I'm far from having this all worked out yet, thus the need for the word challenges in the title, but I began working on this during the Trusty dev cycle so I suppose I should start with what I know, but please be sure to browse this entirely before jumping in head first - particularly the Challenges and Known Issues and please help if you can.
There are changes to be aware of since I wrote my Precise Classic notes:
First, there has been continual session renaming since Precise to accommodate the new GNOME Classic session which is actually a GNOME Shell session with some cherry-picked extensions running on top of the Mutter window manager. No PPA is needed to test the new GNOME Classic session in Ubuntu GNOME Trusty but WebUpD8 still has the best description I've found.
Second, metacity settings have now been totally deprecated from gconf in favor of dconf/gsettings so you'll notice quite a number of changes in the commands required to apply theming tweaks such as moving the window management buttons.
Third, and perhaps most importantly, while the "flashback" session is no longer directly supported by the GNOME developers Flashback w/Metacity will continue to be supported by Edubuntu dev and these dedicated people.
My personal focus is on the Flashback w/Metacity session which is supported by Edubuntu and both Ubuntu and Edubuntu Trusty are supported for a full 5 years. I should however say that the Flashback w/Metacity session can also be installed in Ubuntu GNOME Trusty but it's only supported for 3 years.
So what's needed to get started? Well that's still the same as Precise.
Step #1: Simply install 'gnome-panel':
Yep, that's it. In spite of session renaming that still installs all of the dependencies required and it has quite a small footprint in Ubuntu. The footprint in Ubuntu GNOME is a bit heavier because 'flashback' now uses 'unity-settings-daemon' and 'unity-control-center' instead of the GNOME versions of those same packages.
sudo apt-get install gnome-panel
Step #2: Log out, select the desired session, and log back in.
Important Note: DO NOT select GNOME Flashback (Compiz) in Ubuntu GNOME unless you've also installed the package 'compiz'!
Step #3: Enable the "panel-run-dialog" which can be quite useful if you bork your panels and/or menus:
Step #4: Consider what additional packages you may want.
gsettings set org.gnome.desktop.wm.keybindings panel-run-dialog "['<Alt>F2']"
'indicator-applet' and/or 'indicator-applet-session' - as an alternative to 'indicator-applet-complete'
'gnome-tweak-tool' - because it's quite convenient for general theming tweaks such as having the old-style icons appear on the desktop, setting the key sequence for killing X, and changing themes.
'shiki-colors-metacity-theme' - because it provides a rather retro window management button theme
'sensors-applet' - to display system temps
'dconf-tools' which provides the dconf Editor UI.
'caffeine' which serves as a replacement for 'gnome-inhibit-applet' so the screensaver can be disabled while viewing flash videos just by clicking on the "coffee cup" in the panel. It must initially be launched from the Accessories menu, but it's not in the standard Ubuntu repos so if you want it you'll have to install this PPA and update the repos:
UPDATE: The current build of Caffeine (2.7.1) does not work in flashback! As a temporary workaround I copied version 2.5 to my own PPA.
sudo add-apt-repository ppa:lbsolost/ppa
Of those I know I personally want 'indicator-applet' because I prefer using it along with the standard clock applet, 'gnome-tweak-tool', 'shiki-colors-metacity-theme', 'sensors-applet', 'dconf-tools', and 'caffeine'. I can do that in just one more command since I've already installed the caffeine PPA and updated the repos:
sudo apt-get update
Note: If I'm starting with Ubuntu GNOME I additionally install 'light-themes' because ATM only the Ambiance theme seems to work well enough for my liking, and I believe you'll find that both 'gnome-tweak-tool' and 'dconf-tools' are already installed in Ubuntu GNOME.
sudo apt-get install indicator-applet shiki-colors-metacity-theme sensors-applet dconf-tools caffeine gnome-tweak-tool
I can then begin configuring the panels and desktop to my liking. I prefer just one panel at the bottom but there is no "one size fits all":
Note: In order to edit panel preferences and add or remove panel applets in Flashback w/Metacity you must press Alt while right-clicking the panel, and in Flashback w/Compiz you must press Alt+Super while right-clicking panel.
There are still a few things that must be done using either the dconf Editor or via CLI (the highlighted links show the actual position in the dconf Editor):
Step #5: Move the window management buttons to the right if you wish:
Step #6: Disable the overlay scrollbars if you wish:
gsettings set org.gnome.desktop.wm.preferences button-layout :minimize,maximize,close
Step #7: Disable the Unity webapps if you wish:
gsettings set com.canonical.desktop.interface scrollbar-mode normal
Step #8: Restore the missing menu and button icons:
gsettings set com.canonical.unity.webapps integration-allowed false
gsettings set org.gnome.desktop.interface menus-have-icons true
That's about all I know so far.
gsettings set org.gnome.desktop.interface buttons-have-icons true
Challenges and Known Issues - any help would be deeply appreciated
#1: This scares me the most - I've not found a truly reliable method of backing up and restoring a customized configuration, or even resetting all defaults to an out-of-box configuration. I'm sure I'll figure it out but I've borked things badly enough a few times that I've had to completely reinstall the OS, not a big deal for me but that would really make some people mad! I have figured out a few things:
(a) You can reset the panel configuration to it's defaults by running:
But that produces a false crash report so please don't file it. No log-out is needed but it takes at least one full minute for the panels to reset so please be patient.
dconf reset -f /org/gnome/gnome-panel/
(b) Optionally you can reset the panel configuration to it's defaults by running:
But that requires logging out or restarting via terminal or by the use of keyboard shortcut.
XDG_MENU_PREFIX="gnome-flashback-" gnome-panel --replace &
(c) You can reset most general theming and desktop tweaks to their defaults by running:
(d) If you bork the Main Menu it can be launched using the command "alacarte" either in a terminal or using the "panel-run-dialog" - no sudo is needed - then it can be reset to the default configuration.
dconf reset -f /org/gnome/desktop/
(e) You can also launch the dconf Editor using the "panel-run-dialog" if you know exactly what you're looking for. Here's one example where I found it quite useful.
#2: The LibreOffice menu icons load very slowly. I've just been removing all but the main LibreOffice menu item, but I suppose a bug report should be filed?
#3: Some (maybe most) keyboard shortcuts are not set to their respective defaults. This is where dconf Editor comes in handy. Here's an example.
#4: Many of the themes I've tried have various problems. I'm sure the theme devs just need some time to catch up with the changes between GNOME 3.8 and 3.10.