from PySide2 import QtCore, QtWidgets
import web3
from web3 import Web3, HTTPProvider
from populus.utils.wait import wait_for_transaction_receipt
w3 = Web3(HTTPProvider('http://localhost:7545'))
false = False
true = True
abi = [
{
"constant": false,
"gas": 71987,
"inputs": [
{
"name": "tweet",
"type": "bytes32"
}
],
"name": "write_a_tweet",
"outputs": [],
"payable": false,
"type": "function"
},
{
"constant": true,
"gas": 968,
"inputs": [
{
"name": "arg0",
"type": "address"
},
{
"name": "arg1",
"type": "int128"
}
],
"name": "tweets__messages",
"outputs": [
{
"name": "out",
"type": "bytes32"
}
],
"payable": false,
"type": "function"
},
{
"constant": true,
"gas": 787,
"inputs": [
{
"name": "arg0",
"type": "address"
}
],
"name": "tweets__index",
"outputs": [
{
"name": "out",
"type": "int128"
}
],
"payable": false,
"type": "function"
}
]
with open('address.txt', 'r') as f:
address = f.read().rstrip("\n")
TwitterOnBlockchain = w3.eth.contract(address=address, abi=abi)
def strip_x00_from_tweet(tweet):
null_index = tweet.find(b'\x00')
return tweet[:null_index]
class Web3ReadTweetsThread(QtCore.QThread):
fetched_posts = QtCore.Signal(list)
account = ''
def __init__(self, parent=None):
super(Web3ReadTweetsThread, self).__init__(parent)
def setAccount(self, account):
self.account = account
def run(self):
try:
index = TwitterOnBlockchain.functions.tweets__index(Web3.toChecksumAddress(self.account)).call()
except web3.exceptions.ValidationError:
return
tweets = []
for i in range(index):
tweet = TwitterOnBlockchain.functions.tweets__messages(Web3.toChecksumAddress(self.account), i).call()
tweets.append(tweet.decode('utf-8'))
self.fetched_posts.emit(tweets)
class Web3WriteATweetThread(QtCore.QThread):
write_a_tweet = QtCore.Signal()
private_key = ''
tweet = ''
def __init__(self, parent=None):
super(Web3WriteATweetThread, self).__init__(parent)
def setPrivateKey(self, private_key):
self.private_key = private_key
def setTweet(self, tweet):
self.tweet = tweet
def run(self):
try:
account = w3.eth.account.privateKeyToAccount('0x'+self.private_key)
except ValueError:
QtWidgets.QMessageBox.warning(self, 'Error', 'Private key is invalid.')
return
nonce = w3.eth.getTransactionCount(Web3.toChecksumAddress(account.address))
txn = TwitterOnBlockchain.functions.write_a_tweet(self.tweet.encode('utf-8')).buildTransaction({
'from': account.address,
'gas': 70000,
'gasPrice': w3.toWei('1', 'gwei'),
'nonce': nonce
})
signed = w3.eth.account.signTransaction(txn, private_key=self.private_key)
txhash = w3.eth.sendRawTransaction(signed.rawTransaction)
wait_for_transaction_receipt(w3, txhash)
self.write_a_tweet.emit()
class TwitterDapp(QtWidgets.QWidget):
private_key = '0x0'
account = ''
bookmark_file = 'bookmark.txt'
addresses = []
def __init__(self):
super(TwitterDapp, self).__init__()
self.createPrivateKeyGroupBox()
self.createWritingTweetGroupBox()
self.createTweetsGroupBox()
self.createBookmarkGroupBox()
self.setWindowTitle("Twitter-Like Blockchain Dapp")
mainLayout = QtWidgets.QVBoxLayout()
mainLayout.addWidget(self.private_key_group_box)
mainLayout.addLayout(self.write_button_layout)
mainLayout.addWidget(self.tweets_group_box)
mainLayout.addWidget(self.bookmark_group_box)
self.setLayout(mainLayout)
self.web3_read_tweets_thread = Web3ReadTweetsThread()
self.web3_read_tweets_thread.fetched_posts.connect(self.fillPosts)
self.web3_write_a_tweet_thread = Web3WriteATweetThread()
self.web3_write_a_tweet_thread.write_a_tweet.connect(self.successfullyWriteATweet)
def createPrivateKeyGroupBox(self):
self.private_key_group_box = QtWidgets.QGroupBox("Account")
self.private_key_field = QtWidgets.QLineEdit()
self.welcome_message = QtWidgets.QLabel()
layout = QtWidgets.QFormLayout()
layout.addRow(QtWidgets.QLabel("Private key:"), self.private_key_field)
button_box = QtWidgets.QDialogButtonBox(QtWidgets.QDialogButtonBox.Ok)
button_box.button(QtWidgets.QDialogButtonBox.Ok).clicked.connect(self.checkPrivateKey)
layout.addRow(button_box)
layout.addRow(self.welcome_message)
self.private_key_group_box.setLayout(layout)
def createWritingTweetGroupBox(self):
self.tweet_button = QtWidgets.QPushButton("Write a new tweet")
self.tweet_button.setMaximumSize(200,40)
self.write_button_layout = QtWidgets.QHBoxLayout()
self.write_button_layout.addWidget(self.tweet_button)
self.connect(self.tweet_button, QtCore.SIGNAL('clicked()'), self.writeANewTweet)
def createTweetsGroupBox(self):
self.tweets_group_box = QtWidgets.QGroupBox("Tweets")
self.account_address = QtWidgets.QLineEdit()
self.fetch_button = QtWidgets.QPushButton("Fetch")
self.add_to_bookmark_button = QtWidgets.QPushButton("Bookmark it!")
self.connect(self.fetch_button, QtCore.SIGNAL('clicked()'), self.fetchTweets)
self.connect(self.add_to_bookmark_button, QtCore.SIGNAL('clicked()'), self.bookmarkAddress)
account_address_layout = QtWidgets.QHBoxLayout()
account_address_layout.addWidget(self.account_address)
account_address_layout.addWidget(self.fetch_button)
account_address_layout.addWidget(self.add_to_bookmark_button)
self.tweets_layout = QtWidgets.QVBoxLayout()
self.tweets_main_layout = QtWidgets.QVBoxLayout()
self.tweets_main_layout.addWidget(QtWidgets.QLabel("Address:"))
self.tweets_main_layout.addLayout(account_address_layout)
self.tweets_main_layout.addSpacing(20)
self.tweets_main_layout.addLayout(self.tweets_layout)
self.tweets_group_box.setLayout(self.tweets_main_layout)
def createBookmarkGroupBox(self):
self.bookmark_group_box = QtWidgets.QGroupBox("Bookmark")
self.bookmark_layout = QtWidgets.QVBoxLayout()
self.bookmark_group_box.setLayout(self.bookmark_layout)
with open(self.bookmark_file) as f:
addresses = f.readlines()
self.addresses = list(map(lambda x: x.rstrip(), filter(lambda x: len(x) > 1, addresses)))
self.fillBookmark()
@QtCore.Slot()
def fetchTweets(self):
account = self.account_address.displayText()
self.web3_read_tweets_thread.setAccount(account)
self.web3_read_tweets_thread.start()
@QtCore.Slot()
def bookmarkAddress(self):
account = self.account_address.displayText()
if account:
self.addresses.append(account)
self.addresses = list(set(self.addresses))
with open(self.bookmark_file, 'w') as f:
for address in self.addresses:
f.write(address + "\n")
self.fillBookmark()
@QtCore.Slot()
def writeANewTweet(self):
text, ok = QtWidgets.QInputDialog.getText(self, "Write a new tweet",
"Tweet:", QtWidgets.QLineEdit.Normal, "")
if ok and text != '':
self.web3_write_a_tweet_thread.setPrivateKey(self.private_key)
self.web3_write_a_tweet_thread.setTweet(text)
self.web3_write_a_tweet_thread.start()
def checkPrivateKey(self):
self.private_key = self.private_key_field.displayText()
try:
self.account = w3.eth.account.privateKeyToAccount('0x'+self.private_key)
except ValueError:
QtWidgets.QMessageBox.warning(self, 'Error', 'Private key is invalid.')
return
self.welcome_message.setText('Welcome, ' + self.account.address + '!')
self.private_key_field.clear()
def clearTweetsField(self):
while True:
label_item = self.tweets_layout.takeAt(0)
if label_item is None:
break
else:
label_item.widget().close()
def fillPosts(self, posts):
self.clearTweetsField()
for post in posts:
label_field = QtWidgets.QLabel(post)
self.tweets_layout.addWidget(label_field)
def clearBookmarkField(self):
while True:
label_item = self.bookmark_layout.takeAt(0)
if label_item is None:
break
else:
label_item.widget().close()
def fillBookmark(self):
self.clearBookmarkField()
for address in self.addresses:
label_field = QtWidgets.QLabel(address)
label_field.setTextInteractionFlags(label_field.textInteractionFlags() | QtCore.Qt.TextSelectableByMouse)
self.bookmark_layout.addWidget(label_field)
def successfullyWriteATweet(self):
self.welcome_message.setText('You have successfully written a new tweet!')
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
twitter_dapp = TwitterDapp()
twitter_dapp.show()
sys.exit(app.exec_())
