Initial ResizeObserver implementation

third_party/WebKit/Source/core/observer/ResizeObserver.cpp

+// Copyright 2016 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 "core/observer/ResizeObserver.h"
+
+#include "core/observer/ResizeObservation.h"
+#include "core/observer/ResizeObserverCallback.h"
+#include "core/observer/ResizeObserverController.h"
+
+namespace blink {
+
+ResizeObserver* ResizeObserver::create(Document& document, ResizeObserverCallback* callback)
+{
+    auto observer = new ResizeObserver(callback);
+    document.ensureResizeObserverController().addObserver(*observer);
+    return observer;
+}
+
+ResizeObserver::ResizeObserver(ResizeObserverCallback* callback)
+    : m_callback(callback)
+{
+}
+
+void ResizeObserver::observe(Element* target)
+{
+    auto observerMap = target ? target->resizeObserverData() : nullptr;
+    if (observerMap && observerMap->find(this) != observerMap->end())

[szager1, 2016/06/02 20:52:41]

if (observerMap && observerMap->contains(this))

[atotic1, 2016/06/08 18:59:21]

Done.

+        return; // Already registered.
+    m_observations.add(new ResizeObservation(target, this));
+}
+
+void ResizeObserver::unobserve(Element* target)
+{
+    auto observerMap = target ? target->resizeObserverData() : nullptr;
+    if (!observerMap)
+        return;
+    auto observation = observerMap->find(this);
+    if (observation != observerMap->end()) {
+        m_observations.remove(m_observations.find((*observation).value));

[szager1, 2016/06/02 20:52:41]

m_observations.remove(observation->value)

[atotic1, 2016/06/08 18:59:21]

Done.

+        observerMap->remove(observation);
+    }
+}
+
+void ResizeObserver::disconnect()
+{
+    while (!m_observations.isEmpty()) {

[szager1, 2016/06/02 20:52:41]

Vector<ResizeObservation> observations;
copyToVector(m_observations, observations);
m_observations->clear();
for (auto observation : observations) {
  Element* target = observation->target();
  if (target)  // Need this check because ResizeObservation::m_target is weak
    target->ensureResizeObserverData().remove(observation);
}

[atotic1, 2016/06/08 18:59:21]

Done.

+        auto observation = m_observations.first();
+        m_observations.remove(observation);
+        auto observerMap = observation->target()->resizeObserverData();
+        auto observationIt = observerMap->find(this);
+        observerMap->remove(observationIt);
+    }
+    m_activeObservations.clear();
+}
+
+bool ResizeObserver::gatherObservations()
+{
+    m_activeObservations.clear();

[szager1, 2016/06/02 20:52:41]

See previous comment; this should ASSERT(m_activeObservations->isEmpty())

[atotic1, 2016/06/08 18:59:22]

Done. Accomplished by calling clearObservations() from FrameView on error.

+
+    for (auto& observation : m_observations) {
+        if (observation->hasResized())
+            m_activeObservations.append(*observation);
+    }
+
+    return !m_activeObservations.isEmpty();
+}
+
+void ResizeObserver::deliverObservations()
+{
+    if (m_activeObservations.size() == 0)
+        return;
+
+    HeapVector<Member<ResizeObserverEntry>> entries;
+
+    for (auto& observation : m_activeObservations) {
+        auto entry = new ResizeObserverEntry(observation->target());
+        entries.append(entry);
+        observation->setBroadcastSize(entry->contentSize());
+    }
+    m_callback->handleEvent(entries, this);
+    m_activeObservations.clear();
+}
+
+DEFINE_TRACE(ResizeObserver)
+{
+    visitor->trace(m_callback);
+    visitor->trace(m_observations);
+    visitor->trace(m_activeObservations);
+}
+
+} // namespace blink