Overview

ERC-721 compliant contracts MAY implement this EIP to provide standard methods of locking and unlocking the token at its current owner address.

Token owner MAY lock the token and assign locker to some address using lock(uint256 tokenId, address _locker) function, this MUST set locker to _locker. Token owner or approved MAY lock the token using lock(uint256 tokenId) function, this MUST set locker to msg.sender. Token MAY be unlocked by locker using unlock function. unlock function MUST delete locker mapping and default to address(0).

If the token is locked, the lockerOf function MUST return an address that is locker and can unlock the token. For tokens that are not locked, the lockerOf function MUST return address(0).

lock function MUST revert if token is not already locked. unlock function MUST revert if token is not locked. ERC-721 approve function MUST revert if token is locked. ERC-721 _tansfer function MUST revert if token is locked. ERC-721 _transfer function MUST pass if token is locked and msg.sender is approved and locker both. After ERC-721 _transfer, values of locker and approved MUST be purged.

Token MAY be transferred and locked, and OPTIONAL setup approval to locker using transferAndLock function. This is RECOMMENDED for use-cases where Token transfer and subsequent revocation is REQUIRED.

INTERFACE

// SPDX-License-Identifier: CC0-1.0

pragma solidity >=0.7.0 <0.9.0;

/// @title Lockable Extension for ERC721
/// @dev Interface for the Lockable extension
/// @author StreamNFT 

interface IERC7066{

    /**
     * @dev Emitted when tokenId is locked
     */
    event Lock (uint256 indexed tokenId, address _locker);

    /**
     * @dev Emitted when tokenId is unlocked
     */
    event Unlock (uint256 indexed tokenId);

    /**
     * @dev Lock the tokenId if msg.sender is owner or approved and set locker to msg.sender
     */
    function lock(uint256 tokenId) external;

    /**
     * @dev Lock the tokenId if msg.sender is owner and set locker to _locker
     */
    function lock(uint256 tokenId, address _locker) external;

    /**
     * @dev Unlocks the tokenId if msg.sender is locker
     */
    function unlock(uint256 tokenId) external;

    /**
     * @dev Tranfer and lock the token if the msg.sender is owner or approved. 
     *      Lock the token and set locker to caller
     *      Optionally approve caller if bool setApprove flag is true
     */
    function transferAndLock(uint256 tokenId, address from, address to, bool setApprove) external;

    /**
     * @dev Returns the wallet, that is stated as unlocking wallet for the tokenId.
     *      If address(0) returned, that means token is not locked. Any other result means token is locked.
     */
    function lockerOf(uint256 tokenId) external view returns (address);
}