multimonitor, launcher: Provide an option to display either a single launcher or a launcher on each display in a multi-monitor environment

Bug Description

Provide an option to display either a single launcher or a launcher on each display in a multi-monitor environment.

Add the option 'Launcher placement' to the Displays panel.
A drop-down list provides the following options:
Display name 1
Display name 2
...
All displays

By default, the primary display will be selected, to display just a single Launcher on the primary display.

A fallback solution is proposed where proprietary drivers report a single display in the Displays panel (where multiple displays are connected). The drop-down list options revert to:
Primary display
All displays

Please see addendum to System Settings specification: https://docs.google.com/a/canonical.com/document/d/1b3CwE3Wemr347fTxNcu7ixEQBK4YD8JF2pyv5pxiY0U/edit

This addendum also provides a solution proposal for bug 946104: 'multimonitor: Please give me a way to turn off sticky monitor edges': https://bugs.launchpad.net/ayatana-design/+bug/946104

Status changed to 'Confirmed' because the bug affects multiple users.

I remember that there recently was a similar UIFE for unity 3D, so this seems ok.

Status changed to 'Confirmed' because the bug affects multiple users.

This bug was fixed in the package unity-2d - 5.7.0-0ubuntu1

---------------
unity-2d (5.7.0-0ubuntu1) precise; urgency=low

* New upstream release:
- unity-2d-panel crashed with SIGABRT in Unity2dDebug::unity2dQtHandler()
(LP: #925457)
- unity-2d-shell crashed with SIGSEGV in ref() (LP: #947278)
- Launcher - Make Launcher left of screen reveal more responsive and less
prone to false positives (LP: #765819)
- [dash] [launcher] [panel] Tinting based on wallpaper missing
(LP: #882101)
- [launcher] In multimonitor setup Unity-2D only shows launcher on one
monitor (fails MM UX spec #2.8) (LP: #780204)
- [unity-2d] FF exception to add PointerBarrier to Unity2d (LP: #947976)
- multimonitor, launcher: Provide an option to display either a single
launcher or a launcher on each display in a multi-monitor environment
(LP: #950136)
- lens switching is not keyboard navigable (LP: #945220)
- [panel] [multi-monitor] On secondary screen, unable to scrub from
indicator menu to app menu (LP: #844809)
- "Workspaces" button displays previous wallpaper (LP: #900019)
- Dash - cursor should change when pointer is over the search field
(LP: #849175)
- Filter checkboxes are without margins in right to left locales
(LP: #949319)
- [panel] [multi-monitor] Open indicator menu on one screen causes other
indicator to look open too (LP: #844798)
- Dash - horizental divider line in between categories incorrectly drawn
(LP: #841750)
- [launcher] Tile Progress bar starting from left of launcher, not
container (LP: #912777)
- Dash - dash is not closed with alt+f4 (LP: #891818)
- [dash] Rating stars in right-to-left locales behave inconsistently.
(LP: #945719)
- LensButton.qml:72 warning when running unity-2d (LP: #947276)
- [dash] Multi-range filters are rendered incorrectly in right-to-left
locales (LP: #950649)
* debian/unity-2d.gconf-defaults:
- removed: not used anymore and causing regression with hide-mode=2
by default, converted to the gsettings key (LP: #942772)
* debian/unity-2d.preinst:
- removed, was a natty -> oneiric transition
* debian/control, debian/unity-2d-common.install:
- create unity-2d-common and make some packages depending on it
- move some files from unity-2d package to unity-2d-common
(gsettings and apport hook) to have packaging shipping their schema
(LP: #925457)
* debian/unity-2d-common.install.in:
- no more gconf -> gsettings migration shipped
* debian/unity-2d.postinst, prerm, trigger:
- moved to unity-2d-common new package, to ensure even people uninstalling
unity-2d got the right metacity configuration in the session
- update the trigger to the correct directory
* debian/control:
- bump to latest Standards-Version
- fix some too long description
- put the transitional packages in the oldlibs/extra section
- build-dep on libxtst-dev, libxfixes-dev for barrier change
- need latest metacity for barriers to work
-- Didier Roche <email address hidden> 2012年3月19日 14:07:10 +0100

