MouseWheelEventManager is added to handle wheel events.

third_party/WebKit/Source/core/input/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 33 matching lines @@
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/SelectionController.h"
 #include "core/events/EventPath.h"
 #include "core/events/GestureEvent.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/events/MouseEvent.h"
 #include "core/events/PointerEvent.h"
 #include "core/events/TextEvent.h"
 #include "core/events/TouchEvent.h"
-#include "core/events/WheelEvent.h"
 #include "core/frame/Deprecation.h"
 #include "core/frame/EventHandlerRegistry.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/LocalFrameClient.h"
 #include "core/frame/LocalFrameView.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "core/frame/VisualViewport.h"
 #include "core/html/HTMLDialogElement.h"
 #include "core/html/HTMLFrameElementBase.h"
 #include "core/html/HTMLFrameSetElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/input/EventHandlingUtil.h"
 #include "core/input/InputDeviceCapabilities.h"
 #include "core/input/TouchActionUtil.h"
 #include "core/layout/HitTestRequest.h"
 #include "core/layout/HitTestResult.h"
-#include "core/layout/LayoutEmbeddedContent.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/resource/ImageResourceContent.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/DragState.h"
 #include "core/page/FocusController.h"
 #include "core/page/FrameTree.h"
@@ skipping 102 matching lines @@
                    this,
                    &EventHandler::HoverTimerFired),
       cursor_update_timer_(
           TaskRunnerHelper::Get(TaskType::kUnspecedTimer, &frame),
           this,
           &EventHandler::CursorUpdateTimerFired),
       event_handler_will_reset_capturing_mouse_events_node_(0),
       should_only_fire_drag_over_event_(false),
       scroll_manager_(new ScrollManager(frame)),
       mouse_event_manager_(new MouseEventManager(frame, *scroll_manager_)),
+      mouse_wheel_event_manager_(
+          new MouseWheelEventManager(frame, *scroll_manager_)),
       keyboard_event_manager_(
           new KeyboardEventManager(frame, *scroll_manager_)),
       pointer_event_manager_(
           new PointerEventManager(frame, *mouse_event_manager_)),
       gesture_manager_(new GestureManager(frame,
                                           *scroll_manager_,
                                           *mouse_event_manager_,
                                           *pointer_event_manager_,
                                           *selection_controller_)),
       active_interval_timer_(
           TaskRunnerHelper::Get(TaskType::kUserInteraction, &frame),
           this,
           &EventHandler::ActiveIntervalTimerFired) {}
 
 DEFINE_TRACE(EventHandler) {
   visitor->Trace(frame_);
   visitor->Trace(selection_controller_);
   visitor->Trace(capturing_mouse_events_node_);
   visitor->Trace(last_mouse_move_event_subframe_);
   visitor->Trace(last_scrollbar_under_mouse_);
   visitor->Trace(drag_target_);
   visitor->Trace(frame_set_being_resized_);
   visitor->Trace(scroll_manager_);
   visitor->Trace(mouse_event_manager_);
+  visitor->Trace(mouse_wheel_event_manager_);
   visitor->Trace(keyboard_event_manager_);
   visitor->Trace(pointer_event_manager_);
   visitor->Trace(gesture_manager_);
   visitor->Trace(last_deferred_tap_element_);
 }
 
 void EventHandler::Clear() {
   hover_timer_.Stop();
   cursor_update_timer_.Stop();
   active_interval_timer_.Stop();
@@ skipping 98 matching lines @@
 }
 
 IntPoint EventHandler::DragDataTransferLocationForTesting() {
   if (mouse_event_manager_->GetDragState().drag_data_transfer_)
     return mouse_event_manager_->GetDragState()
         .drag_data_transfer_->DragLocation();
 
   return IntPoint();
 }
 
-static LocalFrame* SubframeForTargetNode(Node* node) {
-  if (!node)
-    return nullptr;
-
-  LayoutObject* layout_object = node->GetLayoutObject();
-  if (!layout_object || !layout_object->IsLayoutEmbeddedContent())
-    return nullptr;
-
-  LocalFrameView* frame_view =
-      ToLayoutEmbeddedContent(layout_object)->ChildFrameView();
-  if (!frame_view)
-    return nullptr;
-
-  return &frame_view->GetFrame();
-}
-
 static LocalFrame* SubframeForHitTestResult(

