From 915e132c335f8a4c70538088d7c6ce602de0f054 Mon Sep 17 00:00:00 2001
From: ThomasV <thomasv@electrum.org>
Date: Fri, 27 Nov 2020 12:48:32 +0100
Subject: [PATCH] fix 'max' button in Kivy (fix #6169)

---
 electrum/gui/kivy/main_window.py                 |  7 ++++++-
 electrum/gui/kivy/uix/dialogs/amount_dialog.py   |  5 ++++-
 .../kivy/uix/dialogs/lightning_open_channel.py   |  3 ++-
 electrum/gui/kivy/uix/screens.py                 | 16 +++++++++++-----
 4 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/electrum/gui/kivy/main_window.py b/electrum/gui/kivy/main_window.py
index 5e051767e..189763b48 100644
--- a/electrum/gui/kivy/main_window.py
+++ b/electrum/gui/kivy/main_window.py
@@ -1173,7 +1173,12 @@ class ElectrumWindow(App, Logger):
             amount, u = str(amount).split()
             assert u == self.base_unit
         def cb(amount):
-            screen.amount = amount
+            if amount == '!':
+                screen.is_max = True
+                screen.amount = self.get_max_amount() + ' ' + self.base_unit
+            else:
+                screen.amount = amount
+                screen.is_max = False
         popup = AmountDialog(show_max, amount, cb)
         popup.open()
 
diff --git a/electrum/gui/kivy/uix/dialogs/amount_dialog.py b/electrum/gui/kivy/uix/dialogs/amount_dialog.py
index ca95f73cd..673c62f8f 100644
--- a/electrum/gui/kivy/uix/dialogs/amount_dialog.py
+++ b/electrum/gui/kivy/uix/dialogs/amount_dialog.py
@@ -49,6 +49,7 @@ Builder.load_string('''
                 amount: ''
                 fiat_amount: ''
                 is_fiat: False
+                is_max: False
                 on_fiat_amount: if self.is_fiat: self.amount = app.fiat_to_btc(self.fiat_amount)
                 on_amount: if not self.is_fiat: self.fiat_amount = app.btc_to_fiat(self.amount)
                 size_hint: 1, None
@@ -92,6 +93,7 @@ Builder.load_string('''
                     on_release:
                         kb.is_fiat = False
                         kb.amount = app.get_max_amount()
+                        kb.is_max = True
                 Button:
                     size_hint: 1, None
                     height: '48dp'
@@ -99,6 +101,7 @@ Builder.load_string('''
                     on_release:
                         kb.amount = ''
                         kb.fiat_amount = ''
+                        kb.is_max = False
             Widget:
                 size_hint: 1, 0.2
             BoxLayout:
@@ -112,7 +115,7 @@ Builder.load_string('''
                     height: '48dp'
                     text: _('OK')
                     on_release:
-                        root.callback(btc.text if kb.amount else '')
+                        root.callback('!' if kb.is_max else btc.text if kb.amount else '')
                         popup.dismiss()
 ''')
 
diff --git a/electrum/gui/kivy/uix/dialogs/lightning_open_channel.py b/electrum/gui/kivy/uix/dialogs/lightning_open_channel.py
index 6eb73840b..c4e4d2671 100644
--- a/electrum/gui/kivy/uix/dialogs/lightning_open_channel.py
+++ b/electrum/gui/kivy/uix/dialogs/lightning_open_channel.py
@@ -23,6 +23,7 @@ Builder.load_string('''
     title: _('Open Lightning Channel')
     pubkey: ''
     amount: ''
+    is_max: False
     ipport: ''
     BoxLayout
         spacing: '12dp'
@@ -154,7 +155,7 @@ class LightningOpenChannelDialog(Factory.Popup, Logger):
         conn_str = self.pubkey
         if self.ipport:
             conn_str += '@' + self.ipport.strip()
-        amount = self.app.get_amount(self.amount)
+        amount = '!' if self.is_max else self.app.get_amount(self.amount)
         self.app.protected('Create a new channel?', self.do_open_channel, (conn_str, amount))
         self.dismiss()
 
diff --git a/electrum/gui/kivy/uix/screens.py b/electrum/gui/kivy/uix/screens.py
index eab111488..a949cf47a 100644
--- a/electrum/gui/kivy/uix/screens.py
+++ b/electrum/gui/kivy/uix/screens.py
@@ -196,6 +196,7 @@ class SendScreen(CScreen, Logger):
         self.address = uri.get('address', '')
         self.message = uri.get('message', '')
         self.amount = self.app.format_amount_and_units(amount) if amount else ''
+        self.is_max = False
         self.payment_request = None
         self.is_lightning = False
 
@@ -260,6 +261,7 @@ class SendScreen(CScreen, Logger):
         self.is_lightning = False
         self.is_bip70 = False
         self.parsed_URI = None
+        self.is_max = False
 
     def set_request(self, pr: 'PaymentRequest'):
         self.address = pr.get_requestor()
@@ -298,11 +300,14 @@ class SendScreen(CScreen, Logger):
         if not self.amount:
             self.app.show_error(_('Please enter an amount'))
             return
-        try:
-            amount = self.app.get_amount(self.amount)
-        except:
-            self.app.show_error(_('Invalid amount') + ':\n' + self.amount)
-            return
+        if self.is_max:
+            amount = '!'
+        else:
+            try:
+                amount = self.app.get_amount(self.amount)
+            except:
+                self.app.show_error(_('Invalid amount') + ':\n' + self.amount)
+                return
         message = self.message
         if self.is_lightning:
             return LNInvoice.from_bech32(address)
@@ -439,6 +444,7 @@ class ReceiveScreen(CScreen):
     def clear(self):
         self.address = ''
         self.amount = ''
+        self.is_max = False # not used for receiving (see app.amount_dialog)
         self.message = ''
         self.lnaddr = ''