man/man3/RestrictEv.3 - toolchains/skids - Git at Google

 '\"
 '\" Copyright (c) 1990 The Regents of the University of California.
 '\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
 '\"
 '\" See the file "license.terms" for information on usage and redistribution
 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 '\"
 '\" RCS: @(#) $Id: RestrictEv.3,v 1.2 1998/09/14 18:22:53 stanton Exp $
 '\"
 '\" The definitions below are for supplemental macros used in Tcl/Tk
 '\" manual entries.
 '\"
 '\" .AP type name in/out ?indent?
 '\"	Start paragraph describing an argument to a library procedure.
 '\"	type is type of argument (int, etc.), in/out is either "in", "out",
 '\"	or "in/out" to describe whether procedure reads or modifies arg,
 '\"	and indent is equivalent to second arg of .IP (shouldn't ever be
 '\"	needed;  use .AS below instead)
 '\"
 '\" .AS ?type? ?name?
 '\"	Give maximum sizes of arguments for setting tab stops.  Type and
 '\"	name are examples of largest possible arguments that will be passed
 '\"	to .AP later.  If args are omitted, default tab stops are used.
 '\"
 '\" .BS
 '\"	Start box enclosure.  From here until next .BE, everything will be
 '\"	enclosed in one large box.
 '\"
 '\" .BE
 '\"	End of box enclosure.
 '\"
 '\" .CS
 '\"	Begin code excerpt.
 '\"
 '\" .CE
 '\"	End code excerpt.
 '\"
 '\" .VS ?version? ?br?
 '\"	Begin vertical sidebar, for use in marking newly-changed parts
 '\"	of man pages.  The first argument is ignored and used for recording
 '\"	the version when the .VS was added, so that the sidebars can be
 '\"	found and removed when they reach a certain age.  If another argument
 '\"	is present, then a line break is forced before starting the sidebar.
 '\"
 '\" .VE
 '\"	End of vertical sidebar.
 '\"
 '\" .DS
 '\"	Begin an indented unfilled display.
 '\"
 '\" .DE
 '\"	End of indented unfilled display.
 '\"
 '\" .SO
 '\"	Start of list of standard options for a Tk widget.  The
 '\"	options follow on successive lines, in four columns separated
 '\"	by tabs.
 '\"
 '\" .SE
 '\"	End of list of standard options for a Tk widget.
 '\"
 '\" .OP cmdName dbName dbClass
 '\"	Start of description of a specific option.  cmdName gives the
 '\"	option's name as specified in the class command, dbName gives
 '\"	the option's name in the option database, and dbClass gives
 '\"	the option's class in the option database.
 '\"
 '\" .UL arg1 arg2
 '\"	Print arg1 underlined, then print arg2 normally.
 '\"
 '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
 '\"
 '\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
 .if t .wh -1.3i ^B
 .nr ^l \n(.l
 .ad b
 '\"	# Start an argument description
 .de AP
 .ie !"\\$4"" .TP \\$4
 .el \{\
 .   ie !"\\$2"" .TP \\n()Cu
 .   el          .TP 15
 .\}
 .ta \\n()Au \\n()Bu
 .ie !"\\$3"" \{\
 \&\\$1	\\fI\\$2\\fP	(\\$3)
 .\".b
 .\}
 .el \{\
 .br
 .ie !"\\$2"" \{\
 \&\\$1	\\fI\\$2\\fP
 .\}
 .el \{\
 \&\\fI\\$1\\fP
 .\}
 .\}
 ..
 '\"	# define tabbing values for .AP
 .de AS
 .nr )A 10n
 .if !"\\$1"" .nr )A \\w'\\$1'u+3n
 .nr )B \\n()Au+15n
 .\"
 .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
 .nr )C \\n()Bu+\\w'(in/out)'u+2n
 ..
 .AS Tcl_Interp Tcl_CreateInterp in/out
 '\"	# BS - start boxed text
 '\"	# ^y = starting y location
 '\"	# ^b = 1
 .de BS
 .br
 .mk ^y
 .nr ^b 1u
 .if n .nf
 .if n .ti 0
 .if n \l'\\n(.lu\(ul'
 .if n .fi
 ..
 '\"	# BE - end boxed text (draw box now)
 .de BE
 .nf
 .ti 0
 .mk ^t
 .ie n \l'\\n(^lu\(ul'
 .el \{\
 .\"	Draw four-sided box normally, but don't draw top of
 .\"	box if the box started on an earlier page.
 .ie !\\n(^b-1 \{\
 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
 .\}
 .el \}\
 \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
 .\}
 .\}
 .fi
 .br
 .nr ^b 0
 ..
 '\"	# VS - start vertical sidebar
 '\"	# ^Y = starting y location
 '\"	# ^v = 1 (for troff;  for nroff this doesn't matter)
 .de VS
 .if !"\\$2"" .br
 .mk ^Y
 .ie n 'mc \s12\(br\s0
 .el .nr ^v 1u
 ..
 '\"	# VE - end of vertical sidebar
 .de VE
 .ie n 'mc
 .el \{\
 .ev 2
 .nf
 .ti 0
 .mk ^t
 \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
 .sp -1
 .fi
 .ev
 .\}
 .nr ^v 0
 ..
 '\"	# Special macro to handle page bottom:  finish off current
 '\"	# box/sidebar if in box/sidebar mode, then invoked standard
 '\"	# page bottom macro.
 .de ^B
 .ev 2
 'ti 0
 'nf
 .mk ^t
 .if \\n(^b \{\
 .\"	Draw three-sided box if this is the box's first page,
 .\"	draw two sides but no top otherwise.
 .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
 .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
 .\}
 .if \\n(^v \{\
 .nr ^x \\n(^tu+1v-\\n(^Yu
 \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
 .\}
 .bp
 'fi
 .ev
 .if \\n(^b \{\
 .mk ^y
 .nr ^b 2
 .\}
 .if \\n(^v \{\
 .mk ^Y
 .\}
 ..
 '\"	# DS - begin display
 .de DS
 .RS
 .nf
 .sp
 ..
 '\"	# DE - end display
 .de DE
 .fi
 .RE
 .sp
 ..
 '\"	# SO - start of list of standard options
 .de SO
 .SH "STANDARD OPTIONS"
 .LP
 .nf
 .ta 5.5c 11c
 .ft B
 ..
 '\"	# SE - end of list of standard options
 .de SE
 .fi
 .ft R
 .LP
 See the \\fBoptions\\fR manual entry for details on the standard options.
 ..
 '\"	# OP - start of full description for a single option
 .de OP
 .LP
 .nf
 .ta 4c
 Command-Line Name:	\\fB\\$1\\fR
 Database Name:	\\fB\\$2\\fR
 Database Class:	\\fB\\$3\\fR
 .fi
 .IP
 ..
 '\"	# CS - begin code excerpt
 .de CS
 .RS
 .nf
 .ta .25i .5i .75i 1i
 ..
 '\"	# CE - end code excerpt
 .de CE
 .fi
 .RE
 ..
 .de UL
 \\$1\l'|0\(ul'\\$2
 ..
 .TH Tk_RestrictEvents 3 "" Tk "Tk Library Procedures"
 .BS
 .SH NAME
 Tk_RestrictEvents \- filter and selectively delay X events
 .SH SYNOPSIS
 .nf
 \fB#include <tk.h>\fR
 .sp
 Tk_RestrictProc *
 \fBTk_RestrictEvents\fR(\fIproc, clientData, prevClientDataPtr\fR)
 .SH ARGUMENTS
 .AS Tk_RestrictProc **prevClientDataPtr
 .AP Tk_RestrictProc *proc in
 Predicate procedure to call to filter incoming X events.
 NULL means do not restrict events at all.
 .AP ClientData clientData in
 Arbitrary argument to pass to \fIproc\fR.
 .AP ClientData *prevClientDataPtr out
 Pointer to place to save argument to previous restrict procedure.
 .BE

 .SH DESCRIPTION
 .PP
 This procedure is useful in certain situations where applications
 are only prepared to receive certain X events.  After
 \fBTk_RestrictEvents\fR is called, \fBTk_DoOneEvent\fR (and
 hence \fBTk_MainLoop\fR) will filter X input events through
 \fIproc\fR.  \fIProc\fR indicates whether a
 given event is to be processed immediately, deferred until some
 later time (e.g. when the event restriction is lifted), or discarded.
 \fIProc\fR
 is a procedure with arguments and result that match
 the type \fBTk_RestrictProc\fR:
 .CS
 typedef Tk_RestrictAction Tk_RestrictProc(
 	ClientData \fIclientData\fR,
 	XEvent *\fIeventPtr\fR);
 .CE
 The \fIclientData\fR argument is a copy of the \fIclientData\fR passed
 to \fBTk_RestrictEvents\fR; it may be used to provide \fIproc\fR with
 information it needs to filter events.  The \fIeventPtr\fR points to
 an event under consideration.  \fIProc\fR returns a restrict action
 (enumerated type \fBTk_RestrictAction\fR) that indicates what
 \fBTk_DoOneEvent\fR should do with the event.  If the return value is
 \fBTK_PROCESS_EVENT\fR, then the event will be handled immediately.
 If the return value is \fBTK_DEFER_EVENT\fR, then the event will be
 left on the event queue for later processing.  If the return value is
 \fBTK_DISCARD_EVENT\fR, then the event will be removed from the event
 queue and discarded without being processed.
 .PP
 \fBTk_RestrictEvents\fR uses its return value and \fIprevClientDataPtr\fR
 to return information about the current event restriction procedure
 (a NULL return value means there are currently no restrictions).
 These values may be used to restore the previous restriction state
 when there is no longer any need for the current restriction.
 .PP
 There are very few places where \fBTk_RestrictEvents\fR is needed.
 In most cases, the best way to restrict events is by changing the
 bindings with the \fBbind\fR Tcl command or by calling
 \fBTk_CreateEventHandler\fR and \fBTk_DeleteEventHandler\fR from C.
 The main place where \fBTk_RestrictEvents\fR must be used is when
 performing synchronous actions (for example, if you need to wait
 for a particular event to occur on a particular window but you don't
 want to invoke any handlers for any other events).  The ``obvious''
 solution in these situations is to call \fBXNextEvent\fR or
 \fBXWindowEvent\fR, but these procedures cannot be used because
 Tk keeps its own event queue that is separate from the X event
 queue.  Instead, call \fBTk_RestrictEvents\fR to set up a filter,
 then call \fBTk_DoOneEvent\fR to retrieve the desired event(s).
 .SH KEYWORDS
 delay, event, filter, restriction
	'\"
	'\" Copyright (c) 1990 The Regents of the University of California.
	'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
	'\"
	'\" See the file "license.terms" for information on usage and redistribution
	'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
	'\"
	'\" RCS: @(#) $Id: RestrictEv.3,v 1.2 1998/09/14 18:22:53 stanton Exp $
	'\"
	'\" The definitions below are for supplemental macros used in Tcl/Tk
	'\" manual entries.
	'\"
	'\" .AP type name in/out ?indent?
	'\" Start paragraph describing an argument to a library procedure.
	'\" type is type of argument (int, etc.), in/out is either "in", "out",
	'\" or "in/out" to describe whether procedure reads or modifies arg,
	'\" and indent is equivalent to second arg of .IP (shouldn't ever be
	'\" needed; use .AS below instead)
	'\"
	'\" .AS ?type? ?name?
	'\" Give maximum sizes of arguments for setting tab stops. Type and
	'\" name are examples of largest possible arguments that will be passed
	'\" to .AP later. If args are omitted, default tab stops are used.
	'\"
	'\" .BS
	'\" Start box enclosure. From here until next .BE, everything will be
	'\" enclosed in one large box.
	'\"
	'\" .BE
	'\" End of box enclosure.
	'\"
	'\" .CS
	'\" Begin code excerpt.
	'\"
	'\" .CE
	'\" End code excerpt.
	'\"
	'\" .VS ?version? ?br?
	'\" Begin vertical sidebar, for use in marking newly-changed parts
	'\" of man pages. The first argument is ignored and used for recording
	'\" the version when the .VS was added, so that the sidebars can be
	'\" found and removed when they reach a certain age. If another argument
	'\" is present, then a line break is forced before starting the sidebar.
	'\"
	'\" .VE
	'\" End of vertical sidebar.
	'\"
	'\" .DS
	'\" Begin an indented unfilled display.
	'\"
	'\" .DE
	'\" End of indented unfilled display.
	'\"
	'\" .SO
	'\" Start of list of standard options for a Tk widget. The
	'\" options follow on successive lines, in four columns separated
	'\" by tabs.
	'\"
	'\" .SE
	'\" End of list of standard options for a Tk widget.
	'\"
	'\" .OP cmdName dbName dbClass
	'\" Start of description of a specific option. cmdName gives the
	'\" option's name as specified in the class command, dbName gives
	'\" the option's name in the option database, and dbClass gives
	'\" the option's class in the option database.
	'\"
	'\" .UL arg1 arg2
	'\" Print arg1 underlined, then print arg2 normally.
	'\"
	'\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
	'\"
	'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
	.if t .wh -1.3i ^B
	.nr ^l \n(.l
	.ad b
	'\" # Start an argument description
	.de AP
	.ie !"\\$4"" .TP \\$4
	.el \{\
	. ie !"\\$2"" .TP \\n()Cu
	. el .TP 15
	.\}
	.ta \\n()Au \\n()Bu
	.ie !"\\$3"" \{\
	\&\\$1 \\fI\\$2\\fP (\\$3)
	.\".b
	.\}
	.el \{\
	.br
	.ie !"\\$2"" \{\
	\&\\$1 \\fI\\$2\\fP
	.\}
	.el \{\
	\&\\fI\\$1\\fP
	.\}
	.\}
	..
	'\" # define tabbing values for .AP
	.de AS
	.nr )A 10n
	.if !"\\$1"" .nr )A \\w'\\$1'u+3n
	.nr )B \\n()Au+15n
	.\"
	.if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
	.nr )C \\n()Bu+\\w'(in/out)'u+2n
	..
	.AS Tcl_Interp Tcl_CreateInterp in/out
	'\" # BS - start boxed text
	'\" # ^y = starting y location
	'\" # ^b = 1
	.de BS
	.br
	.mk ^y
	.nr ^b 1u
	.if n .nf
	.if n .ti 0
	.if n \l'\\n(.lu\(ul'
	.if n .fi
	..
	'\" # BE - end boxed text (draw box now)
	.de BE
	.nf
	.ti 0
	.mk ^t
	.ie n \l'\\n(^lu\(ul'
	.el \{\
	.\" Draw four-sided box normally, but don't draw top of
	.\" box if the box started on an earlier page.
	.ie !\\n(^b-1 \{\
	\h'-1.5n'\L'\|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'\|0u-1.5n\(ul'
	.\}
	.el \}\
	\h'-1.5n'\L'\|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'\|0u-1.5n\(ul'
	.\}
	.\}
	.fi
	.br
	.nr ^b 0
	..
	'\" # VS - start vertical sidebar
	'\" # ^Y = starting y location
	'\" # ^v = 1 (for troff; for nroff this doesn't matter)
	.de VS
	.if !"\\$2"" .br
	.mk ^Y
	.ie n 'mc \s12\(br\s0
	.el .nr ^v 1u
	..
	'\" # VE - end of vertical sidebar
	.de VE
	.ie n 'mc
	.el \{\
	.ev 2
	.nf
	.ti 0
	.mk ^t
	\h'\|\\n(^lu+3n'\L'\|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-\|\\n(^lu+3n'
	.sp -1
	.fi
	.ev
	.\}
	.nr ^v 0
	..
	'\" # Special macro to handle page bottom: finish off current
	'\" # box/sidebar if in box/sidebar mode, then invoked standard
	'\" # page bottom macro.
	.de ^B
	.ev 2
	'ti 0
	'nf
	.mk ^t
	.if \\n(^b \{\
	.\" Draw three-sided box if this is the box's first page,
	.\" draw two sides but no top otherwise.
	.ie !\\n(^b-1 \h'-1.5n'\L'\|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'\|0u'\c
	.el \h'-1.5n'\L'\|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'\|0u'\c
	.\}
	.if \\n(^v \{\
	.nr ^x \\n(^tu+1v-\\n(^Yu
	\kx\h'-\\nxu'\h'\|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'\|0u'\c
	.\}
	.bp
	'fi
	.ev
	.if \\n(^b \{\
	.mk ^y
	.nr ^b 2
	.\}
	.if \\n(^v \{\
	.mk ^Y
	.\}
	..
	'\" # DS - begin display
	.de DS
	.RS
	.nf
	.sp
	..
	'\" # DE - end display
	.de DE
	.fi
	.RE
	.sp
	..
	'\" # SO - start of list of standard options
	.de SO
	.SH "STANDARD OPTIONS"
	.LP
	.nf
	.ta 5.5c 11c
	.ft B
	..
	'\" # SE - end of list of standard options
	.de SE
	.fi
	.ft R
	.LP
	See the \\fBoptions\\fR manual entry for details on the standard options.
	..
	'\" # OP - start of full description for a single option
	.de OP
	.LP
	.nf
	.ta 4c
	Command-Line Name: \\fB\\$1\\fR
	Database Name: \\fB\\$2\\fR
	Database Class: \\fB\\$3\\fR
	.fi
	.IP
	..
	'\" # CS - begin code excerpt
	.de CS
	.RS
	.nf
	.ta .25i .5i .75i 1i
	..
	'\" # CE - end code excerpt
	.de CE
	.fi
	.RE
	..
	.de UL
	\\$1\l'\|0\(ul'\\$2
	..
	.TH Tk_RestrictEvents 3 "" Tk "Tk Library Procedures"
	.BS
	.SH NAME
	Tk_RestrictEvents \- filter and selectively delay X events
	.SH SYNOPSIS
	.nf
	\fB#include <tk.h>\fR
	.sp
	Tk_RestrictProc *
	\fBTk_RestrictEvents\fR(\fIproc, clientData, prevClientDataPtr\fR)
	.SH ARGUMENTS
	.AS Tk_RestrictProc **prevClientDataPtr
	.AP Tk_RestrictProc *proc in
	Predicate procedure to call to filter incoming X events.
	NULL means do not restrict events at all.
	.AP ClientData clientData in
	Arbitrary argument to pass to \fIproc\fR.
	.AP ClientData *prevClientDataPtr out
	Pointer to place to save argument to previous restrict procedure.
	.BE

	.SH DESCRIPTION
	.PP
	This procedure is useful in certain situations where applications
	are only prepared to receive certain X events. After
	\fBTk_RestrictEvents\fR is called, \fBTk_DoOneEvent\fR (and
	hence \fBTk_MainLoop\fR) will filter X input events through
	\fIproc\fR. \fIProc\fR indicates whether a
	given event is to be processed immediately, deferred until some
	later time (e.g. when the event restriction is lifted), or discarded.
	\fIProc\fR
	is a procedure with arguments and result that match
	the type \fBTk_RestrictProc\fR:
	.CS
	typedef Tk_RestrictAction Tk_RestrictProc(
	ClientData \fIclientData\fR,
	XEvent *\fIeventPtr\fR);
	.CE
	The \fIclientData\fR argument is a copy of the \fIclientData\fR passed
	to \fBTk_RestrictEvents\fR; it may be used to provide \fIproc\fR with
	information it needs to filter events. The \fIeventPtr\fR points to
	an event under consideration. \fIProc\fR returns a restrict action
	(enumerated type \fBTk_RestrictAction\fR) that indicates what
	\fBTk_DoOneEvent\fR should do with the event. If the return value is
	\fBTK_PROCESS_EVENT\fR, then the event will be handled immediately.
	If the return value is \fBTK_DEFER_EVENT\fR, then the event will be
	left on the event queue for later processing. If the return value is
	\fBTK_DISCARD_EVENT\fR, then the event will be removed from the event
	queue and discarded without being processed.
	.PP
	\fBTk_RestrictEvents\fR uses its return value and \fIprevClientDataPtr\fR
	to return information about the current event restriction procedure
	(a NULL return value means there are currently no restrictions).
	These values may be used to restore the previous restriction state
	when there is no longer any need for the current restriction.
	.PP
	There are very few places where \fBTk_RestrictEvents\fR is needed.
	In most cases, the best way to restrict events is by changing the
	bindings with the \fBbind\fR Tcl command or by calling
	\fBTk_CreateEventHandler\fR and \fBTk_DeleteEventHandler\fR from C.
	The main place where \fBTk_RestrictEvents\fR must be used is when
	performing synchronous actions (for example, if you need to wait
	for a particular event to occur on a particular window but you don't
	want to invoke any handlers for any other events). The ``obvious''
	solution in these situations is to call \fBXNextEvent\fR or
	\fBXWindowEvent\fR, but these procedures cannot be used because
	Tk keeps its own event queue that is separate from the X event
	queue. Instead, call \fBTk_RestrictEvents\fR to set up a filter,
	then call \fBTk_DoOneEvent\fR to retrieve the desired event(s).
	.SH KEYWORDS
	delay, event, filter, restriction