openzeppelin-contracts/contracts/token/ERC721/extensions/ERC721PausableUpgradeable.sol

// 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;
}