TestToken

pragma solidity ^0.5.0;

import "./RC20.sol";

contract TestToken is ERC20 {
    event IncreaseSupply(address indexed addr, uint256 value);
    event DecreaseSupply(address indexed addr, uint256 value);
    
    string public name;             // Token name
    string public symbol;           // Token symbol
    uint8 public decimals;          // Token decimals
    uint256 public totalSupply;     // Number of tokens
    address public owner;           // contract owner
    
    // The related value of the contract token passed in when deploying the contract
    constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _totalSupply) public {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        totalSupply = _totalSupply.mul(10 ** uint256(_decimals));
        
        owner = msg.sender;
        _balances[owner] = totalSupply;
    }
    
    modifier onlyOwner() {
        require(owner == msg.sender, "Not the owner operation!");
        _;
    }
    
    // Increase the number of tokens
    function increaseSupply(uint256 addValue) public onlyOwner {
        uint256 addSupply = addValue.mul(10 ** uint256(decimals));
        
        totalSupply = totalSupply.add(addSupply);
        _balances[owner] = _balances[owner].add(addSupply);
        
        emit IncreaseSupply(owner, addSupply);
    }
    
    // Reduce the number of tokens
    function decreaseSupply(uint256 subValue) public onlyOwner {
        uint256 subSupply = subValue.mul(10 ** uint256(decimals));
        
        _balances[owner] = _balances[owner].sub(subSupply);
        totalSupply = totalSupply.sub(subSupply);
        
        emit DecreaseSupply(owner, subSupply);
    } 

}