Contract Source Code:
// SPDX-License-Identifier: GPL-3.0
/// @title The Nouns ERC-721 token
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pragma solidity ^0.8.6;
import { Ownable } from '@openzeppelin/contracts/access/Ownable.sol';
import { ERC721Checkpointable } from './base/ERC721Checkpointable.sol';
import { INounsDescriptor } from './interfaces/INounsDescriptor.sol';
import { INounsSeeder } from './interfaces/INounsSeeder.sol';
import { INounsToken } from './interfaces/INounsToken.sol';
import { ERC721 } from './base/ERC721.sol';
import { IERC721 } from '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import { IProxyRegistry } from './external/opensea/IProxyRegistry.sol';
contract NounsToken is INounsToken, Ownable, ERC721Checkpointable {
// The nounders DAO address (creators org)
address public noundersDAO;
// An address who has permissions to mint Nouns
address public minter;
// The Nouns token URI descriptor
INounsDescriptor public descriptor;
// The Nouns token seeder
INounsSeeder public seeder;
// Whether the minter can be updated
bool public isMinterLocked;
// Whether the descriptor can be updated
bool public isDescriptorLocked;
// Whether the seeder can be updated
bool public isSeederLocked;
// The noun seeds
mapping(uint256 => INounsSeeder.Seed) public seeds;
// The internal noun ID tracker
uint256 private _currentNounId;
// IPFS content hash of contract-level metadata
string private _contractURIHash = 'QmZi1n79FqWt2tTLwCqiy6nLM6xLGRsEPQ5JmReJQKNNzX';
// OpenSea's Proxy Registry
IProxyRegistry public immutable proxyRegistry;
/**
* @notice Require that the minter has not been locked.
*/
modifier whenMinterNotLocked() {
require(!isMinterLocked, 'Minter is locked');
_;
}
/**
* @notice Require that the descriptor has not been locked.
*/
modifier whenDescriptorNotLocked() {
require(!isDescriptorLocked, 'Descriptor is locked');
_;
}
/**
* @notice Require that the seeder has not been locked.
*/
modifier whenSeederNotLocked() {
require(!isSeederLocked, 'Seeder is locked');
_;
}
/**
* @notice Require that the sender is the nounders DAO.
*/
modifier onlyNoundersDAO() {
require(msg.sender == noundersDAO, 'Sender is not the nounders DAO');
_;
}
/**
* @notice Require that the sender is the minter.
*/
modifier onlyMinter() {
require(msg.sender == minter, 'Sender is not the minter');
_;
}
constructor(
address _noundersDAO,
address _minter,
INounsDescriptor _descriptor,
INounsSeeder _seeder,
IProxyRegistry _proxyRegistry
) ERC721('Nouns', 'NOUN') {
noundersDAO = _noundersDAO;
minter = _minter;
descriptor = _descriptor;
seeder = _seeder;
proxyRegistry = _proxyRegistry;
}
/**
* @notice The IPFS URI of contract-level metadata.
*/
function contractURI() public view returns (string memory) {
return string(abi.encodePacked('ipfs://', _contractURIHash));
}
/**
* @notice Set the _contractURIHash.
* @dev Only callable by the owner.
*/
function setContractURIHash(string memory newContractURIHash) external onlyOwner {
_contractURIHash = newContractURIHash;
}
/**
* @notice Override isApprovedForAll to whitelist user's OpenSea proxy accounts to enable gas-less listings.
*/
function isApprovedForAll(address owner, address operator) public view override(IERC721, ERC721) returns (bool) {
// Whitelist OpenSea proxy contract for easy trading.
if (proxyRegistry.proxies(owner) == operator) {
return true;
}
return super.isApprovedForAll(owner, operator);
}
/**
* @notice Mint a Noun to the minter, along with a possible nounders reward
* Noun. Nounders reward Nouns are minted every 10 Nouns, starting at 0,
* until 183 nounder Nouns have been minted (5 years w/ 24 hour auctions).
* @dev Call _mintTo with the to address(es).
