// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @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
* ====
*/functionisContract(address account) internalviewreturns (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].
*/functionsendValue(addresspayable 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._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value
) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytesmemory 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._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
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._
*/functionfunctionStaticCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytesmemory 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._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionDelegateCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytesmemory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/functionverifyCallResult(bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalpurereturns (bytesmemory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
Contract Source Code
File 2 of 18: Catbotica.sol
//Contract based on [https://docs.openzeppelin.com/contracts/3.x/erc721](https://docs.openzeppelin.com/contracts/3.x/erc721)// SPDX-License-Identifier: MITpragmasolidity ^0.8.9;import'@openzeppelin/contracts/utils/Counters.sol';
import'@openzeppelin/contracts/access/Ownable.sol';
import'@openzeppelin/contracts/security/Pausable.sol';
import'@openzeppelin/contracts/utils/Strings.sol';
import'@openzeppelin/contracts/interfaces/IERC20.sol';
import'@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol';
import'@openzeppelin/contracts/security/ReentrancyGuard.sol';
import'@openzeppelin/contracts/interfaces/IERC165.sol';
import'@openzeppelin/contracts/interfaces/IERC2981.sol';
import'@openzeppelin/contracts/utils/introspection/ERC165.sol';
contractCatboticaisERC721Enumerable, Ownable, Pausable, ReentrancyGuard, IERC2981{
usingStringsforuint256;
usingCountersforCounters.Counter;
Counters.Counter private _redeemIds;
Counters.Counter private _tokenIds;
boolpublic saleActive =false;
stringpublic PROVENANCE_HASH;
stringprivate baseURI;
stringprivate tokenSuffixURI;
stringprivate contractMetadata ='contract.json';
uint256publicconstant TICK_PERIOD =30minutes; // Time period to decrease priceuint256publicconstant PUBLIC_SALE_PERIOD =4hours; // Dutch Auction Time Perioduint256publicconstant STARTING_PRICE =200000000000000000; // 0.2 ETHuint256publicconstant BOTTOM_PRICE =80000000000000000; // 0.08 ETHuint256publicconstant SALE_PRICE_STEP =20000000000000000; // 0.02 ETHuint256publicconstant PRIVATE_SALE_PRICE =80000000000000000; // 0.08 ETHuint256publicconstant MINT_BATCH_LIMIT =5; // Max number of Tokens minted in a txnuint256publicconstant RESERVED_TOKEN_ID_OFFSET =500; // Tokens reserved for RWA listuint256public saleStartsAt;
uint256public publicsaleStartsAt;
uint256public publicsaleEndsAt;
uint256public privatesaleStartsAt;
uint256public privatesaleEndsAt;
uint256public redemptionEndsAt;
uint16publicconstant MAX_PRIVATE_SALE_SUPPLY =3000; // Cap for tokens to be sold in private sale is 2500 in addition to 500 for redmeption by RWA listuint16publicconstant MAX_TOKENS =12000; // Max number of token sold in saleaddress[] private recipients;
uint16[] private splits;
uint16publicconstant SPLIT_BASE =10000;
mapping(address=>bool) public proxyRegistryAddress;
// schema of the RWA/PWA list recordstructwaRecord {
uint8 balance; // amount allowed to redeembool exists; // if the user is whitelisted or notbool redeemed;
uint8 limit; // max num tokens allowed to buy in private salebool minted;
}
mapping(address=> waRecord) public _waList;
eventTokenMinted(addressindexed owner, uint256indexed quantity);
eventSaleStatusChange(addressindexed issuer, boolindexed status);
eventContractWithdraw(addressindexed initiator, uint256 amount);
eventContractWithdrawToken(addressindexed initiator, addressindexed token, uint256 amount);
eventProvenanceHashSet(addressindexed initiator, string previousHash, string newHash);
eventWithdrawAddressChanged(addressindexed previousAddress, addressindexed newAddress);
uint16internal royalty =750; // base 10000, 7.5%uint16publicconstant BASE =10000;
constructor(uint256 _saleStartTime,
uint256 _privateSaleEndsAt,
uint256 _publicSaleStartsAt,
uint256 _publicsaleEndsAt,
uint256 _redemptionEndsAt,
stringmemory _baseContractURI,
stringmemory _tokenSuffixURI,
stringmemory _provenanceHash,
address[] memory _recipients,
uint16[] memory _splits,
address _proxyAddress
) ERC721('Catbotica', 'CBOT') {
baseURI = _baseContractURI;
tokenSuffixURI = _tokenSuffixURI;
saleStartsAt = _saleStartTime; // Unix Timestamp for sale starting time
privatesaleStartsAt = saleStartsAt; // Start Private Sale
privatesaleEndsAt = _privateSaleEndsAt; // End of Private Sale
publicsaleStartsAt = _publicSaleStartsAt; // Start of Public Sale
publicsaleEndsAt = _publicsaleEndsAt; // End of Public Sale
redemptionEndsAt = _redemptionEndsAt; // End of period for members to redeem free tokens
PROVENANCE_HASH = _provenanceHash;
recipients = _recipients;
splits = _splits;
proxyRegistryAddress[_proxyAddress] =true;
}
functionmintNFT(address recipient, uint8 numTokens) publiconlyOwner{
uint256 time = (block.timestamp);
require(time > privatesaleEndsAt && time < publicsaleStartsAt, 'Not Allowed');
require(
(_tokenIds.current() + numTokens + RESERVED_TOKEN_ID_OFFSET) <= MAX_PRIVATE_SALE_SUPPLY,
'Private sale over'
);
for (uint8 i =0; i < numTokens; i++) {
_tokenIds.increment();
_safeMint(recipient, _tokenIds.current() + RESERVED_TOKEN_ID_OFFSET);
}
emit TokenMinted(recipient, numTokens);
}
functionclaimUnredeemed(address recipient, uint8 numTokens) publiconlyOwner{
uint256 time = (block.timestamp);
require(time > redemptionEndsAt, 'Redemption still active');
require((_redeemIds.current() + numTokens) <= RESERVED_TOKEN_ID_OFFSET, 'Tokens Redeemed');
for (uint8 i =0; i < numTokens; i++) {
_redeemIds.increment();
_safeMint(recipient, _redeemIds.current());
}
emit TokenMinted(recipient, numTokens);
}
/**
* @dev mints equivalent of `msg.sender` whitelisted balance of Catbotica token and assigns it to
* `msg.sender` by calling _safeMint function. Dedicated for free redemotion for Catbotica RWA List.
*
* Emits a {TokenMinted} event.
* Emits two {TransferSingle} events via ERC721 Contract.
*
* Requirements:
* - `saleActive` must be set to true.
* - Current timestamp must greater than or equal `saleStartsAt`.
* - `msg.sender` is among whitelisted Catbotica RWA list members and hasn't redeemed the token before.
* - Max number of tokens assigned for free redemption not reahced
*/functionmemberRedeem() public{
require(block.timestamp>= saleStartsAt &&block.timestamp< redemptionEndsAt, 'Redeem not active');
uint8 userBalance = _waList[msg.sender].balance;
require((_redeemIds.current()) + userBalance <= RESERVED_TOKEN_ID_OFFSET, 'Tokens Redeemed');
require(_waList[msg.sender].exists, 'Restricted access');
require(!_waList[msg.sender].redeemed, 'Tokens redeemed');
_waList[msg.sender].redeemed =true;
for (uint8 i =0; i < userBalance; i++) {
_redeemIds.increment();
_safeMint(msg.sender, _redeemIds.current());
}
emit TokenMinted(msg.sender, userBalance);
}
/**
* @dev mints `numTokens` tokens of Catbotica token and assigns it to
* `msg.sender` by calling _safeMint function.
*
* Emits a {TokenMinted} event.
* Emits two {TransferSingle} events via ERC721 Contract.
*
* Requirements:
* - `saleActive` must be set to true.
* - Current timestamp must greater than or equal `saleStartsAt`.
* - Current timestamp must within period of private sale `privatesaleStartsAt` - `privatesaleEndsAt`.
* - `msg.sender` is among whitelisted Catbotica memebrs or partners
* - Ether amount sent greater or equal the base price multipled by `numTokens`.
* - `numTokens` within limits of max number of tokens minted in single txn.
