Adding phase info to wheel events migrated to wheel phase handler class.

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <Carbon/Carbon.h>
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
@@ skipping 422 matching lines @@
     display_link_->NotifyCurrentTime(base::TimeTicks::Now());
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewMac, public:
 
 RenderWidgetHostViewMac::RenderWidgetHostViewMac(RenderWidgetHost* widget,
                                                  bool is_guest_view_hack)
     : render_widget_host_(RenderWidgetHostImpl::From(widget)),
       page_at_minimum_scale_(true),
+      mouse_wheel_phase_handler_(RenderWidgetHostImpl::From(widget), this),
       is_loading_(false),
       allow_pause_for_resize_or_repaint_(true),
       is_guest_view_hack_(is_guest_view_hack),
       fullscreen_parent_host_view_(nullptr),
       needs_flush_input_(false),
       weak_factory_(this) {
   // |cocoa_view_| owns us and we will be deleted when |cocoa_view_|
   // goes away.  Since we autorelease it, our caller must put
   // |GetNativeView()| into the view hierarchy right after calling us.
   cocoa_view_ = [[[RenderWidgetHostViewCocoa alloc]
@@ skipping 1293 matching lines @@
   if (changed_metrics & DisplayObserver::DISPLAY_METRIC_DEVICE_SCALE_FACTOR) {
     RenderWidgetHostImpl* host =
         RenderWidgetHostImpl::From(GetRenderWidgetHost());
     if (host && host->delegate())
       host->delegate()->UpdateDeviceScaleFactor(display.device_scale_factor());
   }
 
   UpdateScreenInfo(cocoa_view_);
 }
 
-void RenderWidgetHostViewMac::ScheduleMouseWheelEndDispatching(
-    blink::WebMouseWheelEvent wheel_event,
-    bool should_route_event) {
-  mouse_wheel_end_dispatch_timer_.Start(
-      FROM_HERE,
-      base::TimeDelta::FromMilliseconds(
-          kDefaultMouseWheelLatchingTransactionMs),
-      base::Bind(
-          &RenderWidgetHostViewMac::SendSyntheticWheelEventWithPhaseEnded,
-          base::Unretained(this), wheel_event, should_route_event));
-}
-
-void RenderWidgetHostViewMac::DispatchPendingWheelEndEvent() {
-  if (mouse_wheel_end_dispatch_timer_.IsRunning()) {
-    base::Closure task = mouse_wheel_end_dispatch_timer_.user_task();
-    mouse_wheel_end_dispatch_timer_.Stop();
-    task.Run();
-  }
-}
-
-void RenderWidgetHostViewMac::IgnorePendingWheelEndEvent() {
-  mouse_wheel_end_dispatch_timer_.Stop();
-}
-
-bool RenderWidgetHostViewMac::HasPendingWheelEndEvent() {
-  return mouse_wheel_end_dispatch_timer_.IsRunning();
-}
-
-void RenderWidgetHostViewMac::SendSyntheticWheelEventWithPhaseEnded(
-    blink::WebMouseWheelEvent wheel_event,
-    bool should_route_event) {
-  wheel_event.dispatch_type =
-      blink::WebInputEvent::DispatchType::kEventNonBlocking;
-  if (should_route_event) {
-    render_widget_host_->delegate()
-        ->GetInputEventRouter()
-        ->RouteMouseWheelEvent(this, &wheel_event,
-                               ui::LatencyInfo(ui::SourceEventType::WHEEL));
-  } else {
-    ProcessMouseWheelEvent(wheel_event,
-                           ui::LatencyInfo(ui::SourceEventType::WHEEL));
-  }
-}
-
 }  // namespace content
 
 // RenderWidgetHostViewCocoa ---------------------------------------------------
 
 @implementation RenderWidgetHostViewCocoa
 @synthesize selectedRange = selectedRange_;
 @synthesize suppressNextEscapeKeyUp = suppressNextEscapeKeyUp_;
 @synthesize markedRange = markedRange_;
 
 - (id)initWithRenderWidgetHostViewMac:(RenderWidgetHostViewMac*)r {
@@ skipping 581 matching lines @@
       [event phase] != NSEventPhaseCancelled) {
     return;
   }
 
   if (renderWidgetHostView_->render_widget_host_) {
     // History-swiping is not possible if the logic reaches this point.
     WebMouseWheelEvent webEvent = WebMouseWheelEventBuilder::Build(
         event, self);
     webEvent.rails_mode = mouseWheelFilter_.UpdateRailsMode(webEvent);
     if (renderWidgetHostView_->wheel_scroll_latching_enabled()) {
-      renderWidgetHostView_->ScheduleMouseWheelEndDispatching(webEvent, false);
+      renderWidgetHostView_->mouse_wheel_phase_handler_
+          .AddPhaseIfNeededAndScheduleEndEvent(webEvent, false);
     } else {
       ui::LatencyInfo latency_info(ui::SourceEventType::WHEEL);
       latency_info.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
       renderWidgetHostView_->render_widget_host_
           ->ForwardWheelEventWithLatencyInfo(webEvent, latency_info);
     }
   }
 
   if (endWheelMonitor_) {
     [NSEvent removeMonitor:endWheelMonitor_];
@@ skipping 192 matching lines @@
       }];
   }
 
   // This is responsible for content scrolling!
   if (renderWidgetHostView_->render_widget_host_) {
     WebMouseWheelEvent webEvent = WebMouseWheelEventBuilder::Build(event, self);
     webEvent.rails_mode = mouseWheelFilter_.UpdateRailsMode(webEvent);
     ui::LatencyInfo latency_info(ui::SourceEventType::WHEEL);
     latency_info.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
     if (renderWidgetHostView_->wheel_scroll_latching_enabled()) {
+      renderWidgetHostView_->mouse_wheel_phase_handler_
+          .AddPhaseIfNeededAndScheduleEndEvent(
+              webEvent, renderWidgetHostView_->ShouldRouteEvent(webEvent));
       if (webEvent.phase == blink::WebMouseWheelEvent::kPhaseEnded) {
-        // Don't send the wheel end event immediately, start a timer instead to
-        // see whether momentum phase of the scrolling starts or not.
-        renderWidgetHostView_->ScheduleMouseWheelEndDispatching(
-            webEvent, renderWidgetHostView_->ShouldRouteEvent(webEvent));
+        // A wheel end event is scheduled and will get dispatched if momentum
+        // phase doesn't start in 100ms. Don't sent the wheel end event
+        // immediately.
         return;
       }
-      if (webEvent.phase == blink::WebMouseWheelEvent::kPhaseBegan) {
-        // A new scrolling sequence has started, send the pending wheel end
-        // event to end the previous scrolling sequence.
-        renderWidgetHostView_->DispatchPendingWheelEndEvent();
-
-      } else if (webEvent.momentum_phase ==
-                 blink::WebMouseWheelEvent::kPhaseBegan) {
-        // Momentum phase has started, drop the pending wheel end event to make
-        // sure that no wheel end event will be sent during the momentum phase
-        // of scrolling.
-        renderWidgetHostView_->IgnorePendingWheelEndEvent();
-      }
     }
 
     if (renderWidgetHostView_->ShouldRouteEvent(webEvent)) {
       renderWidgetHostView_->render_widget_host_->delegate()
           ->GetInputEventRouter()
           ->RouteMouseWheelEvent(renderWidgetHostView_.get(), &webEvent,
                                  latency_info);
     } else {
       renderWidgetHostView_->ProcessMouseWheelEvent(webEvent, latency_info);
     }
@@ skipping 948 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end