*/
function mint() public override onlyMinter returns (uint256) {
if (_currentNounId <= 1820 && _currentNounId % 10 == 0) {
_mintTo(noundersDAO, _currentNounId++);
}
return _mintTo(minter, _currentNounId++);
}
/**
* @notice Burn a noun.
*/
function burn(uint256 nounId) public override onlyMinter {
_burn(nounId);
emit NounBurned(nounId);
}
/**
* @notice A distinct Uniform Resource Identifier (URI) for a given asset.
* @dev See {IERC721Metadata-tokenURI}.
*/
function tokenURI(uint256 tokenId) public view override returns (string memory) {
require(_exists(tokenId), 'NounsToken: URI query for nonexistent token');
return descriptor.tokenURI(tokenId, seeds[tokenId]);
}
/**
* @notice Similar to `tokenURI`, but always serves a base64 encoded data URI
* with the JSON contents directly inlined.
*/
function dataURI(uint256 tokenId) public view override returns (string memory) {
require(_exists(tokenId), 'NounsToken: URI query for nonexistent token');
return descriptor.dataURI(tokenId, seeds[tokenId]);
}
/**
* @notice Set the nounders DAO.
* @dev Only callable by the nounders DAO when not locked.
*/
function setNoundersDAO(address _noundersDAO) external override onlyNoundersDAO {
noundersDAO = _noundersDAO;
emit NoundersDAOUpdated(_noundersDAO);
}
/**
* @notice Set the token minter.
* @dev Only callable by the owner when not locked.
*/
function setMinter(address _minter) external override onlyOwner whenMinterNotLocked {
minter = _minter;
emit MinterUpdated(_minter);
}
/**
* @notice Lock the minter.
* @dev This cannot be reversed and is only callable by the owner when not locked.
*/
function lockMinter() external override onlyOwner whenMinterNotLocked {
isMinterLocked = true;
emit MinterLocked();
}
/**
* @notice Set the token URI descriptor.
* @dev Only callable by the owner when not locked.
*/
function setDescriptor(INounsDescriptor _descriptor) external override onlyOwner whenDescriptorNotLocked {
descriptor = _descriptor;
emit DescriptorUpdated(_descriptor);
}
/**
* @notice Lock the descriptor.
* @dev This cannot be reversed and is only callable by the owner when not locked.
*/
function lockDescriptor() external override onlyOwner whenDescriptorNotLocked {
isDescriptorLocked = true;
emit DescriptorLocked();
}
/**
* @notice Set the token seeder.
* @dev Only callable by the owner when not locked.
*/
function setSeeder(INounsSeeder _seeder) external override onlyOwner whenSeederNotLocked {
seeder = _seeder;
emit SeederUpdated(_seeder);
}
/**
* @notice Lock the seeder.
* @dev This cannot be reversed and is only callable by the owner when not locked.
*/
function lockSeeder() external override onlyOwner whenSeederNotLocked {
isSeederLocked = true;
emit SeederLocked();
}
/**
* @notice Mint a Noun with `nounId` to the provided `to` address.
*/
function _mintTo(address to, uint256 nounId) internal returns (uint256) {
INounsSeeder.Seed memory seed = seeds[nounId] = seeder.generateSeed(nounId, descriptor);
_mint(owner(), to, nounId);
emit NounCreated(nounId, seed);
return nounId;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_setOwner(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_setOwner(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_setOwner(newOwner);
}
function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: BSD-3-Clause
/// @title Vote checkpointing for an ERC-721 token
/*********************************
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// LICENSE
// ERC721Checkpointable.sol uses and modifies part of Compound Lab's Comp.sol:
// https://github.com/compound-finance/compound-protocol/blob/ae4388e780a8d596d97619d9704a931a2752c2bc/contracts/Governance/Comp.sol
//
// Comp.sol source code Copyright 2020 Compound Labs, Inc. licensed under the BSD-3-Clause license.
// With modifications by Nounders DAO.
//
// Additional conditions of BSD-3-Clause can be found here: https://opensource.org/licenses/BSD-3-Clause
//
// MODIFICATIONS
// Checkpointing logic from Comp.sol has been used with the following modifications:
// - `delegates` is renamed to `_delegates` and is set to private
// - `delegates` is a public function that uses the `_delegates` mapping look-up, but unlike
// Comp.sol, returns the delegator's own address if there is no delegate.
// This avoids the delegator needing to "delegate to self" with an additional transaction
// - `_transferTokens()` is renamed `_beforeTokenTransfer()` and adapted to hook into OpenZeppelin's ERC721 hooks.
pragma solidity ^0.8.6;
import './ERC721Enumerable.sol';
abstract contract ERC721Checkpointable is ERC721Enumerable {
/// @notice Defines decimals as per ERC-20 convention to make integrations with 3rd party governance platforms easier
uint8 public constant decimals = 0;
/// @notice A record of each accounts delegate
mapping(address => address) private _delegates;
/// @notice A checkpoint for marking number of votes from a given block
struct Checkpoint {
uint32 fromBlock;
uint96 votes;
}
/// @notice A record of votes checkpoints for each account, by index
mapping(address => mapping(uint32 => Checkpoint)) public checkpoints;
/// @notice The number of checkpoints for each account
mapping(address => uint32) public numCheckpoints;
/// @notice The EIP-712 typehash for the contract's domain
bytes32 public constant DOMAIN_TYPEHASH =
keccak256('EIP712Domain(string name,uint256 chainId,address verifyingContract)');
/// @notice The EIP-712 typehash for the delegation struct used by the contract
bytes32 public constant DELEGATION_TYPEHASH =
keccak256('Delegation(address delegatee,uint256 nonce,uint256 expiry)');
/// @notice A record of states for signing / validating signatures
mapping(address => uint256) public nonces;
/// @notice An event thats emitted when an account changes its delegate
event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);
/// @notice An event thats emitted when a delegate account's vote balance changes
event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance);
/**
* @notice The votes a delegator can delegate, which is the current balance of the delegator.
* @dev Used when calling `_delegate()`
*/
function votesToDelegate(address delegator) public view returns (uint96) {
return safe96(balanceOf(delegator), 'ERC721Checkpointable::votesToDelegate: amount exceeds 96 bits');
}
/**
* @notice Overrides the standard `Comp.sol` delegates mapping to return
* the delegator's own address if they haven't delegated.
* This avoids having to delegate to oneself.
*/
function delegates(address delegator) public view returns (address) {
address current = _delegates[delegator];
return current == address(0) ? delegator : current;
}
/**
* @notice Adapted from `_transferTokens()` in `Comp.sol` to update delegate votes.
* @dev hooks into OpenZeppelin's `ERC721._transfer`
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal override {
super._beforeTokenTransfer(from, to, tokenId);
/// @notice Differs from `_transferTokens()` to use `delegates` override method to simulate auto-delegation
_moveDelegates(delegates(from), delegates(to), 1);
}
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegatee The address to delegate votes to
*/
function delegate(address delegatee) public {
if (delegatee == address(0)) delegatee = msg.sender;
return _delegate(msg.sender, delegatee);
}
/**
* @notice Delegates votes from signatory to `delegatee`
* @param delegatee The address to delegate votes to
* @param nonce The contract state required to match the signature
* @param expiry The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function delegateBySig(
address delegatee,
uint256 nonce,
uint256 expiry,
uint8 v,
bytes32 r,
bytes32 s
) public {
bytes32 domainSeparator = keccak256(
abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), getChainId(), address(this))
);
bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
bytes32 digest = keccak256(abi.encodePacked('\x19\x01', domainSeparator, structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != address(0), 'ERC721Checkpointable::delegateBySig: invalid signature');
require(nonce == nonces[signatory]++, 'ERC721Checkpointable::delegateBySig: invalid nonce');
require(block.timestamp <= expiry, 'ERC721Checkpointable::delegateBySig: signature expired');
return _delegate(signatory, delegatee);
}
/**
