From faf66a4c256ff9ca0e9887e97d9ee871e862fef6 Mon Sep 17 00:00:00 2001
From: Markus Katharina Brechtel <markus.katharina.brechtel@thengo.net>
Date: Mon, 13 Jan 2020 11:53:45 +0100
Subject: [PATCH] mate-screensaver-helper-inhibition script

---
 files/mate-screensaver-helper-inhibition.py | 142 ++++++++++++++++++++
 tasks/main.yaml                             |   9 ++
 2 files changed, 151 insertions(+)
 create mode 100644 files/mate-screensaver-helper-inhibition.py

diff --git a/files/mate-screensaver-helper-inhibition.py b/files/mate-screensaver-helper-inhibition.py
new file mode 100644
index 0000000..8b541b6
--- /dev/null
+++ b/files/mate-screensaver-helper-inhibition.py
@@ -0,0 +1,142 @@
+#!/usr/bin/python3
+import os
+import sys
+import time
+
+import dbus
+import dbus.service
+import dbus.mainloop.glib
+dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
+from gi.repository import GObject as gobject
+
+# DBus connection information for MATE screensaver
+DBUS_MSCR_WAIT = 60
+DBUS_MSCR_DBUS = dbus.SessionBus()
+DBUS_MSCR_NAME = "org.mate.ScreenSaver"
+DBUS_MSCR_PATH = "/"
+DBUS_MSCR_IFACE_MAIN = "org.mate.ScreenSaver"
+
+# DBus listening information for the Idle Inhibition Spec
+DBUS_IIS_DBUS = dbus.SessionBus()
+DBUS_IIS_NAME = "org.freedesktop.ScreenSaver"
+DBUS_IIS_PATH = "/org/freedesktop/ScreenSaver"
+DBUS_IIS_PATH2= "/ScreenSaver"
+DBUS_IIS_IFACE_MAIN = "org.freedesktop.ScreenSaver"
+
+# Connect to the system and session bus
+bus_system  = dbus.SystemBus()
+bus_session = dbus.SessionBus()
+
+# Connect to MATE screensaver
+print("Waiting for screensaver...")
+for i in range(DBUS_MSCR_WAIT):
+	try:
+		mate_screensaver = dbus.Interface(
+				bus_session.get_object(DBUS_MSCR_NAME, DBUS_MSCR_PATH),
+				DBUS_MSCR_IFACE_MAIN
+		)
+	except dbus.exceptions.DBusException:
+		# Screensaver not running yet
+		if i < (DBUS_MSCR_WAIT - 1):
+			time.sleep(1)
+		else:
+			print("MATE screensaver not running, aborting!", file=sys.stderr)
+			sys.exit(2)
+	else:
+		print("MATE screensaver connected!")
+		break
+
+
+class IdleInhibitor(object):
+	"""
+	Represents a single client that inhibits the screensaver
+	"""
+	def __init__(self, screensaver, name, reason, cookie, unique_name):
+		self.screensaver = screensaver
+
+		self.name        = name
+		self.reason      = reason
+		self.cookie      = cookie
+		self.unique_name = unique_name
+
+		# Tell MATE screensaver about the application we are proxying
+		self._cookie = self.screensaver.Inhibit(name, reason)
+
+	def destroy(self):
+		# Stop bothering MATE screensaver
+		self.screensaver.UnInhibit(self._cookie)
+
+
+# Create DBus interface
+class IdleInhibitionService(dbus.service.Object):
+	def __init__(self, mate_screensaver):
+		# Store connection to screensaver
+		self.screensaver = mate_screensaver
+
+		# Counter for inhibition requests (used for cookies)
+		self.counter = 1
+
+		# Storage for clients
+		self.inhibitors = []
+
+		# Store constants
+		self.bus   = DBUS_IIS_DBUS
+		self.path  = DBUS_IIS_PATH
+		self.path2 = DBUS_IIS_PATH2
+
+		# Claim bus name with both paths used by GNOME
+		dbus.service.Object.__init__(self,
+				self.bus, self.path, dbus.service.BusName(DBUS_IIS_NAME, self.bus)
+		)
+		dbus.service.Object.__init__(self,
+                self.bus, self.path2, dbus.service.BusName(DBUS_IIS_NAME, self.bus)
+        )
+
+	def on_name_change(self, sender, unique_name):
+		print("mate-screensaver-helper-inhibition: on_name_change: '%s', '%s'" % (sender, unique_name))
+
+		if sender != unique_name:
+			for inhibitor in self.inhibitors:
+				if inhibitor.unique_name == sender:
+					self.UnInhibit(inhibitor.cookie, sender)
+
+	@dbus.service.method(DBUS_IIS_IFACE_MAIN, "ss", "u", sender_keyword="sender")
+	def Inhibit(self, application_name, reason_for_inhibit, sender):
+		print("mate-screensaver-helper-inhibition: Inhibit: '%s', '%s' -> %d (from '%s')"
+				% (application_name, reason_for_inhibit, self.counter + 1, sender))
+
+		# Create new cookie
+		self.counter += 1
+
+		# Add inhibitor
+		self.inhibitors.append(IdleInhibitor(
+			self.screensaver,
+			application_name,
+			reason_for_inhibit,
+			self.counter,
+			sender
+		))
+
+		# Watch if bus name owner disappears
+		self.bus.watch_name_owner(sender, lambda name: self.on_name_change(sender, name))
+
+		return self.counter
+
+	@dbus.service.method(DBUS_IIS_IFACE_MAIN, "u", "", sender_keyword="sender")
+	def UnInhibit(self, cookie, sender):
+		print("mate-screensaver-helper-inhibition: UnInhibit: %d (from '%s')" % (cookie, sender))
+
+		for inhibitor in self.inhibitors:
+			if inhibitor.cookie == cookie and inhibitor.unique_name == sender:
+				# Stop inhibiting
+				inhibitor.destroy()
+
+				# Remove inhibitor from list
+				self.inhibitors.remove(inhibitor)
+
+
+# Create service
+service = IdleInhibitionService(mate_screensaver)
+
+# Wait for stuff to happen
+gobject.MainLoop().run()
diff --git a/tasks/main.yaml b/tasks/main.yaml
index 7adc736..83abff5 100644
--- a/tasks/main.yaml
+++ b/tasks/main.yaml
@@ -12,6 +12,7 @@
     pkg:
       - mate-screensaver
       - xscreensaver-gl
+      - python3
 
 - name: gdmflexiserver dummy script
   copy:
@@ -19,6 +20,14 @@
     dest: /usr/local/bin/gdmflexiserver
     mode: 0755
 
+# Bug: https://github.com/mate-desktop/mate-screensaver/issues/57
+# https://gist.github.com/alexander255/9b991816418e4e60ee7c
+- name: mate-screensaver-helper-inhibition script
+  copy:
+    src: mate-screensaver-helper-inhibition.py
+    dest: /usr/local/bin/mate-screensaver-helper-inhibition
+    mode: 0755
+
 - import_role:
     name: dconf-lock
   vars: