kivy: remove dynamic screen loading.

The performance gain it brings is negligible,
and it causes object duplication, which makes
things difficult to debug.

electrum/gui/kivy/uix/screens.py

@@ -58,7 +58,6 @@ class PaymentRecycleView(RecycleView):
 class CScreen(Factory.Screen):
     __events__ = ('on_activate', 'on_deactivate', 'on_enter', 'on_leave')
     action_view = ObjectProperty(None)
-    loaded = False
     kvname = None
     app = App.get_running_app()  # type: ElectrumWindow
 
@@ -80,17 +79,8 @@ class CScreen(Factory.Screen):
     def update(self):
         pass
 
-    @profiler
-    def load_screen(self):
-        self.screen = Builder.load_file('electrum/gui/kivy/uix/ui_screens/' + self.kvname + '.kv')
-        self.add_widget(self.screen)
-        self.loaded = True
-        self.update()
-        setattr(self.app, self.kvname + '_screen', self)
-
     def on_activate(self):
-        if self.kvname and not self.loaded:
+        setattr(self.app, self.kvname + '_screen', self)
-            self.load_screen()
         #Clock.schedule_once(lambda dt: self._change_action_view())
 
     def on_leave(self):
@@ -114,6 +104,12 @@ TX_ICONS = [
     "confirmed",
 ]
 
+
+Builder.load_file('electrum/gui/kivy/uix/ui_screens/history.kv')
+Builder.load_file('electrum/gui/kivy/uix/ui_screens/send.kv')
+Builder.load_file('electrum/gui/kivy/uix/ui_screens/receive.kv')
+
+
 class HistoryScreen(CScreen):
 
     tab = ObjectProperty(None)
@@ -182,7 +178,7 @@ class HistoryScreen(CScreen):
             return
         self.history = wallet.get_full_history(self.app.fx)
         history = reversed(self.history.values())
-        history_card = self.screen.ids.history_container
+        history_card = self.ids.history_container
         history_card.data = [self.get_card(item) for item in history]
 
 
@@ -204,11 +200,11 @@ class SendScreen(CScreen):
             return
         self.parsed_URI = uri
         amount = uri.get('amount')
-        self.screen.address = uri.get('address', '')
+        self.address = uri.get('address', '')
-        self.screen.message = uri.get('message', '')
+        self.message = uri.get('message', '')
-        self.screen.amount = self.app.format_amount_and_units(amount) if amount else ''
+        self.amount = self.app.format_amount_and_units(amount) if amount else ''
         self.payment_request = None
-        self.screen.is_lightning = False
+        self.is_lightning = False
 
     def set_ln_invoice(self, invoice):
         try:
@@ -217,15 +213,13 @@ class SendScreen(CScreen):
         except Exception as e:
             self.app.show_info(invoice + _(" is not a valid Lightning invoice: ") + repr(e)) # repr because str(Exception()) == ''
             return
-        self.screen.address = invoice
+        self.address = invoice
-        self.screen.message = dict(lnaddr.tags).get('d', None)
+        self.message = dict(lnaddr.tags).get('d', None)
-        self.screen.amount = self.app.format_amount_and_units(lnaddr.amount * bitcoin.COIN) if lnaddr.amount else ''
+        self.amount = self.app.format_amount_and_units(lnaddr.amount * bitcoin.COIN) if lnaddr.amount else ''
         self.payment_request = None
-        self.screen.is_lightning = True
+        self.is_lightning = True
 
     def update(self):
-        if not self.loaded:
-            return
         if self.app.wallet and self.payment_request_queued:
             self.set_URI(self.payment_request_queued)
             self.payment_request_queued = None
@@ -233,7 +227,7 @@ class SendScreen(CScreen):
         _list.reverse()
         lnworker_logs = self.app.wallet.lnworker.logs if self.app.wallet.lnworker else {}
         _list = [x for x in _list if x and x.get('status') != PR_PAID or x.get('rhash') in lnworker_logs]
-        payments_container = self.screen.ids.payments_container
+        payments_container = self.ids.payments_container
         payments_container.data = [self.get_card(item) for item in _list]
 
     def show_item(self, obj):
@@ -263,20 +257,20 @@ class SendScreen(CScreen):
         }
 
     def do_clear(self):
-        self.screen.amount = ''
+        self.amount = ''
-        self.screen.message = ''
+        self.message = ''
-        self.screen.address = ''
+        self.address = ''
         self.payment_request = None
-        self.screen.is_lightning = False
+        self.is_lightning = False
-        self.screen.is_bip70 = False
+        self.is_bip70 = False
         self.parsed_URI = None
 
     def set_request(self, pr: 'PaymentRequest'):
-        self.screen.address = pr.get_requestor()
+        self.address = pr.get_requestor()
         amount = pr.get_amount()
-        self.screen.amount = self.app.format_amount_and_units(amount) if amount else ''
+        self.amount = self.app.format_amount_and_units(amount) if amount else ''
-        self.screen.message = pr.get_memo()
+        self.message = pr.get_memo()
-        self.screen.locked = True
+        self.locked = True
         self.payment_request = pr
 
     def do_paste(self):
@@ -301,20 +295,20 @@ class SendScreen(CScreen):
             self.set_URI(data)
 
     def read_invoice(self):
-        address = str(self.screen.address)
+        address = str(self.address)
         if not address:
             self.app.show_error(_('Recipient not specified.') + ' ' + _('Please scan a Bitcoin address or a payment request'))
             return
-        if not self.screen.amount:
+        if not self.amount:
             self.app.show_error(_('Please enter an amount'))
             return
         try:
-            amount = self.app.get_amount(self.screen.amount)
+            amount = self.app.get_amount(self.amount)
         except:
-            self.app.show_error(_('Invalid amount') + ':\n' + self.screen.amount)
+            self.app.show_error(_('Invalid amount') + ':\n' + self.amount)
             return
-        message = self.screen.message
+        message = self.message
-        if self.screen.is_lightning:
+        if self.is_lightning:
             return self.app.wallet.lnworker.parse_bech32_invoice(address)
         else:  # on-chain
             if self.payment_request:
@@ -423,32 +417,32 @@ class ReceiveScreen(CScreen):
         return self.app.electrum_config.get('request_expiry', PR_DEFAULT_EXPIRATION_WHEN_CREATING)
 
     def clear(self):
-        self.screen.address = ''
+        self.address = ''
-        self.screen.amount = ''
+        self.amount = ''
-        self.screen.message = ''
+        self.message = ''
-        self.screen.lnaddr = ''
+        self.lnaddr = ''
 
     def set_address(self, addr):
-        self.screen.address = addr
+        self.address = addr
 
     def on_address(self, addr):
         req = self.app.wallet.get_request(addr)
-        self.screen.status = ''
+        self.status = ''
         if req:
-            self.screen.message = req.get('memo', '')
+            self.message = req.get('memo', '')
             amount = req.get('amount')
-            self.screen.amount = self.app.format_amount_and_units(amount) if amount else ''
+            self.amount = self.app.format_amount_and_units(amount) if amount else ''
             status = req.get('status', PR_UNKNOWN)
-            self.screen.status = _('Payment received') if status == PR_PAID else ''
+            self.status = _('Payment received') if status == PR_PAID else ''
 
     def get_URI(self):
         from electrum.util import create_bip21_uri
-        amount = self.screen.amount
+        amount = self.amount
         if amount:
-            a, u = self.screen.amount.split()
+            a, u = self.amount.split()
             assert u == self.app.base_unit
             amount = Decimal(a) * pow(10, self.app.decimal_point())
-        return create_bip21_uri(self.screen.address, amount, self.screen.message)
+        return create_bip21_uri(self.address, amount, self.message)
 
     def do_copy(self):
         uri = self.get_URI()
@@ -456,17 +450,17 @@ class ReceiveScreen(CScreen):
         self.app.show_info(_('Request copied to clipboard'))
 
