Screen Orientation API: screen.orientation & orientationchange event

Source/modules/screen_orientation/ScreenOrientationController.cpp

+// Copyright 2014 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 "config.h"
+#include "modules/screen_orientation/ScreenOrientationController.h"
+
+#include "core/page/Page.h"
+
+namespace WebCore {
+
+PassOwnPtr<ScreenOrientationController> ScreenOrientationController::create()
+{
+    return adoptPtr(new ScreenOrientationController());
+}
+
+ScreenOrientationController::~ScreenOrientationController()
+{
+}

[abarth-chromium, 2014/02/18 01:34:27]

Please ASSERT(m_observers.isEmpty()) here.

[Inactive, 2014/02/18 20:52:47]

observers are now in the Dispatcher class, which is a singleton (similarly to
DeviceOrientation module) so this is no longer needed.

+
+void ScreenOrientationController::addObserver(ScreenOrientation* observer)
+{
+    m_observers.add(observer);
+}
+
+void ScreenOrientationController::removeObserver(ScreenOrientation* observer)
+{
+    m_observers.remove(observer);
+}
+
+const char* ScreenOrientationController::supplementName()
+{
+    return "ScreenOrientationController";
+}
+
+ScreenOrientationController::ScreenOrientationController()
+    // FIXME: This orientation is not necessary the right one until the first orientationchange
+    // event is fired.
+    : m_orientation(OrientationPortraitPrimary)
+{
+}
+
+ScreenOrientationController* ScreenOrientationController::from(Page* page)
+{
+    return static_cast<ScreenOrientationController*>(Supplement<Page>::from(page, supplementName()));
+}
+
+void ScreenOrientationController::orientationChanged(ScreenOrientationValue orientation)
+{
+    if (m_orientation == orientation)
+        return;
+
+    m_orientation = orientation;
+    for (ObserversSet::iterator it = m_observers.begin(); it != m_observers.end(); ++it)
+        (*it)->orientationChanged();

[abarth-chromium, 2014/02/18 01:34:27]

This is a weak iteration pattern.  What if m_observers changes during this
iteration?  Notice that we're executing JavaScript synchronously below this call
stack.  That means ScreenOrientationController could even be destroyed.

To fix this iteration, you'll need to create a local variable with
RefPtr<Screen>s to hold on to the screen objects and (transitively) the
ScreenOrientation objects before executing any JavaScript.  You'll also need to
be careful not to touch the |this| pointer after executing JavaScript.

[Inactive, 2014/02/18 20:52:47]

Done, used the same code as DeviceOrientation.

+}
+
+void provideScreenOrientationTo(Page* page)
+{
+    ScreenOrientationController::provideTo(page, ScreenOrientationController::supplementName(), ScreenOrientationController::create());
+}
+
+} // namespace WebCore