Tk_CreateBindingTable, Tk_DeleteBindingTable, Tk_Create
Binding, Tk_DeleteBinding, Tk_GetBinding, Tk_GetAllBind
ings, Tk_DeleteAllBindings, Tk_BindEvent - invoke scripts
in response to X events
Tk_CreateBinding(interp, bindingTable, object, eventString, script, append)
Tk_DeleteBinding(interp, bindingTable, object, eventString)
Tk_GetBinding(interp, bindingTable, object, eventString)
Tk_GetAllBindings(interp, bindingTable, object)
Tk_BindEvent(bindingTable, eventPtr, tkwin, numObjects, objectPtr)
Tcl_Interp *interp (in) Interpreter to
use when invok
ing bindings in
Also used for
Tk_BindingTable bindingTable (in) Token for bind
must have been
call to Tk_Cre
ClientData object (in) Identifies
char *eventString (in) String describ
char *script (in) Tcl script to
int append (in) Non-zero means
any; zero means
ing script with
XEvent *eventPtr (in) X event to
Tk_Window tkwin (in) Identifier for
any window on
where the event
to find dis
such as key
int numObjects (in) Number of
ClientData *objectPtr (in) Points to an
array of object
for each of
in order from
first to last.
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 bind
ing tags such as all. Tk also keeps a separate binding
table for each canvas widget, which manages bindings cre
ated 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 documenta
tion 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 bind
ings. 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
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.
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 bind
ingTable associated with object. If there are no bindings
for object then an empty string is returned in
Tk_DeleteAllBindings deletes all of the bindings in bind
ingTable 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 pri
ority 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.
binding, event, object, script