kivy: do not show balance in every tab. fixes #3350

gui/kivy/main.kv

@@ -397,7 +397,7 @@
             slide: 1
         CleanHeader:
             id: history_tab
-            text: _('History')
+            text: _('Balance')
             slide: 2
         CleanHeader:
             id: receive_tab

gui/kivy/main_window.py

@@ -83,6 +83,7 @@ class ElectrumWindow(App):
     num_chains = NumericProperty(0)
     blockchain_name = StringProperty('')
     fee_status = StringProperty('Fee')
+    balance = StringProperty('')
     blockchain_checkpoint = NumericProperty(0)
 
     auto_connect = BooleanProperty(False)
@@ -634,16 +635,16 @@ class ElectrumWindow(App):
             if not self.wallet.up_to_date or server_height == 0:
                 status = _("Synchronizing...")
             elif server_lag > 1:
-                status = _("Server lagging ({} blocks)").format(server_lag)
+                status = _("Server lagging")
             else:
-                c, u, x = self.wallet.get_balance()
-                text = self.format_amount(c+x+u)
-                status = str(text.strip() + ' ' + self.base_unit)
+                status = ''
         else:
             status = _("Disconnected")
-
-        n = self.wallet.basename()
-        self.status = '[size=15dp]%s[/size]\n%s' %(n, status)
+        self.status = self.wallet.basename() + (' [size=15dp](%s)[/size]'%status if status else '')
+        # balance
+        c, u, x = self.wallet.get_balance()
+        text = self.format_amount(c+x+u)
+        self.balance = str(text.strip() + ' ' + self.base_unit)
         #fiat_balance = self.fx.format_amount_and_units(c+u+x) or ''
 
     def get_max_amount(self):

gui/kivy/uix/screens.py

@@ -162,13 +162,8 @@ class HistoryScreen(CScreen):
         count = 0
         for item in history:
             ri = self.get_card(*item)
-            count += 1
             history_card.add_widget(ri)
 
-        if count == 0:
-            msg = _('This screen shows your list of transactions. It is currently empty.')
-            history_card.add_widget(EmptyLabel(text=msg))
-
 
 class SendScreen(CScreen):
 

gui/kivy/uix/ui_screens/history.kv

@@ -62,13 +62,23 @@
 HistoryScreen:
     name: 'history'
     content: content
-    ScrollView:
-        id: content
-        do_scroll_x: False
-        GridLayout
-            id: history_container
-            cols: 1
-            size_hint: 1, None
-            height: self.minimum_height
-            padding: '12dp'
-            spacing: '2dp'
+    BoxLayout:
+        orientation: 'vertical'
+        Label:
+            text: app.balance
+            color: .699, .699, .699, 1
+            font_size: '22dp'
+            bold: True
+            size_hint: 1, 0.25
+        ScrollView:
+            id: content
+            do_scroll_x: False
+            size_hint: 1, 0.75
+            #height: self.minimum_height
+            GridLayout
+                id: history_container
+                cols: 1
+                size_hint: 1, None
+                height: self.minimum_height
+                padding: '12dp'
+                spacing: '2dp'