third_party/blink/renderer/core/css/media_query_set_owner.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_CSS_MEDIA_QUERY_SET_OWNER_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_MEDIA_QUERY_SET_OWNER_H_

namespace blink {

class MediaQuerySet;

// MediaQuerySet objects are immutable, for caching purposes. However,
// CSSOM (MediaList) offers an API to mutate the underlying media queries,
// so we fulfill that API by instead replacing the entire MediaQuerySet
// upon mutation. Since MediaList does not own the MediaQuerySet it is mutating
// (replacing), MediaList instead holds a reference to the object that does
// (a MediaQuerySetOwner). This way the MediaQuerySet can be replaced at the
// source.
class CORE_EXPORT MediaQuerySetOwner {
 public:
  virtual const MediaQuerySet* MediaQueries() const = 0;
  virtual void SetMediaQueries(const MediaQuerySet*) = 0;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_MEDIA_QUERY_SET_OWNER_H_