Add EventHandlerRegistry

Source/core/page/scrolling/ScrollingCoordinator.cpp

Index: Source/core/page/scrolling/ScrollingCoordinator.cpp
diff --git a/Source/core/page/scrolling/ScrollingCoordinator.cpp b/Source/core/page/scrolling/ScrollingCoordinator.cpp
index ba8cca0f7d5d8ef99e1b655de4918b0e15d4b823..c0d62476d0326a074a679ddecb9856d8b3cf91f9 100644
--- a/Source/core/page/scrolling/ScrollingCoordinator.cpp
+++ b/Source/core/page/scrolling/ScrollingCoordinator.cpp
@@ -29,13 +29,14 @@
 
 #include "RuntimeEnabledFeatures.h"
 #include "core/dom/Document.h"
+#include "core/dom/EventHandlerRegistry.h"
 #include "core/dom/FullscreenElementStack.h"
 #include "core/dom/Node.h"
-#include "core/dom/WheelController.h"
-#include "core/html/HTMLElement.h"
+#include "core/frame/DOMWindow.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
+#include "core/html/HTMLElement.h"
 #include "core/page/Page.h"
 #include "core/plugins/PluginView.h"
 #include "core/rendering/RenderGeometryMap.h"
@@ -630,15 +631,22 @@ void ScrollingCoordinator::willDestroyRenderLayer(RenderLayer* layer)
     m_layersWithTouchRects.remove(layer);
 }
 
-void ScrollingCoordinator::setWheelEventHandlerCount(unsigned count)
+void ScrollingCoordinator::updateHaveWheelEventHandlers()
 {
-    if (WebLayer* scrollLayer = toWebLayer(m_page->mainFrame()->view()->layerForScrolling()))
-        scrollLayer->setHaveWheelEventHandlers(count > 0);
+    if (WebLayer* scrollLayer = toWebLayer(m_page->mainFrame()->view()->layerForScrolling())) {
+        LocalFrame* frame = m_page->mainFrame();
+        bool haveHandlers = EventHandlerRegistry::from(*frame->document())->hasEventHandlers(EventHandlerRegistry::WheelEvent);
+        scrollLayer->setHaveWheelEventHandlers(haveHandlers);
+    }
 }
 
-void ScrollingCoordinator::recomputeWheelEventHandlerCountForFrameView(FrameView*)
+void ScrollingCoordinator::updateHaveScrollEventHandlers()
 {
-    setWheelEventHandlerCount(computeCurrentWheelEventHandlerCount());
+    if (WebLayer* scrollLayer = toWebLayer(m_page->mainFrame()->view()->layerForScrolling())) {

[Ian Vollick, 2014/04/08 15:40:51]

It took a fair bit of reading in cc to figure out why it would still be correct
to only apply the event handlers setting to the main scrolling layer when this
needs to affect all scrolling on the page. Perhaps add a comment here with a
brief explanation?

[Sami, 2014/04/08 16:25:00]

Yes, that could use a clarification. Added a comment.

+        LocalFrame* frame = m_page->mainFrame();
+        bool haveHandlers = EventHandlerRegistry::from(*frame->document())->hasEventHandlers(EventHandlerRegistry::ScrollEvent);
+        scrollLayer->setHaveScrollEventHandlers(haveHandlers);
+    }
 }
 
 void ScrollingCoordinator::setShouldUpdateScrollLayerPositionOnMainThread(MainThreadScrollingReasons reasons)
@@ -725,21 +733,21 @@ Region ScrollingCoordinator::computeShouldHandleScrollGestureOnMainThreadRegion(
     return shouldHandleScrollGestureOnMainThreadRegion;
 }
 
-static void accumulateDocumentTouchEventTargetRects(LayerHitTestRects& rects, const Document* document)
+static void accumulateDocumentTouchEventTargetRects(LayerHitTestRects& rects, Document* document)
 {
     ASSERT(document);
-    if (!document->touchEventTargets())
+    const EventTargetSet* targets = EventHandlerRegistry::from(*document)->eventHandlerTargets(EventHandlerRegistry::TouchEvent);
+    if (!targets)
         return;
 
-    const TouchEventTargetSet* targets = document->touchEventTargets();
-
-    // If there's a handler on the document, html or body element (fairly common in practice),
+    // If there's a handler on the window, document, html or body element (fairly common in practice),
     // then we can quickly mark the entire document and skip looking at any other handlers.
     // Note that technically a handler on the body doesn't cover the whole document, but it's
     // reasonable to be conservative and report the whole document anyway.
-    for (TouchEventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter) {
-        Node* target = iter->key;
-        if (target == document || target == document->documentElement() || target == document->body()) {
+    for (EventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter) {
+        EventTarget* target = iter->key;
+        Node* node = target->toNode();
+        if (target->toDOMWindow() || node == document || node == document->documentElement() || node == document->body()) {
             if (RenderObject* renderer = document->renderer()) {
                 renderer->computeLayerHitTestRects(rects);
             }
@@ -747,19 +755,20 @@ static void accumulateDocumentTouchEventTargetRects(LayerHitTestRects& rects, co
         }
     }
 
-    for (TouchEventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter) {
-        const Node* target = iter->key;
-        if (!target->inDocument())
+    for (EventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter) {
+        EventTarget* target = iter->key;
+        Node* node = target->toNode();
+        if (!node->inDocument())
             continue;
 
-        if (target->isDocumentNode()) {
-            ASSERT(target != document);
-            accumulateDocumentTouchEventTargetRects(rects, toDocument(target));
-        } else if (RenderObject* renderer = target->renderer()) {
+        if (node->isDocumentNode()) {
+            ASSERT(node != document);
+            accumulateDocumentTouchEventTargetRects(rects, toDocument(node));
+        } else if (RenderObject* renderer = node->renderer()) {
             // If the set also contains one of our ancestor nodes then processing
             // this node would be redundant.
             bool hasTouchEventTargetAncestor = false;
-            for (Node* ancestor = target->parentNode(); ancestor && !hasTouchEventTargetAncestor; ancestor = ancestor->parentNode()) {
+            for (Node* ancestor = node->parentNode(); ancestor && !hasTouchEventTargetAncestor; ancestor = ancestor->parentNode()) {
                 if (targets->contains(ancestor))
                     hasTouchEventTargetAncestor = true;
             }
@@ -798,24 +807,20 @@ void ScrollingCoordinator::computeTouchEventTargetRects(LayerHitTestRects& rects
     accumulateDocumentTouchEventTargetRects(rects, document);
 }
 
-unsigned ScrollingCoordinator::computeCurrentWheelEventHandlerCount()
+void ScrollingCoordinator::haveWheelEventHandlersChangedForPage()
 {
-    unsigned wheelEventHandlerCount = 0;
-
-    for (LocalFrame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
-        if (frame->document())
-            wheelEventHandlerCount += WheelController::from(*frame->document())->wheelEventHandlerCount();
-    }
+    ASSERT(isMainThread());
+    ASSERT(m_page);
 
-    return wheelEventHandlerCount;
+    updateHaveWheelEventHandlers();
 }
 
-void ScrollingCoordinator::frameViewWheelEventHandlerCountChanged(FrameView* frameView)
+void ScrollingCoordinator::haveScrollEventHandlersChangedForPage()
 {
     ASSERT(isMainThread());
     ASSERT(m_page);
 
-    recomputeWheelEventHandlerCountForFrameView(frameView);
+    updateHaveScrollEventHandlers();
 }
 
 void ScrollingCoordinator::frameViewHasSlowRepaintObjectsDidChange(FrameView* frameView)
@@ -867,7 +872,8 @@ void ScrollingCoordinator::frameViewRootLayerDidChange(FrameView* frameView)
         return;
 
     notifyLayoutUpdated();
-    recomputeWheelEventHandlerCountForFrameView(frameView);
+    updateHaveWheelEventHandlers();
+    updateHaveScrollEventHandlers();
 }
 
 #if OS(MACOSX)