--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/velib_python/settingsdevice.py	Sun Dec 05 14:35:36 2021 +1030
@@ -0,0 +1,118 @@
+import dbus
+import logging
+import time
+from functools import partial
+
+# Local imports
+from vedbus import VeDbusItemImport
+
+## Indexes for the setting dictonary.
+PATH = 0
+VALUE = 1
+MINIMUM = 2
+MAXIMUM = 3
+SILENT = 4
+
+## The Settings Device class.
+# Used by python programs, such as the vrm-logger, to read and write settings they
+# need to store on disk. And since these settings might be changed from a different
+# source, such as the GUI, the program can pass an eventCallback that will be called
+# as soon as some setting is changed.
+#
+# The settings are stored in flash via the com.victronenergy.settings service on dbus.
+# See https://github.com/victronenergy/localsettings for more info.
+#
+# If there are settings in de supportSettings list which are not yet on the dbus, 
+# and therefore not yet in the xml file, they will be added through the dbus-addSetting
+# interface of com.victronenergy.settings.
+class SettingsDevice(object):
+	## The constructor processes the tree of dbus-items.
+	# @param bus the system-dbus object
+	# @param name the dbus-service-name of the settings dbus service, 'com.victronenergy.settings'
+	# @param supportedSettings dictionary with all setting-names, and their defaultvalue, min, max and whether
+	# the setting is silent. The 'silent' entry is optional. If set to true, no changes in the setting will
+	# be logged by localsettings.
+	# @param eventCallback function that will be called on changes on any of these settings
+	# @param timeout Maximum interval to wait for localsettings. An exception is thrown at the end of the
+	# interval if the localsettings D-Bus service has not appeared yet.
+	def __init__(self, bus, supportedSettings, eventCallback, name='com.victronenergy.settings', timeout=0):
+		logging.debug("===== Settings device init starting... =====")
+		self._bus = bus
+		self._dbus_name = name
+		self._eventCallback = eventCallback
+		self._values = {} # stored the values, used to pass the old value along on a setting change
+		self._settings = {}
+
+		count = 0
+		while True:
+			if 'com.victronenergy.settings' in self._bus.list_names():
+				break
+			if count == timeout:
+				raise Exception("The settings service com.victronenergy.settings does not exist!")
+			count += 1
+			logging.info('waiting for settings')
+			time.sleep(1)
+
+		# Add the items.
+		self.addSettings(supportedSettings)
+
+		logging.debug("===== Settings device init finished =====")
+
+	def addSettings(self, settings):
+		for setting, options in settings.items():
+			silent = len(options) > SILENT and options[SILENT]
+			busitem = self.addSetting(options[PATH], options[VALUE],
+				options[MINIMUM], options[MAXIMUM], silent, callback=partial(self.handleChangedSetting, setting))
+			self._settings[setting] = busitem
+			self._values[setting] = busitem.get_value()
+
+	def addSetting(self, path, value, _min, _max, silent=False, callback=None):
+		busitem = VeDbusItemImport(self._bus, self._dbus_name, path, callback)
+		if busitem.exists and (value, _min, _max, silent) == busitem._proxy.GetAttributes():
+			logging.debug("Setting %s found" % path)
+		else:
+			logging.info("Setting %s does not exist yet or must be adjusted" % path)
+
+			# Prepare to add the setting. Most dbus types extend the python
+			# type so it is only necessary to additionally test for Int64.
+			if isinstance(value, (int, dbus.Int64)):
+				itemType = 'i'
+			elif isinstance(value, float):
+				itemType = 'f'
+			else:
+				itemType = 's'
+
+			# Add the setting
+			# TODO, make an object that inherits VeDbusItemImport, and complete the D-Bus settingsitem interface
+			settings_item = VeDbusItemImport(self._bus, self._dbus_name, '/Settings', createsignal=False)
+			setting_path = path.replace('/Settings/', '', 1)
+			if silent:
+				settings_item._proxy.AddSilentSetting('', setting_path, value, itemType, _min, _max)
+			else:
+				settings_item._proxy.AddSetting('', setting_path, value, itemType, _min, _max)
+
+			busitem = VeDbusItemImport(self._bus, self._dbus_name, path, callback)
+
+		return busitem
+
+	def handleChangedSetting(self, setting, servicename, path, changes):
+		oldvalue = self._values[setting] if setting in self._values else None
+		self._values[setting] = changes['Value']
+
+		if self._eventCallback is None:
+			return
+
+		self._eventCallback(setting, oldvalue, changes['Value'])
+
+	def setDefault(self, path):
+                item = VeDbusItemImport(self._bus, self._dbus_name, path, createsignal=False)
+                item.set_default()
+
+	def __getitem__(self, setting):
+		return self._settings[setting].get_value()
+
+	def __setitem__(self, setting, newvalue):
+		result = self._settings[setting].set_value(newvalue)
+		if result != 0:
+			# Trying to make some false change to our own settings? How dumb!
+			assert False