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diff --git a/doc/event.n b/doc/event.n new file mode 100644 index 0000000..a7d12b5 --- /dev/null +++ b/doc/event.n @@ -0,0 +1,338 @@ +'\" +'\" Copyright (c) 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. +'\" +'\" SCCS: @(#) event.n 1.6 97/10/31 12:58:54 +'\" +.so man.macros +.TH event n 4.4 Tk "Tk Built-In Commands" +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +event \- Miscellaneous event facilities: define virtual events and generate events +.SH SYNOPSIS +\fBevent\fI option \fR?\fIarg arg ...\fR? +.BE + +.SH DESCRIPTION +.PP +The \fBevent\fR command provides several facilities for dealing with +window system events, such as defining virtual events and synthesizing +events. The command has several different forms, determined by the +first argument. The following forms are currently supported: +.TP +\fBevent add <<\fIvirtual\fB>>\fI sequence \fR?\fIsequence ...\fR? +Associates the virtual event \fIvirtual\fR with the physical +event sequence(s) given by the \fIsequence\fR arguments, so that +the virtual event will trigger whenever any one of the \fIsequence\fRs +occurs. +\fIVirtual\fR may be any string value and \fIsequence\fR may have +any of the values allowed for the \fIsequence\fR argument to the +\fBbind\fR command. +If \fIvirtual\fR is already defined, the new physical event sequences +add to the existing sequences for the event. +.TP +\fBevent delete <<\fIvirtual\fB>> \fR?\fIsequence\fR \fIsequence ...\fR? +Deletes each of the \fIsequence\fRs from those associated with +the virtual event given by \fIvirtual\fR. +\fIVirtual\fR may be any string value and \fIsequence\fR may have +any of the values allowed for the \fIsequence\fR argument to the +\fBbind\fR command. +Any \fIsequence\fRs not currently associated with \fIvirtual\fR +are ignored. +If no \fIsequence\fR argument is provided, all physical event sequences +are removed for \fIvirtual\fR, so that the virtual event will not +trigger anymore. +.TP +\fBevent generate \fIwindow event \fR?\fIoption value option value ...\fR? +Generates a window event and arranges for it to be processed just as if +it had come from the window system. +\fIWindow\fR gives the path name of the window for which the event +.VS +will be generated; it may also be an identifier (such as returned by +\fBwinfo id\fR) as long as it is for a window in the current application. +.VE +\fIEvent\fR provides a basic description of +the event, such as \fB<Shift-Button-2>\fR or \fB<<Paste>>\fR. +\fIEvent\fR may have any of the forms allowed for the \fIsequence\fR +argument of the \fBbind\fR command except that it must consist +of a single event pattern, not a sequence. +\fIOption-value\fR pairs may be used to specify additional +attributes of the event, such as the x and y mouse position; see +EVENT FIELDS below. If the \fB\-when\fR option is not specified, the +event is processed immediately: all of the handlers for the event +will complete before the \fBevent generate\fR command returns. +If the \fB\-when\fR option is specified then it determines when the +event is processed. +.TP +\fBevent info \fR?<<\fIvirtual\fB>>\fR? +Returns information about virtual events. +If the \fB<<\fIvirtual\fB>>\fR argument is omitted, the return value +is a list of all the virtual events that are currently defined. +If \fB<<\fIvirtual\fB>>\fR is specified then the return value is +a list whose elements are the physical event sequences currently +defined for the given virtual event; if the virtual event is +not defined then an empty string is returned. + +.SH "EVENT FIELDS" +.PP +The following options are supported for the \fBevent generate\fR +command. These correspond to the ``%'' expansions +allowed in binding scripts for the \fBbind\fR command. +.TP +\fB\-above\fI window\fR +\fIWindow\fR specifies the \fIabove\fR field for the event, +either as a window path name or as an integer window id. +Valid for \fBConfigure\fR events. +Corresponds to the \fB%a\fR substitution for binding scripts. +.TP +\fB\-borderwidth\fI size\fR +\fISize\fR must be a screen distance; it specifies the +\fIborder_width\fR field for the event. +Valid for \fBConfigure\fR events. +Corresponds to the \fB%B\fR substitution for binding scripts. +.TP +\fB\-button\fI number\fR +\fINumber\fR must be an integer; it specifies the \fIdetail\fR field +for a \fBButtonPress\fR or \fBButtonRelease\fR event, overriding +any button number provided in the base \fIevent\fR argument. +Corresponds to the \fB%b\fR substitution for binding scripts. +.TP +\fB\-count\fI number\fR +\fINumber\fR must be an integer; it specifies the \fIcount\fR field +for the event. Valid for \fBExpose\fR events. +Corresponds to the \fB%c\fR substitution for binding scripts. +.TP +\fB\-detail\fI detail\fR +\fIDetail\fR specifies the \fIdetail\fR field for the event +and must be one of the following: +.RS +.DS +.ta 6c +\fBNotifyAncestor NotifyNonlinearVirtual +NotifyDetailNone NotifyPointer +NotifyInferior NotifyPointerRoot +NotifyNonlinear NotifyVirtual\fR +.DE +Valid for \fBEnter\fR, \fBLeave\fR, \fBFocusIn\fR and +\fBFocusOut\fR events. +Corresponds to the \fB%d\fR substitution for binding scripts. +.RE +.TP +\fB\-focus\fI boolean\fR +\fIBoolean\fR must be a boolean value; it specifies the \fIfocus\fR +field for the event. +Valid for \fBEnter\fR and \fBLeave\fR events. +Corresponds to the \fB%f\fR substitution for binding scripts. +.TP +\fB\-height\fI size\fR +\fISize\fR must be a screen distance; it specifies the \fIheight\fR +field for the event. Valid for \fBConfigure\fR events. +Corresponds to the \fB%h\fR substitution for binding scripts. +.TP +\fB\-keycode\fI number\fR +\fINumber\fR must be an integer; it specifies the \fIkeycode\fR +field for the event. +Valid for \fBKeyPress\fR and \fBKeyRelease\fR events. +Corresponds to the \fB%k\fR substitution for binding scripts. +.TP +\fB\-keysym\fI name\fR +\fIName\fR must be the name of a valid keysym, such as \fBg\fR, +\fBspace\fR, or \fBReturn\fR; its corresponding +keycode value is used as the \fIkeycode\fR field for event, overriding +any detail specified in the base \fIevent\fR argument. +Valid for \fBKeyPress\fR and \fBKeyRelease\fR events. +Corresponds to the \fB%K\fR substitution for binding scripts. +.TP +\fB\-mode\fI notify\fR +\fINotify\fR specifies the \fImode\fR field for the event and must be +one of \fBNotifyNormal\fR, \fBNotifyGrab\fR, \fBNotifyUngrab\fR, or +\fBNotifyWhileGrabbed\fR. +Valid for \fBEnter\fR, \fBLeave\fR, \fBFocusIn\fR, and +\fBFocusOut\fR events. +Corresponds to the \fB%m\fR substitution for binding scripts. +.TP +\fB\-override\fI boolean\fR +\fIBoolean\fR must be a boolean value; it specifies the +\fIoverride_redirect\fR field for the event. +Valid for \fBMap\fR, \fBReparent\fR, and \fBConfigure\fR events. +Corresponds to the \fB%o\fR substitution for binding scripts. +.TP +\fB\-place\fI where\fR +\fIWhere\fR specifies the \fIplace\fR field for the event; it must be +either \fBPlaceOnTop\fR or \fBPlaceOnBottom\fR. +Valid for \fBCirculate\fR events. +Corresponds to the \fB%p\fR substitution for binding scripts. +.TP +\fB\-root\fI window\fR +\fIWindow\fR must be either a window path name or an integer window +identifier; it specifies the \fIroot\fR field for the event. +Valid for \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBEnter\fR, \fBLeave\fR, and \fBMotion\fR +events. +Corresponds to the \fB%R\fR substitution for binding scripts. +.TP +\fB\-rootx\fI coord\fR +\fICoord\fR must be a screen distance; it specifies the \fIx_root\fR +field for the event. +Valid for \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBEnter\fR, \fBLeave\fR, and \fBMotion\fR +events. Corresponds to the \fB%X\fR substitution for binding scripts. +.TP +\fB\-rooty\fI coord\fR +\fICoord\fR must be a screen distance; it specifies th \fIy_root\fR +field for the event. +Valid for \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBEnter\fR, \fBLeave\fR, and \fBMotion\fR +events. +Corresponds to the \fB%Y\fR substitution for binding scripts. +.TP +\fB\-sendevent\fI boolean\fR +\fBBoolean\fR must be a boolean value; it specifies the \fIsend_event\fR +field for the event. Valid for all events. Corresponds to the +\fB%E\fR substitution for binding scripts. +.TP +\fB\-serial\fI number\fR +\fINumber\fR must be an integer; it specifies the \fIserial\fR field +for the event. Valid for all events. +Corresponds to the \fB%#\fR substitution for binding scripts. +.TP +\fB\-state\fI state\fR +\fIState\fR specifies the \fIstate\fR field for the event. +For \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBEnter\fR, \fBLeave\fR, and \fBMotion\fR events +it must be an integer value. +For \fBVisibility\fR events it must be one of \fBVisibilityUnobscured\fR, +\fBVisibilityPartiallyObscured\fR, or \fBVisibilityFullyObscured\fR. +This option overrides any modifiers such as \fBMeta\fR or \fBControl\fR +specified in the base \fIevent\fR. +Corresponds to the \fB%s\fR substitution for binding scripts. +.TP +\fB\-subwindow\fI window\fR +\fIWindow\fR specifies the \fIsubwindow\fR field for the event, either +as a path name for a Tk widget or as an integer window identifier. +Valid for \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBEnter\fR, \fBLeave\fR, and \fBMotion\fR events. +Similar to \fB%S\fR substitution for binding scripts. +.TP +\fB\-time\fI integer\fR +\fIInteger\fR must be an integer value; it