Add ERC20Token contract from voting app

truffle/contracts/ERC20Token.sol

@@ -0,0 +1,125 @@
+pragma solidity ^0.4.15;
+
+// ----------------------------------------------------------------------------------------------
+// Sample fixed supply token contract
+// Enjoy. (c) BokkyPooBah 2017. The MIT Licence.
+// ----------------------------------------------------------------------------------------------
+
+// ERC Token Standard #20 Interface
+// https://github.com/ethereum/EIPs/issues/20
+contract ERC20Interface {
+    // Get the total token supply
+    function totalSupply() constant returns (uint256);
+
+    // Get the account balance of another account with address _owner
+    function balanceOf(address _owner) constant returns (uint256 balance);
+
+    // Send _value amount of tokens to address _to
+    function transfer(address _to, uint256 _value) returns (bool success);
+
+    // Send _value amount of tokens from address _from to address _to
+    function transferFrom(address _from, address _to, uint256 _value) returns (bool success);
+
+    // Allow _spender to withdraw from your account, multiple times, up to the _value amount.
+    // If this function is called again it overwrites the current allowance with _value.
+    // this function is required for some DEX functionality
+    function approve(address _spender, uint256 _value) returns (bool success);
+
+    // Returns the amount which _spender is still allowed to withdraw from _owner
+    function allowance(address _owner, address _spender) constant returns (uint256 remaining);
+
+    // Triggered when tokens are transferred.
+    event Transfer(address indexed _from, address indexed _to, uint256 _value);
+
+    // Triggered whenever approve(address _spender, uint256 _value) is called.
+    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
+}
+
+contract ERC20Token is ERC20Interface {
+    string public constant symbol = "EAE";
+    string public constant name = "Example Aeternity";
+    uint8 public constant decimals = 18;
+    uint256 public constant initialBalance = 5 * uint256(10) ** decimals;
+    uint256 _totalSupply = 1000000 * uint256(10) ** decimals;
+
+    // Owner of this contract
+    address public owner;
+
+    // Balances for each account
+    mapping(address => uint256) balances;
+
+    // Owner of account approves the transfer of an amount to another account
+    mapping(address => mapping (address => uint256)) allowed;
+
+    // Functions with this modifier can only be executed by the owner
+    modifier onlyOwner() {
+        require(msg.sender == owner);
+        _;
+    }
+
+    // Constructor
+    function ERC20Token() {
+        owner = msg.sender;
+        balances[owner] = _totalSupply;
+    }
+
+    function totalSupply() constant returns (uint256) {
+        return _totalSupply;
+    }
+
+    // What is the balance of a particular account?
+    function balanceOf(address _owner) constant returns (uint256 balance) {
+        return balances[_owner] + initialBalance;
+    }
+
+    // Transfer the balance from owner's account to another account
+    function transfer(address _to, uint256 _amount) returns (bool success) {
+        if (balances[msg.sender] + initialBalance >= _amount
+            && _amount > 0
+            && balances[_to] + _amount > balances[_to]) {
+            balances[msg.sender] -= _amount;
+            balances[_to] += _amount;
+            Transfer(msg.sender, _to, _amount);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    // Send _value amount of tokens from address _from to address _to
+    // The transferFrom method is used for a withdraw workflow, allowing contracts to send
+    // tokens on your behalf, for example to "deposit" to a contract address and/or to charge
+    // fees in sub-currencies; the command should fail unless the _from account has
+    // deliberately authorized the sender of the message via some mechanism; we propose
+    // these standardized APIs for approval:
+    function transferFrom(
+        address _from,
+        address _to,
+        uint256 _amount
+    ) returns (bool success) {
+        if (balances[_from] + initialBalance >= _amount
+            && allowed[_from][msg.sender] >= _amount
+            && _amount > 0
+            && balances[_to] + _amount > balances[_to]) {
+            balances[_from] -= _amount;
+            allowed[_from][msg.sender] -= _amount;
+            balances[_to] += _amount;
+            Transfer(_from, _to, _amount);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    // Allow _spender to withdraw from your account, multiple times, up to the _value amount.
+    // If this function is called again it overwrites the current allowance with _value.
+    function approve(address _spender, uint256 _amount) returns (bool success) {
+        allowed[msg.sender][_spender] = _amount;
+        Approval(msg.sender, _spender, _amount);
+        return true;
+    }
+
+    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
+        return allowed[_owner][_spender];
+    }
+}