1Tk_CreateBindingTable(3) Tk Library Procedures Tk_CreateBindingTable(3)
2______________________________________________________________________________
6
8 Tk_CreateBindingTable, Tk_DeleteBindingTable, Tk_CreateBinding,
9 Tk_DeleteBinding, Tk_GetBinding, Tk_GetAllBindings, Tk_DeleteAllBind‐
10 ings, Tk_BindEvent - invoke scripts in response to X events
11
13 #include <tk.h>
14 Tk_BindingTable
16 Tk_CreateBindingTable(interp)
17 Tk_DeleteBindingTable(bindingTable)
19 unsigned long
21 Tk_CreateBinding(interp, bindingTable, object, eventString, script, append)
22 int
24 Tk_DeleteBinding(interp, bindingTable, object, eventString)
25 const char *
27 Tk_GetBinding(interp, bindingTable, object, eventString)
28 Tk_GetAllBindings(interp, bindingTable, object)
30 Tk_DeleteAllBindings(bindingTable, object)
32 Tk_BindEvent(bindingTable, eventPtr, tkwin, numObjects, objectPtr)
34
36 Tcl_Interp *interp (in) Interpreter to use when in‐
37 voking bindings in binding
38 table. Also used for re‐
39 turning results and errors
40 from binding procedures.
41 Tk_BindingTable bindingTable (in) Token for binding table;
43 must have been returned by
44 some previous call to
45 Tk_CreateBindingTable.
46 ClientData object (in) Identifies object with which
48 binding is associated.
49 const char *eventString (in) String describing event se‐
51 quence.
52 const char *script (in) Tcl script to invoke when
54 binding triggers.
55 int append (in) Non-zero means append script
57 to existing script for bind‐
58 ing, if any; zero means re‐
59 place existing script with
60 new one.
61 XEvent *eventPtr (in) X event to match against
63 bindings in bindingTable.
64 Tk_Window tkwin (in) Identifier for any window on
66 the display where the event
67 occurred. Used to find dis‐
68 play-related information
69 such as key maps.
70 int numObjects (in) Number of object identifiers
72 pointed to by objectPtr.
73 ClientData *objectPtr (in) Points to an array of object
75 identifiers: bindings will
76 be considered for each of
77 these objects in order from
78 first to last.
79______________________________________________________________________________
80
82 These procedures provide a general-purpose mechanism for creating and
83 invoking bindings. Bindings are organized in terms of binding tables.
84 A binding table consists of a collection of bindings plus a history of
85 recent events. Within a binding table, bindings are associated with
86 objects. The meaning of an object is defined by clients of the binding
87 package. For example, Tk keeps uses one binding table to hold all of
88 the bindings created by the bind command. For this table, objects are
89 pointers to strings such as window names, class names, or other binding
90 tags such as all. Tk also keeps a separate binding table for each can‐
91 vas widget, which manages bindings created by the canvas's bind widget
92 command; within this table, an object is either a pointer to the in‐
93 ternal structure for a canvas item or a Tk_Uid identifying a tag.
94 The procedure Tk_CreateBindingTable creates a new binding table and as‐
96 sociates interp with it (when bindings in the table are invoked, the
97 scripts will be evaluated in interp). Tk_CreateBindingTable returns a
98 token for the table, which must be used in calls to other procedures
99 such as Tk_CreateBinding or Tk_BindEvent.
100 Tk_DeleteBindingTable frees all of the state associated with a binding
102 table. Once it returns the caller should not use the bindingTable to‐
103 ken again.
104 Tk_CreateBinding adds a new binding to an existing table. The object
106 argument identifies the object with which the binding is to be associ‐
107 ated, and it may be any one-word value. Typically it is a pointer to a
108 string or data structure. The eventString argument identifies the
109 event or sequence of events for the binding; see the documentation for
110 the bind command for a description of its format. script is the Tcl
111 script to be evaluated when the binding triggers. append indicates
112 what to do if there already exists a binding for object and
113 eventString: if append is zero then script replaces the old script;
114 if append is non-zero then the new script is appended to the old one.
115 Tk_CreateBinding returns an X event mask for all the events associated
116 with the bindings. This information may be useful to invoke XSelectIn‐
117 put to select relevant events, or to disallow the use of certain events
118 in bindings. If an error occurred while creating the binding (e.g.,
119 eventString refers to a non-existent event), then 0 is returned and an
120 error message is left as the result of interpreter interp.
121 Tk_DeleteBinding removes from bindingTable the binding given by object
123 and eventString, if such a binding exists. Tk_DeleteBinding always re‐
124 turns TCL_OK. In some cases it may reset the interpreter result to the
125 default empty value.
126 Tk_GetBinding returns a pointer to the script associated with
128 eventString and object in bindingTable. If no such binding exists then
129 NULL is returned and an error message is left as the result of inter‐
130 preter interp.
131 Tk_GetAllBindings returns in interp's result a list of all the event
133 strings for which there are bindings in bindingTable associated with
134 object. If there are no bindings for object, the result will be an
135 empty string.
136 Tk_DeleteAllBindings deletes all of the bindings in bindingTable that
138 are associated with object.
139 Tk_BindEvent is called to process an event. It makes a copy of the
141 event in an internal history list associated with the binding table,
142 then it checks for bindings that match the event. Tk_BindEvent pro‐
143 cesses each of the objects pointed to by objectPtr in turn. For each
144 object, it finds all the bindings that match the current event history,
145 selects the most specific binding using the priority mechanism de‐
146 scribed in the documentation for bind, and invokes the script for that
147 binding. If there are no matching bindings for a particular object,
148 then the object is skipped. Tk_BindEvent continues through all of the
149 objects, handling exceptions such as errors, break, and continue as de‐
150 scribed in the documentation for bind.
151
153 binding, event, object, script
154Tk 4.0 Tk_CreateBindingTable(3)