add 'sat' as base unit option

gui/kivy/uix/dialogs/choice_dialog.py

@@ -44,14 +44,19 @@ Builder.load_string('''
 
 class ChoiceDialog(Factory.Popup):
 
-    def __init__(self, title, choices, key, callback):
+    def __init__(self, title, choices, key, callback, keep_choice_order=False):
         Factory.Popup.__init__(self)
         print(choices, type(choices))
+        if keep_choice_order:
+            orig_index = {choice: i for (i, choice) in enumerate(choices)}
+            sort_key = lambda x: orig_index[x[0]]
+        else:
+            sort_key = lambda x: x
         if type(choices) is list:
             choices = dict(map(lambda x: (x,x), choices))
         layout = self.ids.choices
         layout.bind(minimum_height=layout.setter('height'))
-        for k, v in sorted(choices.items()):
+        for k, v in sorted(choices.items(), key=sort_key):
             l = Label(text=v)
             l.height = '48dp'
             l.size_hint_x = 4

gui/kivy/uix/dialogs/settings.py

@@ -3,7 +3,7 @@ from kivy.factory import Factory
 from kivy.properties import ObjectProperty
 from kivy.lang import Builder
 
-from electrum.util import base_units
+from electrum.util import base_units_list
 from electrum.i18n import languages
 from electrum_gui.kivy.i18n import _
 from electrum.plugins import run_hook
@@ -136,7 +136,8 @@ class SettingsDialog(Factory.Popup):
             def cb(text):
                 self.app._set_bu(text)
                 item.bu = self.app.base_unit
-            self._unit_dialog = ChoiceDialog(_('Denomination'), list(base_units.keys()), self.app.base_unit, cb)
+            self._unit_dialog = ChoiceDialog(_('Denomination'), base_units_list,
+                                             self.app.base_unit, cb, keep_choice_order=True)
         self._unit_dialog.open()
 
     def coinselect_status(self):

gui/qt/amountedit.py

@@ -5,7 +5,7 @@ from PyQt5.QtGui import *
 from PyQt5.QtWidgets import (QLineEdit, QStyle, QStyleOptionFrame)
 
 from decimal import Decimal
-from electrum.util import format_satoshis_plain
+from electrum.util import format_satoshis_plain, decimal_point_to_base_unit_name
 
 
 class MyLineEdit(QLineEdit):
@@ -80,14 +80,7 @@ class BTCAmountEdit(AmountEdit):
         self.decimal_point = decimal_point
 
     def _base_unit(self):
-        p = self.decimal_point()
-        if p == 8:
-            return 'BTC'
-        if p == 5:
-            return 'mBTC'
-        if p == 2:
-            return 'bits'
-        raise Exception('Unknown base unit')
+        return decimal_point_to_base_unit_name(self.decimal_point())
 
     def get_amount(self):
         try:

gui/qt/main_window.py

@@ -47,7 +47,9 @@ from electrum.i18n import _
 from electrum.util import (format_time, format_satoshis, format_fee_satoshis,
                            format_satoshis_plain, NotEnoughFunds, PrintError,
                            UserCancelled, NoDynamicFeeEstimates, profiler,
-                           export_meta, import_meta, bh2u, bfh, InvalidPassword)
+                           export_meta, import_meta, bh2u, bfh, InvalidPassword,
+                           base_units, base_units_list, base_unit_name_to_decimal_point,
+                           decimal_point_to_base_unit_name)
 from electrum import Transaction
 from electrum import util, bitcoin, commands, coinchooser
 from electrum import paymentrequest
@@ -655,14 +657,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         return self.decimal_point
 
     def base_unit(self):
-        assert self.decimal_point in [2, 5, 8]
-        if self.decimal_point == 2:
-            return 'bits'
-        if self.decimal_point == 5:
-            return 'mBTC'
-        if self.decimal_point == 8:
-            return 'BTC'
-        raise Exception('Unknown base unit')
+        return decimal_point_to_base_unit_name(self.decimal_point)
 
     def connect_fields(self, window, btc_e, fiat_e, fee_e):
 
@@ -2727,9 +2722,9 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         SSL_id_e.setReadOnly(True)
         id_widgets.append((SSL_id_label, SSL_id_e))
 
-        units = ['BTC', 'mBTC', 'bits']
+        units = base_units_list
         msg = (_('Base unit of your wallet.')
-               + '\n1 BTC = 1000 mBTC. 1 mBTC = 1000 bits.\n'
+               + '\n1 BTC = 1000 mBTC. 1 mBTC = 1000 bits. 1 bit = 100 sat.\n'
                + _('This setting affects the Send tab, and all balance related fields.'))
         unit_label = HelpLabel(_('Base unit') + ':', msg)
         unit_combo = QComboBox()
@@ -2741,14 +2736,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
                 return
             edits = self.amount_e, self.fee_e, self.receive_amount_e
             amounts = [edit.get_amount() for edit in edits]
-            if unit_result == 'BTC':
-                self.decimal_point = 8
-            elif unit_result == 'mBTC':
-                self.decimal_point = 5
-            elif unit_result == 'bits':
-                self.decimal_point = 2
-            else:
-                raise Exception('Unknown base unit')
+            self.decimal_point = base_unit_name_to_decimal_point(unit_result)
             self.config.set_key('decimal_point', self.decimal_point, True)
             nz.setMaximum(self.decimal_point)
             self.history_list.update()

lib/util.py

@@ -40,7 +40,26 @@ def inv_dict(d):
     return {v: k for k, v in d.items()}
 
 
-base_units = {'BTC':8, 'mBTC':5, 'uBTC':2}
+base_units = {'BTC':8, 'mBTC':5, 'bits':2, 'sat':0}
+base_units_inverse = inv_dict(base_units)
+base_units_list = ['BTC', 'mBTC', 'bits', 'sat']  # list(dict) does not guarantee order
+
+
+def decimal_point_to_base_unit_name(dp: int) -> str:
+    # e.g. 8 -> "BTC"
+    try:
+        return base_units_inverse[dp]
+    except KeyError:
+        raise Exception('Unknown base unit')
+
+
+def base_unit_name_to_decimal_point(unit_name: str) -> int:
+    # e.g. "BTC" -> 8
+    try:
+        return base_units[unit_name]
+    except KeyError:
+        raise Exception('Unknown base unit')
+
 
 def normalize_version(v):
     return [int(x) for x in re.sub(r'(\.0+)*$','', v).split(".")]