* - Max number of tokens for the private sale not reahced
* @param numTokens - Number of tokens to be minted
*/functionmintPrivateSale(uint8 numTokens) publicpayable{
require(saleActive &&block.timestamp>= saleStartsAt, 'Sale not active');
uint256 time = (block.timestamp);
require(time > privatesaleStartsAt && time < privatesaleEndsAt, 'Private sale over');
require(_waList[msg.sender].exists, 'Restricted access');
require(!_waList[msg.sender].minted, 'Tokens minted');
uint8 tokenLimit = _waList[msg.sender].limit;
require(numTokens <= tokenLimit, 'Above limit');
require(
(_tokenIds.current() + numTokens + RESERVED_TOKEN_ID_OFFSET) <= MAX_PRIVATE_SALE_SUPPLY,
'Private sale sold'
);
require(msg.value>= PRIVATE_SALE_PRICE * numTokens, 'Insufficient ETH');
require(numTokens >0, 'Wrong Num Token');
for (uint8 i =0; i < numTokens; i++) {
_tokenIds.increment();
_waList[msg.sender].limit = _waList[msg.sender].limit -1;
_safeMint(msg.sender, _tokenIds.current() + RESERVED_TOKEN_ID_OFFSET);
}
if (_waList[msg.sender].limit ==0) {
_waList[msg.sender].minted =true;
}
emit TokenMinted(msg.sender, numTokens);
}
/**
* @dev mints `numTokens` tokens of Catbotica token and assigns it to
* `msg.sender` by calling _safeMint function.
*
* Emits a {TokenMinted} event.
* Emits two {TransferSingle} events via ERC721 Contract.
*
* Requirements:
* - `saleActive` must be set to true.
* - Current timestamp must greater than or equal `saleStartsAt`.
* - Current timestamp must within period of public sale `publicsaleStartsAt` - `publicsaleEndsAt`.
* - Ether amount sent greater or equal the current price multipled by `numTokens`.
* - `numTokens` within limits of max number of tokens minted in single txn.
* - Max number of tokens for the sale not reahced
* @param numTokens - Number of tokens to be minted
*/functionmintPublicSale(uint8 numTokens) publicpayable{
require(saleActive &&block.timestamp>= saleStartsAt, 'Sale not active');
uint256 time = (block.timestamp);
require(time > publicsaleStartsAt && time < publicsaleEndsAt, 'Public sale over');
uint256 currentPrice = _getCurrentPrice();
require(msg.value>= currentPrice * numTokens, 'Insufficient ETH');
require(numTokens <= MINT_BATCH_LIMIT && numTokens >0, 'Wrong Num Token');
require((_tokenIds.current() + numTokens + RESERVED_TOKEN_ID_OFFSET) <= MAX_TOKENS, 'Public sale sold');
for (uint8 i =0; i < numTokens; i++) {
_tokenIds.increment();
_safeMint(msg.sender, _tokenIds.current() + RESERVED_TOKEN_ID_OFFSET);
}
emit TokenMinted(msg.sender, numTokens);
}
function_getCurrentPrice() internalviewreturns (uint256) {
uint256 time = (block.timestamp);
uint256 price = BOTTOM_PRICE;
if (time > (PUBLIC_SALE_PERIOD + publicsaleStartsAt)) {
return price;
}
uint256 timeSlot = (time - publicsaleStartsAt) / TICK_PERIOD;
if (timeSlot >0) {
timeSlot = timeSlot -1;
}
price = STARTING_PRICE - (SALE_PRICE_STEP * timeSlot);
return price;
}
functiongetCurrentPrice() publicviewreturns (uint256) {
uint256 time = (block.timestamp);
if (time < privatesaleEndsAt) {
return PRIVATE_SALE_PRICE;
}
if (time > privatesaleEndsAt && time < publicsaleStartsAt) {
return STARTING_PRICE;
}
return _getCurrentPrice();
}
/**
* @dev Adds list of wallet addresses and their Catbotica membership card balances to whitelisted members in '_memberslist'.
*
* @param users - List of wallet addresses
* @param balances - Whitelisted Users allowed balances for redeem
* @param limits - Whitelisted Users limit in private sale
*/functionwhitelistMembers(address[] memory users,
uint8[] memory balances,
uint8[] memory limits
) publiconlyOwner{
require(!saleActive, 'Cant whitelist');
for (uint16 i =0; i < users.length; i++) {
_waList[users[i]].exists =true;
_waList[users[i]].balance= balances[i];
_waList[users[i]].limit = limits[i];
}
}
/**
* @dev removes list of wallet addresses of already whitelisted members from '_walist'.
