added most of immo invest fields, layout still crap

immo_gui.py

@@ -50,14 +50,25 @@ class ImmoApp(App):
     def build(self):
         self.title = 'hello world'
         Clock.schedule_interval(self._update_clock, 1 / 60.)
+        self.root.ids.per_qm.text = "iaeiae"
 
     def _update_clock(self, dt):
         self.time = time()
 
+    def _update_cost_qm(self):
+        surface = float('0' + self.root.ids.surface.text)
+        price = int('0' + self.root.ids.price.text)
+
+        if surface is not None and surface > 0 and price is not None and price > 0:
+            self.root.ids.per_qm.text = (str(price / surface))
+
     def on_text(self, args):
         # print('The widget', instance, 'have:', value)
-        print(args[1])
-        # exit()
+        text_input = args[0]
+        print(text_input.name)
+
+        if text_input.name in ["price", "surface"]:
+            self._update_cost_qm()
 
 
 if __name__ == '__main__':