Tk Library Procedures Tk_CreateBindingTable(3TK)
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NAME
Tk_CreateBindingTable, Tk_DeleteBindingTable,
Tk_CreateBinding, Tk_DeleteBinding, Tk_GetBinding,
Tk_GetAllBindings, Tk_DeleteAllBindings, Tk_BindEvent -
invoke scripts in response to X eventsSYNOPSIS
#include
Tk_BindingTable
Tk_CreateBindingTable(interp)
Tk_DeleteBindingTable(bindingTable)
unsigned longTk_CreateBinding(interp, bindingTable, object, eventString, script, append)
intTk_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)
ARGUMENTSTcl_Interp *interp (in) Interpreter to
use when invokingbindings in bind-
ing table. Alsoused for return-
ing results anderrors from bind-
ing procedures.Tk_BindingTable bindingTable (in) Token for binding
table; must have been returned by some previous call toTk_CreateBindingTable.
ClientData object (in) Identifies objectwith which bind-
ing is associ-
ated. Tk Last change: 4.0 1Tk Library Procedures Tk_CreateBindingTable(3TK)
CONST char *eventString (in) String describing event sequence. char *script (in) Tcl script toinvoke when bind-
ing 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 finddisplay-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 interms of binding tables. A binding table consists of a col-
lection of bindings plus a history of recent events. Within a binding table, bindings are associated with objects. The Tk Last change: 4.0 2Tk Library Procedures Tk_CreateBindingTable(3TK)
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 pointerto 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 asTk_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 thebinding is to be associated, and it may be any one-word
value. Typically it is a pointer to a string or data struc-
ture. 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 isnon-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 use-
ful 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., eventStringrefers 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 isleft in interp->result.
Tk Last change: 4.0 3Tk Library Procedures Tk_CreateBindingTable(3TK)
Tk_GetAllBindings returns in interp->result a list of all
the event strings for which there are bindings in bindingT-
able associated with object. If there are no bindings forobject then an empty string is returned in interp->result.
Tk_DeleteAllBindings deletes all of the bindings in bin-
dingTable 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 theevent. 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 forthat binding. If there are no matching bindings for a par-
ticular 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, scriptATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:_______________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE|
|____________________|__________________|_
| Availability | runtime/tk-8 |
|____________________|__________________|_
| Interface Stability| Uncommitted ||____________________|_________________|
NOTES Source for Tk is available on http://opensolaris.org. Tk Last change: 4.0 4