Read and set radio address from config if possible

If we have a stored link_uri in the user config we parse it and set the
address field in the main ui to this value. This can save time for
someone who has changed their address for their single Crazyflie that
they are working with.

Closes bitcraze#382

src/cfclient/ui/main.py

@@ -185,6 +185,7 @@ def __init__(self, *args):
 
         self._connectivity_manager.connect_button_clicked.connect(self._connect)
         self._connectivity_manager.scan_button_clicked.connect(self._scan)
+        self._set_address()
 
         self._auto_reconnect_enabled = Config().get("auto_reconnect")
         self.autoReconnectCheckBox.toggled.connect(
@@ -360,6 +361,17 @@ def __init__(self, *args):
             self._theme_group.addAction(node)
             self.menuThemes.addAction(node)
 
+    def _set_address(self):
+        address = 0xE7E7E7E7E7
+        try:
+            link_uri = Config().get("link_uri")
+            if len(link_uri) > 0:
+                address = int(link_uri.split('/')[-1], 16)
+        except Exception as err:
+            logger.warn('failed to parse address from config: %s' % str(err))
+        finally:
+            self.address.setValue(address)
+
     def _theme_selected(self, *args):
         """ Callback when a theme is selected. """
         for checkbox in self._theme_checkboxes: