Create MouseEventManager and EventHandlingUtil

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
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 45 matching lines @@
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.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/LayoutPart.h"
 #include "core/layout/LayoutTextControlSingleLine.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoader.h"
@@ skipping 108 matching lines @@
     , m_hoverTimer(this, &EventHandler::hoverTimerFired)
     , m_cursorUpdateTimer(this, &EventHandler::cursorUpdateTimerFired)
     , m_mouseDownMayStartAutoscroll(false)
     , m_fakeMouseMoveEventTimer(this, &EventHandler::fakeMouseMoveEventTimerFired)
     , m_svgPan(false)
     , m_eventHandlerWillResetCapturingMouseEventsNode(0)
     , m_clickCount(0)
     , m_shouldOnlyFireDragOverEvent(false)
     , m_mousePositionIsUnknown(true)
     , m_mouseDownTimestamp(0)
-    , m_pointerEventManager(frame)
     , m_scrollManager(frame)
+    , m_mouseEventManager(frame)
     , m_keyboardEventManager(frame, &m_scrollManager)
+    , m_pointerEventManager(frame, &m_mouseEventManager)
     , m_gestureManager(frame, &m_scrollManager, &m_pointerEventManager, m_selectionController)
     , m_activeIntervalTimer(this, &EventHandler::activeIntervalTimerFired)
 {
 }
 
 EventHandler::~EventHandler()
 {
     ASSERT(!m_fakeMouseMoveEventTimer.isActive());
 }
 
 DEFINE_TRACE(EventHandler)
 {
     visitor->trace(m_frame);
     visitor->trace(m_mousePressNode);
     visitor->trace(m_capturingMouseEventsNode);
     visitor->trace(m_nodeUnderMouse);
     visitor->trace(m_lastMouseMoveEventSubframe);
     visitor->trace(m_lastScrollbarUnderMouse);
     visitor->trace(m_clickNode);
     visitor->trace(m_dragTarget);
     visitor->trace(m_frameSetBeingResized);
     visitor->trace(m_lastDeferredTapElement);
     visitor->trace(m_selectionController);
     visitor->trace(m_pointerEventManager);
     visitor->trace(m_scrollManager);
     visitor->trace(m_keyboardEventManager);
     visitor->trace(m_gestureManager);
+    visitor->trace(m_mouseEventManager);

[dtapuska, 2016/09/02 03:26:27]

The trace should probably happen the order of the fields listed in the class for
clarity.

[Navid Zolghadr, 2016/09/02 16:36:45]

Done.

 }
 
 DragState& EventHandler::dragState()
 {
     DEFINE_STATIC_LOCAL(DragState, state, (new DragState));
     return state;
 }
 
 void EventHandler::clear()
 {
@@ skipping 13 matching lines @@
     m_lastKnownMousePosition = IntPoint();
     m_lastKnownMouseGlobalPosition = IntPoint();
     m_lastMouseDownUserGestureToken.clear();
     m_mousePressNode = nullptr;
     m_mousePressed = false;
     m_capturesDragging = false;
     m_capturingMouseEventsNode = nullptr;
     m_pointerEventManager.clear();
     m_scrollManager.clear();
     m_gestureManager.clear();
+    m_mouseEventManager.clear();
     m_mouseDownMayStartDrag = false;
     m_lastDeferredTapElement = nullptr;
     m_eventHandlerWillResetCapturingMouseEventsNode = false;
     m_mouseDownMayStartAutoscroll = false;
     m_svgPan = false;
     m_mouseDownPos = IntPoint();
     m_mouseDownTimestamp = 0;
     m_dragStartPos = LayoutPoint();
     m_mouseDown = PlatformMouseEvent();
 }
 
