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

ui/views/animation/ink_drop_host_view.cc

 // 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.
 
 #include "ui/views/animation/ink_drop_host_view.h"
 
 #include "ui/events/event.h"
 #include "ui/events/scoped_target_handler.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/gfx/geometry/size_conversions.h"
@@ skipping 23 matching lines @@
 // static
 const int InkDropHostView::kInkDropSmallCornerRadius = 2;
 
 // An EventHandler that is guaranteed to be invoked and is not prone to
 // InkDropHostView descendents who do not call
 // InkDropHostView::OnGestureEvent().
 //
 // TODO(bruthig): Consider getting rid of this class.
 class InkDropHostView::InkDropGestureHandler : public ui::EventHandler {
  public:
-  InkDropGestureHandler(View* view, InkDrop* ink_drop)
-      : ink_drop_(ink_drop), target_handler_(view, this) {}
+  InkDropGestureHandler(InkDropHostView* host_view, InkDrop* ink_drop)
+      : target_handler_(new ui::ScopedTargetHandler(host_view, this)),
+        host_view_(host_view),
+        ink_drop_(ink_drop) {}
 
   ~InkDropGestureHandler() override {}
 
   // ui::EventHandler:
   void OnGestureEvent(ui::GestureEvent* event) override {
     InkDropState current_ink_drop_state = ink_drop_->GetTargetInkDropState();
 
     InkDropState ink_drop_state = InkDropState::HIDDEN;
     switch (event->type()) {
       case ui::ET_GESTURE_TAP_DOWN:
@@ skipping 22 matching lines @@
 
     if (ink_drop_state == InkDropState::HIDDEN &&
         (current_ink_drop_state == InkDropState::ACTION_TRIGGERED ||
          current_ink_drop_state == InkDropState::ALTERNATE_ACTION_TRIGGERED ||
          current_ink_drop_state == InkDropState::DEACTIVATED)) {
       // These InkDropStates automatically transition to the HIDDEN state so we
       // don't make an explicit call. Explicitly animating to HIDDEN in this
       // case would prematurely pre-empt these animations.
       return;
     }
-    ink_drop_->AnimateToState(ink_drop_state);
+    host_view_->AnimateInkDrop(ink_drop_state, event);
   }
 
  private:
+  // Allows |this| to handle all GestureEvents on |host_view_|.
+  std::unique_ptr<ui::ScopedTargetHandler> target_handler_;
+
+  // The host view to cache ui::Events to when animating the ink drop.
+  InkDropHostView* host_view_;
+
   // Animation controller for the ink drop ripple effect.
   InkDrop* ink_drop_;
 
-  // An instance of ScopedTargetHandler allowing |this| to handle events.
-  ui::ScopedTargetHandler target_handler_;
-
   DISALLOW_COPY_AND_ASSIGN(InkDropGestureHandler);
 };
 
 InkDropHostView::InkDropHostView()
     : ink_drop_(new InkDropStub()),
       ink_drop_size_(kInkDropSize, kInkDropSize),
       destroying_(false) {}
 
 InkDropHostView::~InkDropHostView() {
   // TODO(bruthig): Improve InkDropImpl to be safer about calling back to
@@ skipping 12 matching lines @@
   // No need to do anything when called during shutdown, and if a derived
   // class has overridden Add/RemoveInkDropLayer, running this implementation
   // would be wrong.
   if (destroying_)
     return;
   layer()->Remove(ink_drop_layer);
   SetPaintToLayer(false);
 }
 
 std::unique_ptr<InkDropRipple> InkDropHostView::CreateInkDropRipple() const {
+  return CreateDefaultInkDropRipple(GetLocalBounds().CenterPoint());
+}
+
+std::unique_ptr<InkDropHighlight> InkDropHostView::CreateInkDropHighlight()
+    const {
+  return CreateDefaultInkDropHighlight(GetLocalBounds().CenterPoint());
+}
+
+// static
+const ui::LocatedEvent* InkDropHostView::AsLocatedEvent(

[Evan Stade, 2016/06/15 20:34:42]

I'm not a big fan of putting this here. It's not particularly relevant to
InkDropHostView. I'd add it to Event ("MaybeAsLocatedEvent"/"ToLocatedEvent" or
something.). If the owners of Event don't think it's worth having such a
function, then you'll just have to insert the ternary everywhere.

