third_party/WebKit/Source/web/CompositorMutatorImpl.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 "web/CompositorMutatorImpl.h"

#include "core/animation/CustomCompositorAnimationManager.h"
#include "core/dom/CompositorProxy.h"
#include "platform/ThreadSafeFunctional.h"
#include "platform/TraceEvent.h"
#include "platform/WaitableEvent.h"
#include "platform/graphics/CompositorMutationsTarget.h"
#include "platform/graphics/CompositorMutatorClient.h"
#include "platform/heap/Handle.h"
#include "public/platform/Platform.h"
#include "web/CompositorProxyClientImpl.h"

namespace blink {

namespace {

void createCompositorMutatorClient(std::unique_ptr<CompositorMutatorClient>* ptr, WaitableEvent* doneEvent)
{
    CompositorMutatorImpl* mutator = CompositorMutatorImpl::create();
    ptr->reset(new CompositorMutatorClient(mutator, mutator->animationManager()));
    mutator->setClient(ptr->get());
    doneEvent->signal();
}

} // namespace

CompositorMutatorImpl::CompositorMutatorImpl()
    : m_animationManager(adoptPtr(new CustomCompositorAnimationManager))
    , m_client(nullptr)
{
}

std::unique_ptr<CompositorMutatorClient> CompositorMutatorImpl::createClient()
{
    std::unique_ptr<CompositorMutatorClient> mutatorClient;
    WaitableEvent doneEvent;
    if (WebThread* compositorThread = Platform::current()->compositorThread()) {
        compositorThread->getWebTaskRunner()->postTask(BLINK_FROM_HERE, threadSafeBind(&createCompositorMutatorClient, AllowCrossThreadAccess(&mutatorClient), AllowCrossThreadAccess(&doneEvent)));
    } else {
        createCompositorMutatorClient(&mutatorClient, &doneEvent);
    }
    // TODO(flackr): Instead of waiting for this event, we may be able to just set the
    // mutator on the CompositorProxyClient directly from the compositor thread before
    // it gets used there. We still need to make sure we only create one mutator though.
    doneEvent.wait();
    return mutatorClient;
}

CompositorMutatorImpl* CompositorMutatorImpl::create()
{
    return new CompositorMutatorImpl();
}

bool CompositorMutatorImpl::mutate(double monotonicTimeNow, CompositorMutableStateProvider* stateProvider)
{
    TRACE_EVENT0("compositor-worker", "CompositorMutatorImpl::mutate");
    bool needToReinvoke = false;
    // TODO(vollick): we should avoid executing the animation frame
    // callbacks if none of the proxies in the global scope are affected by
    // m_mutations.
    for (CompositorProxyClientImpl* client : m_proxyClients) {
        if (client->mutate(monotonicTimeNow, stateProvider))
            needToReinvoke = true;
    }

    return needToReinvoke;
}

void CompositorMutatorImpl::registerProxyClient(CompositorProxyClientImpl* client)
{
    TRACE_EVENT0("compositor-worker", "CompositorMutatorImpl::registerClient");
    m_proxyClients.add(client);
    setNeedsMutate();
}

void CompositorMutatorImpl::setNeedsMutate()
{
    TRACE_EVENT0("compositor-worker", "CompositorMutatorImpl::setNeedsMutate");
    m_client->setNeedsMutate();
}

} // namespace blink