/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* A struct defining a media feature change. */

#ifndef mozilla_MediaFeatureChange_h__

#define mozilla_MediaFeatureChange_h__

#include "nsChangeHint.h"

#include "mozilla/Attributes.h"

#include "mozilla/TypedEnumBits.h"

namespace mozilla {

enum class MediaFeatureChangeReason

{

  // The viewport size the document has used has changed.

  //

  // This affects size media queries like min-width.

  ViewportChange = 1 << 0,

  // The effective text zoom has changed. This affects the meaning of em units,

  // and thus affects any media query that uses a Length.

  ZoomChange = 1 << 1,

  // The base min font size has changed. This can affect the meaning of em

  // units, if the previous default font-size has changed, and also zoom.

  MinFontSizeChange = 1 << 2,

  // The resolution has changed. This can affect device-pixel-ratio media

  // queries, for example.

  ResolutionChange = 1 << 3,

  // The medium has changed.

  MediumChange = 1 << 4,

  // The size-mode has changed.

  SizeModeChange = 1 << 5,

  // A system metric or multiple have changed. This affects all the media

  // features that expose the presence of a system metric directly.

  SystemMetricsChange = 1 << 6,

  // The fact of whether the device size is the page size has changed, thus

  // resolution media queries can change.

  DeviceSizeIsPageSizeChange = 1 << 7,

  // display-mode changed on the document, thus the display-mode media queries

  // may have changed.

  DisplayModeChange = 1 << 8,

};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(MediaFeatureChangeReason)

struct MediaFeatureChange

{

  nsRestyleHint mRestyleHint;

  nsChangeHint mChangeHint;

  MediaFeatureChangeReason mReason;

  MOZ_IMPLICIT MediaFeatureChange(MediaFeatureChangeReason aReason)

    : MediaFeatureChange(nsRestyleHint(0), nsChangeHint(0), aReason)

  {

  }

  MediaFeatureChange(nsRestyleHint aRestyleHint,

                     nsChangeHint aChangeHint,

                     MediaFeatureChangeReason aReason)

    : mRestyleHint(aRestyleHint)

    , mChangeHint(aChangeHint)

    , mReason(aReason)

  {

  }

  inline MediaFeatureChange& operator|=(const MediaFeatureChange& aOther)

  {

    mRestyleHint |= aOther.mRestyleHint;

    mChangeHint |= aOther.mChangeHint;

    mReason |= aOther.mReason;

    return *this;

  }

};

} // namespace mozilla

#endif