[bruthig, 2016/06/15 21:43:19]

Moved to event_utils(h|cc) as ToLocatedEventOrNull(...).

+    const ui::Event* event) {
+  return event && event->IsLocatedEvent() ? event->AsLocatedEvent() : nullptr;
+}
+
+std::unique_ptr<InkDropRipple> InkDropHostView::CreateDefaultInkDropRipple(
+    const gfx::Point& center_point) const {
   std::unique_ptr<InkDropRipple> ripple(new SquareInkDropRipple(
       CalculateLargeInkDropSize(ink_drop_size_), kInkDropLargeCornerRadius,
-      ink_drop_size_, kInkDropSmallCornerRadius, GetInkDropCenter(),
+      ink_drop_size_, kInkDropSmallCornerRadius, center_point,
       GetInkDropBaseColor()));
   return ripple;
 }
 
-std::unique_ptr<InkDropHighlight> InkDropHostView::CreateInkDropHighlight()
-    const {
+std::unique_ptr<InkDropHighlight>
+InkDropHostView::CreateDefaultInkDropHighlight(
+    const gfx::Point& center_point) const {
   std::unique_ptr<InkDropHighlight> highlight(
       new InkDropHighlight(ink_drop_size_, kInkDropSmallCornerRadius,
-                           GetInkDropCenter(), GetInkDropBaseColor()));
+                           center_point, GetInkDropBaseColor()));
   highlight->set_explode_size(CalculateLargeInkDropSize(ink_drop_size_));
   return highlight;
 }
 
+gfx::Point InkDropHostView::GetInkDropCenterBasedOnLastEvent() const {
+  return last_ripple_triggering_event_
+             ? last_ripple_triggering_event_->location()
+             : GetLocalBounds().CenterPoint();
+}
+
+void InkDropHostView::AnimateInkDrop(InkDropState state,
+                                     const ui::LocatedEvent* event) {
+  last_ripple_triggering_event_.reset(
+      event ? ui::Event::Clone(*event).release()->AsLocatedEvent() : nullptr);
+  ink_drop_->AnimateToState(state);
+}
+
 void InkDropHostView::VisibilityChanged(View* starting_from, bool is_visible) {
   View::VisibilityChanged(starting_from, is_visible);
   if (GetWidget() && !is_visible) {
     ink_drop()->AnimateToState(InkDropState::HIDDEN);
     ink_drop()->SetHovered(false);
   }
 }
 
 void InkDropHostView::OnFocus() {
   views::View::OnFocus();
@@ skipping 14 matching lines @@
       break;
     case ui::ET_MOUSE_EXITED:
       ink_drop_->SetHovered(false);
       break;
     default:
       break;
   }
   View::OnMouseEvent(event);
 }
 
-gfx::Point InkDropHostView::GetInkDropCenter() const {
-  return GetLocalBounds().CenterPoint();
-}
-
 SkColor InkDropHostView::GetInkDropBaseColor() const {
   NOTREACHED();
   return gfx::kPlaceholderColor;
 }
 
 bool InkDropHostView::ShouldShowInkDropForFocus() const {
   return false;
 }
 
 void InkDropHostView::SetHasInkDrop(bool has_an_ink_drop) {
   if (has_an_ink_drop) {
     ink_drop_ = InkDropFactory::CreateInkDrop(this);
     gesture_handler_.reset(new InkDropGestureHandler(this, ink_drop_.get()));
   } else {
     gesture_handler_.reset();
     ink_drop_.reset(new InkDropStub());
   }
 }
 
-void InkDropHostView::AnimateInkDrop(InkDropState ink_drop_state) {
-  ink_drop_->AnimateToState(ink_drop_state);
-}
-
 }  // namespace views