*
* @param users - List of wallet addresses
*/functionremoveWhitelistMembers(address[] memory users) publiconlyOwner{
for (uint8 i =0; i < users.length; i++) {
delete _waList[users[i]];
}
}
functionsetBaseURI(stringmemory baseContractURI) publiconlyOwner{
baseURI = baseContractURI;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/functiontokenURI(uint256 tokenId) publicviewoverridereturns (stringmemory) {
require(_exists(tokenId), 'ERC721Metadata: URI query for nonexistent token');
stringmemory baseContractURI = _baseURI();
returnbytes(baseContractURI).length>0
? string(abi.encodePacked(baseContractURI, tokenId.toString(), tokenSuffixURI))
: '';
}
/**
* @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() internalviewoverridereturns (stringmemory) {
return baseURI;
}
/**
* @dev returns the base contract metadata json object
* this metadat file is used by OpenSea see {https://docs.opensea.io/docs/contract-level-metadata}
*
*/functioncontractURI() publicviewreturns (stringmemory) {
stringmemory baseContractURI = _baseURI();
returnstring(abi.encodePacked(baseContractURI, contractMetadata));
}
/**
* @dev Changes the sale status 'saleActive' from active to not active and vice versa
*
* Only Contract Owner can execute
*
* Emits a {SaleStatusChange} event.
*/functionchangeSaleStatus() publiconlyOwner{
saleActive =!saleActive;
emit SaleStatusChange(msg.sender, saleActive);
}
/**
* @dev withdraws the contract balance and send it to the withdraw Addresses based on split ratio.
*
* Emits a {ContractWithdraw} event.
*/functionwithdraw() publicnonReentrant{
uint256 balance =address(this).balance;
for (uint256 i =0; i < recipients.length; i++) {
(bool sent, ) =payable(recipients[i]).call{value: (balance * splits[i]) / SPLIT_BASE}('');
require(sent, 'Withdraw Failed.');
}
emit ContractWithdraw(msg.sender, balance);
}
/**
* @dev Queries `_memberslist` and returns if '_address' exists or not.
*
* @param _address - user address
*/functionisWhitelisted(address _address) publicviewreturns (bool) {
return (_waList[_address].exists);
}
/// @notice Calculate the royalty payment/// @param _salePrice the sale price of the tokenfunctionroyaltyInfo(uint256, uint256 _salePrice)
externalviewoverridereturns (address receiver, uint256 royaltyAmount)
{
return (address(this), (_salePrice * royalty) / BASE);
}
/// @dev set the royalty/// @param _royalty the royalty in base 10000, 500 = 5%functionsetRoyalty(uint16 _royalty) publiconlyOwner{
require(_royalty >=0&& _royalty <=1000, 'Royalty must be between 0% and 10%.');
royalty = _royalty;
}
/// @dev withdraw ERC20 tokens divided by splitsfunctionwithdrawTokens(address _tokenContract) externalnonReentrant{
IERC20 tokenContract = IERC20(_tokenContract);
// transfer the token from address of Catbotica addressuint256 balance = tokenContract.balanceOf(address(this));
for (uint256 i =0; i < recipients.length; i++) {
tokenContract.transfer(recipients[i], (balance * splits[i]) / SPLIT_BASE);
}
emit ContractWithdrawToken(msg.sender, _tokenContract, balance);
}
functionsupportsInterface(bytes4 interfaceId) publicviewoverride(ERC721Enumerable, IERC165) returns (bool) {
return interfaceId ==type(IERC2981).interfaceId||super.supportsInterface(interfaceId);
}
functionchangeWithdrawAddress(address _recipient) external{
require(_recipient !=address(0), 'Cannot use zero address');
require(_recipient !=address(this), 'Cannot use this contract address');
// loop over all the recipients and update the addressbool _found =false;
for (uint256 i =0; i < recipients.length; i++) {
// if the sender matches one of the recipients, update the addressif (recipients[i] ==msg.sender) {
recipients[i] = _recipient;
_found =true;
break;
}
}
require(_found, 'The sender is not a recipient.');
emit WithdrawAddressChanged(msg.sender, _recipient);
}
functiongetRemPrivateSaleSupply() publicviewreturns (uint256) {
if (_tokenIds.current() > (MAX_PRIVATE_SALE_SUPPLY - RESERVED_TOKEN_ID_OFFSET)) return0;
return (MAX_PRIVATE_SALE_SUPPLY - RESERVED_TOKEN_ID_OFFSET - _tokenIds.current());
}
functiongetRemPublicSaleSupply() publicviewreturns (uint256) {
return (MAX_TOKENS - RESERVED_TOKEN_ID_OFFSET - _tokenIds.current());
}
// function getTotalPrivateSaleSupply() public pure returns (uint256) {// return MAX_PRIVATE_SALE_SUPPLY;// }// function getTotalPublicSaleSupply() public pure returns (uint256) {// return MAX_TOKENS;// }/*
* Set the provenance
*
* Only Contract Owner can execute
*
*/functionsetProvenanceHash(stringmemory provenanceHash) publiconlyOwner{
emit ProvenanceHashSet(msg.sender, PROVENANCE_HASH, provenanceHash);
PROVENANCE_HASH = provenanceHash;
}
/*
* Function to allow receiving ETH sent to contract
*
*/receive() externalpayable{}
/**
* Override isApprovedForAll to whitelisted marketplaces to enable gas-free listings.
