bind(3Tk) bind(3Tk)
bind - Arrange for X events to invoke Tcl scripts
bind tag
bind tag sequence
bind tag sequence script
bind tag sequence +script
The bind command associates Tcl scripts with X events. If all three
arguments are specified, bind will arrange for script (a Tcl script) to
be evaluated whenever the event(s) given by sequence occur in the
window(s) identified by tag. If script is prefixed with a ``+'', then it
is appended to any existing binding for sequence; otherwise script
replaces any existing binding. If script is an empty string then the
current binding for sequence is destroyed, leaving sequence unbound. In
all of the cases where a script argument is provided, bind returns an
empty string.
If sequence is specified without a script, then the script currently
bound to sequence is returned, or an empty string is returned if there is
no binding for sequence. If neither sequence nor script is specified,
then the return value is a list whose elements are all the sequences for |
which there exist bindings for tag. |
The tag argument determines which window(s) the binding applies to. If |
tag begins with a dot, as in .a.b.c, then it must be the path name for a |
window; otherwise it may be an arbitrary string. Each window has an |
associated list of tags, and a binding applies to a particular window if |
its tag is among those specified for the window. Although the bindtags |
command may be used to assign an arbitrary set of binding tags to a |
window, the default binding tags provide the following behavior:
If a tag is the name of an internal window the binding applies to
that window.
If the tag is the name of a toplevel window the binding applies to
the toplevel window and all its internal windows.
If the tag is the name of a class of widgets, such as Button, the
binding applies to all widgets in that class;
If tag has the value all, the binding applies to all windows in the
application.
The sequence argument specifies a sequence of one or more event patterns,
with optional white space between the patterns. Each event pattern may
take either of two forms. In the simplest case it is a single printing
Page 1
bind(3Tk) bind(3Tk)
ASCII character, such as a or [. The character may not be a space
character or the character <. This form of pattern matches a KeyPress
event for the particular character. The second form of pattern is longer
but more general. It has the following syntax:
<modifier-modifier-type-detail>
The entire event pattern is surrounded by angle brackets. Inside the
angle brackets are zero or more modifiers, an event type, and an extra
piece of information (detail) identifying a particular button or keysym.
Any of the fields may be omitted, as long as at least one of type and
detail is present. The fields must be separated by white space or
dashes.
Modifiers consist of any of the following values: |
Control Mod2, M2 |
Shift Mod3, M3 |
Lock Mod4, M4 |
Button1, B1 Mod5, M5 |
Button2, B2 Meta, M |
Button3, B3 Alt |
Button4, B4 Double |
Button5, B5 Triple |
Mod1, M1 |
Where more than one value is listed, separated by commas, the values are |
equivalent. Most of the modifiers have the obvious X meanings. For |
example, Button1 requires that button 1 be depressed when the event |
occurs. For a binding to match a given event, the modifiers in the event|
must include all of those specified in the event pattern. An event may |
also contain additional modifiers not specified in the binding. For |
example, if button 1 is pressed while the shift and control keys are |
down, the pattern <Control-Button-1> will match the event, but <Mod1- |
Button-1> will not. If no modifiers are specified, then any combination |
of modifiers may be present in the event. |
Meta and M refer to whichever of the M1 through M5 modifiers is |
associated with the meta key(s) on the keyboard (keysyms Meta_R and |
Meta_L). If there are no meta keys, or if they are not associated with |
any modifiers, then Meta and M will not match any events. Similarly, the|
Alt modifier refers to whichever modifier is associated with the alt |
key(s) on the keyboard (keysyms Alt_L and Alt_R).
The Double and Triple modifiers are a convenience for specifying double
mouse clicks and other repeated events. They cause a particular event
pattern to be repeated 2 or 3 times, and also place a time and space
requirement on the sequence: for a sequence of events to match a Double
or Triple pattern, all of the events must occur close together in time
and without substantial mouse motion in between. For example, <Double-
bind(3Tk) bind(3Tk)
Button-1> is equivalent to <Button-1><Button-1> with the extra time and
space requirement.
