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|
This is Xlibscm.info, produced by makeinfo version 4.7 from
Xlibscm.texi.
INFO-DIR-SECTION The Algorithmic Language Scheme
START-INFO-DIR-ENTRY
* Xlibscm: (Xlibscm). SCM Language X Interface.
END-INFO-DIR-ENTRY
File: Xlibscm.info, Node: Top, Next: Xlibscm, Prev: (dir), Up: (dir)
This manual documents the X - SCM Language X Interface. The most recent
information about SCM can be found on SCM's "WWW" home page:
`http://swiss.csail.mit.edu/~jaffer/SCM'
Copyright (C) 1990-1999 Free Software Foundation
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation
approved by the author.
* Menu:
* Xlibscm::
* Display and Screens::
* Drawables::
* Graphics Context::
* Cursor::
* Colormap::
* Rendering::
* Images::
* Event::
* Index::
File: Xlibscm.info, Node: Xlibscm, Next: Display and Screens, Prev: Top, Up: Top
1 Xlibscm
*********
"Xlibscm" is a SCM interface to "X". The X Window System is a
network-transparent window system that was designed at MIT. SCM is a
portable Scheme implementation written in C. The interface can be
compiled into SCM or, on those platforms supporting dynamic linking,
compiled separately and loaded with `(require 'Xlib)'.
Much of this X documentation is dervied from:
Xlib - C Language X Interface
X Consortium Standard
X Version 11, Release 6.3
The X Window System is a trademark of X Consortium, Inc.
TekHVC is a trademark of Tektronix, Inc.
Copyright (C) 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1994, 1996 X
Consortium
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the name of the X Consortium shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization from
the X Consortium.
Copyright (C) 1985, 1986, 1987, 1988, 1989, 1990, 1991 by Digital
Equipment Corporation
Portions Copyright (C) 1990, 1991 by Tektronix, Inc.
Permission to use, copy, modify and distribute this documentation for
any purpose and without fee is hereby granted, provided that the above
copyright notice appears in all copies and that both that copyright
notice and this permission notice appear in all copies, and that the
names of Digital and Tektronix not be used in in advertising or
publicity pertaining to this documentation without specific, written
prior permission. Digital and Tektronix makes no representations about
the suitability of this documentation for any purpose. It is provided
"as is" without express or implied warranty.
File: Xlibscm.info, Node: Display and Screens, Next: Drawables, Prev: Xlibscm, Up: Top
2 Display and Screens
*********************
-- Function: x:open-display display-name
DISPLAY-NAME Specifies the hardware display name, which determines
the display and communications domain to be used. On a
POSIX-conformant system, if the display-name is #f, it defaults to
the value of the DISPLAY environment variable.
The encoding and interpretation of DISPLAY-NAME is
implementation-dependent. On POSIX-conformant systems, the
DISPLAY-NAME or DISPLAY environment variable can be a string in
the format:
-- Special Form: hostname:number.screen-number
HOSTNAME specifies the name of the host machine on which the
display is physically attached. Follow the HOSTNAME with
either a single colon (:) or a double colon (::).
NUMBER specifies the number of the display server on that host
machine. You may optionally follow this display number with
a period (.). A single CPU can have more than one display.
Multiple displays are usually numbered starting with zero.
SCREEN-NUMBER specifies the screen to be used on that server.
Multiple screens can be controlled by a single X server. The
SCREEN-NUMBER sets an internal variable that can be accessed
by using the x:default-screen procedure.
-- Function: x:close display
DISPLAY specifies the connection to the X server.
The `x:close' function closes the connection to the X server for
the DISPLAY specified and destroys all windows, resource IDs
(Window, Font, Pixmap, Colormap, Cursor, and GContext), or other
resources that the client has created on this display, unless the
close-down mode of the resource has been changed (see
`x:set-close-down-mode'). Therefore, these windows, resource IDs,
and other resources should not be used again or an error will be
generated. Before exiting, you should call X:CLOSE-DISPLAY or
X:FLUSH explicitly so that any pending errors are reported.
-- Function: x:protocol-version display
Returns cons of the major version number (11) of the X protocol
associated with the connected DISPLAY and the minor protocol
revision number of the X server.
-- Function: x:server-vendor display
Returns a string that provides some identification of the owner of
the X server implementation. The contents of the string are
implementation-dependent.
-- Function: x:vendor-release display
Returns a number related to a vendor's release of the X server.
A display consists of one or more "Screen"s. Each screen has a
"root-window", "default-graphics-context", and "colormap".
-- Function: x:screen-count display
Returns the number of available screens.
-- Function: x:default-screen display
Returns the default screen number specified by the `x:open-display'
function. Use this screen number in applications which will use
only a single screen.
-- Function: x:root-window display screen-number
-- Function: x:root-window display
SCREEN-NUMBER, if givien, specifies the appropriate screen number
on the host server. Otherwise the default-screen for DISPLAY is
used.
Returns the root window for the specified SCREEN-NUMBER. Use
`x:root-window' for functions that need a drawable of a particular
screen or for creating top-level windows.
-- Function: x:root-window window
Returns the root window for the specified WINDOW's screen.
-- Function: x:default-colormap display screen-number
-- Function: x:default-colormap display
-- Function: x:default-colormap window
Returns the default colormap of the specified screen.
-- Function: x:default-ccc display screen-number
-- Function: x:default-ccc display
-- Function: x:default-ccc window
Returns the default Color-Conversion-Context (ccc) of the specified
screen.
-- Function: x:default-gc display screen-number
-- Function: x:default-gc display
-- Function: x:default-gc window
Returns the default graphics-context of the specified screen.
-- Function: x:screen-depths display screen-number
-- Function: x:screen-depths display
-- Function: x:screen-depths window
Returns an array of depths supported by the specified screen.
The "Visual" type describes possible colormap depths and arrangements.
-- Function: x:default-visual display screen-number
-- Function: x:default-visual display
-- Function: x:default-visual window
Returns the default Visual type for the specified screen.
-- Function: x:make-visual display depth class
-- Function: x:make-visual window depth class
The integer DEPTH specifies the number of bits per pixel. The
CLASS argument specifies one of the possible visual classes for a
screen:
* x:Static-Gray
* x:Static-Color
* x:True-Color
* x:Gray-Scale
* x:Pseudo-Color
* x:Direct-Color
`X:make-visual' returns a visual type for the screen specified by
DISPLAY or WINDOW if successful; #f if not.
-- Function: x:visual-class visual
-- Function: x:visual-class screen
-- Function: x:visual-class display
Returns the (integer) visual class of its argument.
-- Function: x:visual-geometry visual
-- Function: x:visual-geometry screen
-- Function: x:visual-geometry display
Returns a list of the:
* red_mask
* green_mask
* blue_mask
* colormap_size
-- Function: x:screen-cells display screen-number
-- Function: x:screen-cells display
-- Function: x:screen-cells window
Returns the number of entries in the default colormap.
-- Function: x:screen-depth display screen-number
Returns the depth of the root window of the specified screen.
-- Function: x:screen-depth display
-- Function: x:screen-depth window
-- Function: x:screen-depth visual
Returns the depth of argument.
The "depth" of a window or pixmap is the number of bits per pixel
it has. The "depth" of a graphics context is the depth of the
drawables it can be used in conjunction with graphics output.
-- Function: x:screen-size display screen-number
-- Function: x:screen-size display
-- Function: x:screen-size window
Returns a list of integer height and width of the screen in pixels.
-- Function: x:screen-dimensions display screen-number
-- Function: x:screen-dimensions display
-- Function: x:screen-dimensions window
Returns a list of integer height and width of the screen in
millimeters.
-- Function: x:screen-white display screen-number
-- Function: x:screen-white display
-- Function: x:screen-white window
Returns the white pixel value of the specified screen.
-- Function: x:screen-black display screen-number
-- Function: x:screen-black display
-- Function: x:screen-black window
Returns the black pixel value of the specified screen.
File: Xlibscm.info, Node: Drawables, Next: Graphics Context, Prev: Display and Screens, Up: Top
3 Drawables
***********
A "Drawable" is either a window or pixmap.
* Menu:
* Windows and Pixmaps::
* Window Attributes::
* Window Properties and Visibility::
File: Xlibscm.info, Node: Windows and Pixmaps, Next: Window Attributes, Prev: Drawables, Up: Drawables
3.1 Windows and Pixmaps
=======================
-- Function: x:create-window window position size border-width depth
class visual field-name value ...
Creates and returns an unmapped Input-Output subwindow for a
specified parent WINDOW and causes the X server to generate a
CreateNotify event. The created window is placed on top in the
stacking order with respect to siblings. Any part of the window
that extends outside its parent WINDOW is clipped. The
BORDER-WIDTH for an x:Input-Only window must be zero.
The coordinate system has the X axis horizontal and the Y axis
vertical with the origin [0, 0] at the upper-left corner.
Coordinates are integral, in terms of pixels, and coincide with
pixel centers. Each window and pixmap has its own coordinate
system. For a window, the origin is inside the border at the
inside, upper-left corner.
CLASS can be x:Input-Output, x:Input-Only, or x:Copy-From-Parent.
For class x:Input-Output, the VISUAL type and DEPTH must be a
combination supported for the screen. The DEPTH need not be the
same as the parent, but the parent must not be a window of class
x:Input-Only. For an x:Input-Only window, the DEPTH must be zero,
and the VISUAL must be one supported by the screen.
The returned window will have the attributes specified by
FIELD-NAMEs and VALUE.
-- Function: x:create-window window position size border-width border
background
The returned window inherits its depth, class, and visual from its
parent. All other window attributes, except BACKGROUND and
BORDER, have their default values.
-- Function: x:create-pixmap drawable size depth
-- Function: x:create-pixmap display size depth
SIZE is a list, vector, or pair of nonzero integers specifying the
width and height desired in the new pixmap.
X:CREATE-PIXMAP returns a new pixmap of the width, height, and
DEPTH specified. It is valid to pass an x:Input-Only window to the
drawable argument. The DEPTH argument must be one of the depths
supported by the screen of the specified DRAWABLE.
-- Function: x:close window
Destroys the specified WINDOW as well as all of its subwindows and
causes the X server to generate a DestroyNotify event for each
window. The window should not be used again. If the window
specified by the WINDOW argument is mapped, it is unmapped
automatically. The ordering of the DestroyNotify events is such
that for any given window being destroyed, DestroyNotify is
generated on any inferiors of the window before being generated on
the window itself. The ordering among siblings and across
subhierarchies is not otherwise constrained. If the WINDOW you
specified is a root window, an error is signaled. Destroying a
mapped WINDOW will generate x:Expose events on other windows that
were obscured by the window being destroyed.
-- Function: x:close pixmap
Deletes the association between the PIXMAP and its storage. The X
server frees the pixmap storage when there are no references to it.
-- Function: x:window-geometry drawable
Returns a list of:
coordinates
`list' of x and y coordinates that define the location of the
DRAWABLE. For a window, these coordinates specify the
upper-left outer corner relative to its parent's origin. For
pixmaps, these coordinates are always zero.
size
`list' of the DRAWABLE's dimensions (width and height). For
a window, these dimensions specify the inside size, not
including the border.
border-width
The border width in pixels. If the DRAWABLE is a pixmap,
this is zero.
depth
The depth of the DRAWABLE (bits per pixel for the object).
-- Function: x:window-geometry-set! window field-name value ...
Changes the "Configuration" components specified by FIELD-NAMEs
for the specified WINDOW.
These are the attributes settable by `x:window-geometry-set!'. That
these attributes are encoded by small integers - just like those of the
next section. Be warned therefore that confusion of attribute names
will likely not signal errors, just cause mysterious behavior.
-- Attribute: x:CWX
-- Attribute: x:CWY
-- Attribute: x:CW-Width
-- Attribute: x:CW-Height
The x:CWX and x:CYY members are used to set the window's x and y
coordinates, which are relative to the parent's origin and
indicate the position of the upper-left outer corner of the
window. The x:CW-Width and x:CW-Height members are used to set
the inside size of the window, not including the border, and must
be nonzero. Attempts to configure a root window have no effect.
If a window's size actually changes, the window's subwindows move
according to their window gravity. Depending on the window's bit
gravity, the contents of the window also may be moved
-- Attribute: x:CW-Border-Width
The integer x:CW-Border-Width is used to set the width of the
border in pixels. Note that setting just the border width leaves
the outer-left corner of the window in a fixed position but moves
the absolute position of the window's origin. It is an error to
set the border-width attribute of an InputOnly window nonzero.
-- Attribute: x:CW-Sibling
The sibling member is used to set the sibling window for stacking
operations.
-- Attribute: x:CW-Stack-Mode
The x:CW-Stack-Mode member is used to set how the window is to be
restacked and can be set to x:Above, x:Below, x:Top-If,
x:Bottom-If, or x:Opposite.
If a sibling and a stack-mode are specified, the window is restacked as
follows:
`x:Above'
The window is placed just above the sibling.
`x:Below'
The window is placed just below the sibling.
`x:Top-If'
If the sibling occludes the window, the window is placed at the
top of the stack.
`x:Bottom-If'
If the window occludes the sibling, the window is placed at the
bottom of the stack.
`x:Opposite'
If the sibling occludes the window, the window is placed at the
top of the stack. If the window occludes the sibling, the window
is placed at the bottom of the stack.
If a stack-mode is specified but no sibling is specified, the window is
restacked as follows:
`x:Above'
The window is placed at the top of the stack.
`x:Below'
The window is placed at the bottom of the stack.
`x:Top-If'
If any sibling occludes the window, the window is placed at the
top of the stack.
`x:Bottom-If'
If the window occludes any sibling, the window is placed at the
bottom of the stack.
`x:Opposite'
If any sibling occludes the window, the window is placed at the
top of the stack. If the window occludes any sibling, the window
is placed at the bottom of the stack.
File: Xlibscm.info, Node: Window Attributes, Next: Window Properties and Visibility, Prev: Windows and Pixmaps, Up: Drawables
3.2 Window Attributes
=====================
-- Function: x:window-set! window field-name value ...
Changes the components specified by FIELD-NAMEs for the specified
WINDOW. The restrictions are the same as for `x:create-window'.
The order in which components are verified and altered is server
dependent. If an error occurs, a subset of the components may
have been altered.
The `x:create-window' and `x:window-set!' procedures take five and one
argument (respectively) followed by pairs of arguments, where the first
is one of the property-name symbols (or its top-level value) listed
below; and the second is the value to associate with that property.
-- Attribute: x:CW-Back-Pixmap
Sets the background pixmap of the WINDOW to the specified pixmap.
The background pixmap can immediately be freed if no further
explicit references to it are to be made. If x:Parent-Relative is
specified, the background pixmap of the window's parent is used,
or on the root window, the default background is restored. It is
an error to perform this operation on an x:Input-Only window. If
the background is set to #f or None, the window has no defined
background.
-- Attribute: x:CW-Back-Pixel
Sets the background of the WINDOW to the specified pixel value.
Changing the background does not cause the WINDOW contents to be
changed. It is an error to perform this operation on an
x:Input-Only window.
-- Attribute: x:CW-Border-Pixmap
Sets the border pixmap of the WINDOW to the pixmap you specify.
The border pixmap can be freed if no further explicit references
to it are to be made. If you specify x:Copy-From-Parent, a copy
of the parent window's border pixmap is used. It is an error to
perform this operation on an x:Input-Only WINDOW.
-- Attribute: x:CW-Border-Pixel
Sets the border of the WINDOW to the pixel VALUE. It is an error
to perform this operation on an x:Input-Only window.
-- Attribute: x:CW-Bit-Gravity
-- Attribute: x:CW-Win-Gravity
The bit gravity of a window defines which region of the window
should be retained when an x:Input-Output window is resized. The
default value for the bit-gravity attribute is x:Forget-Gravity.
The window gravity of a window allows you to define how the
x:Input-Output or x:Input-Only window should be repositioned if
its parent is resized. The default value for the win-gravity
attribute is x:North-West-Gravity.
If the inside width or height of a window is not changed and if the
window is moved or its border is changed, then the contents of the
window are not lost but move with the window. Changing the inside
width or height of the window causes its contents to be moved or
lost (depending on the bit-gravity of the window) and causes
children to be reconfigured (depending on their win-gravity). For
a change of width and height, the (x, y) pairs are defined:
Gravity Direction Coordinates
x:North-West-Gravity (0, 0)
x:North-Gravity (Width/2, 0)
x:North-East-Gravity (Width, 0)
x:West-Gravity (0, Height/2)
x:Center-Gravity (Width/2, Height/2)
x:East-Gravity (Width, Height/2)
x:South-West-Gravity (0, Height)
x:South-Gravity (Width/2, Height)
x:South-East-Gravity (Width, Height)
When a window with one of these bit-gravity values is resized, the
corresponding pair defines the change in position of each pixel in
the window. When a window with one of these win-gravities has its
parent window resized, the corresponding pair defines the change
in position of the window within the parent. When a window is so
repositioned, a x:Gravity-Notify event is generated (see section
10.10.5).
A bit-gravity of x:Static-Gravity indicates that the contents or
origin should not move relative to the origin of the root window.