*
*/functionisApprovedForAll(address _owner, address _operator) publicviewoverridereturns (bool isOperator) {
// check if this is an approved marketplaceif (proxyRegistryAddress[_operator]) {
returntrue;
}
// otherwise, use the default ERC721 isApprovedForAll()returnsuper.isApprovedForAll(_owner, _operator);
}
/*
* Function to set status of proxy contracts addresses
*
*/functionsetProxy(address _proxyAddress, bool _value) publiconlyOwner{
proxyRegistryAddress[_proxyAddress] = _value;
}
}
Contract Source Code
File 3 of 18: Context.sol
// SPDX-License-Identifier: MITpragmasolidity ^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.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
Contract Source Code
File 4 of 18: Counters.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
*/libraryCounters{
structCounter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add// this feature: see https://github.com/ethereum/solidity/issues/4637uint256 _value; // default: 0
}
functioncurrent(Counter storage counter) internalviewreturns (uint256) {
return counter._value;
}
functionincrement(Counter storage counter) internal{
unchecked {
counter._value +=1;
}
}
functiondecrement(Counter storage counter) internal{
uint256 value = counter._value;
require(value >0, "Counter: decrement overflow");
unchecked {
counter._value = value -1;
}
}
functionreset(Counter storage counter) internal{
counter._value =0;
}
}
Contract Source Code
File 5 of 18: ERC165.sol
// SPDX-License-Identifier: MITpragmasolidity ^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.
*/abstractcontractERC165isIERC165{
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverridereturns (bool) {
return interfaceId ==type(IERC165).interfaceId;
}
}
Contract Source Code
File 6 of 18: ERC721.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"./IERC721.sol";
import"./IERC721Receiver.sol";
import"./extensions/IERC721Metadata.sol";
import"../../utils/Address.sol";
import"../../utils/Context.sol";
import"../../utils/Strings.sol";
import"../../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}.
*/contractERC721isContext, ERC165, IERC721, IERC721Metadata{
usingAddressforaddress;
usingStringsforuint256;
// Token namestringprivate _name;
// Token symbolstringprivate _symbol;
// Mapping from token ID to owner addressmapping(uint256=>address) private _owners;
// Mapping owner address to token countmapping(address=>uint256) private _balances;
// Mapping from token ID to approved addressmapping(uint256=>address) private _tokenApprovals;
// Mapping from owner to operator approvalsmapping(address=>mapping(address=>bool)) private _operatorApprovals;
/**
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/constructor(stringmemory name_, stringmemory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverride(ERC165, IERC165) returns (bool) {
return
interfaceId ==type(IERC721).interfaceId||
interfaceId ==type(IERC721Metadata).interfaceId||super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/functionbalanceOf(address owner) publicviewvirtualoverridereturns (uint256) {
require(owner !=address(0), "ERC721: balance query for the zero address");
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/functionownerOf(uint256 tokenId) publicviewvirtualoverridereturns (address) {
address owner = _owners[tokenId];
require(owner !=address(0), "ERC721: owner query for nonexistent token");
return owner;
}
/**
* @dev See {IERC721Metadata-name}.