specifies the \fItime\fR field +for the event. +Valid for \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBEnter\fR, \fBLeave\fR, \fBMotion\fR, +and \fBProperty\fR events. +Corresponds to the \fB%t\fR substitution for binding scripts. +.TP +\fB\-width\fI size\fR +\fISize\fR must be a screen distance; it specifies the \fIwidth\fR field +for the event. +Valid for \fBConfigure\fR events. +Corresponds to the \fB%w\fR substitution for binding scripts. +.TP +\fB\-when\fI when\fR +\fIWhen\fR determines when the event will be processed; it must have one +of the following values: +.RS +.IP \fBnow\fR 10 +Process the event immediately, before the command returns. +This also happens if the \fB\-when\fR option is omitted. +.IP \fBtail\fR 10 +Place the event on Tcl's event queue behind any events already +queued for this application. +.IP \fBhead\fR 10 +Place the event at the front of Tcl's event queue, so that it +will be handled before any other events already queued. +.IP \fBmark\fR 10 +Place the event at the front of Tcl's event queue but behind any +other events already queued with \fB\-when mark\fR. +This option is useful when generating a series of events that should +be processed in order but at the front of the queue. +.RE +.TP +\fB\-x\fI coord\fR +\fICoord\fR must be a screen distance; it specifies the \fIx\fR field +for the event. +Valid for \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBMotion\fR, \fBEnter\fR, \fBLeave\fR, +\fBExpose\fR, \fBConfigure\fR, \fBGravity\fR, and \fBReparent\fR +events. +Corresponds to the the \fB%x\fR substitution for binding scripts. +.TP +\fB\-y\fI coord\fR +\fICoord\fR must be a screen distance; it specifies the \fIy\fR +field for the event. +Valid for \fBKeyPress\fR, \fBKeyRelease\fR, \fBButtonPress\fR, +\fBButtonRelease\fR, \fBMotion\fR, \fBEnter\fR, \fBLeave\fR, +\fBExpose\fR, \fBConfigure\fR, \fBGravity\fR, and \fBReparent\fR +events. +Corresponds to the the \fB%y\fR substitution for binding scripts. +.PP +Any options that are not specified when generating an event are filled +with the value 0, except for \fIserial\fR, which is filled with the +next X event serial number. + +.SH "VIRTUAL EVENT EXAMPLES" +.PP +In order for a virtual event binding to trigger, two things must +happen. First, the virtual event must be defined with the +\fBevent add\fR command. Second, a binding must be created for +the virtual event with the \fBbind\fR command. +Consider the following virtual event definitions: +.CS +event add <<Paste>> <Control-y> +event add <<Paste>> <Button-2> +event add <<Save>> <Control-X><Control-S> +event add <<Save>> <Shift-F12> +.CE +In the \fBbind\fR command, a virtual event can be bound like any other +builtin event type as follows: +.CS +bind Entry <<Paste>> {%W insert [selection get]} +.CE +The double angle brackets are used to specify that a virtual event is being +bound. If the user types Control-y or presses button 2, or if +a \fB<<Paste>>\fR virtual event is synthesized with \fBevent generate\fR, +then the \fB<<Paste>>\fR binding will be invoked. +.PP +If a virtual binding has the exact same sequence as a separate +physical binding, then the physical binding will take precedence. +Consider the following example: +.CS +event add <<Paste>> <Control-y> <Meta-Control-y> +bind Entry <Control-y> {puts Control-y} +bind Entry <<Paste>> {puts Paste} +.CE +When the user types Control-y the \fB<Control-y>\fR binding +will be invoked, because a physical event is considered +more specific than a virtual event, all other things being equal. +However, when the user types Meta-Control-y the +\fB<<Paste>>\fR binding will be invoked, because the +\fBMeta\fR modifier in the physical pattern associated with the +virtual binding is more specific than the \fB<Control-y\fR> sequence for +the physical event. +.PP +Bindings on a virtual event may be created before the virtual event exists. +Indeed, the virtual event never actually needs to be defined, for instance, +on platforms where the specific virtual event would meaningless or +ungeneratable. +.PP +When a definition of a virtual event changes at run time, all windows +will respond immediately to the new definition. +Starting from the preceding example, if the following code is executed: +.CS +bind <Entry> <Control-y> {} +event add <<Paste>> <Key-F6> +.CE +the behavior will change such in two ways. First, the shadowed +\fB<<Paste>>\fR binding will emerge. +Typing Control-y will no longer invoke the \fB<Control-y>\fR binding, +but instead invoke the virtual event \fB<<Paste>>\fR. Second, +pressing the F6 key will now also invoke the \fB<<Paste>>\fR binding. + +.SH "SEE ALSO" +bind + +.SH KEYWORDS +event, binding, define, handle, virtual event |