If the change in size of the window is coupled with a change in
position (x, y), then for bit-gravity the change in position of
each pixel is (-x, -y), and for win-gravity the change in position
of a child when its parent is so resized is (-x, -y). Note that
x:Static-Gravity still only takes effect when the width or height
of the window is changed, not when the window is moved.
A bit-gravity of x:Forget-Gravity indicates that the window's
contents are always discarded after a size change, even if a
backing store or save under has been requested. The window is
tiled with its background and zero or more x:Expose events are
generated. If no background is defined, the existing screen
contents are not altered. Some X servers may also ignore the
specified bit-gravity and always generate x:Expose events.
The contents and borders of inferiors are not affected by their
parent's bit-gravity. A server is permitted to ignore the
specified bit-gravity and use x:Forget-Gravity instead.
A win-gravity of x:Unmap-Gravity is like x:North-West-Gravity (the
window is not moved), except the child is also unmapped when the
parent is resized, and an x:Unmap-Notify event is generated.
-- Attribute: x:CW-Backing-Store
Some implementations of the X server may choose to maintain the
contents of x:Input-Output windows. If the X server maintains the
contents of a window, the off-screen saved pixels are known as
backing store. The backing store advises the X server on what to
do with the contents of a window. The backing-store attribute can
be set to x:Not-Useful (default), x:When-Mapped, or x:Always. A
backing-store attribute of x:Not-Useful advises the X server that
maintaining contents is unnecessary, although some X
implementations may still choose to maintain contents and,
therefore, not generate x:Expose events. A backing-store
attribute of x:When-Mapped advises the X server that maintaining
contents of obscured regions when the window is mapped would be
beneficial. In this case, the server may generate an x:Expose
event when the window is created. A backing-store attribute of
x:Always advises the X server that maintaining contents even when
the window is unmapped would be beneficial. Even if the window is
larger than its parent, this is a request to the X server to
maintain complete contents, not just the region within the parent
window boundaries. While the X server maintains the window's
contents, x:Expose events normally are not generated, but the X
server may stop maintaining contents at any time.
When the contents of obscured regions of a window are being
maintained, regions obscured by noninferior windows are included
in the destination of graphics requests (and source, when the
window is the source). However, regions obscured by inferior
windows are not included.
-- Attribute: x:CW-Backing-Planes
-- Attribute: x:CW-Backing-Pixel
You can set backing planes to indicate (with bits set to 1) which
bit planes of an x:Input-Output window hold dynamic data that must
be preserved in backing store and during save unders. The default
value for the backing-planes attribute is all bits set to 1. You
can set backing pixel to specify what bits to use in planes not
covered by backing planes. The default value for the
backing-pixel attribute is all bits set to 0. The X server is
free to save only the specified bit planes in the backing store or
the save under and is free to regenerate the remaining planes with
the specified pixel value. Any extraneous bits in these values
(that is, those bits beyond the specified depth of the window) may
be simply ignored. If you request backing store or save unders,
you should use these members to minimize the amount of off-screen
memory required to store your window.
-- Attribute: x:CW-Override-Redirect
To control window placement or to add decoration, a window manager
often needs to intercept (redirect) any map or configure request.
Pop-up windows, however, often need to be mapped without a window
manager getting in the way. To control whether an x:Input-Output
or x:Input-Only window is to ignore these structure control
facilities, use the override-redirect flag.
The override-redirect flag specifies whether map and configure
requests on this window should override a
x:Substructure-Redirect-Mask on the parent. You can set the
override-redirect flag to #t or #f (default). Window managers use
this information to avoid tampering with pop-up windows.
-- Attribute: x:CW-Save-Under
Some server implementations may preserve contents of
x:Input-Output windows under other x:Input-Output windows. This
is not the same as preserving the contents of a window for you.
You may get better visual appeal if transient windows (for
example, pop-up menus) request that the system preserve the screen
contents under them, so the temporarily obscured applications do
not have to repaint.
You can set the save-under flag to True or False (default). If
save-under is True, the X server is advised that, when this window
is mapped, saving the contents of windows it obscures would be
beneficial.
-- Attribute: x:CW-Event-Mask
The event mask defines which events the client is interested in
for this x:Input-Output or x:Input-Only window (or, for some event
types, inferiors of this window). The event mask is the bitwise
inclusive OR of zero or more of the valid event mask bits. You
can specify that no maskable events are reported by setting
x:No-Event-Mask (default).
The following table lists the event mask constants you can pass to
the event-mask argument and the circumstances in which you would
want to specify the event mask:
Event Mask Circumstances
x:No-Event-Mask No events wanted
x:Key-Press-Mask Keyboard down events wanted
x:Key-Release-Mask Keyboard up events wanted
x:Button-Press-Mask Pointer button down events wanted
x:Button-Release-Mask Pointer button up events wanted
x:Enter-Window-Mask Pointer window entry events wanted
x:Leave-Window-Mask Pointer window leave events wanted
x:Pointer-Motion-Mask Pointer motion events wanted
x:Pointer-Motion-Hint-Mask If x:Pointer-Motion-Hint-Mask is
selected in combination with one or
more motion-masks, the X server is
free to send only one x:Motion-Notify
event (with the is_hint member of
the X:Pointer-Moved-Event structure
set to x:Notify-Hint) to the client
for the event window, until either
the key or button state changes, the
pointer leaves the event window, or
the client calls X:Query-Pointer or
X:Get-Motion-Events. The server
still may send x:Motion-Notify
events without is_hint set to
x:Notify-Hint.
x:Button1-Motion-Mask Pointer motion while button 1 down
x:Button2-Motion-Mask Pointer motion while button 2 down
x:Button3-Motion-Mask Pointer motion while button 3 down
x:Button4-Motion-Mask Pointer motion while button 4 down
x:Button5-Motion-Mask Pointer motion while button 5 down
x:Button-Motion-Mask Pointer motion while any button down
x:Keymap-State-Mask Keyboard state wanted at window
entry and focus in
x:Exposure-Mask Any exposure wanted
x:Visibility-Change-Mask Any change in visibility wanted
x:Structure-Notify-Mask Any change in window structure wanted
x:Resize-Redirect-Mask Redirect resize of this window
x:Substructure-Notify-Mask Substructure notification wanted
x:Substructure-Redirect-Mask Redirect structure requests on
children
x:Focus-Change-Mask Any change in input focus wanted
x:Property-Change-Mask Any change in property wanted
x:Colormap-Change-Mask Any change in colormap wanted
x:Owner-Grab-Button-Mask Automatic grabs should activate with
owner_events set to True
-- Attribute: x:CW-Dont-Propagate
The do-not-propagate-mask attribute defines which events should
not be propagated to ancestor windows when no client has the event
type selected in this x:Input-Output or x:Input-Only window. The
do-not-propagate-mask is the bitwise inclusive OR of zero or more
of the following masks: x:Key-Press, x:Key-Release, x:Button-Press,
x:Button-Release, x:Pointer-Motion, x:Button1Motion,
x:Button2Motion, x:Button3Motion, x:Button4Motion,
x:Button5Motion, and x:Button-Motion. You can specify that all
events are propagated by setting x:No-Event-Mask (default).
-- Attribute: x:CW-Colormap
The colormap attribute specifies which colormap best reflects the
true colors of the x:Input-Output window. The colormap must have
the same visual type as the window. X servers capable of
supporting multiple hardware colormaps can use this information,
and window managers can use it for calls to X:Install-Colormap.
You can set the colormap attribute to a colormap or to
x:Copy-From-Parent (default).
If you set the colormap to x:Copy-From-Parent, the parent window's
colormap is copied and used by its child. However, the child
window must have the same visual type as the parent. The parent
window must not have a colormap of x:None. The colormap is copied
by sharing the colormap object between the child and parent, not
by making a complete copy of the colormap contents. Subsequent
changes to the parent window's colormap attribute do not affect
the child window.
-- Attribute: x:CW-Cursor
The cursor attribute specifies which cursor is to be used when the
pointer is in the x:Input-Output or x:Input-Only window. You can
set the cursor to a cursor or x:None (default).
If you set the cursor to x:None, the parent's cursor is used when
the pointer is in the x:Input-Output or x:Input-Only window, and
any change in the parent's cursor will cause an immediate change
in the displayed cursor. On the root window, the default cursor
is restored.
-- Function: x:window-ref window field-name ...
Returns a list of the components specified by FIELD-NAMEs for the
specified WINDOW. Allowable FIELD-NAMEs are a subset of those for
`x:window-set!':
* x:CW-Back-Pixel
* x:CW-Bit-Gravity
* x:CW-Win-Gravity
* x:CW-Backing-Store
* x:CW-Backing-Planes
* x:CW-Backing-Pixel
* x:CW-Override-Redirect
* x:CW-Save-Under
* x:CW-Event-Mask
* x:CW-Dont-Propagate
* x:CW-Colormap
File: Xlibscm.info, Node: Window Properties and Visibility, Prev: Window Attributes, Up: Drawables
3.3 Window Properties and Visibility
====================================
-- Function: x:get-window-property window property
Returns the (string or list of numbers) value of PROPERTY of
WINDOW.
-- Function: x:get-window-property window property #t
Removes and returns the (string or list of numbers) value of
PROPERTY of WINDOW.
-- Function: x:list-properties window
Returns a list of the properties (strings) defined for WINDOW.
In X parlance, a window which is hidden even when not obscured by other
windows is "unmapped"; one which shows is "mapped". It is an
unfortunate name-collision with Scheme, and is ingrained in the
attribute names.
-- Function: x:map-window window
Maps the WINDOW and all of its subwindows that have had map
requests. Mapping a window that has an unmapped ancestor does not
display the window but marks it as eligible for display when the
ancestor becomes mapped. Such a window is called unviewable.
When all its ancestors are mapped, the window becomes viewable and
will be visible on the screen if it is not obscured by another
window. This function has no effect if the WINDOW is already
mapped.
If the override-redirect of the window is False and if some other
client has selected x:Substructure-Redirect-Mask on the parent
window, then the X server generates a MapRequest event, and the
`x:map-window' function does not map the WINDOW. Otherwise, the
WINDOW is mapped, and the X server generates a MapNotify event.
If the WINDOW becomes viewable and no earlier contents for it are
remembered, the X server tiles the WINDOW with its background. If
the window's background is undefined, the existing screen contents
are not altered, and the X server generates zero or more x:Expose
events. If backing-store was maintained while the WINDOW was
unmapped, no x:Expose events are generated. If backing-store will
now be maintained, a full-window exposure is always generated.
Otherwise, only visible regions may be reported. Similar tiling
and exposure take place for any newly viewable inferiors.
If the window is an Input-Output window, `x:map-window' generates
x:Expose events on each Input-Output window that it causes to be
displayed. If the client maps and paints the window and if the
client begins processing events, the window is painted twice. To
avoid this, first ask for x:Expose events and then map the window,
so the client processes input events as usual. The event list
will include x:Expose for each window that has appeared on the
screen. The client's normal response to an x:Expose event should
be to repaint the window. This method usually leads to simpler
programs and to proper interaction with window managers.
-- Function: x:map-subwindows window
Maps all subwindows of a specified WINDOW in top-to-bottom
stacking order. The X server generates x:Expose events on each
newly displayed window. This may be much more efficient than
mapping many windows one at a time because the server needs to
perform much of the work only once, for all of the windows, rather
than for each window.
-- Function: x:unmap-window window
Unmaps the specified WINDOW and causes the X server to generate an
UnmapNotify event. If the specified WINDOW is already unmapped,
`x:unmap-window' has no effect. Normal exposure processing on
formerly obscured windows is performed. Any child window will no
longer be visible until another map call is made on the parent.
In other words, the subwindows are still mapped but are not
visible until the parent is mapped. Unmapping a WINDOW will
generate x:Expose events on windows that were formerly obscured by
it.
-- Function: x:unmap-subwindows window
Unmaps all subwindows for the specified WINDOW in bottom-to-top
stacking order. It causes the X server to generate an UnmapNotify
event on each subwindow and x:Expose events on formerly obscured
windows. Using this function is much more efficient than
unmapping multiple windows one at a time because the server needs
to perform much of the work only once, for all of the windows,
rather than for each window.
File: Xlibscm.info, Node: Graphics Context, Next: Cursor, Prev: Drawables, Up: Top
4 Graphics Context
******************
Most attributes of graphics operations are stored in "GC"s. These
include line width, line style, plane mask, foreground, background,
tile, stipple, clipping region, end style, join style, and so on.
Graphics operations (for example, drawing lines) use these values to
determine the actual drawing operation.
-- Function: x:create-gc drawable field-name value ...
Creates and returns graphics context. The graphics context can be
used with any destination drawable having the same root and depth
as the specified DRAWABLE.
-- Function: x:gc-set! graphics-context field-name value ...
Changes the components specified by FIELD-NAMEs for the specified
GRAPHICS-CONTEXT. The restrictions are the same as for
`x:create-gc'. The order in which components are verified and
altered is server dependent. If an error occurs, a subset of the
components may have been altered.
-- Function: x:copy-gc-fields! gcontext-src gcontext-dst field-name ...
Copies the components specified by FIELD-NAMEs from GCONTEXT-SRC
to GCONTEXT-DST. GCONTEXT-SRC and GCONTEXT-DST must have the same
root and depth.
-- Function: x:gc-ref graphics-context field-name ...
Returns a list of the components specified by FIELD-NAMEs ...
from the specified GRAPHICS-CONTEXT.
GC Attributes
=============
Both `x:create-gc' and `x:change-gc' take one argument followed by
pairs of arguments, where the first is one of the property-name symbols
(or its top-level value) listed below; and the second is the value to
associate with that property.
-- Attribute: x:GC-Function
The function attributes of a GC are used when you update a section
of a drawable (the destination) with bits from somewhere else (the
source). The function in a GC defines how the new destination
bits are to be computed from the source bits and the old
destination bits. x:G-Xcopy is typically the most useful because
it will work on a color display, but special applications may use
other functions, particularly in concert with particular planes of
a color display. The 16 functions are:
x:G-Xclear 0
x:G-Xand (AND src dst)
x:G-Xand-Reverse (AND src (NOT dst))
x:G-Xcopy src
x:G-Xand-Inverted (AND (NOT src) dst)
x:G-Xnoop dst
x:G-Xxor (XOR src dst)
x:G-Xor (OR src dst)
x:G-Xnor (AND (NOT src) (NOT dst))
x:G-Xequiv (XOR (NOT src) dst)
x:G-Xinvert (NOT dst)
x:G-Xor-Reverse (OR src (NOT dst))
x:G-Xcopy-Inverted (NOT src)
x:G-Xor-Inverted (OR (NOT src) dst)
x:G-Xnand (OR (NOT src) (NOT dst))
x:G-Xset 1
-- Attribute: x:GC-Plane-Mask
Many graphics operations depend on either pixel values or planes
in a GC. The planes attribute is an integer which specifies which
planes of the destination are to be modified, one bit per plane.
A monochrome display has only one plane and will be the least
significant bit of the integer. As planes are added to the
display hardware, they will occupy more significant bits in the
plane mask.
In graphics operations, given a source and destination pixel, the
result is computed bitwise on corresponding bits of the pixels.
That is, a Boolean operation is performed in each bit plane. The
plane-mask restricts the operation to a subset of planes.
`x:All-Planes' can be used to refer to all planes of the screen
simultaneously. The result is computed by the following:
(OR (AND (FUNC src dst) plane-mask) (AND dst (NOT plane-mask)))
Range checking is not performed on a plane-mask value. It is
simply truncated to the appropriate number of bits.
-- Attribute: x:GC-Foreground
-- Attribute: x:GC-Background
Range checking is not performed on the values for foreground or
background. They are simply truncated to the appropriate number of
bits.
Note that foreground and background are not initialized to any
values likely to be useful in a window.
-- Attribute: x:GC-Line-Width
The line-width is measured in pixels and either can be greater
than or equal to one (wide line) or can be the special value zero
(thin line).
Thin lines (zero line-width) are one-pixel-wide lines drawn using
an unspecified, device-dependent algorithm. There are only two
constraints on this algorithm.
* If a line is drawn unclipped from [x1,y1] to [x2,y2] and if
another line is drawn unclipped from [x1+dx,y1+dy] to
[x2+dx,y2+dy], a point [x,y] is touched by drawing the first
line if and only if the point [x+dx,y+dy] is touched by
drawing the second line.
* The effective set of points comprising a line cannot be
affected by clipping. That is, a point is touched in a
clipped line if and only if the point lies inside the
clipping region and the point would be touched by the line
when drawn unclipped.
A wide line drawn from [x1,y1] to [x2,y2] always draws the same
pixels as a wide line drawn from [x2,y2] to [x1,y1], not counting
cap-style and join-style. It is recommended that this property be
true for thin lines, but this is not required. A line-width of
zero may differ from a line-width of one in which pixels are
drawn. This permits the use of many manufacturers' line drawing
hardware, which may run many times faster than the more precisely
specified wide lines.
In general, drawing a thin line will be faster than drawing a wide
line of width one. However, because of their different drawing
algorithms, thin lines may not mix well aesthetically with wide
lines. If it is desirable to obtain precise and uniform results
across all displays, a client should always use a line-width of
one rather than a linewidth of zero.
-- Attribute: x:GC-Line-Style
The line-style defines which sections of a line are drawn:
x:Line-Solid
The full path of the line is drawn.
x:Line-Double-Dash
The full path of the line is drawn, but the even dashes are
filled differently from the odd dashes (see fill-style) with
x:Cap-Butt style used where even and odd dashes meet.
x:Line-On-Off-Dash
Only the even dashes are drawn, and cap-style applies to all
internal ends of the individual dashes, except x:Cap-Not-Last
is treated as x:Cap-Butt.
-- Attribute: x:GC-Cap-Style
The cap-style defines how the endpoints of a path are drawn:
x:Cap-Not-Last
This is equivalent to x:Cap-Butt except that for a line-width
of zero the final endpoint is not drawn.
x:Cap-Butt
The line is square at the endpoint (perpendicular to the
slope of the line) with no projection beyond.
x:Cap-Round
The line has a circular arc with the diameter equal to the
line-width, centered on the endpoint. (This is equivalent to
x:Cap-Butt for line-width of zero).
x:Cap-Projecting
The line is square at the end, but the path continues beyond
the endpoint for a distance equal to half the line-width.
(This is equivalent to x:Cap-Butt for line-width of zero).
-- Attribute: x:GC-Join-Style
The join-style defines how corners are drawn for wide lines:
x:Join-Miter
The outer edges of two lines extend to meet at an angle.
However, if the angle is less than 11 degrees, then a
x:Join-Bevel join-style is used instead.
x:Join-Round
The corner is a circular arc with the diameter equal to the
line-width, centered on the x:Join-point.
x:Join-Bevel
The corner has x:Cap-Butt endpoint styles with the triangular
notch filled.
-- Attribute: x:GC-Fill-Style
The fill-style defines the contents of the source for line, text,
and fill requests. For all text and fill requests (for example,
X:Draw-Text, X:Fill-Rectangle, X:Fill-Polygon, and X:Fill-Arc);
for line requests with linestyle x:Line-Solid (for example,
X:Draw-Line, X:Draw-Segments, X:Draw-Rectangle, X:Draw-Arc); and
for the even dashes for line requests with line-style
x:Line-On-Off-Dash or x:Line-Double-Dash, the following apply:
x:Fill-Solid
Foreground
x:Fill-Tiled
Tile
x:Fill-Opaque-Stippled
A tile with the same width and height as stipple, but with
background everywhere stipple has a zero and with foreground
everywhere stipple has a one
x:Fill-Stippled
Foreground masked by stipple
When drawing lines with line-style x:Line-Double-Dash, the odd
dashes are controlled by the fill-style in the following manner:
x:Fill-Solid
Background
x:Fill-Tiled
Same as for even dashes
x:Fill-Opaque-Stippled
Same as for even dashes
x:Fill-Stippled
Background masked by stipple
-- Attribute: x:GC-Fill-Rule
The fill-rule defines what pixels are inside (drawn) for paths
given in X:Fill-Polygon requests and can be set to x:Even-Odd-Rule
or x:Winding-Rule.
x:Even-Odd-Rule
A point is inside if an infinite ray with the point as origin
crosses the path an odd number of times.
x:Winding-Rule
A point is inside if an infinite ray with the point as origin
crosses an unequal number of clockwise and counterclockwise
directed path segments.
A clockwise directed path segment is one that crosses the ray from
left to right as observed from the point. A counterclockwise
segment is one that crosses the ray from right to left as observed
from the point. The case where a directed line segment is
coincident with the ray is uninteresting because you can simply
choose a different ray that is not coincident with a segment.
For both x:Even-Odd-Rule and x:Winding-Rule, a point is infinitely
small, and the path is an infinitely thin line. A pixel is inside
if the center point of the pixel is inside and the center point is
not on the boundary. If the center point is on the boundary, the
pixel is inside if and only if the polygon interior is immediately
to its right (x increasing direction). Pixels with centers on a
horizontal edge are a special case and are inside if and only if
the polygon interior is immediately below (y increasing direction).
-- Attribute: x:GC-Tile
-- Attribute: x:GC-Stipple
The tile/stipple represents an infinite two-dimensional plane,
with the tile/stipple replicated in all dimensions.
The tile pixmap must have the same root and depth as the GC, or an
error results. The stipple pixmap must have depth one and must
have the same root as the GC, or an error results. For stipple
operations where the fill-style is x:Fill-Stippled but not
x:Fill-Opaque-Stippled, the stipple pattern is tiled in a single
plane and acts as an additional clip mask to be ANDed with the
clip-mask. Although some sizes may be faster to use than others,
any size pixmap can be used for tiling or stippling.
-- Attribute: x:GC-Tile-Stip-X-Origin
-- Attribute: x:GC-Tile-Stip-Y-Origin
When the tile/stipple plane is superimposed on a drawable for use
in a graphics operation, the upper-left corner of some instance of
the tile/stipple is at the coordinates within the drawable
specified by the tile/stipple origin. The tile/stipple origin is
interpreted relative to the origin of whatever destination
drawable is specified in a graphics request.
-- Attribute: x:GC-Font
The font to be used for drawing text.
-- Attribute: x:GC-Subwindow-Mode
You can set the subwindow-mode to x:Clip-By-Children or
x:Include-Inferiors.
x:Clip-By-Children
Both source and destination windows are additionally clipped
by all viewable Input-Output children.
x:Include-Inferiors
Neither source nor destination window is clipped by
inferiors. This will result in including subwindow contents
in the source and drawing through subwindow boundaries of the
destination. The use of `x:Include-Inferiors' on a window of
one depth with mapped inferiors of differing depth is not
illegal, but the semantics are undefined by the core protocol.
-- Attribute: x:GC-Graphics-Exposures
The graphics-exposure flag controls x:Graphics-Expose event
generation for X:Copy-Area and X:Copy-Plane requests (and any
similar requests defined by extensions).
-- Attribute: x:GC-Clip-X-Origin
-- Attribute: x:GC-Clip-Y-Origin
The clip-mask origin is interpreted relative to the origin of
whatever destination drawable is specified in a graphics request.
-- Attribute: x:GC-Clip-Mask
The clip-mask restricts writes to the destination drawable. If the
clip-mask is set to a pixmap, it must have depth one and have the
same root as the GC, or an error results. If clip-mask is set to "x:None",
the pixels are always drawn regardless of the clip origin. The
clip-mask also can be set by calling `X:Set-Region'. Only pixels
where the clip-mask has a bit set to 1 are drawn. Pixels are not
drawn outside the area covered by the clip-mask or where the
clip-mask has a bit set to 0. The clip-mask affects all graphics
requests. The clip-mask does not clip sources. The clip-mask
origin is interpreted relative to the origin of whatever
destination drawable is specified in a graphics request.
-- Attribute: x:GC-Dash-Offset
Defines the phase of the pattern, specifying how many pixels into
the dash-list the pattern should actually begin in any single
graphics request. Dashing is continuous through path elements
combined with a join-style but is reset to the dash-offset between
each sequence of joined lines.
The unit of measure for dashes is the same for the ordinary
coordinate system. Ideally, a dash length is measured along the
slope of the line, but implementations are only required to match
this ideal for horizontal and vertical lines. Failing the ideal
semantics, it is suggested that the length be measured along the
major axis of the line. The major axis is defined as the x axis
for lines drawn at an angle of between -45 and +45 degrees or
between 135 and 225 degrees from the x axis. For all other lines,
the major axis is the y axis.
-- Attribute: x:GC-Dash-List
There must be at least one element in the specified DASH-LIST.
The initial and alternating elements (second, fourth, and so on)
of the DASH-LIST are the even dashes, and the others are the odd
dashes. Each element specifies a dash length in pixels. All of
the elements must be nonzero. Specifying an odd-length list is
equivalent to specifying the same list concatenated with itself to
produce an even-length list.
-- Attribute: x:GC-Arc-Mode
The arc-mode controls filling in the X:Fill-Arcs function and can
be set to x:Arc-Pie-Slice or x:Arc-Chord.
x:Arc-Pie-Slice
The arcs are pie-slice filled.
x:Arc-Chord
The arcs are chord filled.
File: Xlibscm.info, Node: Cursor, Next: Colormap, Prev: Graphics Context, Up: Top
5 Cursor
********
-- Function: x:create-cursor display shape
X provides a set of standard cursor shapes in a special font named "cursor".
Applications are encouraged to use this interface for their
cursors because the font can be customized for the individual
display type. The SHAPE argument specifies which glyph of the
standard fonts to use.