     def new_request(self, lightning):
-        amount = self.screen.amount
+        amount = self.amount
         amount = self.app.get_amount(amount) if amount else 0
-        message = self.screen.message
+        message = self.message
         if lightning:
             key = self.app.wallet.lnworker.add_request(amount, message, self.expiry())
         else:
-            addr = self.screen.address or self.app.wallet.get_unused_address()
+            addr = self.address or self.app.wallet.get_unused_address()
             if not addr:
                 self.app.show_info(_('No address available. Please remove some of your pending requests.'))
                 return
-            self.screen.address = addr
+            self.address = addr
             req = self.app.wallet.make_payment_request(addr, amount, message, self.expiry())
             self.app.wallet.add_payment_request(req)
             key = addr
@@ -497,11 +491,9 @@ class ReceiveScreen(CScreen):
         return ci
 
     def update(self):
-        if not self.loaded:
-            return
         _list = self.app.wallet.get_sorted_requests()
         _list.reverse()
-        requests_container = self.screen.ids.requests_container
+        requests_container = self.ids.requests_container
         requests_container.data = [self.get_card(item) for item in _list if item.get('status') != PR_PAID]
 
     def show_item(self, obj):

electrum/gui/kivy/uix/ui_screens/history.kv

@@ -76,7 +76,7 @@
         orientation: 'vertical'
 
 
-HistoryScreen:
+<HistoryScreen>:
     name: 'history'
     content: history_container
     BoxLayout:

electrum/gui/kivy/uix/ui_screens/receive.kv

@@ -60,7 +60,7 @@
         orientation: 'vertical'
 
 
-ReceiveScreen:
+<ReceiveScreen>:
     id: s
     name: 'receive'
     address: ''
@@ -135,22 +135,22 @@ ReceiveScreen:
                 icon: 'atlas://electrum/gui/kivy/theming/light/list'
                 size_hint: 0.5, None
                 height: '48dp'
-                on_release: Clock.schedule_once(lambda dt: s.parent.clear_requests_dialog())
+                on_release: Clock.schedule_once(lambda dt: s.clear_requests_dialog())
             IconButton:
                 icon: 'atlas://electrum/gui/kivy/theming/light/clock1'
                 size_hint: 0.5, None
                 height: '48dp'
-                on_release: Clock.schedule_once(lambda dt: s.parent.expiration_dialog(s))
+                on_release: Clock.schedule_once(lambda dt: s.expiration_dialog(s))
             Button:
                 text: _('Clear')
                 size_hint: 1, None
                 height: '48dp'
-                on_release: Clock.schedule_once(lambda dt: s.parent.clear())
+                on_release: Clock.schedule_once(lambda dt: s.clear())
             Button:
                 text: _('Request')
                 size_hint: 1, None
                 height: '48dp'
-                on_release: Clock.schedule_once(lambda dt: s.parent.new_request(root.is_lightning))
+                on_release: Clock.schedule_once(lambda dt: s.new_request(root.is_lightning))
         Widget:
             size_hint: 1, 0.1
         RequestRecycleView:

electrum/gui/kivy/uix/ui_screens/send.kv

@@ -62,7 +62,7 @@
         height: self.minimum_height
         orientation: 'vertical'
 
-SendScreen:
+<SendScreen>:
     id: s
     name: 'send'
     address: ''
@@ -150,12 +150,12 @@ SendScreen:
             height: '48dp'
             IconButton:
                 size_hint: 0.5, 1
-                on_release: s.parent.do_save()
+                on_release: s.do_save()
                 icon: 'atlas://electrum/gui/kivy/theming/light/save'
             IconButton:
                 size_hint: 0.5, 1
                 icon: 'atlas://electrum/gui/kivy/theming/light/copy'
-                on_release: s.parent.do_paste()
+                on_release: s.do_paste()
             IconButton:
                 id: qr
                 size_hint: 1, 1
@@ -164,11 +164,11 @@ SendScreen:
             Button:
                 text: _('Clear')
                 size_hint: 1, 1
-                on_release: s.parent.do_clear()
+                on_release: s.do_clear()
             Button:
                 text: _('Pay')
                 size_hint: 1, 1
-                on_release: s.parent.do_pay()
+                on_release: s.do_pay()
         Widget:
             size_hint: 1, 0.1
         PaymentRecycleView: