show the BTC value in other currency.

lib/exchange_rate.py

@@ -1,12 +1,37 @@
+import decimal
+import httplib
+import json
+
 class Exchanger:
 
-    def __init__(self, quote_currencies):
-        self.quote_currencies = quote_currencies
+    def __init__(self, quote_currencies, refresh_balance):
+        self.refresh_balance = refresh_balance
+        self.quote_currencies = {}
 
     def exchange(self, btc_amount, quote_currency):
-        assert quote_currency in self.quote_currencies
+        return btc_amount * self.quote_currencies[quote_currency]
 
-        return btc_amount * 6
+    def discovery(self):
+        connection = httplib.HTTPSConnection('intersango.com')
+        connection.request("GET", "/api/ticker.php")
+        response = connection.getresponse()
+        if response.status == 404:
+            return
+        response = json.loads(response.read())
+        # 1 = BTC:GBP
+        # 2 = BTC:EUR
+        # 3 = BTC:USD
+        # 4 = BTC:PLN
+        try:
+            self.quote_currencies["GBP"] = self.lookup_rate(response, 1)
+            self.quote_currencies["EUR"] = self.lookup_rate(response, 2)
+            self.quote_currencies["USD"] = self.lookup_rate(response, 3)
+            self.refresh_balance()
+        except KeyError:
+            pass
+
+    def lookup_rate(self, response, quote_id):
+        return decimal.Decimal(response[str(quote_id)]["last"])
 
 if __name__ == "__main__":
     exch = Exchanger(("EUR", "USD", "GBP"))

lib/gui_lite.py

@@ -86,10 +86,12 @@ class MiniWindow(QDialog):
 
         self.btc_balance = 0
         self.quote_currencies = ("EUR", "USD", "GBP")
-        self.exchanger = exchange_rate.Exchanger(self.quote_currencies)
+        self.exchanger = exchange_rate.Exchanger(self.quote_currencies,
+                                                 self.refresh_balance)
 
         self.balance_label = BalanceLabel(self.change_quote_currency)
         self.balance_label.setObjectName("balance_label")
+        self.exchanger.discovery()
 
         copy_button = QPushButton(_("&Copy Address"))
         copy_button.setObjectName("copy_button")
@@ -163,13 +165,17 @@ class MiniWindow(QDialog):
     def change_quote_currency(self):
         self.quote_currencies = \
             self.quote_currencies[1:] + self.quote_currencies[0:1]
+        self.refresh_balance()
+
+    def refresh_balance(self):
         self.set_balances(self.btc_balance)
 
     def set_balances(self, btc_balance):
         self.btc_balance = btc_balance
-        btc_balance /= bitcoin(1)
-        quote_balance = "%.2f" % (btc_balance * 6)
         quote_currency = self.quote_currencies[0]
+        quote_balance = self.exchanger.exchange(btc_balance, quote_currency)
+        quote_balance = "%.2f" % (quote_balance / bitcoin(1))
+        btc_balance = "%.2f" % (btc_balance / bitcoin(1))
         self.balance_label.set_balances( \
             btc_balance, quote_balance, quote_currency)
         main_account_info = \