1Tk_SetClassProcs(3) Tk Library Procedures Tk_SetClassProcs(3)
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8 Tk_SetClassProcs - register widget specific procedures
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11 #include <tk.h>
12 Tk_SetClassProcs(tkwin, procs, instanceData)
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16 Tk_Window tkwin (in) Token for window to modify.
17 Tk_ClassProcs *procs (in) Pointer to data structure con‐
19 taining widget specific proce‐
20 dures. The data structure
21 pointed to by procs must be
22 static: Tk keeps a reference to
23 it as long as the window
24 exists.
25 ClientData instanceData (in) Arbitrary one-word value to
27 pass to widget callbacks.
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32 Tk_SetClassProcs is called to register a set of procedures that are
33 used as callbacks in different places.
34 The structure pointed to by procs contains the following:
36 typedef struct Tk_ClassProcs {
37 unsigned int size;
38 Tk_ClassWorldChangedProc *worldChangedProc;
39 Tk_ClassCreateProc *createProc;
40 Tk_ClassModalProc *modalProc;
41 } Tk_ClassProcs;
42 The size field is used to simplify future expansion of the structure.
43 It should always be set to (literally) sizeof(Tk_ClassProcs).
44 worldChangedProc is invoked when the system has altered in some way
46 that requires some reaction from the widget. For example, when a font
47 alias (see the font manual entry) is reconfigured, widgets configured
48 to use that font alias must update their display accordingly. world‐
49 ChangedProc should have arguments and results that match the type
50 Tk_ClassWorldChangedProc:
51 typedef void Tk_ClassWorldChangedProc(
52 ClientData instanceData);
53 The instanceData parameter passed to the worldChangedProc will be iden‐
54 tical to the instanceData parameter passed to Tk_SetClassProcs.
55 createProc is used to create platform-dependant windows. It is invoked
57 by Tk_MakeWindowExist. createProc should have arguments and results
58 that match the type Tk_ClassCreateProc:
59 typedef Window Tk_ClassCreateProc(
60 Tk_Window tkwin,
61 Window parent,
62 ClientData instanceData);
63 The tkwin and instanceData parameters will be identical to the tkwin
64 and instanceData parameters passed to Tk_SetClassProcs. The parent
65 parameter will be the parent of the window to be created. The cre‐
66 ateProc should return the created window.
67 modalProc is invoked after all bindings on a widget have been triggered
69 in order to handle a modal loop. modalProc should have arguments and
70 results that match the type Tk_ClassModalProc:
71 typedef void Tk_ClassModalProc(
72 Tk_Window tkwin,
73 XEvent *eventPtr);
74 The tkwin parameter to modalProc will be identical to the tkwin parame‐
75 ter passed to Tk_SetClassProcs. The eventPtr parameter will be a
76 pointer to an XEvent structure describing the event being processed.
77
80 callback, class
81Tk 8.4 Tk_SetClassProcs(3)