mash: Move the shelf DimmerView out of shelf_widget.cc.

ash/shelf/dimmer_view.h

Index: ash/shelf/dimmer_view.h
diff --git a/ash/shelf/dimmer_view.h b/ash/shelf/dimmer_view.h
new file mode 100644
index 0000000000000000000000000000000000000000..cc3405624585c1d079c3e03084cd06e4b96078ad
--- /dev/null
+++ b/ash/shelf/dimmer_view.h
@@ -0,0 +1,104 @@
+// 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.
+

[James Cook, 2016/08/03 03:09:11]

header guards please

[msw, 2016/08/03 16:48:24]

Done.

+#include "ash/common/wm/background_animator.h"
+#include "ash/common/wm_window_observer.h"
+#include "ui/views/view.h"
+#include "ui/views/widget/widget_delegate.h"

[James Cook, 2016/08/03 03:09:11]

base/macros.h too

[msw, 2016/08/03 16:48:24]

Done.

+

[James Cook, 2016/08/03 03:09:10]

event_handler.h too

[msw, 2016/08/03 16:48:24]

Done.

+namespace ash {
+
+class WmShelf;
+
+// Class used to slightly dim shelf items when maximized and visible.

[James Cook, 2016/08/03 03:09:11]

nit: "when a window is maximized and visible"

[msw, 2016/08/03 16:48:24]

Done.

+class DimmerView : public views::View,
+                   public views::WidgetDelegate,
+                   public BackgroundAnimatorDelegate,
+                   public WmWindowObserver {
+ public:
+  // Creates and shows a DimmerView and its Widget.
+  static DimmerView* Create(WmShelf* shelf, bool disable_animations_for_test);
+
+  // If |disable_animations_for_test| is set, all changes apply instantly.
+  DimmerView(WmShelf* shelf, bool disable_animations_for_test);

[James Cook, 2016/08/03 03:09:11]

Could these be private, or are they accessed from outside?

[msw, 2016/08/03 16:48:24]

Done.

+  ~DimmerView() override;
+
+  // Called by |DimmerEventFilter| when the mouse |hovered| state changes.
+  void SetHovered(bool hovered);
+
+  // Force the dimmer to be undimmed.
+  void ForceUndimming(bool force);
+
+  // views::WidgetDelegate overrides:
+  views::Widget* GetWidget() override;
+  const views::Widget* GetWidget() const override;
+
+  // BackgroundAnimatorDelegate overrides:
+  void UpdateBackground(BackgroundAnimator* animator, int alpha) override;
+  void BackgroundAnimationEnded(BackgroundAnimator* animator) override;
+
+  // views::View overrides:

[James Cook, 2016/08/03 03:09:10]

nit: make the overridden function declaration order match the order of the
subclasses in the "class DimmerView" declaration.

[msw, 2016/08/03 16:48:24]

Done.

+  void OnPaintBackground(gfx::Canvas* canvas) override;
+
+  // WmWindowObserver overrides:
+  // This will be called when the shelf itself changes its absolute position.
+  // Since the |dimmer_| panel needs to be placed in screen coordinates it needs
+  // to be repositioned. The difference to the OnBoundsChanged call above is
+  // that this gets also triggered when the shelf only moves.
+  void OnWindowBoundsChanged(WmWindow* window,
+                             const gfx::Rect& old_bounds,
+                             const gfx::Rect& new_bounds) override;
+
+  // A function to test the current alpha used.
+  int get_dimming_alpha_for_test() { return alpha_; }
+
+ private:
+  // This class monitors mouse events to see if it is on top of the shelf.
+  class DimmerEventFilter : public ui::EventHandler {
+   public:
+    explicit DimmerEventFilter(DimmerView* owner);
+    ~DimmerEventFilter() override;
+
+    // Overridden from ui::EventHandler:
+    void OnMouseEvent(ui::MouseEvent* event) override;
+    void OnTouchEvent(ui::TouchEvent* event) override;
+
+   private:
+    // The owning class.
+    DimmerView* owner_;
+
+    // TRUE if the mouse is inside the shelf.

[James Cook, 2016/08/03 03:09:11]

nit: TRUE -> True, and below. Some previous code author apparently liked to
shout. :-)

[msw, 2016/08/03 16:48:24]

Done.

+    bool mouse_inside_;
+
+    // TRUE if a touch event is inside the shelf.
+    bool touch_inside_;
+
+    DISALLOW_COPY_AND_ASSIGN(DimmerEventFilter);
+  };
+
+  // The shelf that uses this dimmer.
+  WmShelf* shelf_;
+
+  // The alpha to use for covering the shelf.
+  int alpha_;
+
+  // True if the event filter claims that we should not be dimmed.
+  bool is_hovered_;
+
+  // True if someone forces us not to be dimmed (e.g. a menu is open).
+  bool force_hovered_;
+
+  // True if animations should be suppressed for a test.
+  bool disable_animations_for_test_;
+
+  // The animator for the background transitions.
+  BackgroundAnimator background_animator_;
+
+  // Notification of entering / exiting of the shelf area by mouse.
+  std::unique_ptr<DimmerEventFilter> event_filter_;
+
+  DISALLOW_COPY_AND_ASSIGN(DimmerView);
+};
+
+}  // namespace ash