Token.sol

pragma solidity >=0.4.4;

import 'Common.sol';

//ERC20 token

contract Token is SafeMath, Owned, Constants {
    uint public totalSupply;

    address ico;
    address controller;

    string public name;
    uint8 public decimals; 
    string public symbol;     

    modifier onlyControllers() {
        if (msg.sender != ico &&
            msg.sender != controller) throw;
        _;
    }

    modifier onlyPayloadSize(uint numwords) {
        assert(msg.data.length == numwords * 32 + 4);
        _;
    } 

    function Token() { 
        owner = msg.sender;
        name = "Monolith TKN";
        decimals = uint8(DECIMALS);
        symbol = "TKN";
    }

    function setICO(address _ico) onlyOwner {
        if (ico != 0) throw;
        ico = _ico;
    }
    function setController(address _controller) onlyOwner {
        if (controller != 0) throw;
        controller = _controller;
    }
    
    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
    event Mint(address owner, uint amount);

    //only called from contracts so don't need msg.data.length check
    function mint(address addr, uint amount) onlyControllers {
        if (maxSupply > 0 && safeAdd(totalSupply, amount) > maxSupply) throw;
        balanceOf[addr] = safeAdd(balanceOf[addr], amount);
        totalSupply = safeAdd(totalSupply, amount);
        Mint(addr, amount);
    }

    mapping(address => uint) public balanceOf;
    mapping (address => mapping (address => uint)) public allowance;

    function transfer(address _to, uint _value) 
    onlyPayloadSize(2)
    returns (bool success) {
        if (balanceOf[msg.sender] < _value) return false;

        balanceOf[msg.sender] = balanceOf[msg.sender] - _value;
        balanceOf[_to] = safeAdd(balanceOf[_to], _value);
        Transfer(msg.sender, _to, _value);
        return true;
    }

    function transferFrom(address _from, address _to, uint _value) 
    onlyPayloadSize(3)
    returns (bool success) {
        if (balanceOf[_from] < _value) return false; 

        var allowed = allowance[_from][msg.sender];
        if (allowed < _value) return false;

        balanceOf[_to] = safeAdd(balanceOf[_to], _value);
        balanceOf[_from] = safeSub(balanceOf[_from], _value);
        allowance[_from][msg.sender] = safeSub(allowed, _value);
        Transfer(_from, _to, _value);
        return true;
    }

    function approve(address _spender, uint _value) 
    onlyPayloadSize(2)
    returns (bool success) {
        //require user to set to zero before resetting to nonzero
        if ((_value != 0) && (allowance[msg.sender][_spender] != 0)) {
            return false;
        }
    
        allowance[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    function increaseApproval (address _spender, uint _addedValue) 
    onlyPayloadSize(2)
    returns (bool success) {
        uint oldValue = allowance[msg.sender][_spender];
        allowance[msg.sender][_spender] = safeAdd(oldValue, _addedValue);
        return true;
    }

    function decreaseApproval (address _spender, uint _subtractedValue) 
    onlyPayloadSize(2)
    returns (bool success) {
        uint oldValue = allowance[msg.sender][_spender];
        if (_subtractedValue > oldValue) {
            allowance[msg.sender][_spender] = 0;
        } else {
            allowance[msg.sender][_spender] = safeSub(oldValue, _subtractedValue);
        }
        return true;
    }

    //Holds accumulated dividend tokens other than TKN
    TokenHolder tokenholder;

    //once locked, can no longer upgrade tokenholder
    bool lockedTokenHolder;

    function lockTokenHolder() onlyOwner {
        lockedTokenHolder = true;
    }

    //while unlocked, 
    //this gives owner lots of power over held dividend tokens
    //effectively can deny access to all accumulated tokens
    //thus crashing TKN value
    function setTokenHolder(address _th) onlyOwner {
        if (lockedTokenHolder) throw;
        tokenholder = TokenHolder(_th);
    }

    event Burn(address burner, uint amount);

    function burn(uint _amount) returns (bool result) {
        if (_amount > balanceOf[msg.sender]) return false;
        balanceOf[msg.sender] = safeSub(balanceOf[msg.sender], _amount);
        totalSupply = safeSub(totalSupply, _amount);
        result = tokenholder.burn(msg.sender, _amount);
        if (!result) throw;
        Burn(msg.sender, _amount);
    }

    uint public maxSupply;

    function setMaxSupply(uint _maxSupply) {
        if (msg.sender != controller) throw;
        if (maxSupply > 0) throw;
        maxSupply = _maxSupply;
    }
}

contract TokenHolder {
    function burn(address _burner, uint _amount)
    returns (bool result) { 
        return false;
    }
}