Provided by: tk8.5-doc_8.5.15-2ubuntu3_all bug


       bind - Arrange for X events to invoke Tcl scripts


       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 one of three forms.  In the
       simplest  case it is a single printing 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:
       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.

       The third form of pattern is used to specify a user-defined, named virtual event.  It  has
       the following syntax:
       The entire virtual event pattern is surrounded by double angle brackets.  Inside the angle
       brackets is the user-defined name of the virtual  event.   Modifiers,  such  as  Shift  or
       Control,  may  not  be  combined with a virtual event to modify it.  Bindings on a virtual
       event may be created before the virtual event is defined,  and  if  the  definition  of  a
       virtual  event  changes  dynamically, all windows bound to that virtual event will respond
       immediately to the new definition.

       Some widgets (e.g. menu and text) issue  virtual  events  when  their  internal  state  is
       updated in some ways.  Please see the manual page for each widget for details.

       Modifiers  consist  of  any  of  the  following  values: Control                 Mod1, M1,
       Command  Alt                     Mod2,   M2,   Option   Shift                   Mod3,   M3
       Lock                    Mod4,     M4     Extended                Mod5,     M5     Button1,
       B1             Meta,  M  Button2,  B2             Double  Button3,   B3             Triple
       Button4, B4        Quadruple Button5, B5 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,  Triple and Quadruple modifiers are a convenience for specifying double mouse
       clicks and other repeated events. They cause a particular event pattern to be repeated  2,
       3  or 4 times, and also place a time and space requirement on the sequence: for a sequence
       of events to match a Double, Triple or Quadruple pattern, all of  the  events  must  occur
       close  together  in  time  and  without substantial mouse motion in between.  For example,
       <Double-Button-1> is equivalent to <Button-1><Button-1> with  the  extra  time  and  space

       The  Command  and  Option modifiers are equivalents of Mod1 resp. Mod2, they correspond to
       Macintosh-specific modifier keys.

       The Extended modifier is, at present, specific to Windows.  It appears on events that  are │
       associated  with the keys on the “extended keyboard”.  On a US keyboard, the extended keys │
       include the Alt and Control keys at the right of the keyboard,  the  cursor  keys  in  the │
       cluster  to  the  left of the numeric pad, the NumLock key, the Break key, the PrintScreen │
       key, and the / and Enter keys in the numeric keypad.

       The type field may be any of the standard X event types, with a few  extra  abbreviations.
       The  type  field  will  also accept a couple non-standard X event types that were added to
       better support the Macintosh and Windows platforms.  Below is a  list  of  all  the  valid
       types;     where     two     names     appear     together,     they     are     synonyms.
       Activate              Destroy         Map ButtonPress, Button   Enter           MapRequest
       ButtonRelease         Expose          Motion
       Circulate             FocusIn         MouseWheel
       CirculateRequest      FocusOut        Property
       Colormap              Gravity         Reparent             Configure             KeyPress,
       Key   ResizeRequest                            ConfigureRequest      KeyRelease      Unmap
       Create                Leave           Visibility Deactivate Most of the above events  have
       the  same  fields  and  behaviors  as events in the X Windowing system.  You can find more
       detailed descriptions of these events in any X window programming book.  A couple  of  the
       events  are  extensions  to the X event system to support features unique to the Macintosh
       and Windows platforms.  We provide a little more  detail  on  these  events  here.   These

       Activate, Deactivate
            These  two  events are sent to every sub-window of a toplevel when they change state.
            In addition to the focus Window, the Macintosh platform and Windows platforms have  a
            notion  of  an active window (which often has but is not required to have the focus).
            On the Macintosh, widgets in the active  window  have  a  different  appearance  than
            widgets  in deactive windows.  The Activate event is sent to all the sub-windows in a
            toplevel when it changes from being deactive to active.  Likewise, the Deactive event
            is sent when the window's state changes from active to deactive.  There are no useful
            percent substitutions you would make when binding to these events.

            Many contemporary mice support a mouse wheel, which is used for  scrolling  documents
            without  using  the  scrollbars.   By  rolling  the  wheel,  the system will generate
            MouseWheel events that the application can use to scroll.  Like Key events the  event
            is  always  routed to the window that currently has focus. When the event is received
            you can use the %D substitution to get the delta field for  the  event,  which  is  a
            integer value describing how the mouse wheel has moved.  The smallest value for which
            the system will report is defined by the OS.  On Windows 95 & 98 machines this  value
            is  at  least  120  before it is reported.  However, higher resolution devices may be
            available in the future.  The sign of  the  value  determines  which  direction  your
            widget  should  scroll.   Positive values should scroll up and negative values should
            scroll down.

       KeyPress, KeyRelease
            The KeyPress and KeyRelease events  are  generated  whenever  a  key  is  pressed  or
            released.   KeyPress and KeyRelease events are sent to the window which currently has
            the keyboard focus.

       ButtonPress, ButtonRelease, Motion
            The ButtonPress and ButtonRelease events are  generated  when  the  user  presses  or
            releases  a mouse button.  Motion events are generated whenever the pointer is moved.
            ButtonPress, ButtonRelease, and  Motion  events  are  normally  sent  to  the  window
            containing the pointer.

