Centered flood fill style ink drop ripples on mouse/touch points.

ui/views/animation/ink_drop_host_view.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 UI_VIEWS_ANIMATION_INK_DROP_HOST_VIEW_H_
 #define UI_VIEWS_ANIMATION_INK_DROP_HOST_VIEW_H_
 
 #include <memory>
 
 #include "third_party/skia/include/core/SkColor.h"
+#include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/views/animation/ink_drop.h"
 #include "ui/views/animation/ink_drop_host.h"
 #include "ui/views/view.h"
 
 namespace views {
 
 namespace test {
 class InkDropHostViewTestApi;
 }  // namespace test
 
 class InkDropRipple;
 class InkDropHighlight;
 
 // A view that provides InkDropHost functionality.
 class VIEWS_EXPORT InkDropHostView : public View, public InkDropHost {
  public:
+  InkDropHostView();
+  ~InkDropHostView() override;
+
   // Overridden from InkDropHost:
   void AddInkDropLayer(ui::Layer* ink_drop_layer) override;
   void RemoveInkDropLayer(ui::Layer* ink_drop_layer) override;
   std::unique_ptr<InkDropRipple> CreateInkDropRipple() const override;
   std::unique_ptr<InkDropHighlight> CreateInkDropHighlight() const override;
 
   void set_ink_drop_size(const gfx::Size& size) { ink_drop_size_ = size; }
 
  protected:
-  InkDropHostView();
-  ~InkDropHostView() override;
+  static const int kInkDropSmallCornerRadius;
 
-  static const int kInkDropSmallCornerRadius;
+  // Returns the default InkDropRipple centered on |center_point|.
+  std::unique_ptr<InkDropRipple> CreateDefaultInkDropRipple(
+      const gfx::Point& center_point) const;
+
+  // Returns the default InkDropHighlight centered on |center_point|.
+  std::unique_ptr<InkDropHighlight> CreateDefaultInkDropHighlight(
+      const gfx::Point& center_point) const;
+
+  // Returns the point of the |last_ripple_triggering_event_| if it was a
+  // LocatedEvent, otherwise the center point of the local bounds is returned.
+  gfx::Point GetInkDropCenterBasedOnLastEvent() const;
+
+  // Animates |ink_drop_| to the desired |ink_drop_state|. Caches |event| as the
+  // last_ripple_triggering_event().
+  //
+  // *** NOTE ***: |event| has been plumbed through on a best effort basis for
+  // the purposes of centering ink drop ripples on located Events.  Thus nullptr
+  // has been used by clients who do not have an Event instance available to
+  // them.
+  void AnimateInkDrop(InkDropState state, const ui::LocatedEvent* event);
 
   // View:
   void VisibilityChanged(View* starting_from, bool is_visible) override;
   void OnFocus() override;
   void OnBlur() override;
   void OnMouseEvent(ui::MouseEvent* event) override;
 
   // Overrideable methods to allow views to provide minor tweaks to the default
   // ink drop.
-  virtual gfx::Point GetInkDropCenter() const;
   virtual SkColor GetInkDropBaseColor() const;
 
   // Should return true if the ink drop is also used to depict focus.
   virtual bool ShouldShowInkDropForFocus() const;
 
   InkDrop* ink_drop() { return ink_drop_.get(); }
 
   // Toggle to enable/disable an InkDrop on this View.  Descendants can override
   // CreateInkDropHighlight() and CreateInkDropRipple() to change the look/feel
   // of the InkDrop.
   void SetHasInkDrop(bool has_an_ink_drop);
 
-  // Animates |ink_drop_| to the desired |ink_drop_state|.
-  //
-  // TODO(bruthig): Enhance to accept a ui::Event parameter so InkDrops can be
-  // centered (see https://crbug.com/597273) and disabled for touch events on
-  // Windows (see https://crbug.com/595315).
-  void AnimateInkDrop(InkDropState ink_drop_state);
-
  private:
   class InkDropGestureHandler;
+  friend class InkDropGestureHandler;
   friend class test::InkDropHostViewTestApi;
 
+  // The last user Event to trigger an ink drop ripple animation.
+  std::unique_ptr<ui::LocatedEvent> last_ripple_triggering_event_;
+
   std::unique_ptr<InkDrop> ink_drop_;
 
   // Intentionally declared after |ink_drop_| so that it doesn't access a
   // destroyed |ink_drop_| during destruction.
   std::unique_ptr<InkDropGestureHandler> gesture_handler_;
 
   gfx::Size ink_drop_size_;
 
   // Determines whether the view was already painting to layer before adding ink
   // drop layer.
   bool old_paint_to_layer_;
 
   bool destroying_;
 
   DISALLOW_COPY_AND_ASSIGN(InkDropHostView);
 };
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_INK_DROP_HOST_VIEW_H_