path: root/man/Xrandr.man

.\"
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.de TQ
.br
.ns
.TP \\$1
..
.TH XRANDR __libmansuffix__ __vendorversion__

.SH NAME
 Xrandr \- X Resize, Rotate and Reflection extension.
.SH SYNTAX
\&#include <X11/extensions/Xrandr.h>
.nf    
.sp
Bool XRRQueryExtension \^(\^Display *\fIdpy\fP, 
	int *\fIevent_basep\fP, int *\fIerror_basep\fP\^);
.sp
Status XRRQueryVersion \^(\^Display *\fIdpy\fP,
	int *\fImajor_versionp\fP,
	int *\fIminor_versionp\fP\^);
.sp
XRRScreenConfiguration *XRRGetScreenInfo \^(\^Display *dpy,
	Drawable \fIdraw\fP\^);
.sp
void XRRFreeScreenConfigInfo \^(\^
	\fIXRRScreenConfiguration *config\fP\^);
.sp
Status XRRSetScreenConfig \^(\^Display *\fIdpy\fP, 
	XRRScreenConfiguration *\fIconfig\fP,
	Drawable \fIdraw\fP,
	int \fIsize_index\fP,
	Rotation \fIrotation\fP,
	Time \fItimestamp\fP\^);
.sp
Status XRRSetScreenConfigAndRate \^(\^Display *\fIdpy\fP, 
				  XRRScreenConfiguration *\fIconfig\fP,
				  Drawable \fIdraw\fP,
				  int \fIsize_index\fP,
				  Rotation \fIrotation\fP,
				  short \fIrate\fP,
				  Time \fItimestamp\fP\^);
.sp
Rotation XRRConfigRotations\^(\^
	XRRScreenConfiguration *\fIconfig\fP, 
	Rotation *\fIcurrent_rotation\fP\^);
.sp
Time XRRConfigTimes \^(\^
	XRRScreenConfiguration *\fIconfig\fP, 
	Time *\fIconfig_timestamp\fP\^);
.sp
XRRScreenSize *XRRConfigSizes\^(\^
	XRRScreenConfiguration *\fIconfig\fP, 
	int *\fInsizes\fP\^);
.sp
short *XRRConfigRates \^(\^
	XRRScreenConfiguration *\fIconfig\fP, 
	int \fIsize_index\fP, 
	int *\fInrates\fP\^);
.sp
SizeID XRRConfigCurrentConfiguration \^(\^
	XRRScreenConfiguration *\fIconfig\fP, 
	Rotation *\fIrotation\fP\^);
.sp
short XRRConfigCurrentRate \^(\^
	XRRScreenConfiguration *\fIconfig\fP\^);    
.sp
int XRRRootToScreen\^(\^
	Display *\fIdpy\fP, 
	Window \fIroot\fP\^);
.sp
XRRScreenConfiguration *XRRScreenConfig\^(\^
	Display *\fIdpy\fP, int \fIscreen\fP\^);
.sp
XRRScreenConfiguration *XRRConfig\^(\^Screen *\fIscreen\fP\^);
.sp
void XRRSelectInput\^(\^Display *\fIdpy\fP, Window \fIwindow\fP, int \fImask\fP\^);
.sp
/\(** 
 * intended to take RRScreenChangeNotify,  or 
 * ConfigureNotify \^(\^\fIon the root window\fP\^)
 * returns 1 if it is an event type it understands, 0 if not
 */
int XRRUpdateConfiguration\^(\^XEvent *\fIevent\fP^);
.sp
/\(** 
 * the following are always safe to call, even if RandR is 
 * not implemented on a screen 
 */
.br
Rotation XRRRotations\^(\^
	Display *\fIdpy\fP, int \fIscreen\fP, 
	Rotation *\fIcurrent_rotation\fP\^);
.sp
XRRScreenSize *XRRSizes\^(\^Display *\fIdpy\fP, 
	int \fIscreen\fP, int *\fInsizes\fP\^);
.sp
short *XRRRates \^(\^Display *\fIdpy\fP, int \fIscreen\fP, 
	int \fIsize_index\fP, int *\fInrates\fP\^);
.sp
Time XRRTimes \^(\^Display *\fIdpy\fP, int \fIscreen\fP, Time *\fIconfig_timestamp\fP\^);
.fi
.SH ARGUMENTS
.IP \fIdisplay\fP 1i
Specifies the connection to the X server.
.IP \fIscreen\fP 1i
Specifies which screen.
.IP \fIdraw\fP 1i
Specifies the screen.
.IP \fIrotation\fP 1i
Specifies the rotations or reflections possible of the screen.
.IP \fIcurrent_rotation\fP 1i
Specifies the current rotations and reflection of the screen.
.IP \fItimestamp\fP 1i
Specifies the server timestamp.
.IP \fIconfig_timestamp\fP 1i
Specifies the timestamp when the screen was last (re)configured.
.IP \fIconfig\fP 1i
Specifies the screen configuration being used.
.IP \fIsizes\fP 1i
Specifies the array of sizes supported.
.IP \fIrate\fP 1i
Specifies the refresh rate in Hz.

