third_party/WebKit/Source/modules/vr/NavigatorVR.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 "modules/vr/NavigatorVR.h"

#include "bindings/core/v8/ScriptPromiseResolver.h"
#include "core/dom/DOMException.h"
#include "core/dom/Document.h"
#include "core/dom/ExceptionCode.h"
#include "core/frame/FrameOwner.h"
#include "core/frame/LocalDOMWindow.h"
#include "core/frame/LocalFrame.h"
#include "core/frame/Navigator.h"
#include "core/page/Page.h"
#include "modules/vr/VRController.h"
#include "modules/vr/VRDisplay.h"
#include "modules/vr/VRGetDevicesCallback.h"
#include "modules/vr/VRPose.h"
#include "wtf/PtrUtil.h"

namespace blink {

namespace {

// https://html.spec.whatwg.org/multipage/embedded-content.html#allowed-to-use
bool allowedToUseVR(const Frame* frame)
{
    // To determine whether a Document object |document| is allowed to use the
    // feature indicated by attribute name |allowattribute|, run these steps:

    // 1. If |document| has no browsing context, then return false.
    if (!frame)
        return false;

    // 2. If |document|'s browsing context has no browsing context container, then
    // return true.
    if (frame->isMainFrame())
        return true;

    // 3. If |document|'s browsing context has a browsing context container that
    // is an iframe element with an |allowattribute| attribute specified, and
    // whose node document is allowed to use the feature indicated by
    // |allowattribute|, then return true.
    if (frame->owner() && frame->owner()->allowVR())
        return allowedToUseVR(frame->tree().parent());

    // 4. Return false.
    return false;
}

} // namespace

NavigatorVR* NavigatorVR::from(Document& document)
{
    if (!document.frame() || !document.frame()->domWindow())
        return 0;
    Navigator& navigator = *document.frame()->domWindow()->navigator();
    return &from(navigator);
}

NavigatorVR& NavigatorVR::from(Navigator& navigator)
{
    NavigatorVR* supplement = static_cast<NavigatorVR*>(Supplement<Navigator>::from(navigator, supplementName()));
    if (!supplement) {
        supplement = new NavigatorVR(navigator.frame());
        provideTo(navigator, supplementName(), supplement);
    }
    return *supplement;
}

ScriptPromise NavigatorVR::getVRDisplays(ScriptState* scriptState, Navigator& navigator)
{
    return NavigatorVR::from(navigator).getVRDisplays(scriptState);
}

ScriptPromise NavigatorVR::getVRDisplays(ScriptState* scriptState)
{
    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
    ScriptPromise promise = resolver->promise();

    if (!allowedToUseVR(m_frame)) {
        DOMException* exception = DOMException::create(NotAllowedError, "Access to VR devices is not allowed in this context.");
        resolver->reject(exception);
        return promise;
    }

    Document* document = m_frame ? m_frame->document() : 0;

    if (!document || !controller()) {
        DOMException* exception = DOMException::create(InvalidStateError, "The object is no longer associated to a document.");
        resolver->reject(exception);
        return promise;
    }

    controller()->getDisplays(resolver);

    return promise;
}

bool NavigatorVR::vrEnabled(Navigator& navigator)
{
    return NavigatorVR::from(navigator).vrEnabled();
}

bool NavigatorVR::vrEnabled()
{
    return allowedToUseVR(m_frame);
}

VRController* NavigatorVR::controller()
{
    if (!frame())
        return 0;

    if (!m_controller) {
        m_controller = new VRController(this);
    }

    return m_controller;
}

Document* NavigatorVR::document()
{
    return m_frame ? m_frame->document() : 0;
}

DEFINE_TRACE(NavigatorVR)
{
    visitor->trace(m_controller);

    Supplement<Navigator>::trace(visitor);
    DOMWindowProperty::trace(visitor);
}

NavigatorVR::NavigatorVR(LocalFrame* frame)
    : DOMWindowProperty(frame)
{
}

NavigatorVR::~NavigatorVR()
{
}

const char* NavigatorVR::supplementName()
{
    return "NavigatorVR";
}

void NavigatorVR::fireVRDisplayPresentChange(VRDisplay* display)
{
    enqueueEvent(VRDisplayEvent::create(EventTypeNames::vrdisplaypresentchange, true, false, display, ""));
}

void NavigatorVR::enqueueEvent(VRDisplayEvent* event) {
    if (m_frame && m_frame->localDOMWindow()) {
        m_frame->localDOMWindow()->enqueueWindowEvent(event);
    }
}

} // namespace blink