-WebInputEventResult EventHandler::mergeEventResult(
-    WebInputEventResult resultA, WebInputEventResult resultB)
-{
-    // The ordering of the enumeration is specific. There are times that
-    // multiple events fire and we need to combine them into a single
-    // result code. The enumeration is based on the level of consumption that
-    // is most significant. The enumeration is ordered with smaller specified
-    // numbers first. Examples of merged results are:
-    // (HandledApplication, HandledSystem) -> HandledSystem
-    // (NotHandled, HandledApplication) -> HandledApplication
-    static_assert(static_cast<int>(WebInputEventResult::NotHandled) == 0, "WebInputEventResult not ordered");
-    static_assert(static_cast<int>(WebInputEventResult::HandledSuppressed) < static_cast<int>(WebInputEventResult::HandledApplication), "WebInputEventResult not ordered");
-    static_assert(static_cast<int>(WebInputEventResult::HandledApplication) < static_cast<int>(WebInputEventResult::HandledSystem), "WebInputEventResult not ordered");
-    return static_cast<WebInputEventResult>(max(static_cast<int>(resultA), static_cast<int>(resultB)));
-}
-
-WebInputEventResult EventHandler::toWebInputEventResult(
-    DispatchEventResult result)
-{
-    switch (result) {
-    case DispatchEventResult::NotCanceled:
-        return WebInputEventResult::NotHandled;
-    case DispatchEventResult::CanceledByEventHandler:
-        return WebInputEventResult::HandledApplication;
-    case DispatchEventResult::CanceledByDefaultEventHandler:
-        return WebInputEventResult::HandledSystem;
-    case DispatchEventResult::CanceledBeforeDispatch:
-        return WebInputEventResult::HandledSuppressed;
-    default:
-        ASSERT_NOT_REACHED();
-        return WebInputEventResult::HandledSystem;
-    }
-}
-
 void EventHandler::nodeWillBeRemoved(Node& nodeToBeRemoved)
 {
     if (nodeToBeRemoved.isShadowIncludingInclusiveAncestorOf(m_clickNode.get())) {
         // We don't dispatch click events if the mousedown node is removed
         // before a mouseup event. It is compatible with IE and Firefox.
         m_clickNode = nullptr;
     }
 }
 
 WebInputEventResult EventHandler::handleMousePressEvent(const MouseEventWithHitTestResults& event)
@@ skipping 549 matching lines @@
             return WebInputEventResult::HandledSystem;
         }
     }
 
     // m_selectionInitiationState is initialized after dispatching mousedown
     // event in order not to keep the selection by DOM APIs because we can't
     // give the user the chance to handle the selection by user action like
     // dragging if we keep the selection in case of mousedown. FireFox also has
     // the same behavior and it's more compatible with other browsers.
     selectionController().initializeSelectionState();
-    HitTestResult hitTestResult = hitTestResultInFrame(m_frame, documentPoint, HitTestRequest::ReadOnly);
+    HitTestResult hitTestResult = EventHandlingUtil::hitTestResultInFrame(m_frame, documentPoint, HitTestRequest::ReadOnly);
     InputDeviceCapabilities* sourceCapabilities = mouseEvent.getSyntheticEventType() == PlatformMouseEvent::FromTouch ? InputDeviceCapabilities::firesTouchEventsSourceCapabilities() :
         InputDeviceCapabilities::doesntFireTouchEventsSourceCapabilities();
     if (eventResult == WebInputEventResult::NotHandled)
         eventResult = handleMouseFocus(hitTestResult, sourceCapabilities);
     m_capturesDragging = eventResult == WebInputEventResult::NotHandled || mev.scrollbar();
 
     // If the hit testing originally determined the event was in a scrollbar, refetch the MouseEventWithHitTestResults
     // in case the scrollbar widget was destroyed when the mouse event was handled.
     if (mev.scrollbar()) {
         const bool wasLastScrollBar = mev.scrollbar() == m_lastScrollbarUnderMouse.get();
@@ skipping 204 matching lines @@
 ContainerNode* EventHandler::parentForClickEvent(const Node& node)
 {
     // IE doesn't dispatch click events for mousedown/mouseup events across form
     // controls.
     if (node.isHTMLElement() && toHTMLElement(node).isInteractiveContent())
         return nullptr;
 
     return FlatTreeTraversal::parent(node);
 }
 
 WebInputEventResult EventHandler::handleMouseReleaseEvent(const PlatformMouseEvent& mouseEvent)

[mustaq, 2016/08/30 21:49:23]

This the only function that /needs/ the |m_clickCount| state now, right? Can we
move the state plus some of the dispatch code to ME-manager?

[Navid Zolghadr, 2016/08/31 14:23:47]

I planned to do these in the next CL if you are okay.

 {
     TRACE_EVENT0("blink", "EventHandler::handleMouseReleaseEvent");
 
     // For 4th/5th button in the mouse since Chrome does not yet send
     // button value to Blink but in some cases it does send the event.
     // This check is needed to suppress such an event (crbug.com/574959)
     if (mouseEvent.pointerProperties().button == WebPointerProperties::Button::NoButton)
         return WebInputEventResult::HandledSuppressed;
 
     if (!mouseEvent.fromTouch())
@@ skipping 72 matching lines @@
             m_clickNode->updateDistribution();
             mev.innerNode()->updateDistribution();
             clickTargetNode = mev.innerNode()->commonAncestor(
                 *m_clickNode, parentForClickEvent);
         }
         if (clickTargetNode) {
             // Dispatch mouseup directly w/o calling updateMouseEventTargetNodeAndSendEvents
             // because the mouseup dispatch above has already updated it
             // correctly. Moreover, clickTargetNode is different from
             // mev.innerNode at drag-release.
-            clickEventResult = toWebInputEventResult(clickTargetNode->dispatchMouseEvent(mev.event(),
+            clickEventResult = EventHandlingUtil::toWebInputEventResult(
+                clickTargetNode->dispatchMouseEvent(mev.event(),
                 !RuntimeEnabledFeatures::auxclickEnabled()
                 || (mev.event().pointerProperties().button == WebPointerProperties::Button::Left)
                     ? EventTypeNames::click
                     : EventTypeNames::auxclick,
                 m_clickCount));
         }
     }
 
