simplify exchange_rate hooks

RELEASE-NOTES

@@ -7,13 +7,11 @@
  * The network layer uses select(), so all server communication is
    handled by a single thread. Moreover, the synchronizer, verifier,
    and exchange rate plugin now run as separate jobs within the
-   networking thread instead of as their own threads.  The elimination
-   of so many threads should lead to reduced lock contention and CPU
-   usage.
+   networking thread instead of as their own threads.
  * Plugins are revamped, particularly the exchange rate plugin.
 
 # Release 2.4.4
- * fix bug with trustedcoin plugin
+ * Fix bug with TrustedCoin plugin
 
 # Release 2.4.3
  * Support for KeepKey hardware wallet

gui/qt/main_window.py

@@ -492,7 +492,7 @@ class ElectrumWindow(QMainWindow, PrintError):
         text = self.format_amount(amount) + ' '+ self.base_unit()
         x = run_hook('format_amount_and_units', amount)
         if x:
-            text += ''.join(x)
+            text += x
         return text
 
     def get_decimal_point(self):
@@ -536,9 +536,9 @@ class ElectrumWindow(QMainWindow, PrintError):
                 if x:
                     text +=  " [%s unmatured]"%(self.format_amount(x, True).strip())
                 # append fiat balance and price from exchange rate plugin
-                r = {'text': ''}
-                run_hook('get_fiat_status_text', c + u + x, r)
-                text += r['text']
+                rate = run_hook('get_fiat_status_text', c + u + x)
+                if rate:
+                    text += "1 BTC~%s" % rate
                 icon = QIcon(":icons/status_connected.png")
         else:
             text = _("Not connected")

plugins/exchange_rate.py

@@ -423,14 +423,9 @@ class Plugin(BasePlugin, ThreadJob):
         return '' if rate is None else " (%s %s)" % (self.value_str(btc_balance, rate), self.ccy)
 
     @hook
-    def get_fiat_status_text(self, btc_balance, result):
-        # return status as:   (1.23 USD)    1 BTC~123.45 USD
+    def get_fiat_status_text(self, btc_balance):
         rate = self.exchange_rate()
-        if rate is None:
-            text = _("  (No FX rate available)")
-        else:
-            text =  "1 BTC~%s %s" % (self.value_str(COIN, rate), self.ccy)
-        result['text'] = text
+        return _("  (No FX rate available)") if rate is None else "%s %s" % (self.value_str(COIN, rate), self.ccy)
 
     def get_historical_rates(self):
         if self.show_history():