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@@ -15,7 +15,156 @@ Ian Eure (ee-uhn you-er, he/him/his, IRC: ieure)
In this talk, I’ll explore uses of D-Bus that supercharge your
Emacs Operating System.
+# Discussion
+## Notes
+
+- - <https://codeberg.org/emacs-weirdware/debase>
+
+- <https://codeberg.org/emacs-weirdware/discomfort>
+
+- re: "pushing mindshare"..  Yes, you were very successful on that!
+
+## Questions and answers
+
+- Q: This is such a great overview of dbus.  I hadn't been paying
+ attention to this space because it seemed to be in flux (10-15 years
+ age).  How long has dbus been around and what was in place before
+ that?
+ - A: D-Bus dates to 2002, but really saw stabilization and
+ adoption in the 2010s.  There wasn't really anything prior to
+ D-Bus, you'd do some of the things it does by shelling out and
+ driving command-line programs --- not a great approach.
+- Q: Forgive me if this question is silly: Why is everything dBus
+ prefixed with "org."?
+ - A: D-Bus services generally use reverse-FQDN notation, similar
+ to Java packages, and most stuff using it is not-for-profit
+ software, so `org.` is a very common prefix for those.
+- Q: In your investigations, do most OS/DE/WM interop well over d-bus?
+ Which one(s) have proven more challenging, if any?
+ - A: Since D-Bus is pretty uniform, DE/WM considerations aren't a
+ large concern.  D-Bus isn't widely used on non-Linux systems,
+ so OS differences have little to no impact.
+- Q: Re: using EXWM as a Desktop Environment -- Does EXWM provide a
+ session manager (daemon)?
+ - A: No, but it looks like it can work with external X11 session
+ managers.
+- Q:There is a lot of critisism against d-bus out there, why do you
+ think that might be?
+ - A: Because it's not very good.  It uses XML, which isn't hip,
+ and I think a lot of people have a knee-jerk negative reaction
+ to.
+- Q: Which system services come to mind when thinking about
+ applications, be it at the OS/DE/WM level?
+ - A: Stuff that interacts with hardware: turning WiFi on and off,
+ connecting to networks, pairing Bluetooth devices.  The kind of
+ stuff you find in the upper-right of the dock/menubar in a
+ traditional DE.
+- Q: "If you want to do the kinds of things that dBus does, you're
+ limited": What is something dBus does that you couldn't do before?
+ What is a really cool use of dBus in a modern DE (KDE/Gnome etc)?
+ - A: D-Bus is fundamentally about making it *easier* to do things,
+ and using that increased ease of use to broaden the number of
+ places that kind of thing gets done.  So there's some prior art
+ for doing some of these things, but none of them is as easy as
+ doing it via D-Bus.  As far as specific features: I've been
+ using computers a very long time, and it's still magic to me
+ that you can just plug hardware in and immediately use it
+ without having to do anything --- D-Bus is foundational to that
+ kind of interactivity when it comes to things like storage,
+ network, and Bluetooth-connected devices.
+- Q:  When it comes to managing devices, how are dBus and UDev
+ related?
+ - A: They're orthogonal.  I believe UDisks2 (which is the D-Bus
+ service for managing disks) talks to UDev2, but this is abstract
+ & not a detail you have to care about as a client of UDisks2.
+- Q: As an average GNU/Linux user, I've used signals and methods
+ before but not properties. You gave an example involving properties,
+ but it kind of flew by. Can you explain briefly what clients and
+ services can do with properties?
+ - A: Properties are metadata associated with an object
+ interface[.   They can expose r/o information about the object
+ (the name of the host; the UUID of a disk device; the hardware
+ address of a network device), and you can modify certain
+ properties about the object or service by writing to them.  For
+ example, `org.freedesktop.NetworkManager.Device` has an
+ `AutoConnect` property, which you can use to enable/disable
+ automatic connection.
+- Q: what is the name of the dbus GUI you showed?  defeat? dfeet?
