Tk_CreateBindingTable,     Tk_DeleteBindingTable,     Tk_CreateBinding,
       Tk_DeleteBinding, Tk_GetBinding,  Tk_GetAllBindings,  Tk_DeleteAllBind-
       ings, 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 bind-
                                                  ing,   if  any;  zero  means
                                                  replace existing script with

       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 can-
       vas 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 as-
       sociates  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 associ-
       ated, 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 XSelectIn-
       put 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
       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  pro-
       cesses  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



Tk                                    4.0             Tk_CreateBindingTable(3)