Extract simpler classes for observing context lifecycle and observe Page lifecycle inNavigatorVibra…

Source/core/dom/LifecycleObserver.cpp

+/*
+ * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ *
+ * 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.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "config.h"
+#include "core/dom/LifecycleObserver.h"
+
+#include "core/dom/LifecycleContext.h"
+
+namespace WebCore {
+
+LifecycleObserver::LifecycleObserver(LifecycleContext* lifecycleContext, Type type)
+    : m_lifecycleContext(0)
+{
+    observeContext(lifecycleContext, type);
+}
+
+LifecycleObserver::~LifecycleObserver()
+{
+    if (m_lifecycleContext)
+        observeContext(0, GenericType);
+}
+
+void LifecycleObserver::observeContext(LifecycleContext* context, Type type)
+{
+    if (m_lifecycleContext) {
+        ASSERT(m_lifecycleContext->isContextThread());
+        m_lifecycleContext->wasUnobservedBy(this, type);
+    }
+
+    m_lifecycleContext = context;
+
+    if (m_lifecycleContext) {
+        ASSERT(m_lifecycleContext->isContextThread());
+        m_lifecycleContext->wasObservedBy(this, type);
+    }
+}
+
+void LifecycleObserver::contextDestroyed()
+{
+    m_lifecycleContext = 0;
+}
+
+} // namespace WebCore