implement tracking current window for Gnome+Wayland

Based on information from:
ActivityWatch/aw-watcher-window#46
https://askubuntu.com/questions/1412130/dbus-calls-to-gnome-shell-dont-work-under-ubuntu-22-04
https://github.com/hseliger/window-calls-extended

To avoid opening a security hole, it is wiser to install the "Window calls extended"
extension by hseliger. Then we can regularly query the currently active window.

Compared to the previous version, activity/passivity of the user is not detected anymore.

track-gnome.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+# 
+# Tracks what you are spending your time on
+# 
+#
+# Copyright (c) 2019 Johannes Buchner
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer.
+# 
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+DIR=$HOME/.local/share/activitytracker/
+mkdir -p $DIR
+
+if [ -e $DIR/pid ]
+then
+	pid=$(cat $DIR/pid)
+	# check if still running
+	if kill -0 ${pid} 2>/dev/null
+	then		
+		# check if related
+		if grep -q $0 /proc/${pid}/cmdline
+		then
+			echo "activity tracker already runnning as PID=$pid"
+			exit 0
+		fi
+	fi
+fi
+
+pid=$$
+echo $pid > $DIR/pid
+
+function window_call_info {
+	# call Gnome extension "Window Calls extended" 
+	# https://extensions.gnome.org/extension/4974/window-calls-extended/
+	# needs to be installed!
+	gdbus call --session --dest org.gnome.Shell --object-path /org/gnome/Shell/Extensions/WindowsExt --method org.gnome.Shell.Extensions.WindowsExt.$1 | 
+	sed -n "s/^('\(.*\)',)$/\1/g; s/['\"]//g; p"
+}
+
+while true
+do
+echo '{"timestamp":'$(date +%s)',"windowname":"'$(window_call_info FocusTitle)'","exe":"'$(window_call_info FocusClass)'"}';
+sleep 10;
+done >> $DIR/log