gui: show remaining hold duration in the status line

The status bar now appends "(MM:SS remaining)" to a hold step's text,
kept live by recomputing it on every HoldRemaining message (not just
when the step itself changes) - tasks/sud.py already sent this, the
GUI just wasn't tracking/displaying it.

client/brewpi_gui.py

@@ -269,6 +269,8 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 		self.sud_name = ''
 		self.sud_schedule = []
 		self.sud_step_index = None
+		self.sud_step_descr = None
+		self.sud_step_type = None
 		self.sud_hold_remaining = 0.0
 		# [(t_min, theta), ...] actually measured since the current run
 		# started - the "already happened" part of the dynamic forecast.
@@ -462,6 +464,8 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 			self.sud_name = ''
 			self.sud_schedule = []
 			self.sud_step_index = None
+			self.sud_step_descr = None
+			self.sud_step_type = None
 			self.sud_hold_remaining = 0.0
 			self.forecast_history = []
 			self.set_sud_cooling(False)
@@ -732,17 +736,26 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 				self.sud_user_message = msg['UserMessage']
 			elif "Step" in key:
 				step = msg['Step']
-				descr = step.get('Descr')
-				if descr:
-					self.statusBar().showMessage("Step {}: {}".format(step.get('Index'), descr))
-				else:
-					self.statusBar().clearMessage()
 				self.sud_step_index = step.get('Index')
+				self.sud_step_descr = step.get('Descr')
+				self.sud_step_type = step.get('Type')
 				self.set_sud_cooling(step.get('Cooling', False))
+				self.update_status_step_label()
 			elif "HoldRemaining" in key:
 				self.sud_hold_remaining = msg['HoldRemaining']
+				self.update_status_step_label()
 		self.update_sud_actions()
 
+	def update_status_step_label(self):
+		if not self.sud_step_descr:
+			self.statusBar().clearMessage()
+			return
+		text = "Step {}: {}".format(self.sud_step_index, self.sud_step_descr)
+		if self.sud_step_type == 'hold':
+			remaining = max(self.sud_hold_remaining, 0.0)
+			text += " ({:.0f}:{:02.0f} remaining)".format(remaining // 60, remaining % 60)
+		self.statusBar().showMessage(text)
+
 	def update_sud_forecast(self, doc):
 		try:
 			name, _, schedule, _, _ = Sud._parse_data(doc)