Source/WebCore/css/FontFaceSet.cpp

/*
 * Copyright (C) 2016-2022 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 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 INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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#include "config.h"
#include "FontFaceSet.h"

#include "ContextDestructionObserverInlines.h"
#include "DOMPromiseProxy.h"
#include "DocumentQuirks.h"
#include "DocumentView.h"
#include "EventLoop.h"
#include "EventNames.h"
#include "FontFace.h"
#include "FrameDestructionObserverInlines.h"
#include "FrameLoader.h"
#include "JSDOMBinding.h"
#include "JSDOMPromiseDeferred.h"
#include "JSFontFace.h"
#include "JSFontFaceSet.h"
#include "ScriptExecutionContext.h"
#include <wtf/TZoneMallocInlines.h>

namespace WebCore {

WTF_MAKE_TZONE_ALLOCATED_IMPL(FontFaceSet);

Ref<FontFaceSet> FontFaceSet::create(ScriptExecutionContext& context, const Vector<Ref<FontFace>>& initialFaces)
{
    Ref<FontFaceSet> result = adoptRef(*new FontFaceSet(context, initialFaces));
    result->suspendIfNeeded();
    return result;
}

Ref<FontFaceSet> FontFaceSet::create(ScriptExecutionContext& context, CSSFontFaceSet& backing)
{
    Ref<FontFaceSet> result = adoptRef(*new FontFaceSet(context, backing));
    result->suspendIfNeeded();
    return result;
}

FontFaceSet::FontFaceSet(ScriptExecutionContext& context, const Vector<Ref<FontFace>>& initialFaces)
    : ActiveDOMObject(&context)
    , m_backing(CSSFontFaceSet::create())
    , m_readyPromise(makeUniqueRef<ReadyPromise>(*this, &FontFaceSet::readyPromiseResolve))
{
    m_backing->addFontEventClient(*this);
    for (auto& face : initialFaces)
        add(face);
}

FontFaceSet::FontFaceSet(ScriptExecutionContext& context, CSSFontFaceSet& backing)
    : ActiveDOMObject(&context)
    , m_backing(backing)
    , m_readyPromise(makeUniqueRef<ReadyPromise>(*this, &FontFaceSet::readyPromiseResolve))
{
    if (auto* document = dynamicDowncast<Document>(context)) {
        if (document->frame())
            m_isDocumentLoaded = document->loadEventFinished() && !document->processingLoadEvent();
    }

    if (m_isDocumentLoaded && !backing.hasActiveFontFaces())
        m_readyPromise->resolve(*this);

    m_backing->addFontEventClient(*this);
}

FontFaceSet::~FontFaceSet() = default;

FontFaceSet::Iterator::Iterator(FontFaceSet& set)
    : m_target(set)
{
}

RefPtr<FontFace> FontFaceSet::Iterator::next()
{
    if (m_index >= m_target->size())
        return nullptr;
    return m_target->backing()[m_index++].wrapper(m_target->protectedScriptExecutionContext().get());
}

FontFaceSet::PendingPromise::PendingPromise(LoadPromise&& promise)
    : promise(makeUniqueRef<LoadPromise>(WTF::move(promise)))
{
}

FontFaceSet::PendingPromise::~PendingPromise() = default;

bool FontFaceSet::has(FontFace& face) const
{
    if (face.backing().cssConnection())
        m_backing->updateStyleIfNeeded();
    return m_backing->hasFace(face.backing());
}

size_t FontFaceSet::size()
{
    m_backing->updateStyleIfNeeded();
    return m_backing->faceCount();
}

ExceptionOr<FontFaceSet&> FontFaceSet::add(FontFace& face)
{
    if (m_backing->hasFace(face.backing()))
        return *this;
    if (face.backing().cssConnection())
        return Exception(ExceptionCode::InvalidModificationError);
    m_backing->add(face.backing());
    return *this;
}

bool FontFaceSet::remove(FontFace& face)
{
    if (face.backing().cssConnection())
        return false;
    bool result = m_backing->hasFace(face.backing());
    if (result)
        m_backing->remove(face.backing());
    return result;
}

void FontFaceSet::clear()
{
    auto facesPartitionIndex = m_backing->facesPartitionIndex();
    while (m_backing->faceCount() > facesPartitionIndex) {
        m_backing->remove(m_backing.get()[m_backing->faceCount() - 1]);
        ASSERT(m_backing->facesPartitionIndex() == facesPartitionIndex);
    }
}

void FontFaceSet::load(ScriptExecutionContext& context, const String& font, const String& text, LoadPromise&& promise)
{
    m_backing->updateStyleIfNeeded();
    auto matchingFacesResult = m_backing->matchingFacesExcludingPreinstalledFonts(context, font, text);
    if (matchingFacesResult.hasException()) {
        promise.reject(matchingFacesResult.releaseException());
        return;
    }
    auto matchingFaces = matchingFacesResult.releaseReturnValue();