The type field may be any of the standard X event types, with a few extra
abbreviations. Below is a list of all the valid types; where two names
appear together, they are synonyms.
ButtonPress, Button Expose Map |
ButtonRelease FocusIn Motion |
Circulate FocusOut Property |
Colormap Gravity Reparent |
Configure KeyPress, Key Unmap |
Destroy KeyRelease Visibility |
Enter Leave
The last part of a long event specification is detail. In the case of a
ButtonPress or ButtonRelease event, it is the number of a button (1-5).
If a button number is given, then only an event on that particular button
will match; if no button number is given, then an event on any button
will match. Note: giving a specific button number is different than
specifying a button modifier; in the first case, it refers to a button
being pressed or released, while in the second it refers to some other
button that is already depressed when the matching event occurs. If a
button number is given then type may be omitted: if will default to
ButtonPress. For example, the specifier <1> is equivalent to
<ButtonPress-1>.
If the event type is KeyPress or KeyRelease, then detail may be specified
in the form of an X keysym. Keysyms are textual specifications for
particular keys on the keyboard; they include all the alphanumeric ASCII
characters (e.g. ``a'' is the keysym for the ASCII character ``a''), plus
descriptions for non-alphanumeric characters (``comma'' is the keysym for
the comma character), plus descriptions for all the non-ASCII keys on the
keyboard (``Shift_L'' is the keysm for the left shift key, and ``F1'' is
the keysym for the F1 function key, if it exists). The complete list of
keysyms is not presented here; it is available in other X documentation
and may vary from system to system. If necessary, you can use the %K
notation described below to print out the keysym name for a particular
key. If a keysym detail is given, then the type field may be omitted;
it will default to KeyPress. For example, <Control-comma> is equivalent
to <Control-KeyPress-comma>.
BINDING SCRIPTS AND SUBSTITUTIONS
The script argument to bind is a Tcl script, which will be executed
whenever the given event sequence occurs. Command will be executed in
the same interpreter that the bind command was executed in, and it will
run at global level (only global variables will be accessible). If
script contains any % characters, then the script will not be executed
Page 3
bind(3Tk) bind(3Tk)
directly. Instead, a new script will be generated by replacing each %,
and the character following it, with information from the current event.
The replacement depends on the character following the %, as defined in
the list below. Unless otherwise indicated, the replacement string is |
the decimal value of the given field from the current event. Some of the
substitutions are only valid for certain types of events; if they are
used for other types of events the value substituted is undefined.
%% Replaced with a single percent.
%# The number of the last client request processed by the server (the
serial field from the event). Valid for all event types.
%a The above field from the event, formatted as a hexadecimal number. |
Valid only for Configure events.
%b The number of the button that was pressed or released. Valid only
for ButtonPress and ButtonRelease events.
%c The count field from the event. Valid only for Expose events.
%d The detail field from the event. The %d is replaced by a string
identifying the detail. For Enter, Leave, FocusIn, and FocusOut
events, the string will be one of the following:
NotifyAncestor NotifyNonlinearVirtual
NotifyDetailNone NotifyPointer
NotifyInferior NotifyPointerRoot
NotifyNonlinear NotifyVirtual
For events other than these, the substituted string is undefined.
%f The focus field from the event (0 or 1). Valid only for Enter and
Leave events.
%h The height field from the event. Valid only for Configure, Expose,
and GraphicsExpose events.
%k The keycode field from the event. Valid only for KeyPress and
KeyRelease events.
%m The mode field from the event. The substituted string is one of
NotifyNormal, NotifyGrab, NotifyUngrab, or NotifyWhileGrabbed.
Valid only for EnterWindow, FocusIn, FocusOut, and LeaveWindow
events.
%o The override_redirect field from the event. Valid only for Map,
Reparent, and Configure events.
