Template Version: @(#)sac_nextcase 1.66 04/17/08 SMI
This information is Copyright 2008 Sun Microsystems
1. Introduction
1.1. Project/Component Working Name:
disp_switch
1.2. Name of Document Author/Supplier:
Author: Henry Zhao
1.3 Date of This Document:
13 August, 2008
4. Technical Description
1. Introduction
1.1. Project/Component Working Name:
Hot Key Based Display Device Switch (dispswitch)
1.2. Name of Document Author/Supplier:
Author: Henry Zhao
1.3 Date of This Document:
Aug 7, 2008
4. Technical Description
4.1 With the integration of RandR 1.2 into Xorg, it is possible to
dynamically
add and remove display devices and adjust display modes while X window
system
is running. However only a command line interface is currently available.
Therefore a user needs to type several lengthy commands to add display
devices, and possibly another series of commands to adjust the modes for
each device. This project allows the use of a "hotkey" to probe for
display
devices, turn on or off display devices, and in the case of more than
one
device being turned on, automatically adjust modes to the best shared
resolution. This feature is especially useful in applications such as
connecting a laptop to a projector.
4.2 dispswitch is an X client application that uses Xrandr library functions
XRRGetScreenResources() to gather display output information,
XRRGetScreenSizeRange() and XRRSetCrtcConfig() to switch display devices
and set modes. Switching is triggered by a predefined key stroke - the
"hotkey". If a "hotkey" stroke is 5 seconds or longer after the
previous
switch, system output configuration is re-probed so that any output
configuration changes, such as adding or removing display devices, can
be
detected and adapted to. When two display devices are turned on, the
largest common resolution for both devices will be automatically used.
The
project allows switching among up to three display outputs with one or
two
of them being turned on at a time (Currently most graphics hardware
supports up to two simultaneous displays). For example, in a system with
three devices connected to LCD, VGA and DVI outputs, 6 different states
(excluding states of all on and all off) of them will be cycled through
with consecutive "hotkey" stroke. Side-by-side views are included in the
state cycling when two devices are connected.
4.3 The application works on systems where both X server and driver support
RandR (1.2 or above). It will be added to the Gnome's launcher under
Preference->Session.
4.4 Two "hotkey" interfaces are provided.
4.4.1 On a laptop, if an ACPI notification interface is connected, and
the
notification mechanism is operating, then the keyboard defined
"display device switch function key" is the "hotkey". The
acpi_drv
driver catches this "hotkey" ACPI event and generates a sysevent.
An application that subscribes for such event with sysevent layer
receives ACPI notification on "hotkey" stroke .
4.4.2 Since not all laptops have ACPI notification "hotkey" switch
support,
on a more general sense, the application allows user to use
command
line options (-key <keysym> -mod <modifier>) to define a "hotkey"
to
cover desktops, and laptops where ACPI "hotkey" notification
mechanism is not working. The default is "Shift+F5".
4.5 Usage: dispswitch [options]
where options are:
-display <display>
-key <keysym>
-mod <modifier>
-help
-nosideview
-verbose
-testrun
-key <keysym> -mod <modifier> will let user define "hotkey":
<keysym> is any keysym defined in /usr/X11/include/X11/keysymdef.h, with
prefix XK_ removed, such as F5, F8, Escape. <modifier> is any or
combination of modifiers on the system. User can run /usr/X11/bin/xmodmap
to
find all available modifiers on the system. They can be shift, control,
mod1, mod3, mod4, any. Examples:
-key Escape -mod shift defines the "hotkey" to be 'shift + Esc'
-key F2 -mod "shift+control" defines the "hotkey" to be 'shift + control
+ F2'
-help Prints out a summary of the usage
-nosideview Skips side-by-side views in two device cycling.
-testrun Switches repeatedly without hotkey strokes
-verbose Prints debug messages
Imported Interfaces:
--------------------
RandR 1.2 Uncommitted
(http://www.x.org/wiki/Projects/XRandR)
libsysevent committed
Exported Interfaces:
--------------------
/usr/X11/bin/dispswitch Uncommitted
5. Documentation
Manpage provided
/usr/X11/share/man/man1/dispswitch.1
6. Resources and Schedule
6.1. Projected Availability
The project is to be available in two stages:
6.1.1 Putback of implementation of first "hotkey" interface (4.4.2)
Aug 2008
6.1.2 Putback of implementation of second "hotkey" interface (4.4.1)
Oct 2008
6.4. Steering Committee requested information
6.4.1. Consolidation C-team Name:
X Consolidation (Desktop C-Team)
6.5. ARC review type: FastTrack
6.6. ARC Exposure: open
6. Resources and Schedule
6.4. Steering Committee requested information
6.4.1. Consolidation C-team Name:
X
6.5. ARC review type: FastTrack
6.6. ARC Exposure: open
