dexorder

lib_openzeppelin_contracts/contracts/token/common/ERC2981.sol

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+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.0.0) (token/common/ERC2981.sol)
+
+pragma solidity ^0.8.20;
+
+import {IERC2981} from "../../interfaces/IERC2981.sol";
+import {IERC165, ERC165} from "../../utils/introspection/ERC165.sol";
+
+/**
+ * @dev Implementation of the NFT Royalty Standard, a standardized way to retrieve royalty payment information.
+ *
+ * Royalty information can be specified globally for all token ids via {_setDefaultRoyalty}, and/or individually for
+ * specific token ids via {_setTokenRoyalty}. The latter takes precedence over the first.
+ *
+ * Royalty is specified as a fraction of sale price. {_feeDenominator} is overridable but defaults to 10000, meaning the
+ * fee is specified in basis points by default.
+ *
+ * IMPORTANT: ERC-2981 only specifies a way to signal royalty information and does not enforce its payment. See
+ * https://eips.ethereum.org/EIPS/eip-2981#optional-royalty-payments[Rationale] in the ERC. Marketplaces are expected to
+ * voluntarily pay royalties together with sales, but note that this standard is not yet widely supported.
+ */
+abstract contract ERC2981 is IERC2981, ERC165 {
+    struct RoyaltyInfo {
+        address receiver;
+        uint96 royaltyFraction;
+    }
+
+    RoyaltyInfo private _defaultRoyaltyInfo;
+    mapping(uint256 tokenId => RoyaltyInfo) private _tokenRoyaltyInfo;
+
+    /**
+     * @dev The default royalty set is invalid (eg. (numerator / denominator) >= 1).
+     */
+    error ERC2981InvalidDefaultRoyalty(uint256 numerator, uint256 denominator);
+
+    /**
+     * @dev The default royalty receiver is invalid.
+     */
+    error ERC2981InvalidDefaultRoyaltyReceiver(address receiver);
+
+    /**
+     * @dev The royalty set for an specific `tokenId` is invalid (eg. (numerator / denominator) >= 1).
+     */
+    error ERC2981InvalidTokenRoyalty(uint256 tokenId, uint256 numerator, uint256 denominator);
+
+    /**
+     * @dev The royalty receiver for `tokenId` is invalid.
+     */
+    error ERC2981InvalidTokenRoyaltyReceiver(uint256 tokenId, address receiver);
+
+    /**
+     * @dev See {IERC165-supportsInterface}.
+     */
+    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) {
+        return interfaceId == type(IERC2981).interfaceId || super.supportsInterface(interfaceId);
+    }
+
+    /**
+     * @inheritdoc IERC2981
+     */
+    function royaltyInfo(uint256 tokenId, uint256 salePrice) public view virtual returns (address, uint256) {
+        RoyaltyInfo storage _royaltyInfo = _tokenRoyaltyInfo[tokenId];
+        address royaltyReceiver = _royaltyInfo.receiver;
+        uint96 royaltyFraction = _royaltyInfo.royaltyFraction;
+
+        if (royaltyReceiver == address(0)) {
+            royaltyReceiver = _defaultRoyaltyInfo.receiver;
+            royaltyFraction = _defaultRoyaltyInfo.royaltyFraction;
+        }
+
+        uint256 royaltyAmount = (salePrice * royaltyFraction) / _feeDenominator();
+
+        return (royaltyReceiver, royaltyAmount);
+    }
+
+    /**
+     * @dev The denominator with which to interpret the fee set in {_setTokenRoyalty} and {_setDefaultRoyalty} as a
+     * fraction of the sale price. Defaults to 10000 so fees are expressed in basis points, but may be customized by an
+     * override.
+     */
+    function _feeDenominator() internal pure virtual returns (uint96) {
+        return 10000;
+    }
+
+    /**
+     * @dev Sets the royalty information that all ids in this contract will default to.
+     *
+     * Requirements:
+     *
+     * - `receiver` cannot be the zero address.
+     * - `feeNumerator` cannot be greater than the fee denominator.
+     */
+    function _setDefaultRoyalty(address receiver, uint96 feeNumerator) internal virtual {
+        uint256 denominator = _feeDenominator();
+        if (feeNumerator > denominator) {
+            // Royalty fee will exceed the sale price
+            revert ERC2981InvalidDefaultRoyalty(feeNumerator, denominator);
+        }
+        if (receiver == address(0)) {
+            revert ERC2981InvalidDefaultRoyaltyReceiver(address(0));
+        }
+
+        _defaultRoyaltyInfo = RoyaltyInfo(receiver, feeNumerator);
+    }
+
+    /**
+     * @dev Removes default royalty information.
+     */
+    function _deleteDefaultRoyalty() internal virtual {
+        delete _defaultRoyaltyInfo;
+    }
+
+    /**
+     * @dev Sets the royalty information for a specific token id, overriding the global default.
+     *
+     * Requirements:
+     *
+     * - `receiver` cannot be the zero address.
+     * - `feeNumerator` cannot be greater than the fee denominator.
+     */
+    function _setTokenRoyalty(uint256 tokenId, address receiver, uint96 feeNumerator) internal virtual {
+        uint256 denominator = _feeDenominator();
+        if (feeNumerator > denominator) {
+            // Royalty fee will exceed the sale price
+            revert ERC2981InvalidTokenRoyalty(tokenId, feeNumerator, denominator);
+        }
+        if (receiver == address(0)) {
+            revert ERC2981InvalidTokenRoyaltyReceiver(tokenId, address(0));
+        }
+
+        _tokenRoyaltyInfo[tokenId] = RoyaltyInfo(receiver, feeNumerator);
+    }
+
+    /**
+     * @dev Resets royalty information for the token id back to the global default.
+     */
+    function _resetTokenRoyalty(uint256 tokenId) internal virtual {
+        delete _tokenRoyaltyInfo[tokenId];
+    }
+}

lib_openzeppelin_contracts/contracts/token/common/README.adoc

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+= Common (Tokens)
+
+Functionality that is common to multiple token standards.
+
+* {ERC2981}: NFT Royalties compatible with both ERC-721 and ERC-1155.
+** For ERC-721 consider {ERC721Royalty} which clears the royalty information from storage on burn.
+
+== Contracts
+
+{{ERC2981}}