Provided by: tk8.4-doc_8.4.19-4_all bug

NAME

       Tk_CreateBindingTable,    Tk_DeleteBindingTable,    Tk_CreateBinding,    Tk_DeleteBinding,
       Tk_GetBinding, Tk_GetAllBindings, Tk_DeleteAllBindings, Tk_BindEvent - invoke  scripts  in
       response to X events

SYNOPSIS

       #include <tk.h>

       Tk_BindingTable
       Tk_CreateBindingTable(interp)

       Tk_DeleteBindingTable(bindingTable)

       unsigned long
       Tk_CreateBinding(interp, bindingTable, object, eventString, script, append)

       int
       Tk_DeleteBinding(interp, bindingTable, object, eventString)

       CONST char *
       Tk_GetBinding(interp, bindingTable, object, eventString)

       Tk_GetAllBindings(interp, bindingTable, object)

       Tk_DeleteAllBindings(bindingTable, object)

       Tk_BindEvent(bindingTable, eventPtr, tkwin, numObjects, objectPtr)

ARGUMENTS

       Tcl_Interp        *interp        (in)      Interpreter  to  use  when invoking bindings in
                                                  binding table.  Also used for returning results
                                                  and errors from binding procedures.

       Tk_BindingTable   bindingTable   (in)      Token   for  binding  table;   must  have  been
                                                  returned   by    some    previous    call    to
                                                  Tk_CreateBindingTable.

       ClientData        object         (in)      Identifies   object   with   which  binding  is
                                                  associated.

       CONST char        *eventString   (in)      String describing event sequence.

       char              *script        (in)      Tcl script to invoke when binding triggers.

       int               append         (in)      Non-zero means append script to existing script
                                                  for   binding,   if  any;  zero  means  replace
                                                  existing script with new one.

       XEvent            *eventPtr      (in)      X  event   to   match   against   bindings   in
                                                  bindingTable.

       Tk_Window         tkwin          (in)      Identifier  for any window on the display where
                                                  the event  occurred.   Used  to  find  display-
                                                  related information such as key maps.

       int               numObjects     (in)      Number  of  object  identifiers  pointed  to by
                                                  objectPtr.

       ClientData        *objectPtr     (in)      Points  to  an  array  of  object  identifiers:
                                                  bindings  will  be considered for each of these
                                                  objects in order from first to last.
_________________________________________________________________

DESCRIPTION

       These procedures provide a general-purpose mechanism for creating and  invoking  bindings.
       Bindings  are  organized  in  terms  of  binding  tables.   A  binding table consists of a
       collection of bindings plus a history of recent events.  Within a binding table,  bindings
       are  associated  with  objects.   The  meaning  of  an object is defined by clients of the
       binding package.  For example, Tk keeps uses one binding table to hold all of the bindings
       created  by  the  bind  command.   For this table, objects are pointers to strings such as
       window names, class names, or other binding tags such as all.  Tk also  keeps  a  separate
       binding  table for each canvas widget, which manages bindings created by the canvas's bind
       widget command;  within this table,  an  object  is  either  a  pointer  to  the  internal
       structure for a canvas item or a Tk_Uid identifying a tag.

       The procedure Tk_CreateBindingTable creates a new binding table and associates interp with
       it (when bindings in the table are invoked, the scripts  will  be  evaluated  in  interp).
       Tk_CreateBindingTable  returns a token for the table, which must be used in calls to other
       procedures such as Tk_CreateBinding or Tk_BindEvent.

       Tk_DeleteBindingTable frees all of the state associated with a  binding  table.   Once  it
       returns the caller should not use the bindingTable token again.

       Tk_CreateBinding  adds a new binding to an existing table.  The object argument identifies
       the object with which the binding is to be associated, and it may be any  one-word  value.
       Typically  it  is  a  pointer  to  a  string  or data structure.  The eventString argument
       identifies the event or sequence of events for the binding;  see the documentation for the
       bind  command  for  a description of its format.  script is the Tcl script to be evaluated
       when the binding triggers.  append indicates what to do if there already exists a  binding
       for  object  and  eventString:  if append is zero then script replaces the old script;  if
       append is non-zero then the new script is  appended  to  the  old  one.   Tk_CreateBinding
       returns an X event mask for all the events associated with the bindings.  This information
       may be useful to invoke XSelectInput to select relevant events, or to disallow the use  of
       certain  events  in  bindings.   If  an  error  occurred while creating the binding (e.g.,
       eventString refers to a non-existent event), then 0 is returned and an  error  message  is
       left in interp->result.

       Tk_DeleteBinding removes from bindingTable the binding given by object and eventString, if
       such a binding exists.  Tk_DeleteBinding always returns TCL_OK.   In  some  cases  it  may
       reset interp->result to the default empty value.

       Tk_GetBinding  returns  a  pointer to the script associated with eventString and object in
       bindingTable.  If no such binding exists then NULL is returned and  an  error  message  is
       left in interp->result.

       Tk_GetAllBindings  returns  in  interp->result  a  list of all the event strings for which
       there are bindings in bindingTable associated with object.  If there are no  bindings  for
       object then an empty string is returned in interp->result.

       Tk_DeleteAllBindings  deletes all of the bindings in bindingTable that are associated with
       object.

       Tk_BindEvent is called to process an event.  It makes a copy of the event in  an  internal
       history list associated with the binding table, then it checks for bindings that match the
       event.  Tk_BindEvent processes each of the objects pointed to by objectPtr in  turn.   For
       each  object,  it finds all the bindings that match the current event history, selects the
       most specific binding using the priority mechanism  described  in  the  documentation  for
       bind,  and  invokes  the script for that binding.  If there are no matching bindings for a
       particular object, then the object is skipped.  Tk_BindEvent continues through all of  the
       objects,  handling  exceptions  such  as  errors,  break, and continue as described in the
       documentation for bind.

KEYWORDS

       binding, event, object, script