chromium/ui/accessibility/ax_tree_id.h

// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_ACCESSIBILITY_AX_TREE_ID_H_
#define UI_ACCESSIBILITY_AX_TREE_ID_H_

#include <optional>
#include <string>

#include "base/unguessable_token.h"
#include "ui/accessibility/ax_base_export.h"
#include "ui/accessibility/ax_enums.mojom-forward.h"

namespace mojo {
template <typename DataViewType, typename T>
struct UnionTraits;
}

namespace ax::mojom {
class AXTreeIDDataView;
}

namespace ui {

// A unique ID representing an accessibility tree.
class AX_BASE_EXPORT AXTreeID { … };

// For use in std::unordered_map.
struct AX_BASE_EXPORT AXTreeIDHash { … };

AX_BASE_EXPORT std::ostream& operator<<(std::ostream& stream,
                                        const AXTreeID& value);

// The value to use when an AXTreeID is unknown.
AX_BASE_EXPORT const AXTreeID& AXTreeIDUnknown();

}  // namespace ui

#endif  // UI_ACCESSIBILITY_AX_TREE_ID_H_