     m_scrollManager.clearResizeScrollableArea(false);
 
     if (eventResult == WebInputEventResult::NotHandled)
         eventResult = handleMouseReleaseEvent(mev);
     clearDragHeuristicState();
 
     invalidateClick();
 
-    return mergeEventResult(clickEventResult, eventResult);
+    return EventHandlingUtil::mergeEventResult(clickEventResult, eventResult);
 }
 
 WebInputEventResult EventHandler::dispatchDragEvent(const AtomicString& eventType, Node* dragTarget, const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
     FrameView* view = m_frame->view();
 
     // FIXME: We might want to dispatch a dragleave even if the view is gone.
     if (!view)
         return WebInputEventResult::NotHandled;
 
     DragEvent* me = DragEvent::create(eventType,
         true, true, m_frame->document()->domWindow(),
         0, event.globalPosition().x(), event.globalPosition().y(), event.position().x(), event.position().y(),
         event.movementDelta().x(), event.movementDelta().y(),
         event.getModifiers(),
         0, MouseEvent::platformModifiersToButtons(event.getModifiers()), nullptr, event.timestamp(), dataTransfer, event.getSyntheticEventType());
 
-    return toWebInputEventResult(dragTarget->dispatchEvent(me));
+    return EventHandlingUtil::toWebInputEventResult(dragTarget->dispatchEvent(me));
 }
 
 static bool targetIsFrame(Node* target, LocalFrame*& frame)
 {
     if (!isHTMLFrameElementBase(target))
         return false;
 
     // Cross-process drag and drop is not yet supported.
     if (toHTMLFrameElementBase(target)->contentFrame() && !toHTMLFrameElementBase(target)->contentFrame()->isLocalFrame())
         return false;
@@ skipping 231 matching lines @@
 
 void EventHandler::updateMouseEventTargetNodeAndSendEvents(Node* targetNode,
     const PlatformMouseEvent& mouseEvent, bool isFrameBoundaryTransition)
 {
     Node* lastNodeUnderMouse = updateMouseEventTargetNode(targetNode, mouseEvent);
     m_pointerEventManager.sendMouseAndPossiblyPointerBoundaryEvents(
         lastNodeUnderMouse, m_nodeUnderMouse, mouseEvent,
         isFrameBoundaryTransition);
 }
 
 WebInputEventResult EventHandler::dispatchMouseEvent(const AtomicString& eventType, Node* targetNode, int clickCount, const PlatformMouseEvent& mouseEvent)

[mustaq, 2016/08/30 21:49:23]

The only EventHandler state this function uses is |m_nodeUnderMouse|. Does
moving this state plus this function to ME-Manager make the code cleaner?

[Navid Zolghadr, 2016/08/31 14:23:48]

I planned to do these in the next CL if you are okay.

 {
     updateMouseEventTargetNodeAndSendEvents(targetNode, mouseEvent);
-    if (!m_nodeUnderMouse)
-        return WebInputEventResult::NotHandled;
 
-    MouseEvent* event = MouseEvent::create(eventType, m_nodeUnderMouse->document().domWindow(), mouseEvent, clickCount, nullptr);
-    return toWebInputEventResult(m_nodeUnderMouse->dispatchEvent(event));
+    return m_mouseEventManager.dispatchMouseEvent(m_nodeUnderMouse, eventType,
+        mouseEvent, nullptr, clickCount);
 }
 
 bool EventHandler::isPointerEventActive(int pointerId)
 {
     return m_pointerEventManager.isActive(pointerId);
 }
 
 void EventHandler::setPointerCapture(int pointerId, EventTarget* target)
 {
     // TODO(crbug.com/591387): This functionality should be per page not per frame.
@@ skipping 35 matching lines @@
         lastNodeUnderMouse, &newNodeUnderMouse);
     m_nodeUnderMouse = newNodeUnderMouse;
     return eventResult;
 }
 
 void EventHandler::setClickNode(Node* node)
 {
     m_clickNode = node;
 }
 
 WebInputEventResult EventHandler::handleMouseFocus(const HitTestResult& hitTestResult, InputDeviceCapabilities* sourceCapabilities)

[mustaq, 2016/08/30 21:49:23]

Can we move it to ME-Manager? This applies only if the last comment above
(moving |m_nodeUnderMouse|) works.

[Navid Zolghadr, 2016/08/31 14:23:47]

I planned to do these in the next CL if you are okay.

 {
     // If clicking on a frame scrollbar, do not mess up with content focus.
     if (hitTestResult.scrollbar() && !m_frame->contentLayoutItem().isNull()) {
         if (hitTestResult.scrollbar()->getScrollableArea() == m_frame->contentLayoutItem().getScrollableArea())
             return WebInputEventResult::NotHandled;
     }
 
     // The layout needs to be up to date to determine if an element is focusable.
     m_frame->document()->updateStyleAndLayoutIgnorePendingStylesheets();
 
@@ skipping 110 matching lines @@
         WebInputEventResult result = subframe->eventHandler().handleWheelEvent(event);
         if (result != WebInputEventResult::NotHandled)
             m_scrollManager.setFrameWasScrolledByUser();
         return result;
     }
 
     if (node) {
         WheelEvent* domEvent = WheelEvent::create(event, node->document().domWindow());
         DispatchEventResult domEventResult = node->dispatchEvent(domEvent);
         if (domEventResult != DispatchEventResult::NotCanceled)
-            return toWebInputEventResult(domEventResult);
+            return EventHandlingUtil::toWebInputEventResult(domEventResult);
     }
 
     return WebInputEventResult::NotHandled;
 }
 
 WebInputEventResult EventHandler::handleGestureEvent(const PlatformGestureEvent& gestureEvent)
 {
     // Propagation to inner frames is handled below this function.
     ASSERT(m_frame == m_frame->localFrameRoot());
 
@@ skipping 300 matching lines @@
     applyTouchAdjustment(&adjustedEvent, &hitTestResult);
 
     // Do a new hit-test at the (adjusted) gesture co-ordinates. This is necessary because
     // rect-based hit testing and touch adjustment sometimes return a different node than
     // what a point-based hit test would return for the same point.
     // FIXME: Fix touch adjustment to avoid the need for a redundant hit test. http://crbug.com/398914
     if (shouldApplyTouchAdjustment(gestureEvent)) {
         LocalFrame* hitFrame = hitTestResult.innerNodeFrame();
         if (!hitFrame)
             hitFrame = m_frame;
-        hitTestResult = hitTestResultInFrame(hitFrame, hitFrame->view()->rootFrameToContents(adjustedEvent.position()), (hitType | HitTestRequest::ReadOnly) & ~HitTestRequest::ListBased);
+        hitTestResult = EventHandlingUtil::hitTestResultInFrame(hitFrame, hitFrame->view()->rootFrameToContents(adjustedEvent.position()), (hitType | HitTestRequest::ReadOnly) & ~HitTestRequest::ListBased);
     }
 
     // If we did a rect-based hit test it must be resolved to the best single node by now to
     // ensure consumers don't accidentally use one of the other candidates.
     ASSERT(!hitTestResult.isRectBasedTest());
 
     return GestureEventWithHitTestResults(adjustedEvent, hitTestResult);
 }
 
 void EventHandler::applyTouchAdjustment(PlatformGestureEvent* gestureEvent, HitTestResult* hitTestResult)
@@ skipping 527 matching lines @@
             m_lastScrollbarUnderMouse->mouseExited();
 
         // Send mouse entered if we're setting a new scrollbar.
         if (scrollbar && setLast)
             scrollbar->mouseEntered();
 
         m_lastScrollbarUnderMouse = setLast ? scrollbar : nullptr;
     }
 }
 
-HitTestResult EventHandler::hitTestResultInFrame(LocalFrame* frame, const LayoutPoint& point, HitTestRequest::HitTestRequestType hitType)
-{
-    HitTestResult result(HitTestRequest(hitType), point);
-
-    if (!frame || frame->contentLayoutItem().isNull())
-        return result;
-    if (frame->view()) {
-        IntRect rect = frame->view()->visibleContentRect(IncludeScrollbars);
-        if (!rect.contains(roundedIntPoint(point)))
-            return result;
-    }
-    frame->contentLayoutItem().hitTest(result);
-    return result;
-}
-
 WebInputEventResult EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
 {
     TRACE_EVENT0("blink", "EventHandler::handleTouchEvent");
     return m_pointerEventManager.handleTouchEvents(event);
 }
 
 void EventHandler::setLastKnownMousePosition(const PlatformMouseEvent& event)
 {
     m_mousePositionIsUnknown = false;
     m_lastKnownMousePosition = event.position();
@@ skipping 42 matching lines @@
 
 FrameHost* EventHandler::frameHost() const
 {
     if (!m_frame->page())
         return nullptr;
 
     return &m_frame->page()->frameHost();
 }
 
 } // namespace blink