// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Pausable.sol) pragma solidity ^0.8.0; import "../ERC721Upgradeable.sol"; import "../../../security/PausableUpgradeable.sol"; import "../../../proxy/utils/Initializable.sol"; /** * @dev ERC721 token with pausable token transfers, minting and burning. * * Useful for scenarios such as preventing trades until the end of an evaluation * period, or having an emergency switch for freezing all token transfers in the * event of a large bug. */ abstract contract ERC721PausableUpgradeable is Initializable, ERC721Upgradeable, PausableUpgradeable { function __ERC721Pausable_init() internal onlyInitializing { __Pausable_init_unchained(); } function __ERC721Pausable_init_unchained() internal onlyInitializing { } /** * @dev See {ERC721-_beforeTokenTransfer}. * * Requirements: * * - the contract must not be paused. */ function _beforeTokenTransfer( address from, address to, uint256 tokenId ) internal virtual override { super._beforeTokenTransfer(from, to, tokenId); require(!paused(), "ERC721Pausable: token transfer while paused"); } /** * This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[50] private __gap; }