ResizeObserver pt3: observation computation

third_party/WebKit/Source/web/tests/ResizeObserverTest.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 "platform/testing/UnitTestHelpers.h"
+#include "web/WebViewImpl.h"
+#include "web/tests/sim/SimCompositor.h"
+#include "web/tests/sim/SimDisplayItemList.h"
+#include "web/tests/sim/SimRequest.h"
+#include "web/tests/sim/SimTest.h"
+#include "wtf/CurrentTime.h"
+
+namespace blink {
+
+namespace {
+
+class TestResizeObserverCallback : public ResizeObserverCallback {
+public:
+    TestResizeObserverCallback(Document& document)
+        : m_document(document)
+        , m_callCount(0)
+    { }
+    void handleEvent(const HeapVector<Member<ResizeObserverEntry>>& entries, ResizeObserver*) override
+    {
+        m_callCount++;
+    }
+    ExecutionContext* getExecutionContext() const { return m_document; }
+    int callCount() const { return m_callCount; }
+
+    DEFINE_INLINE_TRACE() {
+        ResizeObserverCallback::trace(visitor);
+        visitor->trace(m_document);
+    }
+
+private:
+    Member<Document> m_document;
+    int m_callCount;
+};
+
+} // namespace
+
+/* Testing:
+ * getTargetSize
+ * setTargetSize
+ * oubservationSizeOutOfSync == false
+ * modify target size
+ * oubservationSizeOutOfSync == true
+ */
+class ResizeObservationUnitTest : public SimTest { };
+
+TEST_F(ResizeObservationUnitTest, ObserveSchedulesFrame)
+{
+    SimRequest mainResource("https://example.com/", "text/html");
+    loadURL("https://example.com/");
+
+    mainResource.start();
+    mainResource.write(
+        "<div id='domTarget' style='width:100px;height:100px'>yo</div>"
+        "<svg height='200' width='200'>"
+            "<circle id='svgTarget' cx='100' cy='100' r='100'/>"
+        "</svg>"
+    );
+    mainResource.finish();
+
+    ResizeObserverCallback* callback = new TestResizeObserverCallback(document());
+    ResizeObserver* observer = ResizeObserver::create(document(), callback);
+    Element* domTarget = document().getElementById("domTarget");
+    Element* svgTarget = document().getElementById("svgTarget");
+    ResizeObservation* domObservation = new ResizeObservation(domTarget, observer);
+    ResizeObservation* svgObservation = new ResizeObservation(svgTarget, observer);
+
+    // Initial observation is out of sync
+    ASSERT_TRUE(domObservation->observationSizeOutOfSync());
+    ASSERT_TRUE(svgObservation->observationSizeOutOfSync());
+
+    // Target size is correct
+    LayoutSize size = ResizeObservation::getTargetSize(domTarget);
+    ASSERT_EQ(size.width(), 100);
+    ASSERT_EQ(size.height(), 100);
+    domObservation->setObservationSize(size);
+
+    size = ResizeObservation::getTargetSize(svgTarget);
+    ASSERT_EQ(size.width(), 200);
+    ASSERT_EQ(size.height(), 200);
+    svgObservation->setObservationSize(size);
+
+    // Target size is in sync
+    ASSERT_FALSE(domObservation->observationSizeOutOfSync());
+
+    // Target depths
+    ASSERT_EQ(svgObservation->targetDepth() - domObservation->targetDepth(), (size_t)1);
+}
+
+} // namespace blink