    if (matchingFaces.isEmpty()) {
        promise.resolve({ });
        return;
    }

    for (auto& face : matchingFaces)
        face.get().load();

    if (CheckedPtr document = dynamicDowncast<Document>(scriptExecutionContext())) {
        if (document->quirks().shouldEnableFontLoadingAPIQuirk()) {
            // HBOMax.com expects that loading fonts will succeed, and will totally break when it doesn't. But when lockdown mode is enabled, fonts
            // fail to load, because that's the whole point of lockdown mode.
            //
            // This is a bit of a hack to say "When lockdown mode is enabled, and lockdown mode has removed all the remote fonts, then just pretend
            // that the fonts loaded successfully." If there are any non-remote fonts still present, don't make any behavior change.
            //
            // See also: https://github.com/w3c/csswg-drafts/issues/7680

            bool hasSource = false;
            for (auto& face : matchingFaces) {
                if (face.get().sourceCount()) {
                    hasSource = true;
                    break;
                }
            }
            if (!hasSource) {
                promise.resolve(matchingFaces.map([scriptExecutionContext = CheckedPtr { scriptExecutionContext() }] (const auto& matchingFace) {
                    return matchingFace.get().wrapper(scriptExecutionContext.get());
                }));
                return;
            }
        }
    }

    for (auto& face : matchingFaces) {
        if (face.get().status() == CSSFontFace::Status::Failure) {
            promise.reject(ExceptionCode::NetworkError);
            return;
        }
    }

    auto pendingPromise = PendingPromise::create(WTF::move(promise));
    bool waiting = false;

    for (auto& face : matchingFaces) {
        pendingPromise->faces.append(face.get().wrapper(protectedScriptExecutionContext().get()));
        if (face.get().status() == CSSFontFace::Status::Success)
            continue;
        waiting = true;
        ASSERT(face.get().existingWrapper());
        m_pendingPromises.add(face.get().existingWrapper(), Vector<Ref<PendingPromise>>()).iterator->value.append(pendingPromise.copyRef());
    }

    if (!waiting)
        pendingPromise->promise->resolve(pendingPromise->faces);
}

ExceptionOr<bool> FontFaceSet::check(ScriptExecutionContext& context, const String& family, const String& text)
{
    m_backing->updateStyleIfNeeded();
    return m_backing->check(context, family, text);
}

auto FontFaceSet::status() const -> LoadStatus
{
    m_backing->updateStyleIfNeeded();

    switch (m_backing->status()) {
    case CSSFontFaceSet::Status::Loading:
        return LoadStatus::Loading;
    case CSSFontFaceSet::Status::Loaded:
        return LoadStatus::Loaded;
    }
    ASSERT_NOT_REACHED();
    return LoadStatus::Loaded;
}

void FontFaceSet::faceFinished(CSSFontFace& face, CSSFontFace::Status newStatus)
{
    if (!face.existingWrapper())
        return;

    auto pendingPromises = m_pendingPromises.take(face.existingWrapper());
    if (pendingPromises.isEmpty())
        return;

    for (auto& pendingPromise : pendingPromises) {
        if (pendingPromise->hasReachedTerminalState)
            continue;
        if (newStatus == CSSFontFace::Status::Success) {
            if (pendingPromise->hasOneRef()) {
                pendingPromise->promise->resolve(pendingPromise->faces);
                pendingPromise->hasReachedTerminalState = true;
            }
        } else {
            ASSERT(newStatus == CSSFontFace::Status::Failure);
            pendingPromise->promise->reject(ExceptionCode::NetworkError);
            pendingPromise->hasReachedTerminalState = true;
        }
    }
}

void FontFaceSet::startedLoading()
{
    if (m_readyPromise->isFulfilled())
        m_readyPromise = makeUniqueRef<ReadyPromise>(*this, &FontFaceSet::readyPromiseResolve);
    queueTaskToDispatchEvent(*this, TaskSource::DOMManipulation, Event::create(eventNames().loadingEvent, Event::CanBubble::No, Event::IsCancelable::No));
}

void FontFaceSet::documentDidFinishLoading()
{
    m_isDocumentLoaded = true;
    if (!m_backing->hasActiveFontFaces() && !m_readyPromise->isFulfilled())
        m_readyPromise->resolve(*this);
}

void FontFaceSet::completedLoading()
{
    if (m_isDocumentLoaded && !m_readyPromise->isFulfilled())
        m_readyPromise->resolve(*this);
}

FontFaceSet& FontFaceSet::readyPromiseResolve()
{
    return *this;
}

ScriptExecutionContext* FontFaceSet::scriptExecutionContext() const
{
    return ActiveDOMObject::scriptExecutionContext();
}


}