cros: Use runtime stylus detection for ash palette.

ash/common/system/chromeos/palette/palette_tray.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_BUTTON_TRAY_H_
 #define ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_BUTTON_TRAY_H_
 
 #include <map>
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/common/palette_delegate.h"
 #include "ash/common/session/session_state_observer.h"
 #include "ash/common/shell_observer.h"
 #include "ash/common/system/chromeos/palette/palette_tool_manager.h"
 #include "ash/common/system/tray/tray_background_view.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "ui/events/devices/input_device_event_observer.h"
 
 namespace gfx {
 class Point;
 }
 
 namespace views {
 class ImageView;
 class Widget;
 }
 
 namespace ash {
 
 class TrayBubbleWrapper;
 class PaletteToolManager;
 
 // The PaletteTray shows the palette in the bottom area of the screen. This
 // class also controls the lifetime for all of the tools available in the
 // palette.
 class ASH_EXPORT PaletteTray : public TrayBackgroundView,
                                public SessionStateObserver,
                                public ShellObserver,
                                public PaletteToolManager::Delegate,
+                               public ui::InputDeviceEventObserver,
                                public views::TrayBubbleView::Delegate {
  public:
   explicit PaletteTray(WmShelf* wm_shelf);
   ~PaletteTray() override;
 
   // ActionableView:
   bool PerformAction(const ui::Event& event) override;
 
   // SessionStateObserver:
   void SessionStateChanged(session_manager::SessionState state) override;
@@ skipping 20 matching lines @@
 
   // Opens up the palette if it is not already open. Returns true if the palette
   // was opened.
   bool ShowPalette();
 
   // Returns true if the palette tray contains the given point. This is useful
   // for determining if an event should be propagated through to the palette.
   bool ContainsPointInScreen(const gfx::Point& point);
 
  private:
+  // ui::InputDeviceObserver:
+  void OnTouchscreenDeviceConfigurationChanged() override;
+  void OnStylusStateChanged(ui::StylusState stylus_state) override;
+
   // views::TrayBubbleView::Delegate:
   void BubbleViewDestroyed() override;
   void OnMouseEnteredView() override;
   void OnMouseExitedView() override;
   base::string16 GetAccessibleNameForBubble() override;
   void OnBeforeBubbleWidgetInit(
       views::Widget* anchor_widget,
       views::Widget* bubble_widget,
       views::Widget::InitParams* params) const override;
   void HideBubble(const views::TrayBubbleView* bubble_view) override;
 
   // PaletteToolManager::Delegate:
   void OnActiveToolChanged() override;
   WmWindow* GetWindow() override;
 
   // Creates a new border for the icon. The padding is determined based on the
   // alignment of the shelf.
   void SetIconBorderForShelfAlignment();
 
   // Updates the tray icon from the palette tool manager.
   void UpdateTrayIcon();
 
   // Sets the icon to visible if the palette can be used.
   void UpdateIconVisibility();
 
-  // Called when a stylus inserted or removed event is received.
-  void OnStylusStateChanged(ui::StylusState stylus_state);
-
   // Called when the palette enabled pref has changed.
   void OnPaletteEnabledPrefChanged(bool enabled);
 
   std::unique_ptr<PaletteToolManager> palette_tool_manager_;
   std::unique_ptr<TrayBubbleWrapper> bubble_;
 
   // Manages the callback OnPaletteEnabledPrefChanged callback registered to
   // the PaletteDelegate instance.
   std::unique_ptr<PaletteDelegate::EnableListenerSubscription>
       palette_enabled_subscription_;
@@ skipping 17 matching lines @@
   int num_actions_in_bubble_ = 0;
 
   base::WeakPtrFactory<PaletteTray> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PaletteTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_BUTTON_TRAY_H_