+ - A: "d-feet" 
+- Q:  Naive Q (me not knowing much about dBus): Is there such a thing
+ as a dBus reflection browser (maybe Emacs based) that lets you
+ discover all the behavior different dBus app participants provide?
+ Thinking something like what macOS Automator does? (actually, wait,
+ think you're showing it)
+ - A: d-feet is the one I showed:
+ <https://wiki.gnome.org/Apps/DFeet>
+ - I'd very much like something similar, but built into Emacs.
+- Q:dbus seems great for extensibility. But then Emacs has no such
+ mechanism. And is fantastically more extensibile. Why do you think
+ this is so?         
+ - A: I think these are different kinds of extensibility.  Emacs is
+ much more malleable than anything D-Bus offers.  You can't
+ change how existing D-Bus services work in the same way as you
+ can with Emacs customizations, variables, advice, or just going
+ and hacking on the code live; you can only add new features by
+ creating new services.
+- Q:  Do you have other cool dbus ideas?
+ - A: I greatly want to see:
+ - A D-Bus browser.
+ - discomfort expanded and made better looking, so there isn't
+ a single storage-related task I can't do with it and dired.
+ - A NetworkManager interface, so I don't have to use
+ nmtui/nmcli.
+ - A Bluez (bluetooth) interface, so I never have to see
+ bluetoothctl again.
+- Q: Are there Busses besides System and Session? Is there anything
+ more to a Bus besides a way to group ~~services~~ objects?
+ - A: There's always at least a System bus; theres one Session bus
+ per logged-in session (so potentially zero).  You can create and
+ connect to as many busses as you want, and they get identified
+ by the socket they listen on, which can be a local UNIX socket
+ or a TCP socket.  This isn't a common usecase, most things use
+ system and session.
+- Q: It looks like dBus is mostly useful for Emacs to do IPC -- IIUC,
+ this is how synctex works when working with LaTeX docs. How does it
+ compare with other ways of doing IPC, for example, communicating
+ over a socket with MPD?
+ - A: D-Bus provides a uniform framework for building these
+ services.  MPD's socket interface only works with MPD, and if
+ you want to connect to one, you have to write code that speaks
+ the protocol before you can do high-level things like "play"
+ or "pause."  D-Bus provides the underlying communication layer
+ as well as the model for the API, so you get all that stuff for
+ free.  If a music player has a D-Bus interface, and you're
+ using a language with D-Bus bindings, you can go from zero to
+ "support playing and pausing" in one line of code.
+- Q: ~~What mainstream/popular d-bus alternatives have you seen out
+ there, if any, maybe beyond pipes, udev, and such? -> somewhat
+ redundant with the above~~
+ - A: There aren't any alternatives on Linux that I'm aware of. 
+ Other operating systems have different ways of doing things
+ similar to what D-Bus does (such as OSA/AppleScript on macOS).
+- Q: I see a python dbus tutorial, does it make sense to have an emacs
+ version?
+ <https://dbus.freedesktop.org/doc/dbus-python/tutorial.html> 
+ - A: That's a really good idea!
+- Q: How if at all do the various web browsers interop (well) via
+ d-bus?
+ - A: It could be better.  Firefox (and forks) have a simple
+ interface that lets you open a URL, but nothing else.  I'm not
+ sure about other browsers, since LibreWolf is what I use.  If
+ you use d-feet to examine the session bus, you can see!
+- Q: Nice, thanks! I had been looking for a udisks tool. Is it available?
+ - A: Yes, https://codeberg.org/emacs-weirdware/discomfort It's alpha, but way nicer than using udisksctl.
+
+Other discussions from IRC:
+
+- Very interesting talk Ian!
+- Pretty interesting... I am already scratching my head thinking on applications!
+- Thanks, fascinating ieure, now onto refactoring everything not yet into Emacs to be managed in Emacs via d-bus...
+- One usage example I've recently stumbled over is the scad-dbus package which can control the openscad gui from Emacs, move around the camera etc.
+- @ieure : Thanks for the great talk, love these expositions of yours, especially of things that have gone under-appreciated - and the packaging into timeless tunes obviously!
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