            When  a  mouse  button  is  pressed,  the window containing the pointer automatically
            obtains a temporary pointer grab.  Subsequent ButtonPress, ButtonRelease, and  Motion
            events  will be sent to that window, regardless of which window contains the pointer,
            until all buttons have been released.

            A Configure event is sent to a window whenever its size, position,  or  border  width
            changes, and sometimes when it has changed position in the stacking order.

       Map, Unmap
            The  Map  and  Unmap  events  are  generated  whenever  the mapping state of a window

            Windows are created in the unmapped state.  Top-level windows become mapped when they
            transition  to the normal state, and are unmapped in the withdrawn and iconic states.
            Other windows become mapped when they are placed under control of a geometry  manager
            (for example pack or grid).

            A  window  is  viewable  only  if  it and all of its ancestors are mapped.  Note that
            geometry managers typically do not map their children until  they  have  been  mapped
            themselves,  and  unmap  all  children when they become unmapped; hence in Tk Map and
            Unmap events indicate whether or not a window is viewable.

            A window is said to be obscured when another window above it in  the  stacking  order
            fully  or partially overlaps it.  Visibility events are generated whenever a window's
            obscurity state changes; the state field (%s) specifies the new state.

            An Expose event is generated whenever all or part of a window should be redrawn  (for
            example,  when a window is first mapped or if it becomes unobscured).  It is normally
            not necessary for client applications to handle Expose events, since Tk handles  them

            A Destroy event is delivered to a window when it is destroyed.

            When  the  Destroy  event is delivered to a widget, it is in a “half-dead” state: the
            widget still exists, but most operations on it will fail.

       FocusIn, FocusOut
            The FocusIn and FocusOut events are generated whenever the keyboard focus changes.  A
            FocusOut  event  is  sent to the old focus window, and a FocusIn event is sent to the
            new one.

            In addition, if the old and new focus windows do not share a common parent,  “virtual
            crossing” focus events are sent to the intermediate windows in the hierarchy.  Thus a
            FocusIn event indicates that the target window or one of its descendants has acquired
            the focus, and a FocusOut event indicates that the focus has been changed to a window
            outside the target window's hierarchy.

            The keyboard focus may be changed explicitly by a call to focus, or implicitly by the
            window manager.

       Enter, Leave
            An  Enter  event is sent to a window when the pointer enters that window, and a Leave
            event is sent when the pointer leaves it.

            If there is a pointer grab in effect, Enter and Leave events are  only  delivered  to
            the window owning the grab.

            In  addition,  when  the  pointer moves between two windows, Enter and Leave “virtual
            crossing” events are sent to intermediate windows in the hierarchy in the same manner
            as for FocusIn and FocusOut events.

            A  Property event is sent to a window whenever an X property belonging to that window
            is changed or deleted.  Property events are not normally delivered to Tk applications
            as they are handled by the Tk core.

            A Colormap event is generated whenever the colormap associated with a window has been
            changed, installed, or uninstalled.

            Widgets may be assigned a private colormap by  specifying  a  -colormap  option;  the
            window manager is responsible for installing and uninstalling colormaps as necessary.

            Note that Tk provides no useful details for this event type.

       MapRequest, CirculateRequest, ResizeRequest, ConfigureRequest, Create
            These  events  are  not normally delivered to Tk applications.  They are included for
            completeness, to make it possible to write X11 window managers in Tk.  (These  events
            are  only  delivered when a client has selected SubstructureRedirectMask on a window;
            the Tk core does not use this mask.)

       Gravity, Reparent, Circulate
            The events Gravity and Reparent are not normally delivered to Tk applications.   They
            are included for completeness.

            A  Circulate event indicates that the window has moved to the top or to the bottom of
            the stacking order as a result of an  XCirculateSubwindows  protocol  request.   Note
            that  the  stacking  order  may  be changed for other reasons which do not generate a
            Circulate event, and that Tk does not use  XCirculateSubwindows()  internally.   This
            event  type  is  included  only  for  completeness; there is no reliable way to track
            changes to a window's position in the stacking order.

       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
       (e.g.   “Shift_L”  is the keysym 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>.


       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
       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.   Indicates  the  sibling  window  immediately below the receiving
            window in the stacking order, or 0 if the receiving window is at the bottom.

       %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.  Indicates that there
            are count pending Expose events which have not yet been delivered to the window.

       %d   The detail or user_data 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
            ConfigureRequest events, the string will be one of:  Above                   Opposite
            Below                   None  BottomIf                TopIf  For  virtual events, the │
            string will be whatever value is stored in the user_data field  when  the  event  was │
            created  (typically  with  event generate), or the empty string if the field is NULL. │
            Virtual events corresponding to key sequence presses (see event add for details)  set │
            the  user_data  to  NULL.   For  events  other  than these, the substituted string is

       %f   The focus field from the event (0 or 1).  Valid only for Enter and Leave  events.   1
            if  the  receiving  window is the focus window or a descendant of the focus window, 0

       %h   The height field from the event.  Valid for the Configure, ConfigureRequest,  Create,
            ResizeRequest,  and  Expose  events.   Indicates  the  new or requested height of the

       %i   The window field from the event, represented as a hexadecimal integer.  Valid for all
            event types.