[bokan, 2017/06/14 15:23:29]

Probably makes sense to move this to EventHandlingUtil as well for consistency

[sahel, 2017/06/14 15:56:34]

Done.

     const MouseEventWithHitTestResults& hit_test_result) {
   if (!hit_test_result.IsOverEmbeddedContentView())
     return nullptr;
-  return SubframeForTargetNode(hit_test_result.InnerNode());
+  return EventHandlingUtil::SubframeForTargetNode(hit_test_result.InnerNode());
 }
 
 static bool IsSubmitImage(Node* node) {
   return isHTMLInputElement(node) &&
          toHTMLInputElement(node)->type() == InputTypeNames::image;
 }
 
 bool EventHandler::UseHandCursor(Node* node, bool is_over_link) {
   if (!node)
     return false;
@@ skipping 493 matching lines @@
     if (!scrollbar)
       scrollbar = mev.GetScrollbar();
 
     UpdateLastScrollbarUnderMouse(scrollbar,
                                   !mouse_event_manager_->MousePressed());
     if (only_update_scrollbars)
       return WebInputEventResult::kHandledSuppressed;
   }
 
   WebInputEventResult event_result = WebInputEventResult::kNotHandled;
-  LocalFrame* new_subframe =
-      capturing_mouse_events_node_.Get()
-          ? SubframeForTargetNode(capturing_mouse_events_node_.Get())
-          : SubframeForHitTestResult(mev);
+  LocalFrame* new_subframe = capturing_mouse_events_node_.Get()
+                                 ? EventHandlingUtil::SubframeForTargetNode(
+                                       capturing_mouse_events_node_.Get())
+                                 : SubframeForHitTestResult(mev);
 
   // We want mouseouts to happen first, from the inside out.  First send a move
   // event to the last subframe so that it will fire mouseouts.
   if (last_mouse_move_event_subframe_ &&
       last_mouse_move_event_subframe_->Tree().IsDescendantOf(frame_) &&
       last_mouse_move_event_subframe_ != new_subframe)
     last_mouse_move_event_subframe_->GetEventHandler().HandleMouseLeaveEvent(
         mev.Event());
 
   if (new_subframe) {
@@ skipping 75 matching lines @@
   }
 
   // Mouse events simulated from touch should not hit-test again.
   DCHECK(!mouse_event.FromTouch());
 
   HitTestRequest::HitTestRequestType hit_type = HitTestRequest::kRelease;
   HitTestRequest request(hit_type);
   MouseEventWithHitTestResults mev =
       EventHandlingUtil::PerformMouseEventHitTest(frame_, request, mouse_event);
   Element* mouse_release_target = mev.InnerElement();
-  LocalFrame* subframe =
-      capturing_mouse_events_node_.Get()
-          ? SubframeForTargetNode(capturing_mouse_events_node_.Get())
-          : SubframeForHitTestResult(mev);
+  LocalFrame* subframe = capturing_mouse_events_node_.Get()
+                             ? EventHandlingUtil::SubframeForTargetNode(
+                                   capturing_mouse_events_node_.Get())
+                             : SubframeForHitTestResult(mev);
   if (event_handler_will_reset_capturing_mouse_events_node_)
     capturing_mouse_events_node_ = nullptr;
   if (subframe)
     return PassMouseReleaseEventToSubframe(mev, subframe);
 