%p The place field from the event, substituted as one of the strings
PlaceOnTop or PlaceOnBottom. Valid only for Circulate events.
Page 4
bind(3Tk) bind(3Tk)
%s The state field from the event. For ButtonPress, ButtonRelease,
Enter, KeyPress, KeyRelease, Leave, and Motion events, a decimal |
string is substituted. For Visibility, one of the strings
VisibilityUnobscured, VisibilityPartiallyObscured, and
VisibilityFullyObscured is substituted.
%t The time field from the event. Valid only for events that contain a
time field.
%w The width field from the event. Valid only for Configure, Expose,
and GraphicsExpose events.
%x The x field from the event. Valid only for events containing an x
field.
%y The y field from the event. Valid only for events containing a y
field.
%A Substitutes the ASCII character corresponding to the event, or the
empty string if the event doesn't correspond to an ASCII character
(e.g. the shift key was pressed). XLookupString does all the work
of translating from the event to an ASCII character. Valid only for
KeyPress and KeyRelease events.
%B The border_width field from the event. Valid only for Configure
events.
%E The send_event field from the event. Valid for all event types.
%K The keysym corresponding to the event, substituted as a textual
string. Valid only for KeyPress and KeyRelease events.
%N The keysym corresponding to the event, substituted as a decimal |
number. Valid only for KeyPress and KeyRelease events.
%R The root window identifier from the event. Valid only for events
containing a root field.
%S The subwindow window identifier from the event, formatted as a |
hexadecimal number. Valid only for events containing a subwindow
field.
%T The type field from the event. Valid for all event types.
%W The path name of the window to which the event was reported (the
window field from the event). Valid for all event types.
%X The x_root field from the event. If a virtual-root window manager |
is being used then the substituted value is the corresponding x- |
coordinate in the virtual root. Valid only for ButtonPress,
ButtonRelease, KeyPress, KeyRelease, and Motion events.
Page 5
bind(3Tk) bind(3Tk)
%Y The y_root field from the event. If a virtual-root window manager |
is being used then the substituted value is the corresponding y- |
coordinate in the virtual root. Valid only for ButtonPress,
ButtonRelease, KeyPress, KeyRelease, and Motion events.
The replacement string for a %-replacement is formatted as a proper Tcl |
list element. This means that it will be surrounded with braces if it |
contains spaces, or special characters such as $ and { may be preceded by|
backslashes. This guarantees that the string will be passed through the |
Tcl parser when the binding script is evaluated. Most replacements are |
numbers or well-defined strings such as Above; for these replacements no|
special formatting is ever necessary. The most common case where |
reformatting occurs is for the %A substitution. For example, if script |
is |
insert %A |
and the character typed is an open square bracket, then the script |
actually executed will be |
insert \[ |
This will cause the insert to receive the original replacement string |
(open square bracket) as its first argument. If the extra backslash |
hadn't been added, Tcl would not have been able to parse the script |
correctly.
It is possible for several bindings to match a given X event. If the |
bindings are associated with different tag's, then each of the bindings |
will be executed, in order. By default, a class binding will be executed|
first, followed by a binding for the widget, a binding for its toplevel, |
and an all binding. The bindtags command may be used to change this |
order for a particular window or to associate additional binding tags |
with the window. |
The continue and break commands may be used inside a binding script to |
control the processing of matching scripts. If continue is invoked, then|
the current binding script is terminated but Tk will continue processing |
binding scripts associated with other tag's. If the break command is |
invoked within a binding script, then that script terminates and no other|
scripts will be invoked for the event. |
If more than one binding matches a particular event and they have the |
same tag, then the most specific binding is chosen and its script is |
evaluated. The following tests are applied, in order, to determine which|
of several matching sequences is more specific: (a) a longer sequence |
(in terms of number of events matched) is more specific than a shorter |
sequence; (b) an event pattern that specifies a specific button or key is|
more specific than one that doesn't; (c) if the modifiers specified in |
one pattern are a subset of the modifiers in another pattern, then the |
Page 6
bind(3Tk) bind(3Tk)
pattern with more modifiers is more specific. If the matching sequences
contain more than one event, then tests (c)-(e) are applied in order from
the most recent event to the least recent event in the sequences. If
these tests fail to determine a winner, then the most recently registered
sequence is the winner.