.SH DATATYPES

.PP
.B Rotations/Reflections
.PP
Can be any of:
.nf
#define RR_Rotate_0             1
#define RR_Rotate_90            2
#define RR_Rotate_180           4
#define RR_Rotate_270           8

/\(** new in 1.0 protocol, to allow reflection of screen */
/\(** reflection is applied after rotation */

#define RR_Reflect_X            16
#define RR_Reflect_Y            32


typedef struct {
    int	width, height;
    int	mwidth, mheight;
} XRRScreenSize;

typedef struct {
    int type;				/\(** event base */
    unsigned long serial;	/\(** # of last request processed by server */
    Bool send_event;		/\(** true if this came from a SendEvent request */
    Display *display;		/\(** Display the event was read from */
    Window window;			/\(** window which selected for this event */
    Window root;			/\(** Root window for changed screen */
    Time timestamp;			/\(** when the screen change occurred */
    Time config_timestamp;	/\(** when the last configuration change */
    SizeID size_index;
    SubpixelOrder subpixel_order;
    Rotation rotation;
    int width;
    int height;
    int mwidth;
    int mheight;
} XRRScreenChangeNotifyEvent;
.sp
.fi
.B XRRScreenSize
structure contains a possible root size in pixels and in millimeters.
.B XRRScreenChangeNotifyEvent
Is sent to a client that has requested notification whenever the screen
configuration is changed.

.B XRRScreenConfiguration
This is an opaque data type containing the configuration information
for a screen.

.B Timestamps
.PP
Time stamps are included and must be used to ensure the client is playing
with a full deck: the screen may change properties
on the fly and this ensures its knowledge of the configuration is up to date.
This is to help issues when screens may become hot-pluggable in the future.

