fix #2614: define non-linear scale for static fees

gui/kivy/uix/dialogs/fee_dialog.py

@@ -58,7 +58,6 @@ class FeeDialog(Factory.Popup):
         Factory.Popup.__init__(self)
         self.app = app
         self.config = config
-        self.fee_step = self.config.max_fee_rate() / 10
         self.fee_rate = self.config.fee_per_kb()
         self.callback = callback
         self.dynfees = self.config.get('dynamic_fees', True)
@@ -77,9 +76,9 @@ class FeeDialog(Factory.Popup):
             slider.step = 1
             slider.value = self.config.get('fee_level', 2)
         else:
-            slider.range = (1, 10)
+            slider.range = (0, 9)
             slider.step = 1
-            slider.value = min(self.fee_rate / self.fee_step, 10)
+            slider.value = self.config.static_fee_index(self.fee_rate)
 
     def get_fee_text(self, value):
         if self.ids.dynfees.active:
@@ -88,7 +87,7 @@ class FeeDialog(Factory.Popup):
                 dynfee = self.config.dynfee(value)
                 tooltip += '\n' + (self.app.format_amount_and_units(dynfee)) + '/kB'
         else:
-            fee_rate = value * self.fee_step
+            fee_rate = self.config.static_fee(value)
             tooltip = self.app.format_amount_and_units(fee_rate) + '/kB'
             if self.config.has_fee_estimates():
                 i = self.config.reverse_dynfee(fee_rate)
@@ -101,7 +100,7 @@ class FeeDialog(Factory.Popup):
         if self.dynfees:
             self.config.set_key('fee_level', value, True)
         else:
-            self.config.set_key('fee_per_kb', value * self.fee_step, True)
+            self.config.set_key('fee_per_kb', self.config.static_fee(value), True)
         self.callback()
 
     def on_slider(self, value):

gui/qt/fee_slider.py

@@ -28,7 +28,7 @@ class FeeSlider(QSlider):
 
     def moved(self, pos):
         with self.lock:
-            fee_rate = self.config.dynfee(pos) if self.dyn else pos * self.fee_step
+            fee_rate = self.config.dynfee(pos) if self.dyn else self.config.static_fee(pos)
             tooltip = self.get_tooltip(pos, fee_rate)
             QToolTip.showText(QCursor.pos(), tooltip, self)
             self.setToolTip(tooltip)
@@ -55,10 +55,9 @@ class FeeSlider(QSlider):
                 self.setRange(0, 4)
                 self.setValue(pos)
             else:
-                self.fee_step = self.config.max_fee_rate() / 10
                 fee_rate = self.config.fee_per_kb()
-                pos = min(fee_rate / self.fee_step, 10)
-                self.setRange(1, 10)
+                pos = self.config.static_fee_index(fee_rate)
+                self.setRange(0, 9)
                 self.setValue(pos)
             tooltip = self.get_tooltip(pos, fee_rate)
             self.setToolTip(tooltip)

gui/qt/main_window.py

@@ -2437,21 +2437,6 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         fee_widgets.append((dynfee_cb, None))
         dynfee_cb.stateChanged.connect(on_dynfee)
 
-        def on_maxfee(x):
-            m = maxfee_e.get_amount()
-            if m: self.config.set_key('max_fee_rate', m)
-            self.fee_slider.update()
-        def update_maxfee():
-            d = self.config.is_dynfee()
-            maxfee_e.setDisabled(d)
-            maxfee_label.setDisabled(d)
-        maxfee_label = HelpLabel(_('Max static fee'), _('Max value of the static fee slider'))
-        maxfee_e = BTCkBEdit(self.get_decimal_point)
-        maxfee_e.setAmount(self.config.max_fee_rate())
-        maxfee_e.textChanged.connect(on_maxfee)
-        update_maxfee()
-        fee_widgets.append((maxfee_label, maxfee_e))
-
         feebox_cb = QCheckBox(_('Edit fees manually'))
         feebox_cb.setChecked(self.config.get('show_fee', False))
         feebox_cb.setToolTip(_("Show fee edit box in send tab."))

lib/simple_config.py

@@ -41,6 +41,8 @@ class SimpleConfig(PrintError):
     They are taken in order (1. overrides config options set in 2., that
     override config set in 3.)
     """
+    fee_rates = [5000, 10000, 20000, 30000, 50000, 70000, 100000, 150000, 200000, 300000]
+
     def __init__(self, options={}, read_system_config_function=None,
                  read_user_config_function=None, read_user_dir_function=None):
 
@@ -230,6 +232,13 @@ class SimpleConfig(PrintError):
             min_target = -1
         return min_target
 
+    def static_fee(self, i):
+        return self.fee_rates[i]
+
+    def static_fee_index(self, value):
+        dist = list(map(lambda x: abs(x - value), self.fee_rates))
+        return min(range(len(dist)), key=dist.__getitem__)
+
     def has_fee_estimates(self):
         return len(self.fee_estimates)==4