If an X event does not match any of the existing bindings, then the event
is ignored. An unbound event is not considered to be an error.
MULTI-EVENT SEQUENCES AND IGNORED EVENTS [Toc] [Back] When a sequence specified in a bind command contains more than one event
pattern, then its script is executed whenever the recent events (leading
up to and including the current event) match the given sequence. This
means, for example, that if button 1 is clicked repeatedly the sequence
<Double-ButtonPress-1> will match each button press but the first. If |
extraneous events that would prevent a match occur in the middle of an |
event sequence then the extraneous events are ignored unless they are |
KeyPress or ButtonPress events. For example, <Double-ButtonPress-1> will|
match a sequence of presses of button 1, even though there will be |
ButtonRelease events (and possibly Motion events) between the ButtonPress|
events. Furthermore, a KeyPress event may be preceded by any number of |
other KeyPress events for modifier keys without the modifier keys |
preventing a match. For example, the event sequence aB will match a |
press of the a key, a release of the a key, a press of the Shift key, and|
a press of the b key: the press of Shift is ignored because it is a |
modifier key. Finally, if several Motion events occur in a row, only the
last one is used for purposes of matching binding sequences.
If an error occurs in executing the script for a binding then the tkerror
mechanism is used to report the error. The tkerror command will be |
executed at global level (outside the context of any Tcl procedure).
tkerror
form, manual
Page 7
bind(3N) bind(3N)
bind - bind a name to a socket
#include <sys/types.h>
bind(int s, caddr_tr name, int namelen);
bind() assigns a name to an unnamed socket. When a socket is created
with socket(3N), it exists in a name space (address family) but has no
name assigned. bind() requests that the name pointed to by name be
assigned to the socket.
If the bind is successful, a 0 value is returned. A return value of -1
indicates an error, which is further specified in the global errno.
The bind() call will fail if:
EBADF s is not a valid descriptor.
ENOTSOCK s is a descriptor for a file, not a socket.
EADDRNOTAVAIL The specified address is not available on the local
machine.
EADDRINUSE The specified address is already in use.
EINVAL namelen is not the size of a valid address for the
specified address family.
EINVAL The socket is already bound to an address.
EACCES The requested address is protected and the current
user has inadequate permission to access it.
ENOSR There were insufficient STREAMS resources for the
operation to complete.
The following errors are specific to binding names in the UNIX domain:
ENOTDIR A component of the path prefix of the pathname in
name is not a directory.
ENOENT A component of the path prefix of the pathname in
name does not exist.
EACCES Search permission is denied for a component of the
path prefix of the pathname in name.
Page 1
bind(3N) bind(3N)
ELOOP Too many symbolic links were encountered in
translating the pathname in name.
EIO An I/O error occurred while making the directory
entry or allocating the inode.
EROFS The inode would reside on a read-only file system.
EISDIR A null pathname was specified.
unlink(2)
Binding a name in the UNIX domain creates a socket in the file system
that must be deleted by the caller when it is no longer needed (using
unlink(2)).
The rules used in name binding vary between communication domains.
The type of address structure passed to bind() depends on the address
family. UNIX domain sockets (address family AF_UNIX) require a struct
socketaddr_un as defined in sys/un.h; Internet domain sockets (address
family AF_INET) require a struct sockaddr_in as defined in netinet/in.h.
Other address families may require other structures. Use the structure
appropriate to the address family; cast the structure address to a
generic caddr_t in the call to bind() and pass the size of the structure
in the length argument.
PPPPaaaaggggeeee 2222 [ Back ]
|
