IntersectionObserver: second cut.

third_party/WebKit/Source/core/dom/Element.cpp

Index: third_party/WebKit/Source/core/dom/Element.cpp
diff --git a/third_party/WebKit/Source/core/dom/Element.cpp b/third_party/WebKit/Source/core/dom/Element.cpp
index a215cf9cc02bbc4ea443f940b799c5c78d6b8f53..1cf2f52c23a1f7229f0e4105ea61775834080977 100644
--- a/third_party/WebKit/Source/core/dom/Element.cpp
+++ b/third_party/WebKit/Source/core/dom/Element.cpp
@@ -60,6 +60,8 @@
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/FirstLetterPseudoElement.h"
 #include "core/dom/Fullscreen.h"
+#include "core/dom/IntersectionObserver.h"
+#include "core/dom/IntersectionObserverRegistry.h"
 #include "core/dom/LayoutTreeBuilder.h"
 #include "core/dom/MutationObserverInterestGroup.h"
 #include "core/dom/MutationRecord.h"
@@ -106,6 +108,8 @@
 #include "core/html/HTMLTemplateElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/inspector/InspectorInstrumentation.h"
+#include "core/layout/LayoutInline.h"
+#include "core/layout/LayoutPart.h"
 #include "core/layout/LayoutTextFragment.h"
 #include "core/layout/LayoutView.h"
 #include "core/loader/DocumentLoader.h"
@@ -1468,8 +1472,21 @@ Node::InsertionNotificationRequest Element::insertedInto(ContainerNode* insertio
     if (!insertionPoint->isInTreeScope())
         return InsertionDone;
 
-    if (hasRareData())
-        elementRareData()->clearClassListValueForQuirksMode();
+    if (hasRareData()) {
+        ElementRareData* rareData = elementRareData();
+        rareData->clearClassListValueForQuirksMode();
+        if (rareData->hasIntersectionObserver()) {

[esprehn, 2015/12/12 00:14:13]

this code should be moved into a separate object for managing observers like
ElementIntersectionObserverData

this should be

if (ElementIntersectionObserverData* observerData =
rareData->intersectionObserverData())
  observerData->updateActive()

or something like that, these loops and such don't belong here.

[szager1, 2015/12/16 19:15:34]

I moved all the logic into ElementRareData and the new class
ElementIntersectionObserverData.

+            IntersectionObserverRegistry* registry = document().intersectionObserverRegistry();
+            for (auto& observer: rareData->intersectionObservers()) {
+                registry->addTrackedObserver(*observer);
+                observer->setActive(true);
+            }
+        }
+        if (rareData->hasIntersectionObservation()) {
+            for (auto& observation: rareData->intersectionObservations())

[esprehn, 2015/12/12 00:14:13]

space before :

this should also be moved into the controller object you hang off the rare data

[szager1, 2015/12/16 19:15:34]

same comment

+                observation->setActive(observation->observer()->isDescendantOfRoot(this));
+        }
+    }
 
     if (isUpgradedCustomElement() && inDocument())
         CustomElement::didAttach(this, document());
@@ -1547,6 +1564,12 @@ void Element::removedFrom(ContainerNode* insertionPoint, Node* next)
 
         if (ElementAnimations* elementAnimations = data->elementAnimations())
             elementAnimations->cssAnimations().cancel();
+
+        if (data->hasIntersectionObserver()) {

[esprehn, 2015/12/12 00:14:13]

if (ElementIntersectionObserverSet* observerSet =
data->intersectionObserverSet())
  observerSet->deactivate();

you can pass |this| to the methods if you don't want to store it.

[szager1, 2015/12/16 19:15:34]

I moved all the logic into ElementRareData and ElementIntersectionObserverData.

+            document().intersectionObserverRegistry()->removeTrackedObserversForRoot(this);
+            data->deactivateAllIntersectionObservers();
+        }
+        data->deactivateAllIntersectionObservations();

[esprehn, 2015/12/12 00:14:13]

this should be inside that same deactivate method, only 2 lines of code in
Element.cpp

[szager1, 2015/12/16 19:15:34]

same comment

     }
 }
 
@@ -3578,6 +3601,27 @@ bool Element::supportsStyleSharing() const
     return true;
 }
 
+WeakPtrWillBeRawPtr<Element> Element::createWeakPtr()
+{
+#if ENABLE(OILPAN)
+    return this;
+#else
+    return ensureElementRareData().createWeakPtr(this);

[esprehn, 2015/12/12 00:14:13]

Remove this, we shouldn't have a createWeakPtr method on Element, you can put it
inside your IntersectionObserverController if needed.

[szager1, 2015/12/16 19:15:34]

Done.

+#endif
+}
+
+void Element::addIntersectionObservation(IntersectionObservation& observation)
+{
+    ensureElementRareData().intersectionObservations().add(&observation);
+}
+
+void Element::removeIntersectionObservation(IntersectionObservation& observation)
+{
+    if (!hasRareData() || !elementRareData()->hasIntersectionObservation())

[esprehn, 2015/12/12 00:14:13]

how do we get here without having observations? normally this is an assert as it
should never happen.

[szager1, 2015/12/16 19:15:34]

Good point, fixed.

+        return;
+    elementRareData()->intersectionObservations().remove(&observation);
+}
+
 void Element::logAddElementIfIsolatedWorldAndInDocument(const char element[], const QualifiedName& attr1)
 {
     if (!inDocument())