Add interface for setting voltage range

There's a switch to toggle whether the range is enabled at all, two
spinbuttons for the range itself which automatically maintain their
ordering, and a button to toggle between high and low voltages
preferred.  What more could a gal ask for?

data/pd-buddy-gtk.ui

@@ -13,6 +13,23 @@
     <property name="page_increment">1</property>
     <signal name="value-changed" handler="on_current_adjustment_value_changed" swapped="no"/>
   </object>
+  <object class="GtkImage" id="order-image">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">go-next-symbolic</property>
+  </object>
+  <object class="GtkAdjustment" id="vmax-adjustment">
+    <property name="upper">21</property>
+    <property name="step_increment">0.10000000000000001</property>
+    <property name="page_increment">1</property>
+    <signal name="value-changed" handler="on_vmax_adjustment_value_changed" swapped="no"/>
+  </object>
+  <object class="GtkAdjustment" id="vmin-adjustment">
+    <property name="upper">21</property>
+    <property name="step_increment">0.10000000000000001</property>
+    <property name="page_increment">1</property>
+    <signal name="value-changed" handler="on_vmin_adjustment_value_changed" swapped="no"/>
+  </object>
   <object class="GtkAdjustment" id="voltage-adjustment">
     <property name="upper">21</property>
     <property name="step_increment">0.10000000000000001</property>
@@ -165,7 +182,7 @@
                                 <property name="label_xalign">0</property>
                                 <child>
                                   <object class="GtkListBox" id="sink-config-list">
-                                    <property name="width_request">342</property>
+                                    <property name="width_request">360</property>
                                     <property name="visible">True</property>
                                     <property name="can_focus">False</property>
                                     <property name="selection_mode">none</property>
@@ -236,6 +253,142 @@
                                         </child>
                                       </object>
                                     </child>
+                                    <child>
+                                      <object class="GtkListBoxRow">
+                                        <property name="width_request">100</property>
+                                        <property name="visible">True</property>
+                                        <property name="can_focus">True</property>
+                                        <property name="activatable">False</property>
+                                        <child>
+                                          <object class="GtkGrid">
+                                            <property name="visible">True</property>
+                                            <property name="can_focus">False</property>
+                                            <property name="margin_left">12</property>
+                                            <property name="margin_right">6</property>
+                                            <property name="margin_top">6</property>
+                                            <property name="margin_bottom">6</property>
+                                            <property name="column_spacing">12</property>
+                                            <child>
+                                              <object class="GtkLabel">
+                                                <property name="visible">True</property>
+                                                <property name="can_focus">False</property>
+                                                <property name="halign">start</property>
+                                                <property name="hexpand">True</property>
+                                                <property name="label" translatable="yes">Voltage _Range</property>
+                                                <property name="use_underline">True</property>
+                                                <property name="mnemonic_widget">vrange-switch</property>
+                                              </object>
+                                              <packing>
+                                                <property name="left_attach">0</property>
+                                                <property name="top_attach">0</property>
+                                              </packing>
+                                            </child>
+                                            <child>
+                                              <object class="GtkSwitch" id="vrange-switch">
+                                                <property name="visible">True</property>
+                                                <property name="can_focus">True</property>
+                                                <property name="halign">end</property>
+                                                <property name="active">True</property>
+                                                <signal name="state-set" handler="on_vrange_switch_state_set" swapped="no"/>
+                                              </object>
+                                              <packing>
+                                                <property name="left_attach">1</property>
+                                                <property name="top_attach">0</property>
+                                              </packing>
+                                            </child>
+                                          </object>
+                                        </child>
+                                      </object>
+                                    </child>
+                                    <child>
+                                      <object class="GtkListBoxRow" id="vrange-row">
+                                        <property name="name">S</property>
+                                        <property name="width_request">100</property>
+                                        <property name="visible">True</property>
+                                        <property name="can_focus">True</property>
+                                        <property name="activatable">False</property>
+                                        <child>
+                                          <object class="GtkGrid">
+                                            <property name="visible">True</property>
+                                            <property name="can_focus">False</property>
+                                            <property name="halign">end</property>
+                                            <property name="margin_left">12</property>
+                                            <property name="margin_right">6</property>
+                                            <property name="margin_bottom">6</property>
+                                            <property name="column_spacing">12</property>
+                                            <child>
+                                              <object class="GtkLabel">
+                                                <property name="visible">True</property>
+                                                <property name="can_focus">False</property>
+                                                <property name="label" translatable="yes">V</property>
+                                                <property name="width_chars">2</property>
+                                              </object>
+                                              <packing>
+                                                <property name="left_attach">1</property>
+                                                <property name="top_attach">0</property>
+                                              </packing>
+                                            </child>
+                                            <child>
+                                              <object class="GtkBox">
+                                                <property name="visible">True</property>
+                                                <property name="can_focus">False</property>
+                                                <child>
+                                                  <object class="GtkSpinButton" id="vmin-spinbutton">
+                                                    <property name="visible">True</property>
+                                                    <property name="can_focus">True</property>
+                                                    <property name="width_chars">6</property>
+                                                    <property name="input_purpose">number</property>
+                                                    <property name="adjustment">vmin-adjustment</property>
+                                                    <property name="digits">2</property>
+                                                  </object>
+                                                  <packing>
+                                                    <property name="expand">False</property>
+                                                    <property name="fill">True</property>
+                                                    <property name="position">0</property>
+                                                  </packing>
+                                                </child>
+                                                <child>
+                                                  <object class="GtkButton" id="hv-preferred-button">
+                                                    <property name="visible">True</property>
+                                                    <property name="can_focus">True</property>
+                                                    <property name="receives_default">True</property>
+                                                    <property name="image">order-image</property>
+                                                    <signal name="clicked" handler="on_hv_preferred_button_clicked" swapped="no"/>
+                                                  </object>
+                                                  <packing>
+                                                    <property name="expand">False</property>
+                                                    <property name="fill">True</property>
+                                                    <property name="position">1</property>
+                                                  </packing>
+                                                </child>
+                                                <child>
+                                                  <object class="GtkSpinButton" id="vmax-spinbutton">
+                                                    <property name="visible">True</property>
+                                                    <property name="can_focus">True</property>
+                                                    <property name="width_chars">6</property>
+                                                    <property name="input_purpose">number</property>
+                                                    <property name="adjustment">vmax-adjustment</property>
+                                                    <property name="digits">2</property>
+                                                  </object>
+                                                  <packing>
+                                                    <property name="expand">False</property>
+                                                    <property name="fill">True</property>
+                                                    <property name="position">2</property>
+                                                  </packing>
+                                                </child>
+                                                <style>
+                                                  <class name="linked"/>
+                                                </style>
+                                              </object>
+                                              <packing>
+                                                <property name="left_attach">0</property>
+                                                <property name="top_attach">0</property>
+                                              </packing>
+                                            </child>
+                                          </object>
+                                        </child>
+                                      </object>
+                                    </child>
                                     <child>
                                       <object class="GtkListBoxRow">
                                         <property name="width_request">100</property>