The hotspot comes from the information stored in the cursor font.
The initial colors of a cursor are a black foreground and a white
background (see X:Recolor-Cursor). The names of all cursor shapes
are defined with the prefix XC: in `x11.scm'.
-- Function: x:create-cursor source-font source-char mask-font
mask-char fgc bgc
Creates a cursor from the source and mask bitmaps obtained from the
specified font glyphs. The integer SOURCE-CHAR must be a defined
glyph in SOURCE-FONT. The integer MASK-CHAR must be a defined
glyph in MASK-FONT. The origins of the SOURCE-CHAR and MASK-CHAR
glyphs are positioned coincidently and define the hotspot. The
SOURCE-CHAR and MASK-CHAR need not have the same bounding box
metrics, and there is no restriction on the placement of the
hotspot relative to the bounding boxes.
-- Function: x:create-cursor source-font source-char #f #f fgc bgc
If MASK-FONT and MASK-CHAR are #f, all pixels of the source are
displayed.
-- Function: x:create-cursor source-pixmap mask-pixmap fgc bgc origin
MASK-PIXMAP must be the same size as the pixmap defined by the
SOURCE-PIXMAP argument. The foreground and background RGB values
must be specified using FOREGROUND-COLOR and BACKGROUND-COLOR,
even if the X server only has a x:Static-Gray or x:Gray-Scale
screen. The hotspot must be a point within the SOURCE-PIXMAP.
`X:Create-Cursor' creates and returns a cursor. The
FOREGROUND-COLOR is used for the pixels set to 1 in the source,
and the BACKGROUND-COLOR is used for the pixels set to 0. Both
source and mask must have depth one but can have any root. The
MASK-PIXMAP defines the shape of the cursor. The pixels set to 1
in MASK-PIXMAP define which source pixels are displayed, and the
pixels set to 0 define which pixels are ignored.
-- Function: x:create-cursor source-pixmap #f fgc bgc origin
If MASK-PIXMAP is #f, all pixels of the source are displayed.
File: Xlibscm.info, Node: Colormap, Next: Rendering, Prev: Cursor, Up: Top
6 Colormap
**********
A "colormap" maps pixel values to "RGB" color space values.
-- Function: x:create-colormap window visual alloc-policy
WINDOW specifies the window on whose screen you want to create a
colormap. VISUAL specifies a visual type supported on the screen.
ALLOC-POLICY Specifies the colormap entries to be allocated. You
can pass `X:Alloc-None' or `X:Alloc-All'.
The `X:Create-Colormap' function creates and returns a colormap of
the specified VISUAL type for the screen on which WINDOW resides.
Note that WINDOW is used only to determine the screen.
`X:Gray-Scale'
`X:Pseudo-Color'
`X:Direct-Color'
The initial values of the colormap entries are undefined.
`X:Static-Gray'
`X:Static-Color'
`X:True-Color'
The entries have defined values, but those values are
specific to VISUAL and are not defined by X. The
ALLOC-POLICY must be `X:Alloc-None'.
For the other visual classes, if ALLOC-POLICY is `X:Alloc-None',
the colormap initially has no allocated entries, and clients can
allocate them.
If ALLOC-POLICY is `X:Alloc-All', the entire colormap is allocated
writable. The initial values of all allocated entries are
undefined.
`X:Gray-Scale'
`X:Pseudo-Color'
The effect is as if an `XAllocColorCells' call returned all
pixel values from zero to N - 1, where N is the colormap
entries value in VISUAL.
`X:Direct-Color'
The effect is as if an `XAllocColorPlanes' call returned a
pixel value of zero and red_mask, green_mask, and blue_mask
values containing the same bits as the corresponding masks in
the specified visual.
To create a new colormap when the allocation out of a previously shared
colormap has failed because of resource exhaustion, use:
-- Function: x:copy-colormap-and-free colormap
Creates and returns a colormap of the same visual type and for the
same screen as the specified COLORMAP. It also moves all of the
client's existing allocation from the specified COLORMAP to the
new colormap with their color values intact and their read-only or
writable characteristics intact and frees those entries in the
specified colormap. Color values in other entries in the new
colormap are undefined. If the specified colormap was created by
the client with alloc set to `X:Alloc-All', the new colormap is
also created with `X:Alloc-All', all color values for all entries
are copied from the specified COLORMAP, and then all entries in
the specified COLORMAP are freed. If the specified COLORMAP was
not created by the client with `X:Alloc-All', the allocations to
be moved are all those pixels and planes that have been allocated
by the client and that have not been freed since they were
allocated.
A "colormap" maps pixel values to elements of the "RGB" datatype. An
RGB is a list or vector of 3 integers, describing the red, green, and
blue intensities respectively. The integers are in the range 0 - 65535.
-- Function: x:alloc-colormap-cells colormap ncolors nplanes
-- Function: x:alloc-colormap-cells colormap ncolors nplanes
contiguous?
The `X:Alloc-Color-Cells' function allocates read/write color
cells. The number of colors, NCOLORS must be positive and the
number of planes, NPLANES nonnegative. If NCOLORS and nplanes are
requested, then NCOLORS pixels and nplane plane masks are
returned. No mask will have any bits set to 1 in common with any
other mask or with any of the pixels. By ORing together each
pixel with zero or more masks, NCOLORS * 2^NPLANES distinct pixels
can be produced. All of these are allocated writable by the
request.
`x:Gray-Scale'
`x:Pseudo-Color'
Each mask has exactly one bit set to 1. If CONTIGUOUS? is
non-false and if all masks are ORed together, a single
contiguous set of bits set to 1 is formed.
`x:Direct-Color'
Each mask has exactly three bits set to 1. If CONTIGUOUS? is
non-false and if all masks are ORed together, three
contiguous sets of bits set to 1 (one within each pixel
subfield) is formed.
The RGB values of the allocated entries are undefined.
`X:Alloc-Color-Cells' returns a list of two uniform arrays if it
succeeded or #f if it failed. The first array has the pixels
allocated and the second has the plane-masks.
-- Function: x:alloc-colormap-cells colormap ncolors rgb
-- Function: x:alloc-colormap-cells colormap ncolors rgb contiguous?
The specified NCOLORS must be positive; and RGB a list or vector
of 3 nonnegative integers. If NCOLORS colors, NREDS reds, NGREENS
greens, and NBLUES blues are requested, NCOLORS pixels are
returned; and the masks have NREDS, NGREENS, and NBLUES bits set
to 1, respectively. If CONTIGUOUS? is non-false, each mask will
have a contiguous set of bits set to 1. No mask will have any
bits set to 1 in common with any other mask or with any of the
pixels.
Each mask will lie within the corresponding pixel subfield. By
ORing together subsets of masks with each pixel value, NCOLORS *
2(NREDS+NGREENS+NBLUES) distinct pixel values can be produced.
All of these are allocated by the request. However, in the
colormap, there are only NCOLORS * 2^NREDS independent red
entries, NCOLORS * 2^NGREENS independent green entries, and
NCOLORS * 2^NBLUES independent blue entries.
`X:Alloc-Color-Cells' returns a list if it succeeded or #f if it
failed. The first element of the list has an array of the pixels
allocated. The second, third, and fourth elements are the red,
green, and blue plane-masks.
-- Function: x:free-colormap-cells colormap pixels planes
-- Function: x:free-colormap-cells colormap pixels
Frees the cells represented by pixels whose values are in the
PIXELS unsigned-integer uniform-vector. The PLANES argument
should not have any bits set to 1 in common with any of the
pixels. The set of all pixels is produced by ORing together
subsets of the PLANES argument with the pixels. The request frees
all of these pixels that were allocated by the client. Note that
freeing an individual pixel obtained from `X:Alloc-Colormap-Cells'
with a planes argument may not actually allow it to be reused
until all of its related pixels are also freed. Similarly, a
read-only entry is not actually freed until it has been freed by
all clients, and if a client allocates the same read-only entry
multiple times, it must free the entry that many times before the
entry is actually freed.
All specified pixels that are allocated by the client in the
COLORMAP are freed, even if one or more pixels produce an error.
It is an error if a specified pixel is not allocated by the client
(that is, is unallocated or is only allocated by another client)
or if the colormap was created with all entries writable (by
passing `x:Alloc-All' to `X:Create-Colormap'). If more than one
pixel is in error, the one that gets reported is arbitrary.
-- Function: x:colormap-find-color colormap rgb
RGB is a list or vector of 3 integers, describing the red, green,
and blue intensities respectively; or an integer `#xrrggbb',
packing red, green and blue intensities in the range 0 - 255.
