Contract Name:
UniversalMobileToken
Contract Source Code:
File 1 of 1 : UniversalMobileToken
/*
*
* Universal Mobile Token smart contract
* Developed by Phenom.team <[email protected]>
*
*/
pragma solidity ^0.4.24;
/**
* @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;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @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 {
require(newOwner != address(0));
emit OwnershipTransferred(owner, newOwner);
owner = newOwner;
}
}
/**
* @title SafeMath
* @dev Math operations with safety checks that throw on error
*/
library SafeMath {
/**
* @dev Multiplies two numbers, throws on overflow.
*/
function mul(uint a, uint b) internal pure returns (uint) {
if (a == 0) {
return 0;
}
uint c = a * b;
assert(c / a == b);
return c;
}
/**
* @dev Integer division of two numbers, truncating the quotient.
*/
function div(uint a, uint b) internal pure returns (uint) {
// assert(b > 0); // Solidity automatically throws when dividing by 0
uint c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Substracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint a, uint b) internal pure returns (uint) {
assert(b <= a);
return a - b;
}
/**
* @dev Adds two numbers, throws on overflow.
*/
function add(uint a, uint b) internal pure returns (uint) {
uint c = a + b;
assert(c >= a);
return c;
}
}
contract UniversalMobileToken is Ownable {
using SafeMath for uint;
/*
Standard ERC20 token
*/
event Transfer(address indexed from, address indexed to, uint tokens);
event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
// Name of token
string public name;
// Short symbol for token
string public symbol;
// Nubmer of decimal places
uint public decimals;
// Token's total supply
uint public totalSupply;
// Is minting active
bool public mintingIsFinished;
// Is transfer possible
bool public transferIsPossible;
modifier onlyEmitter() {
require(emitters[msg.sender] == true);
_;
}
mapping (address => uint) public balances;
mapping (address => bool) public emitters;
mapping (address => mapping (address => uint)) internal allowed;
constructor() Ownable() public {
name = "Universal Mobile Token";
symbol = "UMT";
decimals = 18;
// Make the Owner also an emitter
emitters[msg.sender] = true;
}
/**
* @dev Finish minting process
*/
function finishMinting() public onlyOwner {
mintingIsFinished = true;
transferIsPossible = true;
}
/**
* @dev Send coins
* throws on any error rather then return a false flag to minimize
* user errors
* @param _to target address
* @param _value transfer amount
*
* @return true if the transfer was successful
*/
function transfer(address _to, uint _value) public returns (bool success) {
// Make transfer only if transfer is possible
require(transferIsPossible);
require(_to != address(0) && _to != address(this));
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
return true;
}
/**
* @dev Allows another account/contract to spend some tokens on its behalf
* throws on any error rather then return a false flag to minimize user errors
*
* also, to minimize the risk of the approve/transferFrom attack vector
* approve has to be called twice in 2 separate transactions - once to
* change the allowance to 0 and secondly to change it to the new allowance
* value
*
* @param _spender approved address
* @param _value allowance amount
*
* @return true if the approval was successful
*/
function approve(address _spender, uint _value) public returns (bool success) {
require((_value == 0) || (allowed[msg.sender][_spender] == 0));
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
/**
* @dev An account/contract attempts to get the coins
* throws on any error rather then return a false flag to minimize user errors
*
* @param _from source address
* @param _to target address
* @param _value amount
*
* @return true if the transfer was successful
*/
function transferFrom(address _from, address _to, uint _value) public returns (bool success) {
// Make transfer only if transfer is possible
require(transferIsPossible);
require(_to != address(0) && _to != address(this));
balances[_from] = balances[_from].sub(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(_from, _to, _value);
return true;
}
/**
* @dev Add an emitter account
*
* @param _emitter emitter's address
*/
function addEmitter(address _emitter) public onlyOwner {
emitters[_emitter] = true;
}
/**
* @dev Remove an emitter account
*
* @param _emitter emitter's address
*/
function removeEmitter(address _emitter) public onlyOwner {
emitters[_emitter] = false;
}
/**
* @dev Mint token in batches
*
* @param _adresses token holders' adresses
* @param _values token holders' values
*/
function batchMint(address[] _adresses, uint[] _values) public onlyEmitter {
require(_adresses.length == _values.length);
for (uint i = 0; i < _adresses.length; i++) {
require(minted(_adresses[i], _values[i]));
}
}
/**
* @dev Transfer token in batches
*
* @param _adresses token holders' adresses
* @param _values token holders' values
*/
function batchTransfer(address[] _adresses, uint[] _values) public {
require(_adresses.length == _values.length);
for (uint i = 0; i < _adresses.length; i++) {
require(transfer(_adresses[i], _values[i]));
}
}
/**
* @dev Burn Tokens
* @param _from token holder address which the tokens will be burnt
* @param _value number of tokens to burn
*/
function burn(address _from, uint _value) public onlyEmitter {
// Burn tokens only if minting stage is not finished
require(!mintingIsFinished);
require(_value <= balances[_from]);
balances[_from] = balances[_from].sub(_value);
totalSupply = totalSupply.sub(_value);
}
/**
* @dev Function to check the amount of tokens that an owner allowed to a spender.
*
* @param _tokenOwner the address which owns the funds
* @param _spender the address which will spend the funds
*
* @return the amount of tokens still avaible for the spender
*/
function allowance(address _tokenOwner, address _spender) public constant returns (uint remaining) {
return allowed[_tokenOwner][_spender];
}
/**
* @dev Function to check the amount of tokens that _tokenOwner has.
*
* @param _tokenOwner the address which owns the funds
*
* @return the amount of tokens _tokenOwner has
*/
function balanceOf(address _tokenOwner) public constant returns (uint balance) {
return balances[_tokenOwner];
}
function minted(address _to, uint _value) internal returns (bool) {
// Mint tokens only if minting stage is not finished
require(!mintingIsFinished);
balances[_to] = balances[_to].add(_value);
totalSupply = totalSupply.add(_value);
emit Transfer(address(0), _to, _value);
return true;
}
}