Contract Name:
DemocracyCoins
Contract Source Code:
File 1 of 1 : DemocracyCoins
pragma solidity ^0.5.0;
/**We created Democracy coins 14,000,000 coins and they will go to the people who believe in Democracy,
* (14 coins per each). Most people want to join in this important event but they don't know how to do as me
* so DEMCoin is the best way to bring me to be apart of the big chaining
*/
library SafeMath {
/**
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a, "SafeMath: subtraction overflow");
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, "SafeMath: division by zero");
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b != 0, "SafeMath: modulo by zero");
return a % b;
}
}
/**
* @title Ownable
* @dev The Ownable contract has an owner address, and provides basic authorization control
* functions, this simplifies the implementation of "user permissions".
*/
contract Ownable {
address public owner;
// User fullnames / nicknames
mapping (address => string) users;
/**
* @dev The Ownable constructor sets the original `owner` of the contract to the sender
* account.
*/
constructor() public {
owner = msg.sender;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
/**
* @dev Allows the current owner to transfer control of the contract to a newOwner.
* @param newOwner The address to transfer ownership to.
*/
function transferOwnership(address newOwner) public onlyOwner {
if (newOwner != address(0)) {
owner = newOwner;
}
}
// Register uesrname
function register(string memory userName) public {
users[msg.sender] = userName;
}
// Getter of usernames
function getPublicName(address userAddress) public view returns (string memory) {
return users[userAddress];
}
}
/**
* @title ERC20Basic
* @dev Simpler version of ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20Basic {
uint public totalSupply;
function balanceOf(address who) public view returns (uint);
function transfer(address to, uint value) public;
event Transfer(address indexed from, address indexed to, uint value);
}
/**
* @title Basic token
* @dev Basic version of StandardToken, with no allowances.
*/
contract BasicToken is ERC20Basic {
using SafeMath for uint;
mapping(address => uint) balances;
/**
* @dev transfer token for a specified address
* @param _to The address to transfer to.
* @param _value The amount to be transferred.
*/
function transfer(address _to, uint _value) public {
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
}
/**
* @dev Gets the balance of the specified address.
* @param _owner The address to query the the balance of.
* @return An uint representing the amount owned by the passed address.
*/
function balanceOf(address _owner) public view returns (uint balance) {
return balances[_owner];
}
}
/**
* @title ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20 is ERC20Basic {
function allowance(address owner, address spender) public view returns (uint);
function transferFrom(address from, address to, uint value) public;
function approve(address spender, uint value) public;
event Approval(address indexed owner, address indexed spender, uint value);
}
/**
* @title Standard ERC20 token
*
* @dev Implemantation of the basic standart token.
* @dev https://github.com/ethereum/EIPs/issues/20
* @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
*/
contract StandardToken is BasicToken, ERC20 {
mapping (address => mapping (address => uint)) allowed;
/**
* @dev Transfer tokens from one address to another
* @param _from address The address which you want to send tokens from
* @param _to address The address which you want to transfer to
* @param _value uint the amout of tokens to be transfered
*/
function transferFrom(address _from, address _to, uint _value) public {
uint256 _allowance = allowed[_from][msg.sender];
// Check is not needed because sub(_allowance, _value) will already revert() if this condition is not met
// if (_value > _allowance) revert();
balances[_to] = balances[_to].add(_value);
balances[_from] = balances[_from].sub(_value);
allowed[_from][msg.sender] = _allowance.sub(_value);
emit Transfer(_from, _to, _value);
}
/**
* @dev Aprove the passed address to spend the specified amount of tokens on beahlf of msg.sender.
* @param _spender The address which will spend the funds.
* @param _value The amount of tokens to be spent.
*/
function approve(address _spender, uint _value) public {
// To change the approve amount you first have to reduce the addresses`
// allowance to zero by calling `approve(_spender, 0)` if it is not
// already 0 to mitigate the race condition described here:
// https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
if ((_value != 0) && (allowed[msg.sender][_spender] != 0)) revert("approve revert");
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
}
/**
* @dev Function to check the amount of tokens than an owner allowed to a spender.
* @param _owner address The address which owns the funds.
* @param _spender address The address which will spend the funds.
* @return A uint specifing the amount of tokens still avaible for the spender.
*/
function allowance(address _owner, address _spender) public view returns (uint remaining) {
return allowed[_owner][_spender];
}
}
/**
* @title Mintable token
* @dev ERC20 Token with mintable token creation
* @dev Issue: * https://github.com/OpenZeppelin/zeppelin-solidity/issues/120
* Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
*/
contract MintableToken is StandardToken, Ownable {
event Mint(address indexed to, uint value);
event MintFinished();
bool public mintingFinished = false;
uint public totalSupply = 0;
modifier canMint() {
if(mintingFinished) revert();
_;
}
/**
* @dev Function to mint tokens
* @param _to The address that will recieve the minted tokens.
* @param _amount The amount of tokens to mint.
* @return A boolean that indicates if the operation was successful.
*/
function mint(address _to, uint _amount) public onlyOwner canMint returns (bool) {
totalSupply = totalSupply.add(_amount);
balances[_to] = balances[_to].add(_amount);
emit Mint(_to, _amount);
return true;
}
/**
* @dev Function to stop minting new tokens.
* @return True if the operation was successful.
*/
function finishMinting() public onlyOwner returns (bool) {
mintingFinished = true;
emit MintFinished();
return true;
}
}
/**
* @title Pausable
* @dev Base contract which allows children to implement an emergency stop mechanism.
*/
contract Pausable is Ownable {
event Pause();
event Unpause();
bool public paused = false;
/**
* @dev modifier to allow actions only when the contract IS paused
*/
modifier whenNotPaused() {
if (paused) revert("it's paused");
_;
}
/**
* @dev modifier to allow actions only when the contract IS NOT paused
*/
modifier whenPaused {
if (!paused) revert("it's not paused");
_;
}
/**
* @dev called by the owner to pause, triggers stopped state
*/
function pause() public onlyOwner whenNotPaused returns (bool) {
paused = true;
emit Pause();
return true;
}
/**
* @dev called by the owner to unpause, returns to normal state
*/
function unpause() public onlyOwner whenPaused returns (bool) {
paused = false;
emit Unpause();
return true;
}
}
/**
* Pausable token
*
* ERC20 Token with pausable token creation
**/
contract PausableToken is StandardToken, Pausable {
function transfer(address _to, uint _value) public whenNotPaused {
super.transfer(_to, _value);
}
function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
super.transferFrom(_from, _to, _value);
}
}
/**
* @title ERC20 "Democracy Token"
*/
contract DemocracyCoins is PausableToken, MintableToken {
using SafeMath for uint256;
string public name;
string public symbol;
uint public decimals;
constructor(string memory _name, string memory _symbol, uint _decimals) public {
name = _name;
symbol = _symbol;
decimals = _decimals;
}
}