-- Function: x:colormap-find-color colormap color-name
The case-insensitive string COLOR_NAME specifies the name of a
color (for example, `red')
`X:Colormap-Find-Color' allocates a read-only colormap entry
corresponding to the closest RGB value supported by the hardware.
`X:Colormap-Find-Color' returns the pixel value of the color
closest to the specified RGB or COLOR_NAME elements supported by
the hardware, if successful; otherwise `X:Colormap-Find-Color'
returns #f.
Multiple clients that request the same effective RGB value can be
assigned the same read-only entry, thus allowing entries to be
shared. When the last client deallocates a shared cell, it is
deallocated.
-- Function: x:color-ref colormap pixel
Returns a list of 3 integers, describing the red, green, and blue
intensities respectively of the COLORMAP entry of the cell indexed
by PIXEL.
The integer PIXEL must be a valid index into COLORMAP.
-- Function: X:Color-Set! colormap pixel rgb
RGB is a list or vector of 3 integers, describing the red, green,
and blue intensities respectively; or an integer `#xrrggbb',
packing red, green and blue intensities in the range 0 - 255.
-- Function: X:Color-Set! colormap pixel color-name
The case-insensitive string COLOR_NAME specifies the name of a
color (for example, `red')
The integer PIXEL must be a valid index into COLORMAP.
`X:Color-Set!' changes the COLORMAP entry of the read/write cell
indexed by PIXEL. If the COLORMAP is an installed map for its
screen, the changes are visible immediately.
-- Function: x:install-colormap colormap
Installs the specified COLORMAP for its associated screen. All
windows associated with COLORMAP immediately display with true
colors. A colormap is associated with a window when the window is
created or its attributes changed.
If the specified colormap is not already an installed colormap,
the X server generates a ColormapNotify event on each window that
has that colormap.
-- Function: x:ccc colormap
Returns the Color-Conversion-Context of COLORMAP.
File: Xlibscm.info, Node: Rendering, Next: Images, Prev: Colormap, Up: Top
7 Rendering
***********
-- Function: x:flush display
-- Function: x:flush window
Flushes the output buffer. Some client applications need not use
this function because the output buffer is automatically flushed
as needed by calls to X:Pending, X:Next-Event, and X:Window-Event.
Events generated by the server may be enqueued into the library's
event queue.
-- Function: x:flush gc
Forces sending of GC component changes.
Xlib usually defers sending changes to the components of a GC to
the server until a graphics function is actually called with that
GC. This permits batching of component changes into a single
server request. In some circumstances, however, it may be
necessary for the client to explicitly force sending the changes
to the server. An example might be when a protocol extension uses
the GC indirectly, in such a way that the extension interface
cannot know what GC will be used.
-- Function: x:clear-area window (x-pos y-pos) (width height) expose?
Paints a rectangular area in the specified WINDOW according to the
specified dimensions with the WINDOW's background pixel or pixmap.
The subwindow-mode effectively is `x:Clip-By-Children'. If width
is zero, it is replaced with the current width of the WINDOW minus
x. If height is zero, it is replaced with the current height of
the WINDOW minus y. If the WINDOW has a defined background tile,
the rectangle clipped by any children is filled with this tile.
If the WINDOW has background x:None, the contents of the WINDOW
are not changed. In either case, if EXPOSE? is True, one or more
x:Expose events are generated for regions of the rectangle that
are either visible or are being retained in a backing store. If
you specify a WINDOW whose class is x:Input-Only, an error results.
-- Function: x:fill-rectangle window gcontext position size
Draw Strings
============
-- Function: x:draw-string drawable gc position string
POSITION specifies coordinates relative to the origin of DRAWABLE
of the origin of the first character to be drawn.
`x:draw-string' draws the characters of STRING, starting at
POSITION.
-- Function: x:image-string drawable gc position string
POSITION specifies coordinates relative to the origin of DRAWABLE
of the origin of the first character to be drawn.
`x:image-string' draws the characters _and background_ of STRING,
starting at POSITION.
Draw Shapes
===========
-- Function: x:draw-points drawable gc position ...
POSITION ... specifies coordinates of the point to be drawn.
-- Function: x:draw-points drawable gc x y ...
(X, Y) ... specifies coordinates of the point to be drawn.
-- Function: x:draw-points drawable gc point-array
POINT-ARRAY is a uniform short array of rank 2, whose rightmost
index spans a range of 2.
The `X:Draw-Points' procedure uses the foreground pixel and
function components of the GC to draw points into DRAWABLE at the
positions (relative to the origin of DRAWABLE) specified.
`X:Draw-Points' uses these GC components: function, planemask,
foreground, subwindow-mode, clip-x-origin, clip-y-origin, and
clip-mask.
-- Function: x:draw-segments drawable gc pos1 pos2 ...
POS1, POS2, ... specify coordinates to be connected by segments.
-- Function: x:draw-segments drawable gc x1 y1 x2 y2 ...
(X1, Y1), (X2, Y2) ... specify coordinates to be connected by
segments.
-- Function: x:draw-segments drawable gc point-array
POINT-ARRAY is a uniform short array of rank 2, whose rightmost
index spans a range of 2.
The `X:Draw-Segments' procedure uses the components of the
specified GC to draw multiple unconnected lines between disjoint
adjacent pair of points passed as arguments. It draws the
segments in order and does not perform joining at coincident
endpoints. For any given line, `X:Draw-Segments' does not draw a
pixel more than once. If thin (zero line-width) segments
intersect, the intersecting pixels are drawn multiple times. If
wide segments intersect, the intersecting pixels are drawn only
once, as though the entire PolyLine protocol request were a
single, filled shape. `X:Draw-Segments' treats all coordinates as
relative to the origin of DRAWABLE.
`X:Draw-Segments' uses these GC components: function, plane-mask,
line-width, line-style, cap-style, fill-style, subwindow-mode,
clip-x-origin, clip-y-origin, and clip-mask, join-style. It also
use these GC mode-dependent components: foreground, background,
tile, stipple, tilestipple-x-origin, tile-stipple-y-origin,
dash-offset, and dash-list.
-- Function: x:draw-lines drawable gc pos1 pos2 ...
POS1, POS2, ... specify coordinates to be connected by lines.
-- Function: x:draw-lines drawable gc x1 y1 x2 y2 ...
(X1, Y1), (X2, Y2) ... specify coordinates to be connected by
lines.
-- Function: x:draw-lines drawable gc point-array
POINT-ARRAY is a uniform short array of rank 2, whose rightmost
index spans a range of 2.
The `X:Draw-Lines' procedure uses the components of the specified
GC to draw lines between each adjacent pair of points passed as
arguments. It draws the lines in order. The lines join correctly
at all intermediate points, and if the first and last points
coincide, the first and last lines also join correctly. For any
given line, `X:Draw-Lines' does not draw a pixel more than once.
If thin (zero line-width) lines intersect, the intersecting pixels
are drawn multiple times. If wide lines intersect, the
intersecting pixels are drawn only once, as though the entire
PolyLine protocol request were a single, filled shape.
`X:Draw-Lines' treats all coordinates as relative to the origin of
DRAWABLE.
`X:Draw-Lines' uses these GC components: function, plane-mask,
line-width, line-style, cap-style, fill-style, subwindow-mode,
clip-x-origin, clip-y-origin, and clip-mask, join-style. It also
use these GC mode-dependent components: foreground, background,
tile, stipple, tilestipple-x-origin, tile-stipple-y-origin,
dash-offset, and dash-list.
-- Function: x:fill-polygon drawable gc pos1 pos2 ...
POS1, POS2, ... specify coordinates of the border path.
-- Function: x:fill-polygon drawable gc x1 y1 x2 y2 ...
(X1, Y1), (X2, Y2) ... specify coordinates of the border path.
-- Function: x:fill-polygon drawable gc point-array
POINT-ARRAY is a uniform short array of rank 2, whose rightmost
index spans a range of 2.
The path is closed automatically if the last point in the list or
POINT-ARRAY does not coincide with the first point.
The `X:Fill-Polygon' procedure uses the components of the specified
GC to fill the region closed by the specified path.
`X:Fill-Polygon' does not draw a pixel of the region more than
once. `X:Fill-Polygon' treats all coordinates as relative to the
origin of DRAWABLE.
`X:Fill-Polygon' uses these GC components: function, planemask,
fill-style, fill-rule, subwindow-mode, clip-x-origin,
clip-y-origin, and clip-mask. It also use these GC mode-dependent
components: foreground, background, tile, stipple,
tile-stipple-x-origin, and tile-stipple-y-origin.
File: Xlibscm.info, Node: Images, Next: Event, Prev: Rendering, Up: Top
8 Images
********
-- Function: x:read-bitmap-file drawable file
File: Xlibscm.info, Node: Event, Next: Index, Prev: Images, Up: Top
9 Event
*******
These three status routines always return immediately if there are
events already in the queue.
