pragma solidity 0.4.21;

contract Ownable {
  address public owner;
  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  function Ownable() public {
    owner = msg.sender;
  }
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }
  function transferOwnership(address newOwner) public onlyOwner {
    require(newOwner != address(0));
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }
}

contract ERC20Basic {
  uint256 public totalSupply;
  function balanceOf(address who) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

contract BasicToken is ERC20Basic, Ownable {
    using SafeMath for uint256;
    mapping(address => uint256) balances;
    bool public transfersEnabledFlag;
    modifier transfersEnabled() {
        require(transfersEnabledFlag);
        _;
    }
    function enableTransfers() public onlyOwner {
        transfersEnabledFlag = true;
    }
    function transfer(address _to, uint256 _value) transfersEnabled() public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[msg.sender]);
        // SafeMath.sub will throw if there is not enough balance.
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        Transfer(msg.sender, _to, _value);
        return true;
    }
    function balanceOf(address _owner) public view returns (uint256 balance) {
        return balances[_owner];
    }
}
library SafeMath {
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) public view returns (uint256);
  function transferFrom(address from, address to, uint256 value) public returns (bool);
  function approve(address spender, uint256 value) public returns (bool);
  event Approval(address indexed owner, address indexed spender, uint256 value);
}
contract StandardToken is ERC20, BasicToken {
    mapping (address => mapping (address => uint256)) internal allowed;
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
        Transfer(_from, _to, _value);
        return true;
    }
    function approve(address _spender, uint256 _value) public returns (bool) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }
    function allowance(address _owner, address _spender) public view returns (uint256) {
        return allowed[_owner][_spender];
    }
    function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
        allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
        Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }
    function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
        uint oldValue = allowed[msg.sender][_spender];
        if (_subtractedValue > oldValue) {
            allowed[msg.sender][_spender] = 0;
        }
        else {
            allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
        }
        Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }
}

contract MintableToken is StandardToken {
    event Mint(address indexed to, uint256 amount);
    event MintFinished();
    bool public mintingFinished = false;
    mapping(address => bool) public minters;
    modifier canMint() {
        require(!mintingFinished);
        _;
    }
    modifier onlyMinters() {
        require(minters[msg.sender] || msg.sender == owner);
        _;
    }
    function addMinter(address _addr) public onlyOwner {
        minters[_addr] = true;
    }
    function deleteMinter(address _addr) public onlyOwner {
        delete minters[_addr];
    }
    function mint(address _to, uint256 _amount) onlyMinters canMint public returns (bool) {
        require(_to != address(0));
        totalSupply = totalSupply.add(_amount);
        balances[_to] = balances[_to].add(_amount);
        Mint(_to, _amount);
        Transfer(address(0), _to, _amount);
        return true;
    }
    function finishMinting() onlyOwner canMint public returns (bool) {
        mintingFinished = true;
        MintFinished();
        return true;
    }
}
contract CappedToken is MintableToken {
    uint256 public cap;
    function CappedToken(uint256 _cap) public {
        require(_cap > 0);
        cap = _cap;
    }
    function mint(address _to, uint256 _amount) onlyMinters canMint public returns (bool) {
        require(totalSupply.add(_amount) <= cap);
        return super.mint(_to, _amount);
    }
}
contract ParameterizedToken is CappedToken {
    string public name;
    string public symbol;
    uint256 public decimals;
    function ParameterizedToken(string _name, string _symbol, uint256 _decimals, uint256 _capIntPart) public CappedToken(_capIntPart * 10 ** _decimals) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
    }
}
contract GameXToken is ParameterizedToken {
    function GameXToken() public ParameterizedToken("Game-X Token", "GTK", 8, 100000000) {
    }
}