* @notice Gets the current votes balance for `account`
* @param account The address to get votes balance
* @return The number of current votes for `account`
*/
function getCurrentVotes(address account) external view returns (uint96) {
uint32 nCheckpoints = numCheckpoints[account];
return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
}
/**
* @notice Determine the prior number of votes for an account as of a block number
* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
* @param account The address of the account to check
* @param blockNumber The block number to get the vote balance at
* @return The number of votes the account had as of the given block
*/
function getPriorVotes(address account, uint256 blockNumber) public view returns (uint96) {
require(blockNumber < block.number, 'ERC721Checkpointable::getPriorVotes: not yet determined');
uint32 nCheckpoints = numCheckpoints[account];
if (nCheckpoints == 0) {
return 0;
}
// First check most recent balance
if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
return checkpoints[account][nCheckpoints - 1].votes;
}
// Next check implicit zero balance
if (checkpoints[account][0].fromBlock > blockNumber) {
return 0;
}
uint32 lower = 0;
uint32 upper = nCheckpoints - 1;
while (upper > lower) {
uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
Checkpoint memory cp = checkpoints[account][center];
if (cp.fromBlock == blockNumber) {
return cp.votes;
} else if (cp.fromBlock < blockNumber) {
lower = center;
} else {
upper = center - 1;
}
}
return checkpoints[account][lower].votes;
}
function _delegate(address delegator, address delegatee) internal {
/// @notice differs from `_delegate()` in `Comp.sol` to use `delegates` override method to simulate auto-delegation
address currentDelegate = delegates(delegator);
_delegates[delegator] = delegatee;
emit DelegateChanged(delegator, currentDelegate, delegatee);
uint96 amount = votesToDelegate(delegator);
_moveDelegates(currentDelegate, delegatee, amount);
}
function _moveDelegates(
address srcRep,
address dstRep,
uint96 amount
) internal {
if (srcRep != dstRep && amount > 0) {
if (srcRep != address(0)) {
uint32 srcRepNum = numCheckpoints[srcRep];
uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
uint96 srcRepNew = sub96(srcRepOld, amount, 'ERC721Checkpointable::_moveDelegates: amount underflows');
_writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
}
if (dstRep != address(0)) {
uint32 dstRepNum = numCheckpoints[dstRep];
uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
uint96 dstRepNew = add96(dstRepOld, amount, 'ERC721Checkpointable::_moveDelegates: amount overflows');
_writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
}
}
}
function _writeCheckpoint(
address delegatee,
uint32 nCheckpoints,
uint96 oldVotes,
uint96 newVotes
) internal {
uint32 blockNumber = safe32(
block.number,
'ERC721Checkpointable::_writeCheckpoint: block number exceeds 32 bits'
);
if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
} else {
checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
numCheckpoints[delegatee] = nCheckpoints + 1;
}
emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
}
function safe32(uint256 n, string memory errorMessage) internal pure returns (uint32) {
require(n < 2**32, errorMessage);
return uint32(n);
}
function safe96(uint256 n, string memory errorMessage) internal pure returns (uint96) {
require(n < 2**96, errorMessage);
return uint96(n);
}
function add96(
uint96 a,
uint96 b,
string memory errorMessage
) internal pure returns (uint96) {
uint96 c = a + b;
require(c >= a, errorMessage);
return c;
}
function sub96(
uint96 a,
uint96 b,
string memory errorMessage
) internal pure returns (uint96) {
require(b <= a, errorMessage);
return a - b;
}
function getChainId() internal view returns (uint256) {
uint256 chainId;
assembly {
chainId := chainid()
}
return chainId;
}
}
// SPDX-License-Identifier: GPL-3.0
/// @title Interface for NounsDescriptor
/*********************************
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*********************************/
pragma solidity ^0.8.6;
import { INounsSeeder } from './INounsSeeder.sol';
interface INounsDescriptor {
event PartsLocked();
event DataURIToggled(bool enabled);
event BaseURIUpdated(string baseURI);
function arePartsLocked() external returns (bool);
function isDataURIEnabled() external returns (bool);
function baseURI() external returns (string memory);
function palettes(uint8 paletteIndex, uint256 colorIndex) external view returns (string memory);