-- Function: x:q-length display
Returns the length of the event queue for the connected DISPLAY.
Note that there may be more events that have not been read into the
queue yet (see X:Events-Queued).
-- Function: x:pending display
Returns the number of events that have been received from the X
server but have not been removed from the event queue.
-- Function: x:events-queued display
Returns the number of events already in the queue if the number is
nonzero. If there are no events in the queue, `X:Events-Queued'
attempts to read more events out of the application's connection
without flushing the output buffer and returns the number read.
Both of these routines return an object of type "event".
-- Function: x:next-event display
Removes and returns the first event from the event queue. If the
event queue is empty, `X:Next-Event' flushes the output buffer and
blocks until an event is received.
-- Function: x:peek-event display
Returns the first event from the event queue, but it does not
remove the event from the queue. If the queue is empty,
`X:Peek-Event' flushes the output buffer and blocks until an event
is received.
Each event object has fields dependent on its sub-type.
-- Function: x:event-ref event field-name
window The window on which EVENT was generated
and is referred to as the event window.
root is the event window's root window.
subwindow If the source window is an inferior of
the event window, the SUBWINDOW is the
child of the event window that is the
source window or the child of the event
window that is an ancestor of the
source window. Otherwise, `None'.
X-event:type An integer: X:KEY-PRESS, X:KEY-RELEASE,
X:BUTTON-PRESS, X:BUTTON-RELEASE,
X:MOTION-NOTIFY, X:ENTER-NOTIFY,
X:LEAVE-NOTIFY, X:FOCUS-IN,
X:FOCUS-OUT, X:KEYMAP-NOTIFY, X:EXPOSE,
X:GRAPHICS-EXPOSE, X:NO-EXPOSE,
X:VISIBILITY-NOTIFY, X:CREATE-NOTIFY,
X:DESTROY-NOTIFY, X:UNMAP-NOTIFY,
X:MAP-NOTIFY, X:MAP-REQUEST,
X:REPARENT-NOTIFY, X:CONFIGURE-NOTIFY,
X:CONFIGURE-REQUEST, X:GRAVITY-NOTIFY,
X:RESIZE-REQUEST, X:CIRCULATE-NOTIFY,
X:CIRCULATE-REQUEST, X:PROPERTY-NOTIFY,
X:SELECTION-CLEAR, X:SELECTION-REQUEST,
X:SELECTION-NOTIFY, X:COLORMAP-NOTIFY,
X:CLIENT-MESSAGE, or X:MAPPING-NOTIFY.
X-event:serial The serial number of the protocol
request that generated the EVENT.
X-event:send-event Boolean that indicates whether the
event was sent by a different client.
X-event:time The time when the EVENT was generated
expressed in milliseconds.
X-event:x
X-event:y For window entry/exit events the X and
Y members are set to the coordinates of
the pointer position in the event
window. This position is always the
pointer's final position, not its
initial position. If the event window
is on the same screen as the root
window, X and Y are the pointer
coordinates relative to the event
window's origin. Otherwise, X and Y
are set to zero.
For expose events The X and Y members
are set to the coordinates relative to
the drawable's origin and indicate the
upper-left corner of the rectangle.
For configure, create, gravity, and
reparent events the X and Y members are
set to the window's coordinates
relative to the parent window's origin
and indicate the position of the
upper-left outside corner of the
created window.
X-event:x-root
X-event:y-root The pointer's coordinates relative to
the root window's origin at the time of
the EVENT.
X-event:state For keyboard, pointer and window
entry/exit events, the state member is
set to indicate the logical state of
the pointer buttons and modifier keys
just prior to the EVENT, which is the
bitwise inclusive OR of one or more of
the button or modifier key masks:
X:BUTTON1-MASK, X:BUTTON2-MASK,
X:BUTTON3-MASK, X:BUTTON4-MASK,
X:BUTTON5-MASK, X:SHIFT-MASK,
X:LOCK-MASK, X:CONTROL-MASK,
X:MOD1-MASK, X:MOD2-MASK, X:MOD3-MASK,
X:MOD4-MASK, and X:MOD5-MASK.
For visibility events, the state of the
window's visibility:
X:VISIBILITY-UNOBSCURED,
X:VISIBILITY-PARTIALLY-OBSCURED, or
X:VISIBILITY-FULLY-OBSCURED.
For colormap events, indicates whether
the colormap is installed or
uninstalled: x:Colormap-Installed or
x:Colormap-Uninstalled.
For property events, indicates whether
the property was changed to a new value
or deleted: x:Property-New-Value or
x:Property-Delete.
X-event:keycode An integer that represents a physical
key on the keyboard.
X-event:same-screen Indicates whether the event window is
on the same screen as the root window.
If #t, the event and root windows are
on the same screen. If #f, the event
and root windows are not on the same
screen.
X-event:button The pointer button that changed state;
can be the X:BUTTON1, X:BUTTON2,
X:BUTTON3, X:BUTTON4, or X:BUTTON5
value.
X-event:is-hint Detail of motion-notify events:
X:NOTIFY-NORMAL or X:NOTIFY-HINT.
X-event:mode Indicates whether the EVENT is a normal
event, pseudo-motion event when a grab
activates, or a pseudo-motion event
when a grab deactivates:
X:NOTIFY-NORMAL, X:NOTIFY-GRAB, or
X:NOTIFY-UNGRAB.
X-event:detail Indicates the notification detail:
X:NOTIFY-ANCESTOR, X:NOTIFY-VIRTUAL,
X:NOTIFY-INFERIOR, X:NOTIFY-NONLINEAR,
or X:NOTIFY-NONLINEAR-VIRTUAL.
X-event:focus If the event window is the focus window
or an inferior of the focus window, #t;
otherwise #f.
X-event:width
X-event:height The size (extent) of the rectangle.
X-event:count For mapping events is the number of
keycodes altered.
For expose events Is the number of
Expose or GraphicsExpose events that
are to follow. If count is zero, no
more Expose events follow for this
window. However, if count is nonzero,
at least that number of Expose events
(and possibly more) follow for this
window. Simple applications that do
not want to optimize redisplay by
distinguishing between subareas of its
window can just ignore all Expose
events with nonzero counts and perform
full redisplays on events with zero
counts.
X-event:major-code The major_code member is set to the
graphics request initiated by the
client and can be either X_CopyArea or
X_CopyPlane. If it is X_CopyArea, a
call to XCopyArea initiated the
request. If it is X_CopyPlane, a call
to XCopyPlane initiated the request.
X-event:minor-code Not currently used.
X-event:border-width For configure events, the width of the
window's border, in pixels.
X-event:override-redirect The override-redirect attribute of the
window. Window manager clients
normally should ignore this window if
it is #t.
X-event:from-configure True if the event was generated as a
result of a resizing of the window's
parent when the window itself had a
win-gravity of x:Unmap-Gravity.
X-event:value-mask Indicates which components were
specified in the ConfigureWindow
protocol request. The corresponding
values are reported as given in the
request. The remaining values are
filled in from the current geometry of
the window, except in the case of above
(sibling) and detail (stack-mode),
which are reported as None and Above,
respectively, if they are not given in
the request.
X-event:place The window's position after the restack
occurs and is either x:Place-On-Top or
x:Place-On-Bottom. If it is
x:Place-On-Top, the window is now on
top of all siblings. If it is
x:Place-On-Bottom, the window is now
below all siblings.
X-event:new indicate whether the colormap for the
specified window was changed or
installed or uninstalled and can be
True or False. If it is True, the
colormap was changed. If it is False,
the colormap was installed or
uninstalled.
X-event:format Is 8, 16, or 32 and specifies whether
the data should be viewed as a list of
bytes, shorts, or longs
X-event:request Indicates the kind of mapping change
that occurred and can be
X:MAPPING-MODIFIER, X:MAPPING-KEYBOARD,
or X:MAPPING-POINTER. If it is
X:MAPPING-MODIFIER, the modifier
mapping was changed. If it is
X:MAPPING-KEYBOARD, the keyboard
mapping was changed. If it is
X:MAPPING-POINTER, the pointer button
mapping was changed.
X-event:first-keycode The X-event:first-keycode is set only
if the X-event:request was set to
X:MAPPING-KEYBOARD. The number in
X-event:first-keycode represents the
first number in the range of the
altered mapping, and X-event:count
represents the number of keycodes
altered.
File: Xlibscm.info, Node: Index, Prev: Event, Up: Top
Procedure and Macro Index
*************************
This is an alphabetical list of all the procedures and macros in
Xlibscm.
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