chromium/third_party/blink/renderer/modules/mediastream/media_stream_constraints_util_sets.h

// Copyright 2017 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_MODULES_MEDIASTREAM_MEDIA_STREAM_CONSTRAINTS_UTIL_SETS_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIASTREAM_MEDIA_STREAM_CONSTRAINTS_UTIL_SETS_H_

#include <algorithm>
#include <limits>
#include <optional>
#include <string>
#include <utility>

#include "base/check_op.h"
#include "base/containers/contains.h"
#include "base/gtest_prod_util.h"
#include "third_party/blink/renderer/modules/mediastream/media_constraints.h"
#include "third_party/blink/renderer/modules/modules_export.h"
#include "third_party/blink/renderer/platform/wtf/vector.h"

namespace blink {

struct MediaTrackConstraintSetPlatform;

template <typename ConstraintType>
bool ConstraintHasMax(const ConstraintType& constraint) { … }

template <typename ConstraintType>
bool ConstraintHasMin(const ConstraintType& constraint) { … }

template <typename ConstraintType>
auto ConstraintMax(const ConstraintType& constraint)
    -> decltype(constraint.Max()) { … }

template <typename ConstraintType>
auto ConstraintMin(const ConstraintType& constraint)
    -> decltype(constraint.Min()) { … }

namespace media_constraints {

// This class template represents a set of candidates suitable for a numeric
// range-based constraint.
template <typename T>
class NumericRangeSet { … };

// This class defines a set of discrete elements suitable for resolving
// constraints with a countable number of choices not suitable to be constrained
// by range. Examples are strings, booleans and certain constraints of type
// long. A DiscreteSet can be empty, have their elements explicitly stated, or
// be the universal set. The universal set is a set that contains all possible
// elements. The specific definition of what elements are in the universal set
// is application defined (e.g., it could be all possible boolean values, all
// possible strings of length N, or anything that suits a particular
// application).
// TODO(guidou): Rename this class. https://crbug.com/731166
template <typename T>
class DiscreteSet { … };

// Special case for DiscreteSet<bool> where it is easy to produce an explicit
// set that contains all possible elements.
template <>
inline bool DiscreteSet<bool>::is_universal() const { … }

MODULES_EXPORT DiscreteSet<std::string> StringSetFromConstraint(
    const StringConstraint& constraint);
MODULES_EXPORT DiscreteSet<bool> BoolSetFromConstraint(
    const BooleanConstraint& constraint);

// This class represents a set of (height, width) screen resolution candidates
// determined by width, height and aspect-ratio constraints.
// This class supports widths and heights from 0 to kMaxDimension, both
// inclusive and aspect ratios from 0.0 to positive infinity, both inclusive.
class MODULES_EXPORT ResolutionSet { … };

// Scalar multiplication for Points.
MODULES_EXPORT ResolutionSet::Point operator*(double d,
                                              const ResolutionSet::Point& p);

// This function returns a set of bools from a resizeMode StringConstraint.
// If |resize_mode_constraint| includes
// WebMediaStreamTrack::kResizeModeNone, false is included in the
// returned value. If |resize_mode_constraint| includes
// WebMediaStreamTrack::kResizeModeRescale, true is included in the
// returned value.
MODULES_EXPORT DiscreteSet<bool> RescaleSetFromConstraint(
    const StringConstraint& resize_mode_constraint);

}  // namespace media_constraints
}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIASTREAM_MEDIA_STREAM_CONSTRAINTS_UTIL_SETS_H_