       %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  Enter,  FocusIn,
            FocusOut, and Leave 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 and CirculateRequest events.

       %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.  For Property events, substituted with either
            the  string  NewValue  (indicating that the property has been created or modified) or
            Delete (indicating that the property has been removed).

       %t   The time field from the event.  This is the X server timestamp  (typically  the  time
            since  the  last  server  reset) in milliseconds, when the event occurred.  Valid for
            most events.

       %w   The width field from the event.  Indicates the new or requested width of the  window.
            Valid only for Configure, ConfigureRequest, Create, ResizeRequest, and Expose events.

       %x, %y
            The x and y fields from the event.  For ButtonPress, ButtonRelease, Motion, KeyPress,
            KeyRelease, and MouseWheel events, %x and %y  indicate  the  position  of  the  mouse
            pointer  relative  to the receiving window.  For Enter and Leave events, the position
            where the mouse pointer crossed the window, relative to the  receiving  window.   For
            Configure  and Create requests, the x and y coordinates of the window relative to its
            parent window.

       %A   Substitutes the UNICODE character corresponding to the event, or the empty string  if
            the  event  does  not  correspond  to  a  UNICODE  character  (e.g. the shift key was
            pressed). XmbLookupString (or XLookupString when input method support is turned  off)
            does  all  the work of translating from the event to a UNICODE character.  Valid only
            for KeyPress and KeyRelease events.

       %B   The border_width field from the event.  Valid only for  Configure,  ConfigureRequest,
            and Create events.

       %D   This  reports  the delta value of a MouseWheel event.  The delta value represents the
            rotation units the mouse wheel has been moved.   On  Windows  95  &  98  systems  the
            smallest  value  for  the delta is 120.  Future systems may support higher resolution
            values for the delta.  The sign of the value represents the direction the mouse wheel
            was scrolled.

       %E   The  send_event  field  from the event.  Valid for all event types.  0 indicates that
            this is a “normal” event, 1 indicates that it is a  “synthetic”  event  generated  by

       %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.

       %P   The name of the property being updated or deleted (which may be converted to an XAtom
            using winfo atom.) Valid only for Property events.

       %R   The root window identifier from the event.  Valid only for events containing  a  root

       %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, %Y
            The  x_root  and   y_root fields from the event.  If a virtual-root window manager is
            being used then the substituted values are  the  corresponding  x-coordinate  and  y-
            coordinate in the virtual root.  Valid only for ButtonPress, ButtonRelease, KeyPress,
            KeyRelease, and Motion events.  Same meaning as %x and %y,  except  relative  to  the
            (virtual) root window.

       The  replacement  string  for  a  %-replacement is formatted as a proper Tcl list element.
       This means that 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
              insert %A
       and  the character typed is an open square bracket, then the script actually executed will
              insert \[
       This will cause the insert  to  receive  the  original  replacement  string  (open  square
       bracket)  as its first argument.  If the extra backslash had not 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 binding for the widget will be executed first, followed by a class  binding,  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

       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)    an  event  pattern  that specifies a specific button or key is more specific
                     than one that does not;

              (b)    a longer sequence (in terms of number of events matched)  is  more  specific
                     than a shorter sequence;

              (c)    if  the  modifiers specified in one pattern are a subset of the modifiers in
                     another pattern, then the pattern with more modifiers is more specific.

              (d)    a virtual event whose physical pattern matches the sequence is less specific
                     than the same physical pattern that is not associated with a virtual event.

              (e)    given a sequence that matches two or more virtual events, one of the virtual
                     events will be chosen, but the order is undefined.

       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

       If  there  are  two (or more) virtual events that are both triggered by the same sequence,
       and both of those virtual events are bound to the same window tag, then only  one  of  the
       virtual events will be triggered, and it will be picked at random:
              event add <<Paste>> <Control-y>
              event add <<Paste>> <Button-2>
              event add <<Scroll>> <Button-2>
              bind Entry <<Paste>> {puts Paste}
              bind Entry <<Scroll>> {puts Scroll}
       If  the  user  types  Control-y,  the  <<Paste>>  binding will be invoked, but if the user
       presses button 2 then one of either the <<Paste>>  or  the  <<Scroll>>  bindings  will  be
       invoked, but exactly which one gets invoked is undefined.

       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.


       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 bgerror mechanism is
       used to report the error.  The bgerror command will be executed at global  level  (outside
       the context of any Tcl procedure).


       Arrange  for  a string describing the motion of the mouse to be printed out when the mouse
       is double-clicked:
              bind . <Double-1> {
                  puts "hi from (%x,%y)"

       A little GUI that displays what the keysym name of the last key pressed is:
              set keysym "Press any key"
              pack [label .l -textvariable keysym -padx 2m -pady 1m]
              bind . <Key> {
                  set keysym "You pressed %K"


       bgerror(3tcl), bindtags(3tk), event(3tk), focus(3tk), grab(3tk), keysyms(3tk)


       binding, event