Source/WebCore/css/MediaQuery.cpp

/*
 * CSS Media Query
 *
 * Copyright (C) 2005, 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 *
 * 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 THE AUTHOR ``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,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "MediaQuery.h"

#include "MediaQueryExp.h"
#include <wtf/text/StringBuilder.h>

namespace WebCore {

// http://dev.w3.org/csswg/cssom/#serialize-a-media-query
String MediaQuery::serialize() const
{
    StringBuilder result;
    if (!m_ignored) {
        switch (m_restrictor) {
        case MediaQuery::Only:
            result.appendLiteral("only ");
            break;
        case MediaQuery::Not:
            result.appendLiteral("not ");
            break;
        case MediaQuery::None:
            break;
        }

        if (m_expressions->isEmpty()) {
            result.append(m_mediaType);
            return result.toString();
        }

        if (m_mediaType != "all" || m_restrictor != None) {
            result.append(m_mediaType);
            result.appendLiteral(" and ");
        }

        result.append(m_expressions->at(0)->serialize());
        for (size_t i = 1; i < m_expressions->size(); ++i) {
            result.appendLiteral(" and ");
            result.append(m_expressions->at(i)->serialize());
        }
    } else {
        // If query is invalid, serialized text should turn into "not all".
        result.appendLiteral("not all");
    }
    return result.toString();
}

MediaQuery::MediaQuery(Restrictor r, const String& mediaType, std::unique_ptr<ExpressionVector> exprs)
    : m_restrictor(r)
    , m_mediaType(mediaType.lower())
    , m_expressions(WTF::move(exprs))
    , m_ignored(false)
{
    if (!m_expressions) {
        m_expressions = std::make_unique<ExpressionVector>();
        return;
    }

    std::sort(m_expressions->begin(), m_expressions->end(), [](const std::unique_ptr<MediaQueryExp>& a, const std::unique_ptr<MediaQueryExp>& b) {
        return codePointCompare(a->serialize(), b->serialize()) < 0;
    });

    // remove all duplicated expressions
    String key;
    for (int i = m_expressions->size() - 1; i >= 0; --i) {

        // if not all of the expressions is valid the media query must be ignored.
        if (!m_ignored)
            m_ignored = !m_expressions->at(i)->isValid();

        if (m_expressions->at(i)->serialize() == key)
            m_expressions->remove(i);
        else
            key = m_expressions->at(i)->serialize();
    }
}

MediaQuery::MediaQuery(const MediaQuery& o)
    : m_restrictor(o.m_restrictor)
    , m_mediaType(o.m_mediaType)
    , m_expressions(std::make_unique<ExpressionVector>(o.m_expressions->size()))
    , m_ignored(o.m_ignored)
    , m_serializationCache(o.m_serializationCache)
{
    for (unsigned i = 0; i < m_expressions->size(); ++i)
        (*m_expressions)[i] = std::make_unique<MediaQueryExp>(*o.m_expressions->at(i));
}

MediaQuery::~MediaQuery()
{
}

// http://dev.w3.org/csswg/cssom/#compare-media-queries
bool MediaQuery::operator==(const MediaQuery& other) const
{
    return cssText() == other.cssText();
}

// http://dev.w3.org/csswg/cssom/#serialize-a-list-of-media-queries
String MediaQuery::cssText() const
{
    if (m_serializationCache.isNull())
        const_cast<MediaQuery*>(this)->m_serializationCache = serialize();

    return m_serializationCache;
}

} //namespace