_id;
+  views::View* view;
+};
+
+class ASH_EXPORT PaletteToolManager {
+ public:
+  // Creates the tool manager. |window| allows tool implementations to fetch
+  // relevant global data. |on_tool_changed| is called whenever the active tool
+  // state is changed.
+  PaletteToolManager(WmWindow* window, const base::Closure& on_tool_changed);
+  ~PaletteToolManager();
+
+  // Adds the given |tool| to the tool manager. The tool is assumed to be in a
+  // deactivated state. This class takes ownership over |tool|.
+  void AddTool(std::unique_ptr<PaletteTool> tool);
+
+  // Activates tool_id and deactivates any other active tool in the same
+  // group as tool_id.
+  void ActivateTool(PaletteToolId tool_id);
+
+  // Deactivates the given tool.
+  void DeactivateTool(PaletteToolId tool_id);
+
+  // Optional methods that are not likely to be needed, but will be
+  // implemented if necessary.
+  bool IsToolActive(PaletteToolId tool_id);
+  PaletteToolId GetActiveTool(PaletteGroup group);
+
+  // Create views for all of the registered tools.
+  std::vector<PaletteToolView> CreateViews();
+
+  // Called when the views returned by CreateViews have been destroyed. This
+  // should clear any (now) stale references.
+  void NotifyViewsDestroyed();
+
+ private:
+  PaletteTool* FindToolById(PaletteToolId tool_id);
+
+  base::Closure on_tool_changed_;
+
+  // Unowned pointer to the active tool / group.
+  std::map<PaletteGroup, PaletteTool*> active_tools_;
+
+  // Owned list of all tools.
+  std::vector<std::unique_ptr<PaletteTool>> tools_;
+
+  // Window the tool manager is associated with.
+  WmWindow* window_;
+
+  DISALLOW_COPY_AND_ASSIGN(PaletteToolManager);
+};
+
+}  // namespace ash
+
+#endif  // ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_TOOL_MANAGER_H_