Wake Lock API implementation (Blink part)

Source/modules/wake_lock/ScreenWakeLock.cpp

+// Copyright 2015 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/wake_lock/ScreenWakeLock.h"
+
+#include "core/frame/LocalFrame.h"
+#include "core/frame/Screen.h"
+#include "core/page/PageVisibilityState.h"
+#include "platform/RuntimeEnabledFeatures.h"
+#include "public/platform/modules/wake_lock/WebWakeLockClient.h"
+
+namespace blink {
+
+ScreenWakeLock::ScreenWakeLock(LocalFrame& frame, WebWakeLockClient* client)

[mlamouri (slow - plz ping), 2015/07/05 14:50:14]

nit: could you move around the definitions to match the ordering from the header
file?

+    : PageLifecycleObserver(frame.page())
+    , LocalFrameLifecycleObserver(&frame)
+    , m_keepAwake(false)
+    , m_client(client)
+{
+}
+
+void ScreenWakeLock::setKeepAwake(bool keepAwake)
+{
+    m_keepAwake = keepAwake;
+    updateClient();
+}
+
+// static
+bool ScreenWakeLock::keepAwake(Screen& screen)
+{
+    ScreenWakeLock* screenWakeLock = fromScreen(screen);
+

[mlamouri (slow - plz ping), 2015/07/05 14:50:14]

nit: remove empty line

+    if (!screenWakeLock)
+        return false;
+
+    return screenWakeLock->keepAwake();
+}
+
+// static
+void ScreenWakeLock::setKeepAwake(Screen& screen, bool keepAwake)
+{
+    ScreenWakeLock* screenWakeLock = fromScreen(screen);
+

[mlamouri (slow - plz ping), 2015/07/05 14:50:14]

ditto

+    if (!screenWakeLock)
+        return;
+
+    screenWakeLock->setKeepAwake(keepAwake);
+}
+
+// static
+const char* ScreenWakeLock::supplementName()
+{
+    return "ScreenWakeLock";
+}
+
+// static
+ScreenWakeLock* ScreenWakeLock::from(LocalFrame* frame)
+{
+    return static_cast<ScreenWakeLock*>(WillBeHeapSupplement<LocalFrame>::from(frame, supplementName()));
+}
+
+// static
+void ScreenWakeLock::provideTo(LocalFrame& frame, WebWakeLockClient* client)
+{
+    ASSERT(RuntimeEnabledFeatures::wakeLockEnabled());
+    WillBeHeapSupplement<LocalFrame>::provideTo(
+        frame,
+        ScreenWakeLock::supplementName(),
+        adoptPtrWillBeNoop(new ScreenWakeLock(frame, client)));
+}
+
+void ScreenWakeLock::pageVisibilityChanged()
+{
+    updateClient();
+}
+
+void ScreenWakeLock::didCommitLoad(LocalFrame* committedFrame)
+{
+    // Reset wake lock flag for this frame if it is the one being navigated
+    if (committedFrame == frame()) {
+        setKeepAwake(false);
+    }

[mlamouri (slow - plz ping), 2015/07/05 14:50:14]

Couldn't that be handled by the content layer?

[alogvinov, 2015/07/06 10:18:35]

Probably it could, but we're going to need to reset m_keepAwake here anyway, or
else it would retain the value from the previous loaded page, so some form of
notification would still be needed.

+}
+
+void ScreenWakeLock::willDetachFrameHost()
+{
+    m_client = nullptr;
+}
+
+DEFINE_TRACE(ScreenWakeLock)
+{
+    WillBeHeapSupplement<LocalFrame>::trace(visitor);
+    PageLifecycleObserver::trace(visitor);
+    LocalFrameLifecycleObserver::trace(visitor);
+}
+
+// static
+ScreenWakeLock* ScreenWakeLock::fromScreen(Screen& screen)
+{
+    return screen.frame() ? ScreenWakeLock::from(screen.frame()) : nullptr;
+}
+
+void ScreenWakeLock::updateClient()

[mlamouri (slow - plz ping), 2015/07/05 14:50:14]

nit: could you rename updateClient() to notificyClient()?

+{
+    if (m_client) {

[mlamouri (slow - plz ping), 2015/07/05 14:50:14]

if (!m_client)
    return;

+        bool visible = page() && page()->visibilityState() == PageVisibilityStateVisible;
+        m_client->requestKeepScreenAwake(m_keepAwake && visible);
+    }
+}
+
+} // namespace blink