function backgrounds(uint256 index) external view returns (string memory);
function bodies(uint256 index) external view returns (bytes memory);
function accessories(uint256 index) external view returns (bytes memory);
function heads(uint256 index) external view returns (bytes memory);
function glasses(uint256 index) external view returns (bytes memory);
function backgroundCount() external view returns (uint256);
function bodyCount() external view returns (uint256);
function accessoryCount() external view returns (uint256);
function headCount() external view returns (uint256);
function glassesCount() external view returns (uint256);
function addManyColorsToPalette(uint8 paletteIndex, string[] calldata newColors) external;
function addManyBackgrounds(string[] calldata backgrounds) external;
function addManyBodies(bytes[] calldata bodies) external;
function addManyAccessories(bytes[] calldata accessories) external;
function addManyHeads(bytes[] calldata heads) external;
function addManyGlasses(bytes[] calldata glasses) external;
function addColorToPalette(uint8 paletteIndex, string calldata color) external;
function addBackground(string calldata background) external;
function addBody(bytes calldata body) external;
function addAccessory(bytes calldata accessory) external;
function addHead(bytes calldata head) external;
function addGlasses(bytes calldata glasses) external;
function lockParts() external;
function toggleDataURIEnabled() external;
function setBaseURI(string calldata baseURI) external;
function tokenURI(uint256 tokenId, INounsSeeder.Seed memory seed) external view returns (string memory);
function dataURI(uint256 tokenId, INounsSeeder.Seed memory seed) external view returns (string memory);
function genericDataURI(
string calldata name,
string calldata description,
INounsSeeder.Seed memory seed
) external view returns (string memory);
function generateSVGImage(INounsSeeder.Seed memory seed) external view returns (string memory);
}
// SPDX-License-Identifier: GPL-3.0
/// @title Interface for NounsSeeder
/*********************************
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*********************************/
pragma solidity ^0.8.6;
import { INounsDescriptor } from './INounsDescriptor.sol';
interface INounsSeeder {
struct Seed {
uint48 background;
uint48 body;
uint48 accessory;
uint48 head;
uint48 glasses;
}
function generateSeed(uint256 nounId, INounsDescriptor descriptor) external view returns (Seed memory);
}
// SPDX-License-Identifier: GPL-3.0
/// @title Interface for NounsToken
/*********************************
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
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* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
*********************************/
pragma solidity ^0.8.6;
import { IERC721 } from '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import { INounsDescriptor } from './INounsDescriptor.sol';
import { INounsSeeder } from './INounsSeeder.sol';
interface INounsToken is IERC721 {
event NounCreated(uint256 indexed tokenId, INounsSeeder.Seed seed);
event NounBurned(uint256 indexed tokenId);
event NoundersDAOUpdated(address noundersDAO);
event MinterUpdated(address minter);
event MinterLocked();
event DescriptorUpdated(INounsDescriptor descriptor);
event DescriptorLocked();
event SeederUpdated(INounsSeeder seeder);
event SeederLocked();
function mint() external returns (uint256);
function burn(uint256 tokenId) external;
function dataURI(uint256 tokenId) external returns (string memory);
function setNoundersDAO(address noundersDAO) external;
function setMinter(address minter) external;
function lockMinter() external;
function setDescriptor(INounsDescriptor descriptor) external;
function lockDescriptor() external;
function setSeeder(INounsSeeder seeder) external;
function lockSeeder() external;
}
// SPDX-License-Identifier: MIT
/// @title ERC721 Token Implementation
/*********************************
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
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* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
*********************************/
// LICENSE
// ERC721.sol modifies OpenZeppelin's ERC721.sol:
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/6618f9f18424ade44116d0221719f4c93be6a078/contracts/token/ERC721/ERC721.sol
//
// ERC721.sol source code copyright OpenZeppelin licensed under the MIT License.
