pragma solidity ^0.4.0;

import "browser/Token.sol";

import "browser/ERC20.sol";

import "browser/ERC223.sol";

import "browser/ERC223ReceivingContract.sol";

contract MyFirstToken is Token("MFT", "My First Token", 18, 1000), ERC20, ERC223 {

constructor() public {

_balanceOf[msg.sender] = _totalSupply;

}

function totalSupply() public constant returns (uint) {

return _totalSupply;

}

function balanceOf(address _addr) public constant returns (uint) {

return _balanceOf[_addr];

}

function transfer(address _to, uint _value) public returns (bool) {

if (_value > 0 &&

_value <= _balanceOf[msg.sender] &&

!isContract(_to)) {

_balanceOf[msg.sender] -= _value;

_balanceOf[_to] += _value;

emit Transfer(msg.sender, _to, _value);

return true;

}

return false;

}

function transfer(address _to, uint _value, bytes _data) public returns (bool) {

if (_value > 0 &&

_value <= _balanceOf[msg.sender] &&

isContract(_to)) {

_balanceOf[msg.sender] -= _value;

_balanceOf[_to] += _value;

ERC223ReceivingContract _contract = ERC223ReceivingContract(_to);

_contract.tokenFallback(msg.sender, _value, _data);

emit Transfer(msg.sender, _to, _value, _data);

return true;

}

return false;

}

function isContract(address _addr) public view returns (bool) {

uint codeSize;

assembly {

codeSize := extcodesize(_addr)

}

return codeSize > 0;

}

function transferFrom(address _from, address _to, uint _value) public returns (bool) {

if (_allowances[_from][msg.sender] > 0 &&

_value > 0 &&

_allowances[_from][msg.sender] >= _value &&

_balanceOf[_from] >= _value) {

_balanceOf[_from] -= _value;

_balanceOf[_to] += _value;

_allowances[_from][msg.sender] -= _value;

emit Transfer(_from, _to, _value);

return true;

}

return false;

}

function approve(address _spender, uint _value) public returns (bool) {

_allowances[msg.sender][_spender] = _value;

emit Approval(msg.sender, _spender, _value);

return true;

}

function allowance(address _owner, address _spender) public constant returns (uint) {

return _allowances[_owner][_spender];

}

}