Files
openzeppelin-contracts/contracts/lifecycle/Pausable.sol
Nicolás Venturo 5dfe7215a9 Migrate Contracts to Solidity v0.6 (#2080)
* Initial migration to Solidity 0.6.x - v3.0 first steps (#2063)

* Initial migration, missing GSN, 721, 777 and Crowdsales.

* Add _beforeTokenOperation and _afterTokenOperation.

* Add documentation for hooks.

* Add hooks doc

* Add missing drafts

* Add back ERC721 with hooks

* Bring back ERC777

* Notes on hooks

* Bring back GSN

* Make functions virtual

* Make GSN overrides explicit

* Fix ERC20Pausable tests

* Remove virtual from some view functions

* Update linter

* Delete examples

* Remove unnecessary virtual

* Remove roles from Pausable

* Remove roles

* Remove users of roles

* Adapt ERC20 tests

* Fix ERC721 tests

* Add all ERC721 hooks

* Add ERC777 hooks

* Fix remaining tests

* Bump compiler version

* Move 721BurnableMock into mocks directory

* Remove _before hooks

* Fix tests

* Upgrade linter

* Put modifiers last

* Remove _beforeTokenApproval and _beforeOperatorApproval hooks
2020-02-14 11:12:32 -03:00

74 lines
1.9 KiB
Solidity

pragma solidity ^0.6.0;
import "../GSN/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.
*/
contract Pausable is Context {
/**
* @dev Emitted when the pause is triggered by a pauser (`account`).
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by a pauser (`account`).
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state. Assigns the Pauser role
* to the deployer.
*/
constructor () internal {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*/
modifier whenNotPaused() {
require(!_paused, "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*/
modifier whenPaused() {
require(_paused, "Pausable: not paused");
_;
}
/**
* @dev Called by a pauser to pause, triggers stopped state.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Called by a pauser to unpause, returns to normal state.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
}