// With modifications by Nounders DAO.
//
//
// MODIFICATIONS:
// `_safeMint` and `_mint` contain an additional `creator` argument and
// emit two `Transfer` logs, rather than one. The first log displays the
// transfer (mint) from `address(0)` to the `creator`. The second displays the
// transfer from the `creator` to the `to` address. This enables correct
// attribution on various NFT marketplaces.
pragma solidity ^0.8.6;
import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';
import '@openzeppelin/contracts/utils/Address.sol';
import '@openzeppelin/contracts/utils/Context.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/utils/introspection/ERC165.sol';
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension, but not including the Enumerable extension, which is available separately as
* {ERC721Enumerable}.
*/
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
using Address for address;
using Strings for uint256;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to owner address
mapping(uint256 => address) private _owners;
// Mapping owner address to token count
mapping(address => uint256) private _balances;
// Mapping from token ID to approved address
mapping(uint256 => address) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
/**
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return
interfaceId == type(IERC721).interfaceId ||
interfaceId == type(IERC721Metadata).interfaceId ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
require(owner != address(0), 'ERC721: balance query for the zero address');
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
address owner = _owners[tokenId];
require(owner != address(0), 'ERC721: owner query for nonexistent token');
return owner;
}
/**
* @dev See {IERC721Metadata-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), 'ERC721Metadata: URI query for nonexistent token');
string memory baseURI = _baseURI();
return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, can be overriden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return '';
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = ERC721.ownerOf(tokenId);
require(to != owner, 'ERC721: approval to current owner');
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
'ERC721: approve caller is not owner nor approved for all'
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
require(_exists(tokenId), 'ERC721: approved query for nonexistent token');
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
require(operator != _msgSender(), 'ERC721: approve to caller');
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), 'ERC721: transfer caller is not owner nor approved');
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
safeTransferFrom(from, to, tokenId, '');
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes memory _data
) public virtual override {
require(_isApprovedOrOwner(_msgSender(), tokenId), 'ERC721: transfer caller is not owner nor approved');
_safeTransfer(from, to, tokenId, _data);
}
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* `_data` is additional data, it has no specified format and it is sent in call to `to`.
*
* This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
* implement alternative mechanisms to perform token transfer, such as signature-based.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeTransfer(
address from,
address to,
uint256 tokenId,
bytes memory _data
) internal virtual {
_transfer(from, to, tokenId);
require(_checkOnERC721Received(from, to, tokenId, _data), 'ERC721: transfer to non ERC721Receiver implementer');
}
/**
* @dev Returns whether `tokenId` exists.
*
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
*
* Tokens start existing when they are minted (`_mint`),
* and stop existing when they are burned (`_burn`).
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return _owners[tokenId] != address(0);
}
/**
* @dev Returns whether `spender` is allowed to manage `tokenId`.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
require(_exists(tokenId), 'ERC721: operator query for nonexistent token');
address owner = ERC721.ownerOf(tokenId);
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
}
/**
* @dev Safely mints `tokenId`, transfers it to `to`, and emits two log events -
* 1. Credits the `minter` with the mint.
* 2. Shows transfer from the `minter` to `to`.
*
* Requirements:
*
* - `tokenId` must not exist.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeMint(
address creator,
address to,
uint256 tokenId
) internal virtual {
_safeMint(creator, to, tokenId, '');
}
/**
* @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
* forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
*/
function _safeMint(
address creator,
address to,
uint256 tokenId,
bytes memory _data
) internal virtual {
_mint(creator, to, tokenId);
require(
_checkOnERC721Received(address(0), to, tokenId, _data),
'ERC721: transfer to non ERC721Receiver implementer'
);
}
/**
* @dev Mints `tokenId`, transfers it to `to`, and emits two log events -
* 1. Credits the `creator` with the mint.
* 2. Shows transfer from the `creator` to `to`.