   // Mouse events will be associated with the Document where mousedown
   // occurred. If, e.g., there is a mousedown, then a drag to a different
   // Document and mouseup there, the mouseup's gesture will be associated with
   // the mousedown's Document. It's not absolutely certain that this is the
   // correct behavior.
@@ skipping 274 matching lines @@
          mouse_event_type == EventTypeNames::mouseup);
 
   const auto& event_result = pointer_event_manager_->SendMousePointerEvent(
       UpdateMouseEventTargetNode(target_node), canvas_region_id,
       mouse_event_type, mouse_event, coalesced_events);
   return event_result;
 }
 
 WebInputEventResult EventHandler::HandleWheelEvent(
     const WebMouseWheelEvent& event) {
-#if OS(MACOSX)
-  // Filter Mac OS specific phases, usually with a zero-delta.
-  // https://crbug.com/553732
-  // TODO(chongz): EventSender sends events with
-  // |WebMouseWheelEvent::PhaseNone|,
-  // but it shouldn't.
-  const int kWheelEventPhaseNoEventMask = WebMouseWheelEvent::kPhaseEnded |
-                                          WebMouseWheelEvent::kPhaseCancelled |
-                                          WebMouseWheelEvent::kPhaseMayBegin;
-  if ((event.phase & kWheelEventPhaseNoEventMask) ||
-      (event.momentum_phase & kWheelEventPhaseNoEventMask))
-    return WebInputEventResult::kNotHandled;
-#endif
-  Document* doc = frame_->GetDocument();
-
-  if (doc->GetLayoutViewItem().IsNull())
-    return WebInputEventResult::kNotHandled;
-
-  LocalFrameView* view = frame_->View();
-  if (!view)
-    return WebInputEventResult::kNotHandled;
-
-  LayoutPoint v_point =
-      view->RootFrameToContents(FlooredIntPoint(event.PositionInRootFrame()));
-
-  HitTestRequest request(HitTestRequest::kReadOnly);
-  HitTestResult result(request, v_point);
-  doc->GetLayoutViewItem().HitTest(result);
-
-  Node* node = result.InnerNode();
-  // Wheel events should not dispatch to text nodes.
-  if (node && node->IsTextNode())
-    node = FlatTreeTraversal::Parent(*node);
-
-  // If we're over the frame scrollbar, scroll the document.
-  if (!node && result.GetScrollbar())
-    node = doc->documentElement();
-
-  LocalFrame* subframe = SubframeForTargetNode(node);
-  if (subframe) {
-    WebInputEventResult result =
-        subframe->GetEventHandler().HandleWheelEvent(event);
-    if (result != WebInputEventResult::kNotHandled)
-      scroll_manager_->SetFrameWasScrolledByUser();
-    return result;
-  }
-
-  if (node) {
-    WheelEvent* dom_event =
-        WheelEvent::Create(event, node->GetDocument().domWindow());
-    DispatchEventResult dom_event_result = node->DispatchEvent(dom_event);
-    if (dom_event_result != DispatchEventResult::kNotCanceled)
-      return EventHandlingUtil::ToWebInputEventResult(dom_event_result);
-  }
-
-  return WebInputEventResult::kNotHandled;
+  return mouse_wheel_event_manager_->HandleWheelEvent(event);
 }
 
 WebInputEventResult EventHandler::HandleGestureEvent(
     const WebGestureEvent& gesture_event) {
   // Propagation to inner frames is handled below this function.
   DCHECK_EQ(frame_, &frame_->LocalFrameRoot());
   DCHECK_NE(0, gesture_event.FrameScale());
 
   // Scrolling-related gesture events invoke EventHandler recursively for each
   // frame down the chain, doing a single-frame hit-test per frame. This matches
@@ skipping 814 matching lines @@
     MouseEventWithHitTestResults& mev,
     LocalFrame* subframe) {
   WebInputEventResult result =
       subframe->GetEventHandler().HandleMouseReleaseEvent(mev.Event());
   if (result != WebInputEventResult::kNotHandled)
     return result;
   return WebInputEventResult::kHandledSystem;
 }
 
 }  // namespace blink