1Tk_Grab(3) Tk Library Procedures Tk_Grab(3)
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6
8 Tk_Grab, Tk_Ungrab - manipulate grab state in an application
9
11 #include <tk.h>
12 int
14 Tk_Grab(interp, tkwin, grabGlobal)
15 void
17 Tk_Ungrab(tkwin)
18
20 Tcl_Interp *interp (in) Interpreter to use for error
21 reporting
22 Tk_Window tkwin (in) Window on whose behalf the
24 pointer is to be grabbed or
25 released
26 int grabGlobal (in) Boolean indicating whether
28 the grab is global or appli‐
29 cation local
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31
33 These functions are used to set or release a global or application
34 local grab. When a grab is set on a particular window in a Tk applica‐
35 tion, mouse and keyboard events can only be received by that window and
36 its descendants. Mouse and keyboard events for windows outside the
37 tree rooted at tkwin will be redirected to tkwin. If the grab is
38 global, then all mouse and keyboard events for windows outside the tree
39 rooted at tkwin (even those intended for windows in other applications)
40 will be redirected to tkwin. If the grab is application local, only
41 mouse and keyboard events intended for a windows within the same appli‐
42 cation (but outside the tree rooted at tkwin) will be redirected.
43 Tk_Grab sets a grab on a particular window. Tkwin specifies the window
45 on whose behalf the pointer is to be grabbed. GrabGlobal indicates
46 whether the grab should be global or application local; if it is non-
47 zero, it means the grab should be global. Normally, Tk_Grab returns
48 TCL_OK; if an error occurs and the grab cannot be set, TCL_ERROR is
49 returned and an error message is left if interp's result. Once this
50 call completes successfully, no window outside the tree rooted at tkwin
51 will receive pointer- or keyboard-related events until the next call to
52 Tk_Ungrab. If a previous grab was in effect within the application,
53 then it is replaced with a new one.
54 Tk_Ungrab releases a grab on the mouse pointer and keyboard, if there
56 is one set on the window given by tkwin. Once a grab is released,
57 pointer and keyboard events will start being delivered to other windows
58 again.
59
61 grab, window
62Tk Tk_Grab(3)