.SH DESCRIPTION
.B Xrandr
is a simple library designed to interface the X Resize and Rotate
Extension.  This allows clients to change the size and rotation of the
root window of a screen, along with the ability to reflect the screen
about either axis (if supported by the implementation).  Rotation and
reflection may be implemented by software and may result in slower
performance if rotation and reflection are implemented in this fashion 
(as are all implementations as of October 2002).
.PP
The Xrandr library does some minimal caching to avoid roundtrips to
provide clients frequently used information.  See "The X Resize and
Rotate Extension" for a detailed description; also note that depth
switching, as described in the document is not implemented, and may
(or may not) ever be implemented, as display memory is growing rapidly,
and toolkits are already beginning to support migration, mitigating the
need for depth switching.  If it is implemented in the future, we
expect to do so via an upward compatible extension to the
current library/protocol; functionality described here should continue
to work.
.PP
Rotation and reflection and how they interact can be confusing.  In
Randr, the coordinate system is rotated in a counter-clockwise
direction relative to the normal orientation.  Reflection is along the
window system coordinate system, not the physical screen X and Y axis,
so that rotation and reflection do not interact.  The other way to
consider reflection is to is specified in the "normal" orientation,
before rotation, if you find the other way confusing.
.PP
The 
.B XRRScreenChangeNotify 
event is sent to clients that ask to be informed whenever the root window
configuration changes.  Configuration changes may include resolution,
physical size, subpixel order (see XRender(3)), and rotation.  Note
that changes to any or all of these could occur due to external events
(user control in the X server, a different monitor/flat panel display
being hot-plugged) and is not only the result of a protocol/library
request to the X server.
.PP
Additionally, to eliminate a potential race condition, 
this event may be generated
immediately upon selecting for notification if the screen has changed
since the client of Xrandr connected to the X server, to enable
reliable screen resolution changing when a user may log in and
change the configuration while one or many clients are starting up.
.PP
.B Xlib notification
.PP
Clients must call back into Xlib using
.B XRRUpdateConfiguration
when screen configuration change notify events are generated
(or root window configuration changes occur, to update Xlib's
view of the resolution, size, rotation, reflection or subpixel order.
Generally, toolkits will perform this operation on behalf of applications;
we did not want to change display structure data behind the back of toolkits,
as in multithreaded clients, various race conditions might occur.
Toolkits should provide clients some mechanism for notification of
screen change, of course.

.SH FUNCTIONS
There are two classes of interfaces: those which can be safely called
even if RandR is not implemented on a screen (to make common idioms not
dependent on the server having support), and those which will return
errors if the extension is not present.
.PP
.B XRRRotations
returns both the possible set of rotations/reflections supported
(as a bitmask) as the value of the function, along with the current
rotation/reflection of the screen.
.PP
.B XRRSizes
returns the size and a pointer to the current sizes supported by
the specified screen.  The first size specified is the default size
of the server. If RandR is not supported, it returns 0 for
the number of sizes.
.PP
.B XRRRates
returns a pointer to a the rates supported by the specified size.
If RandR is not supported, it returns 0 for the number of rates.
.PP
.B XRRTimes
returns the time last reported by the server along with the
timestamp the last configuration changed.
If the configuration has changed since the client last updated
its view of the server time, requests to change the configuration
will fail until the client has an up to date timestamp.
.PP
.B XRRRootToScreen
returns the screen number given a root window (for example, from
an \fBXRRScreenChangeNotifyEvent\fI.
.PP
The rest of the functions will fail if applied to screens not
implementing the RandR extension.
.B XRRSetScreenConfig
sets the screen size and rotation and reflection to the desired
values on the screen specified by \fIdraw\fP, or returns a
.B BadValue
error.
\fIsize_index\fP specifies which size configuration is to be used,
\fIrotation\fP specifies which rotation or reflection is to
be used (or a 
.B BadValue
error is returned).
The \fItimestamp\fP is used by the server to make sure the client
has up to date configuration information. Status is returned
to indicate success or failure; a client must refresh its configuration
information if it fails and try the call again (by calling 
\fBXRRGetScreenInfo\fP).
.PP
.B XRRSetScreenConfigAndRate
like
.B XRRSetScreenConfig
but also set the refresh rate. If specified rate is not supported a
.B BadValue
error is returned.
.PP
.B XRRConfigRotations,
.B XRRConfigSizes,
.B XRRConfigCurrentConfiguration,
.B XRRConfigTimes,
.B XRRConfigRates,
and
.B XRRConfigCurrentRate
are used to get specific configuration information out of a screen
configuration.
.PP
.B XRRGetScreenInfo
Returns a screen configuration for later use; the information is
private to the library.
Call
.B XRRFreeScreenConfigInfo
to free this information when you are finished with it.
It forces a round trip to the server.

Other functions include:
.B XRRQueryExtension
which returns the event and error base codes,
.B XRRQueryVersion
, which returns the current version of the extension (this information
is cached by the library).
.SH RESTRICTIONS
.B Xrandr
will remain upward compatible after the current 1.0 release.
.SH AUTHOR
Jim Gettys, and Keith Packard, HP.