Provided by: tk9.0-doc_9.0.1-1_all 
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.
void * object (in) Identifies object with which binding is associated.
const char *eventString (in) String describing event sequence.
const 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.
Tcl_Size numObjects (in) Number of object identifiers pointed to by objectPtr.
void ** 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 as the result of interpreter interp.
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 the interpreter 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 as the result of interpreter
interp.
Tk_GetAllBindings returns in interp's 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, the result will be an empty
string.
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
Tk 4.0 Tk_CreateBindingTable(3tk)