*/functionname() publicviewvirtualoverridereturns (stringmemory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/functionsymbol() publicviewvirtualoverridereturns (stringmemory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/functiontokenURI(uint256 tokenId) publicviewvirtualoverridereturns (stringmemory) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
stringmemory baseURI = _baseURI();
returnbytes(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() internalviewvirtualreturns (stringmemory) {
return"";
}
/**
* @dev See {IERC721-approve}.
*/functionapprove(address to, uint256 tokenId) publicvirtualoverride{
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}.
*/functiongetApproved(uint256 tokenId) publicviewvirtualoverridereturns (address) {
require(_exists(tokenId), "ERC721: approved query for nonexistent token");
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/functionsetApprovalForAll(address operator, bool approved) publicvirtualoverride{
require(operator != _msgSender(), "ERC721: approve to caller");
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/functionisApprovedForAll(address owner, address operator) publicviewvirtualoverridereturns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/functiontransferFrom(addressfrom,
address to,
uint256 tokenId
) publicvirtualoverride{
//solhint-disable-next-line max-line-lengthrequire(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId
) publicvirtualoverride{
safeTransferFrom(from, to, tokenId, "");
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId,
bytesmemory _data
) publicvirtualoverride{
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(addressfrom,
address to,
uint256 tokenId,
bytesmemory _data
) internalvirtual{
_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) internalviewvirtualreturns (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) internalviewvirtualreturns (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` and transfers it 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 to, uint256 tokenId) internalvirtual{
_safeMint(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 to,
uint256 tokenId,
bytesmemory _data
) internalvirtual{
_mint(to, tokenId);
require(
_checkOnERC721Received(address(0), to, tokenId, _data),
"ERC721: transfer to non ERC721Receiver implementer"
);
}
/**
* @dev Mints `tokenId` and transfers it 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 to, uint256 tokenId) internalvirtual{
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), 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) internalvirtual{
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(addressfrom,
address to,
uint256 tokenId
) internalvirtual{
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) internalvirtual{
_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(addressfrom,
address to,
uint256 tokenId,
bytesmemory _data
) privatereturns (bool) {
if (to.isContract()) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver.onERC721Received.selector;
} catch (bytesmemory reason) {
if (reason.length==0) {
revert("ERC721: transfer to non ERC721Receiver implementer");
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
returntrue;
}
}
/**
* @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(addressfrom,
address to,
uint256 tokenId
) internalvirtual{}
}
Contract Source Code
File 7 of 18: ERC721Enumerable.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"../ERC721.sol";
import"./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.
*/abstractcontractERC721EnumerableisERC721, IERC721Enumerable{
// Mapping from owner to list of owned token IDsmapping(address=>mapping(uint256=>uint256)) private _ownedTokens;
// Mapping from token ID to index of the owner tokens listmapping(uint256=>uint256) private _ownedTokensIndex;
// Array with all token ids, used for enumerationuint256[] private _allTokens;
// Mapping from token id to position in the allTokens arraymapping(uint256=>uint256) private _allTokensIndex;
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverride(IERC165, ERC721) returns (bool) {
return interfaceId ==type(IERC721Enumerable).interfaceId||super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/functiontokenOfOwnerByIndex(address owner, uint256 index) publicviewvirtualoverridereturns (uint256) {
require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/functiontotalSupply() publicviewvirtualoverridereturns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/functiontokenByIndex(uint256 index) publicviewvirtualoverridereturns (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(addressfrom,
address to,
uint256 tokenId
) internalvirtualoverride{
super._beforeTokenTransfer(from, to, tokenId);
if (from==address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} elseif (from!= to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to ==address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} elseif (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(addressfrom, 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 unnecessaryif (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 arraydelete _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 arraydelete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"./IERC165.sol";
/**
* @dev Interface for the NFT Royalty Standard
*/interfaceIERC2981isIERC165{
/**
* @dev Called with the sale price to determine how much royalty is owed and to whom.
