Add ink drop masking to TrayBackgroundView

ui/views/animation/ink_drop_mask.h

Index: ui/views/animation/ink_drop_mask.h
diff --git a/ui/views/animation/ink_drop_mask.h b/ui/views/animation/ink_drop_mask.h
new file mode 100644
index 0000000000000000000000000000000000000000..c6a16bc5dfa126d4e934fe71c7739c2ac357a08d
--- /dev/null
+++ b/ui/views/animation/ink_drop_mask.h
@@ -0,0 +1,75 @@
+// 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 UI_VIEWS_ANIMATION_INK_DROP_MASK_H_
+#define UI_VIEWS_ANIMATION_INK_DROP_MASK_H_
+
+#include "base/callback_forward.h"

[bruthig, 2016/11/11 20:16:43]

Is this needed?

[mohsen, 2016/11/13 23:31:29]

Not sure what it's doing here! Removed.

+#include "base/macros.h"
+#include "ui/compositor/layer.h"
+#include "ui/compositor/layer_delegate.h"
+#include "ui/gfx/geometry/point.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/views/views_export.h"
+
+namespace views {
+
+// Base class for different ink drop masks. It is responsible for creating the
+// ui::Layer that can be set as the mask layer for ink drop layer.
+class VIEWS_EXPORT InkDropMask : public ui::LayerDelegate {
+ public:
+  ~InkDropMask() override;
+
+  ui::Layer* layer() { return &layer_; }
+
+ protected:
+  explicit InkDropMask(const gfx::Rect& layer_bounds);
+
+ private:
+  void OnDelegatedFrameDamage(const gfx::Rect& damage_rect_in_dip) override;

[bruthig, 2016/11/11 20:16:43]

nit: Add '// ui::LayerDelegate:' or '// Overridden from ui::LayerDelegate:'

I think the later is the preferred syntax now.

[mohsen, 2016/11/13 23:31:29]

Done.

+
+  void OnDeviceScaleFactorChanged(float device_scale_factor) override;
+
+  ui::Layer layer_;
+
+  DISALLOW_COPY_AND_ASSIGN(InkDropMask);
+};
+
+// A rectangular ink drop mask with rounded corners.
+class VIEWS_EXPORT RoundRectInkDropMask : public InkDropMask {
+ public:
+  RoundRectInkDropMask(const gfx::Rect& layer_bounds,
+                       const gfx::Rect& bounds,

[bruthig, 2016/11/11 20:16:43]

nit: |mask_bounds| would be more descriptive than just |bounds|.

[mohsen, 2016/11/13 23:31:29]

Done.

+                       int corner_radius);
+
+ private:
+  // Overriden from InkDropMask:
+  void OnPaintLayer(const ui::PaintContext& context) override;
+
+  gfx::Rect bounds_;
+  int corner_radius_;
+
+  DISALLOW_COPY_AND_ASSIGN(RoundRectInkDropMask);
+};
+
+// A circular ink drop mask.
+class VIEWS_EXPORT CircleInkDropMask : public InkDropMask {
+ public:
+  CircleInkDropMask(const gfx::Rect& layer_bounds,
+                    const gfx::Point& center,

[bruthig, 2016/11/11 20:16:43]

nit: |mask_center|/|mask_radius| would be more descriptive than just
|center|/|radius|.

[mohsen, 2016/11/13 23:31:29]

Done.

+                    int radius);
+
+ private:
+  // Overriden from InkDropMask:
+  void OnPaintLayer(const ui::PaintContext& context) override;
+
+  gfx::Point center_;
+  int radius_;
+
+  DISALLOW_COPY_AND_ASSIGN(CircleInkDropMask);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_ANIMATION_INK_DROP_MASK_H_