This bug was fixed in the package unity - 5.8.0-0ubuntu1

---------------
unity (5.8.0-0ubuntu1) precise-proposed; urgency=low

* New upstream release.
- New "push mouse offscreen" feature really difficult to get (LP: #923749)
- unity-2d-panel crashed with SIGSEGV in
unity::indicator::DBusIndicators::Impl::RequestSyncAll() (LP: #864737)
- Pressing "Alt+Enter" causes compiz to crash in CompOption::value() from
unity::UnityScreen::showLauncherKeyTerminate (LP: #960957)
- SEGSIGV after unplugging external monitor (LP: #962693)
- Background colorization should use a different heuristic (LP: #865239)
- compiz+unity3d generates > 50 wakeups a second on idle system
(LP: #917210)
- [FFe, UIFe] HUD - The HUD does not respect launcher autohide or icon
size settings (LP: #921506)
- clicking on folders in the file lens does not open nautilus
(LP: #921665)
- No text inside multirange filters (LP: #927710)
- can't alt-tab restore minimized uis which have an instance on another
workspace (LP: #933397)
- Ubuntu Software Center Unity launcher integration is not working
(LP: #932280)
- The line separator between the launcher and the dash is cleared when
selecting a category (LP: #941082)
- unity-panel-service crashed with SIGSEGV in g_hash_table_foreach()
(LP: #937119)
- Alt-F10 locks up Unity (LP: #948522)
- multimonitor, launcher: Provide an option to display either a single
launcher or a launcher on each display in a multi-monitor environment
(LP: #950136)
- multimonitor: Please give me a way to turn off sticky monitor edges
(LP: #946104)
- Unity 5.6: key bindings (such as Super) don't work on empty workspace or
on slow/loaded systems (LP: #953089)
- Alt+arrows keyboard shortcuts don't invoke Back and Forward navigation
(LP: #953783)
- HUD is sending 2 menu signals instead of 1 (LP: #956878)
- 6th item of HUD not fully visible (LP: #957229)
- HUD: seems to trigger operations more than once (LP: #960503)
- Launcher gets always desaturated when using HUD on secondary monitor
(LP: #961169)
- [5.8 pre staging] launcher is displayed on the left screen, not the
primary one (LP: #961281)
- launcher icons do not re-saturate after dash is closed (LP: #961844)
- Launcher shows arrows for applications on all workspaces (LP: #961977)
- Dash - Implement overlay scrollbars in Dash (LP: #608124)
- [UIFe] Dash - No message displayed when no results are returned in the
Dash (LP: #711199)
- Dash - "See more..." line should be base-aligned with section header
(LP: #748101)
- Dash - Missing category separator line in dash (LP: #850984)
- Dash and Launcher - As soon as a user starts dragging a file from the
Dash, there is a 'flicker' before the Launcher icons that are valid drop
receptacles re-saturate (LP: #863230)
- Dash - When multiple results have equal string match relevancy ranking,
those with equal ranking should be then sorted by frequency of use.
(LP: #871900)
- Keyboard shortcut - F10 shortcut is used to show m...

This bug was fixed in the package gnome-control-center - 1:3.3.92-0ubuntu3

---------------
gnome-control-center (1:3.3.92-0ubuntu3) precise-proposed; urgency=low

* debian/patches/51_unity_options_in_display_panel.patch:
- add the options to the display panel for unity multimonitor support.
Choice where the launcher can be set (one monitor, all monitor) and
sticky edges. (LP: #950136)
* debian/patches/revert_git_keyboard_gsettings.patch:
- refreshed
* debian/patches/04_new_appearance_settings.patch:
- revert the "click to get directly to a position" on the scroll bar.
This should be done in gtk to get the same behavior everywhere. Too
late for this cycle though.
- fix the scrolling since gtk introduced GDK_SCROLL_SMOOTH.
-- Didier Roche <email address hidden> 2012年3月23日 15:42:22 +0100

Unfortunately, I think that fixing this has caused another the Displays setting to be confusing: Bug #963731

Status changed to 'Confirmed' because the bug affects multiple users.