* @param tokenId - the NFT asset queried for royalty information
* @param salePrice - the sale price of the NFT asset specified by `tokenId`
* @return receiver - address of who should be sent the royalty payment
* @return royaltyAmount - the royalty payment amount for `salePrice`
*/functionroyaltyInfo(uint256 tokenId, uint256 salePrice)
externalviewreturns (address receiver, uint256 royaltyAmount);
}
Contract Source Code
File 11 of 18: IERC721.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/interfaceIERC721isIERC165{
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/eventApproval(addressindexed owner, addressindexed approved, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/eventApprovalForAll(addressindexed owner, addressindexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/functionbalanceOf(address owner) externalviewreturns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functionownerOf(uint256 tokenId) externalviewreturns (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.
*/functionsafeTransferFrom(addressfrom,
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.
*/functiontransferFrom(addressfrom,
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.
*/functionapprove(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functiongetApproved(uint256 tokenId) externalviewreturns (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.
*/functionsetApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/functionisApprovedForAll(address owner, address operator) externalviewreturns (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.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId,
bytescalldata data
) external;
}
Contract Source Code
File 12 of 18: IERC721Enumerable.sol
// SPDX-License-Identifier: MITpragmasolidity ^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
*/interfaceIERC721EnumerableisIERC721{
/**
* @dev Returns the total amount of tokens stored by the contract.
*/functiontotalSupply() externalviewreturns (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.
*/functiontokenOfOwnerByIndex(address owner, uint256 index) externalviewreturns (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.
*/functiontokenByIndex(uint256 index) externalviewreturns (uint256);
}
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/interfaceIERC721Receiver{
/**
* @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`.
*/functiononERC721Received(address operator,
addressfrom,
uint256 tokenId,
bytescalldata data
) externalreturns (bytes4);
}
Contract Source Code
File 15 of 18: Ownable.sol
// SPDX-License-Identifier: MITpragmasolidity ^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.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/constructor() {
_setOwner(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/modifieronlyOwner() {
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.
*/functionrenounceOwnership() publicvirtualonlyOwner{
_setOwner(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
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);
}
}
Contract Source Code
File 16 of 18: Pausable.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"../utils/Context.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/abstractcontractPausableisContext{
/**
* @dev Emitted when the pause is triggered by `account`.
*/eventPaused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/eventUnpaused(address account);
boolprivate _paused;
/**
* @dev Initializes the contract in unpaused state.
*/constructor() {
_paused =false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/functionpaused() publicviewvirtualreturns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/modifierwhenNotPaused() {
require(!paused(), "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/modifierwhenPaused() {
require(paused(), "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/function_pause() internalvirtualwhenNotPaused{
_paused =true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/function_unpause() internalvirtualwhenPaused{
_paused =false;
emit Unpaused(_msgSender());
}
}
Contract Source Code
File 17 of 18: ReentrancyGuard.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/abstractcontractReentrancyGuard{
// Booleans are more expensive than uint256 or any type that takes up a full// word because each write operation emits an extra SLOAD to first read the// slot's contents, replace the bits taken up by the boolean, and then write// back. This is the compiler's defense against contract upgrades and// pointer aliasing, and it cannot be disabled.// The values being non-zero value makes deployment a bit more expensive,// but in exchange the refund on every call to nonReentrant will be lower in// amount. Since refunds are capped to a percentage of the total// transaction's gas, it is best to keep them low in cases like this one, to// increase the likelihood of the full refund coming into effect.uint256privateconstant _NOT_ENTERED =1;
uint256privateconstant _ENTERED =2;
uint256private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/modifiernonReentrant() {
// On the first call to nonReentrant, _notEntered will be truerequire(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
Contract Source Code
File 18 of 18: Strings.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev String operations.
*/libraryStrings{
bytes16privateconstant _HEX_SYMBOLS ="0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/functiontoString(uint256 value) internalpurereturns (stringmemory) {
// Inspired by OraclizeAPI's implementation - MIT licence// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.solif (value ==0) {
return"0";
}
uint256 temp = value;
uint256 digits;
while (temp !=0) {
digits++;
temp /=10;
}
bytesmemory buffer =newbytes(digits);
while (value !=0) {
digits -=1;
buffer[digits] =bytes1(uint8(48+uint256(value %10)));
value /=10;
}
returnstring(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/functiontoHexString(uint256 value) internalpurereturns (stringmemory) {
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.
*/functiontoHexString(uint256 value, uint256 length) internalpurereturns (stringmemory) {
bytesmemory buffer =newbytes(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");
returnstring(buffer);
}
}