*
* WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
*
* Requirements:
*
* - `tokenId` must not exist.
* - `to` cannot be the zero address.
*
* Emits a {Transfer} event.
*/
function _mint(
address creator,
address to,
uint256 tokenId
) internal virtual {
require(to != address(0), 'ERC721: mint to the zero address');
require(!_exists(tokenId), 'ERC721: token already minted');
_beforeTokenTransfer(address(0), to, tokenId);
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(address(0), creator, tokenId);
emit Transfer(creator, to, tokenId);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId) internal virtual {
address owner = ERC721.ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId);
// Clear approvals
_approve(address(0), tokenId);
_balances[owner] -= 1;
delete _owners[tokenId];
emit Transfer(owner, address(0), tokenId);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/
function _transfer(
address from,
address to,
uint256 tokenId
) internal virtual {
require(ERC721.ownerOf(tokenId) == from, 'ERC721: transfer of token that is not own');
require(to != address(0), 'ERC721: transfer to the zero address');
_beforeTokenTransfer(from, to, tokenId);
// Clear approvals from the previous owner
_approve(address(0), tokenId);
_balances[from] -= 1;
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(from, to, tokenId);
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits a {Approval} event.
*/
function _approve(address to, uint256 tokenId) internal virtual {
_tokenApprovals[tokenId] = to;
emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
* The call is not executed if the target address is not a contract.
*
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/
function _checkOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory _data
) private returns (bool) {
if (to.isContract()) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver(to).onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert('ERC721: transfer to non ERC721Receiver implementer');
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual {}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.6;
interface IProxyRegistry {
function proxies(address) external view returns (address);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
/// @title ERC721 Enumerable Extension
/*********************************
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░██░░░████░░██░░░████░░░ *
* ░░██████░░░████████░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
*********************************/
// LICENSE
// ERC721.sol modifies OpenZeppelin's ERC721Enumerable.sol:
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/6618f9f18424ade44116d0221719f4c93be6a078/contracts/token/ERC721/extensions/ERC721Enumerable.sol
//
// ERC721Enumerable.sol source code copyright OpenZeppelin licensed under the MIT License.
// With modifications by Nounders DAO.
//
// MODIFICATIONS:
// Consumes modified `ERC721` contract. See notes in `ERC721.sol`.
pragma solidity ^0.8.0;
import './ERC721.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol';
/**
* @dev This implements an optional extension of {ERC721} defined in the EIP that adds
* enumerability of all the token ids in the contract as well as all token ids owned by each
* account.
*/
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
// Mapping from owner to list of owned token IDs
mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
// Mapping from token ID to index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
// Array with all token ids, used for enumeration
uint256[] private _allTokens;
// Mapping from token id to position in the allTokens array
mapping(uint256 => uint256) private _allTokensIndex;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
require(index < ERC721.balanceOf(owner), 'ERC721Enumerable: owner index out of bounds');
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
require(index < ERC721Enumerable.totalSupply(), 'ERC721Enumerable: global index out of bounds');
return _allTokens[index];
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
if (from == address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} else if (from != to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to == address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} else if (to != from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/
function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @dev Private function to add a token to this extension's token tracking data structures.
* @param tokenId uint256 ID of the token to be added to the tokens list
*/
function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/
function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary
if (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the array
delete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @dev Private function to remove a token from this extension's token tracking data structures.
* This has O(1) time complexity, but alters the order of the _allTokens array.
* @param tokenId uint256 ID of the token to be removed from the tokens list
*/
function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
// To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = _allTokens.length - 1;
uint256 tokenIndex = _allTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
// rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
// an 'if' statement (like in _removeTokenFromOwnerEnumeration)
uint256 lastTokenId = _allTokens[lastTokenIndex];
_allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
// This also deletes the contents at the last position of the array
delete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Enumerable is IERC721 {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Metadata is IERC721 {
/**
* @dev Returns the token collection name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the token collection symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
assembly {
size := extcodesize(account)
}
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) private pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _HEX_SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}