pd-buddy-gtk.py

@@ -54,7 +54,9 @@ class SelectListStore(Gio.ListStore):
 
 def list_box_update_header_func(row, before, data):
     """Add a separator header to all rows but the first one"""
-    if before is None:
+    name = Gtk.Buildable.get_name(row)
+    # No header over the vrange-row to make it look like part of the row above
+    if before is None or name == "vrange-row":
         row.set_header(None)
         return
 
@@ -255,9 +257,7 @@ class Handler:
     def __init__(self, builder):
         self.builder = builder
         self.serial_port = None
-        self.voltage = None
-        self.current = None
-        self.giveback = None
+        self.vrange_set = False
         self.selectlist = None
 
     def on_pdb_window_realize(self, *args):
@@ -285,6 +285,9 @@ class Handler:
     def on_select_list_row_activated(self, selectlist, serport):
         # Get relevant widgets
         voltage = self.builder.get_object("voltage-adjustment")
+        vr_switch = self.builder.get_object("vrange-switch")
+        vmin_adj = self.builder.get_object("vmin-adjustment")
+        vmax_adj = self.builder.get_object("vmax-adjustment")
         current = self.builder.get_object("current-adjustment")
         current_dim = self.builder.get_object("current-dimension")
         giveback = self.builder.get_object("giveback-switch")
@@ -311,6 +314,10 @@ class Handler:
                             i=0, idim=pdbuddy.SinkDimension.CURRENT)
                 else:
                     self.cfg = pdbs.get_tmpcfg()
+                    if self.cfg.vmin is None:
+                        self.cfg = self.cfg._replace(vmin=0)
+                    if self.cfg.vmax is None:
+                        self.cfg = self.cfg._replace(vmax=0)
         except OSError as e:
             comms_error_dialog(window, e)
             return
@@ -324,6 +331,13 @@ class Handler:
         # Get voltage and current from device and load them into the GUI
         voltage.set_value(self.cfg.v/1000)
 
+        vr_switch.set_active(self.cfg.vmin != 0 or self.cfg.vmax != 0)
+        self.vrange_set = True
+        vmin_adj.set_value(self.cfg.vmin/1000)
+        self._set_hv_pref_image()
+        vmax_adj.set_value(self.cfg.vmax/1000)
+        self.vrange_set = False
+
         if self.cfg.idim == pdbuddy.SinkDimension.CURRENT:
             current_dim.set_active_id("idim-current")
         elif self.cfg.idim == pdbuddy.SinkDimension.POWER:
@@ -432,6 +446,60 @@ class Handler:
 
         self._set_save_button_visibility()
 
+    def on_vrange_switch_state_set(self, switch, state):
+        row = self.builder.get_object("vrange-row")
+        vmin_adj = self.builder.get_object("vmin-adjustment")
+        vmax_adj = self.builder.get_object("vmax-adjustment")
+
+        row.set_visible(state)
+        if not state:
+            self.cfg = self.cfg._replace(vmin=0, vmax=0)
+        self.vrange_set = True
+        vmin_adj.set_value(self.cfg.vmin/1000)
+        vmax_adj.set_value(self.cfg.vmax/1000)
+        self.vrange_set = False
+
+        self._set_save_button_visibility()
+
+    def on_vmin_adjustment_value_changed(self, adj):
+        if not self.vrange_set:
+            self.cfg = self.cfg._replace(vmin=int(adj.get_value() * 1000))
+
+            # Update vmax if necessary
+            vmax_adj = self.builder.get_object("vmax-adjustment")
+            if adj.get_value() > vmax_adj.get_value():
+                vmax_adj.set_value(adj.get_value())
+
+            self._set_save_button_visibility()
+
+    def on_vmax_adjustment_value_changed(self, adj):
+        if not self.vrange_set:
+            self.cfg = self.cfg._replace(vmax=int(adj.get_value() * 1000))
+
+            # Update vmin if necessary
+            vmin_adj = self.builder.get_object("vmin-adjustment")
+            if adj.get_value() < vmin_adj.get_value():
+                vmin_adj.set_value(adj.get_value())
+
+            self._set_save_button_visibility()
+
+    def on_hv_preferred_button_clicked(self, button):
+        self.cfg = self.cfg._replace(
+                flags=self.cfg.flags^pdbuddy.SinkFlags.HV_PREFERRED)
+
+        self._set_hv_pref_image()
+        self._set_save_button_visibility()
+
+    def _set_hv_pref_image(self):
+        hv_pref = self.builder.get_object("hv-preferred-button")
+        image = self.builder.get_object("order-image")
+
+        if self.cfg.flags & pdbuddy.SinkFlags.HV_PREFERRED:
+            image.set_from_icon_name("go-previous-symbolic",
+                    Gtk.IconSize.BUTTON)
+        else:
+            image.set_from_icon_name("go-next-symbolic", Gtk.IconSize.BUTTON)
+
     def on_current_dimension_changed(self, cb):
         item = cb.get_active_id()
         value = self.builder.get_object("current-adjustment")