figenc

menu.tcl (38077B)

---

 # menu.tcl --
 #
 # This file defines the default bindings for Tk menus and menubuttons.
 # It also implements keyboard traversal of menus and implements a few
 # other utility procedures related to menus.
 #
 # Copyright (c) 1992-1994 The Regents of the University of California.
 # Copyright (c) 1994-1997 Sun Microsystems, Inc.
 # Copyright (c) 1998-1999 by Scriptics Corporation.
 # Copyright (c) 2007 Daniel A. Steffen <das@users.sourceforge.net>
 #
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
 
 #-------------------------------------------------------------------------
 # Elements of tk::Priv that are used in this file:
 #
 # cursor -		Saves the -cursor option for the posted menubutton.
 # focus -		Saves the focus during a menu selection operation.
 #			Focus gets restored here when the menu is unposted.
 # grabGlobal -		Used in conjunction with tk::Priv(oldGrab):  if
 #			tk::Priv(oldGrab) is non-empty, then tk::Priv(grabGlobal)
 #			contains either an empty string or "-global" to
 #			indicate whether the old grab was a local one or
 #			a global one.
 # inMenubutton -	The name of the menubutton widget containing
 #			the mouse, or an empty string if the mouse is
 #			not over any menubutton.
 # menuBar -		The name of the menubar that is the root
 #			of the cascade hierarchy which is currently
 #			posted. This is null when there is no menu currently
 #			being pulled down from a menu bar.
 # oldGrab -		Window that had the grab before a menu was posted.
 #			Used to restore the grab state after the menu
 #			is unposted.  Empty string means there was no
 #			grab previously set.
 # popup -		If a menu has been popped up via tk_popup, this
 #			gives the name of the menu.  Otherwise this
 #			value is empty.
 # postedMb -		Name of the menubutton whose menu is currently
 #			posted, or an empty string if nothing is posted
 #			A grab is set on this widget.
 # relief -		Used to save the original relief of the current
 #			menubutton.
 # window -		When the mouse is over a menu, this holds the
 #			name of the menu;  it's cleared when the mouse
 #			leaves the menu.
 # tearoff -		Whether the last menu posted was a tearoff or not.
 #			This is true always for unix, for tearoffs for Mac
 #			and Windows.
 # activeMenu -		This is the last active menu for use
 #			with the <<MenuSelect>> virtual event.
 # activeItem -		This is the last active menu item for
 #			use with the <<MenuSelect>> virtual event.
 #-------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------
 # Overall note:
 # This file is tricky because there are five different ways that menus
 # can be used:
 #
 # 1. As a pulldown from a menubutton. In this style, the variable
 #    tk::Priv(postedMb) identifies the posted menubutton.
 # 2. As a torn-off menu copied from some other menu.  In this style
 #    tk::Priv(postedMb) is empty, and menu's type is "tearoff".
 # 3. As an option menu, triggered from an option menubutton.  In this
 #    style tk::Priv(postedMb) identifies the posted menubutton.
 # 4. As a popup menu.  In this style tk::Priv(postedMb) is empty and
 #    the top-level menu's type is "normal".
 # 5. As a pulldown from a menubar. The variable tk::Priv(menubar) has
 #    the owning menubar, and the menu itself is of type "normal".
 #
 # The various binding procedures use the  state described above to
 # distinguish the various cases and take different actions in each
 # case.
 #-------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------
 # The code below creates the default class bindings for menus
 # and menubuttons.
 #-------------------------------------------------------------------------
 
 bind Menubutton <FocusIn> {}
 bind Menubutton <Enter> {
     tk::MbEnter %W
 }
 bind Menubutton <Leave> {
     tk::MbLeave %W
 }
 bind Menubutton <1> {
     if {$tk::Priv(inMenubutton) ne ""} {
 	tk::MbPost $tk::Priv(inMenubutton) %X %Y
     }
 }
 bind Menubutton <Motion> {
     tk::MbMotion %W up %X %Y
 }
 bind Menubutton <B1-Motion> {
     tk::MbMotion %W down %X %Y
 }
 bind Menubutton <ButtonRelease-1> {
     tk::MbButtonUp %W
 }
 bind Menubutton <space> {
     tk::MbPost %W
     tk::MenuFirstEntry [%W cget -menu]
 }
 bind Menubutton <<Invoke>> {
     tk::MbPost %W
     tk::MenuFirstEntry [%W cget -menu]
 }
 
 # Must set focus when mouse enters a menu, in order to allow
 # mixed-mode processing using both the mouse and the keyboard.
 # Don't set the focus if the event comes from a grab release,
 # though:  such an event can happen after as part of unposting
 # a cascaded chain of menus, after the focus has already been
 # restored to wherever it was before menu selection started.
 
 bind Menu <FocusIn> {}
 
 bind Menu <Enter> {
     set tk::Priv(window) %W
     if {[%W cget -type] eq "tearoff"} {
 	if {"%m" ne "NotifyUngrab"} {
 	    if {[tk windowingsystem] eq "x11"} {
 		tk_menuSetFocus %W
 	    }
 	}
     }
     tk::MenuMotion %W %x %y %s
 }
 
 bind Menu <Leave> {
     tk::MenuLeave %W %X %Y %s
 }
 bind Menu <Motion> {
     tk::MenuMotion %W %x %y %s
 }
 bind Menu <ButtonPress> {
     tk::MenuButtonDown %W
 }
 bind Menu <ButtonRelease> {
    tk::MenuInvoke %W 1
 }
 bind Menu <space> {
     tk::MenuInvoke %W 0
 }
 bind Menu <<Invoke>> {
     tk::MenuInvoke %W 0
 }
 bind Menu <Return> {
     tk::MenuInvoke %W 0
 }
 bind Menu <Escape> {
     tk::MenuEscape %W
 }
 bind Menu <<PrevChar>> {
     tk::MenuLeftArrow %W
 }
 bind Menu <<NextChar>> {
     tk::MenuRightArrow %W
 }
 bind Menu <<PrevLine>> {
     tk::MenuUpArrow %W
 }
 bind Menu <<NextLine>> {
     tk::MenuDownArrow %W
 }
 bind Menu <KeyPress> {
     tk::TraverseWithinMenu %W %A
     break
 }
 
 # The following bindings apply to all windows, and are used to
 # implement keyboard menu traversal.
 
 if {[tk windowingsystem] eq "x11"} {
     bind all <Alt-KeyPress> {
 	tk::TraverseToMenu %W %A
     }
 
     bind all <F10> {
 	tk::FirstMenu %W
     }
 } else {
     bind Menubutton <Alt-KeyPress> {
 	tk::TraverseToMenu %W %A
     }
 
     bind Menubutton <F10> {
 	tk::FirstMenu %W
     }
 }
 
 # ::tk::MbEnter --
 # This procedure is invoked when the mouse enters a menubutton
 # widget.  It activates the widget unless it is disabled.  Note:
 # this procedure is only invoked when mouse button 1 is *not* down.
 # The procedure ::tk::MbB1Enter is invoked if the button is down.
 #
 # Arguments:
 # w -			The  name of the widget.
 
 proc ::tk::MbEnter w {
     variable ::tk::Priv
 
     if {$Priv(inMenubutton) ne ""} {
 	MbLeave $Priv(inMenubutton)
     }
     set Priv(inMenubutton) $w
     if {[$w cget -state] ne "disabled" && [tk windowingsystem] ne "aqua"} {
 	$w configure -state active
     }
 }
 
 # ::tk::MbLeave --
 # This procedure is invoked when the mouse leaves a menubutton widget.
 # It de-activates the widget, if the widget still exists.
 #
 # Arguments:
 # w -			The  name of the widget.
 
 proc ::tk::MbLeave w {
     variable ::tk::Priv
 
     set Priv(inMenubutton) {}
     if {![winfo exists $w]} {
 	return
     }
     if {[$w cget -state] eq "active" && [tk windowingsystem] ne "aqua"} {
 	$w configure -state normal
     }
 }
 
 # ::tk::MbPost --
 # Given a menubutton, this procedure does all the work of posting
 # its associated menu and unposting any other menu that is currently
 # posted.
 #
 # Arguments:
 # w -			The name of the menubutton widget whose menu
 #			is to be posted.
 # x, y -		Root coordinates of cursor, used for positioning
 #			option menus.  If not specified, then the center
 #			of the menubutton is used for an option menu.
 
 proc ::tk::MbPost {w {x {}} {y {}}} {
     global errorInfo
     variable ::tk::Priv
 
     if {[$w cget -state] eq "disabled" || $w eq $Priv(postedMb)} {
 	return
     }
     set menu [$w cget -menu]
     if {$menu eq ""} {
 	return
     }
     set tearoff [expr {[tk windowingsystem] eq "x11" \
 	    || [$menu cget -type] eq "tearoff"}]
     if {[string first $w $menu] != 0} {
 	return -code error -errorcode {TK MENUBUTTON POST_NONCHILD} \
 	    "can't post $menu: it isn't a descendant of $w"
     }
     set cur $Priv(postedMb)
     if {$cur ne ""} {
 	MenuUnpost {}
     }
     if {$::tk_strictMotif} {
         set Priv(cursor) [$w cget -cursor]
         $w configure -cursor arrow
     }
     if {[tk windowingsystem] ne "aqua"} {
 	set Priv(relief) [$w cget -relief]
 	$w configure -relief raised
     } else {
 	$w configure -state active
     }
 
     set Priv(postedMb) $w
     set Priv(focus) [focus]
     $menu activate none
     GenerateMenuSelect $menu
 
     # If this looks like an option menubutton then post the menu so
     # that the current entry is on top of the mouse.  Otherwise post
     # the menu just below the menubutton, as for a pull-down.
 
     update idletasks
     if {[catch {
 	switch [$w cget -direction] {
 	    above {
 		set x [winfo rootx $w]
 		set y [expr {[winfo rooty $w] - [winfo reqheight $menu]}]
 		# if we go offscreen to the top, show as 'below'
 		if {$y < [winfo vrooty $w]} {
 		    set y [expr {[winfo vrooty $w] + [winfo rooty $w] + [winfo reqheight $w]}]
 		}
 		PostOverPoint $menu $x $y
 	    }
 	    below {
 		set x [winfo rootx $w]
 		set y [expr {[winfo rooty $w] + [winfo height $w]}]
 		# if we go offscreen to the bottom, show as 'above'
 		set mh [winfo reqheight $menu]
 		if {($y + $mh) > ([winfo vrooty $w] + [winfo vrootheight $w])} {
 		    set y [expr {[winfo vrooty $w] + [winfo vrootheight $w] + [winfo rooty $w] - $mh}]
 		}
 		PostOverPoint $menu $x $y
 	    }
 	    left {
 		set x [expr {[winfo rootx $w] - [winfo reqwidth $menu]}]
 		set y [expr {(2 * [winfo rooty $w] + [winfo height $w]) / 2}]
 		set entry [MenuFindName $menu [$w cget -text]]
 		if {$entry eq ""} {
                     set entry 0
 		}
 		if {[$w cget -indicatoron]} {
 		    if {$entry == [$menu index last]} {
 			incr y [expr {-([$menu yposition $entry] \
 				+ [winfo reqheight $menu])/2}]
 		    } else {
 			incr y [expr {-([$menu yposition $entry] \
 			        + [$menu yposition [expr {$entry+1}]])/2}]
 		    }
 		}
 		PostOverPoint $menu $x $y
 		if {$entry ne "" \
 			&& [$menu entrycget $entry -state] ne "disabled"} {
 		    $menu activate $entry
 		    GenerateMenuSelect $menu
 		}
 	    }
 	    right {
 		set x [expr {[winfo rootx $w] + [winfo width $w]}]
 		set y [expr {(2 * [winfo rooty $w] + [winfo height $w]) / 2}]
 		set entry [MenuFindName $menu [$w cget -text]]
 		if {$entry eq ""} {
                     set entry 0
 		}
 		if {[$w cget -indicatoron]} {
 		    if {$entry == [$menu index last]} {
 			incr y [expr {-([$menu yposition $entry] \
 				+ [winfo reqheight $menu])/2}]
 		    } else {
 			incr y [expr {-([$menu yposition $entry] \
 			        + [$menu yposition [expr {$entry+1}]])/2}]
 		    }
 		}
 		PostOverPoint $menu $x $y
 		if {$entry ne "" \
 			&& [$menu entrycget $entry -state] ne "disabled"} {
 		    $menu activate $entry
 		    GenerateMenuSelect $menu
 		}
 	    }
 	    default {
 		if {[$w cget -indicatoron]} {
 		    if {$y eq ""} {
 			set x [expr {[winfo rootx $w] + [winfo width $w]/2}]
 			set y [expr {[winfo rooty $w] + [winfo height $w]/2}]
 		    }
 	            PostOverPoint $menu $x $y [MenuFindName $menu [$w cget -text]]
 		} else {
 		    PostOverPoint $menu [winfo rootx $w] [expr {[winfo rooty $w]+[winfo height $w]}]
 		}
 	    }
 	}
     } msg opt]} {
 	# Error posting menu (e.g. bogus -postcommand). Unpost it and
 	# reflect the error.
 
 	MenuUnpost {}
 	return -options $opt $msg
     }
 
     set Priv(tearoff) $tearoff
     if {$tearoff != 0} {
 	focus $menu
 	if {[winfo viewable $w]} {
 	    SaveGrabInfo $w
 	    grab -global $w
 	}
     }
 }
 
 # ::tk::MenuUnpost --
 # This procedure unposts a given menu, plus all of its ancestors up
 # to (and including) a menubutton, if any.  It also restores various
 # values to what they were before the menu was posted, and releases
 # a grab if there's a menubutton involved.  Special notes:
 # 1. It's important to unpost all menus before releasing the grab, so
 #    that any Enter-Leave events (e.g. from menu back to main
 #    application) have mode NotifyGrab.
 # 2. Be sure to enclose various groups of commands in "catch" so that
 #    the procedure will complete even if the menubutton or the menu
 #    or the grab window has been deleted.
 #
 # Arguments:
 # menu -		Name of a menu to unpost.  Ignored if there
 #			is a posted menubutton.
 
 proc ::tk::MenuUnpost menu {
     variable ::tk::Priv
     set mb $Priv(postedMb)
 
     # Restore focus right away (otherwise X will take focus away when
     # the menu is unmapped and under some window managers (e.g. olvwm)
     # we'll lose the focus completely).
 
     catch {focus $Priv(focus)}
     set Priv(focus) ""
 
     # Unpost menu(s) and restore some stuff that's dependent on
     # what was posted.
 
     after cancel [array get Priv menuActivatedTimer]
     unset -nocomplain Priv(menuActivated)
     after cancel [array get Priv menuDeactivatedTimer]
     unset -nocomplain Priv(menuDeactivated)
 
     catch {
 	if {$mb ne ""} {
 	    set menu [$mb cget -menu]
 	    $menu unpost
 	    set Priv(postedMb) {}
 	    if {$::tk_strictMotif} {
 	        $mb configure -cursor $Priv(cursor)
 	    }
 	    if {[tk windowingsystem] ne "aqua"} {
 		$mb configure -relief $Priv(relief)
 	    } else {
 		$mb configure -state normal
 	    }
 	} elseif {$Priv(popup) ne ""} {
 	    $Priv(popup) unpost
 	    set Priv(popup) {}
 	} elseif {[$menu cget -type] ne "menubar" && [$menu cget -type] ne "tearoff"} {
 	    # We're in a cascaded sub-menu from a torn-off menu or popup.
 	    # Unpost all the menus up to the toplevel one (but not
 	    # including the top-level torn-off one) and deactivate the
 	    # top-level torn off menu if there is one.
 
 	    while {1} {
 		set parent [winfo parent $menu]
 		if {[winfo class $parent] ne "Menu" || ![winfo ismapped $parent]} {
 		    break
 		}
 		$parent activate none
 		$parent postcascade none
 		GenerateMenuSelect $parent
 		set type [$parent cget -type]
 		if {$type eq "menubar" || $type eq "tearoff"} {
 		    break
 		}
 		set menu $parent
 	    }
 	    if {[$menu cget -type] ne "menubar"} {
 		$menu unpost
 	    }
 	}
     }
 
     if {($Priv(tearoff) != 0) || $Priv(menuBar) ne ""} {
 	# Release grab, if any, and restore the previous grab, if there
 	# was one.
 	if {$menu ne ""} {
 	    set grab [grab current $menu]
 	    if {$grab ne ""} {
 		grab release $grab
 	    }
 	}
 	RestoreOldGrab
 	if {$Priv(menuBar) ne ""} {
 	    if {$::tk_strictMotif} {
 		$Priv(menuBar) configure -cursor $Priv(cursor)
 	    }
 	    set Priv(menuBar) {}
 	}
 	if {[tk windowingsystem] ne "x11"} {
 	    set Priv(tearoff) 0
 	}
     }
 }
 
 # ::tk::MbMotion --
 # This procedure handles mouse motion events inside menubuttons, and
 # also outside menubuttons when a menubutton has a grab (e.g. when a
 # menu selection operation is in progress).
 #
 # Arguments:
 # w -			The name of the menubutton widget.
 # upDown - 		"down" means button 1 is pressed, "up" means
 #			it isn't.
 # rootx, rooty -	Coordinates of mouse, in (virtual?) root window.
 
 proc ::tk::MbMotion {w upDown rootx rooty} {
     variable ::tk::Priv
 
     if {$Priv(inMenubutton) eq $w} {
 	return
     }
     set new [winfo containing $rootx $rooty]
     if {$new ne $Priv(inMenubutton) \
 	    && ($new eq "" || [winfo toplevel $new] eq [winfo toplevel $w])} {
 	if {$Priv(inMenubutton) ne ""} {
 	    MbLeave $Priv(inMenubutton)
 	}
 	if {$new ne "" \
 		&& [winfo class $new] eq "Menubutton" \
 		&& ([$new cget -indicatoron] == 0) \
 		&& ([$w cget -indicatoron] == 0)} {
 	    if {$upDown eq "down"} {
 		MbPost $new $rootx $rooty
 	    } else {
 		MbEnter $new
 	    }
 	}
     }
 }
 
 # ::tk::MbButtonUp --
 # This procedure is invoked to handle button 1 releases for menubuttons.
 # If the release happens inside the menubutton then leave its menu
 # posted with element 0 activated.  Otherwise, unpost the menu.
 #
 # Arguments:
 # w -			The name of the menubutton widget.
 
 proc ::tk::MbButtonUp w {
     variable ::tk::Priv
 
     set menu [$w cget -menu]
     set tearoff [expr {[tk windowingsystem] eq "x11" || \
 	    ($menu ne "" && [$menu cget -type] eq "tearoff")}]
     if {($tearoff != 0) && $Priv(postedMb) eq $w \
 	    && $Priv(inMenubutton) eq $w} {
 	MenuFirstEntry [$Priv(postedMb) cget -menu]
     } else {
 	MenuUnpost {}
     }
 }
 
 # ::tk::MenuMotion --
 # This procedure is called to handle mouse motion events for menus.
 # It does two things.  First, it resets the active element in the
 # menu, if the mouse is over the menu.  Second, if a mouse button
 # is down, it posts and unposts cascade entries to match the mouse
 # position.
 #
 # Arguments:
 # menu -		The menu window.
 # x -			The x position of the mouse.
 # y -			The y position of the mouse.
 # state -		Modifier state (tells whether buttons are down).
 
 proc ::tk::MenuMotion {menu x y state} {
     variable ::tk::Priv
     if {$menu eq $Priv(window)} {
         set activeindex [$menu index active]
 	if {[$menu cget -type] eq "menubar"} {
 	    if {[info exists Priv(focus)] && $menu ne $Priv(focus)} {
 		$menu activate @$x,$y
 		GenerateMenuSelect $menu
 	    }
 	} else {
 	    $menu activate @$x,$y
 	    GenerateMenuSelect $menu
 	}
         set index [$menu index @$x,$y]
         if {[info exists Priv(menuActivated)] \
                 && $index ne "none" \
                 && $index ne $activeindex} {
             set mode [option get $menu clickToFocus ClickToFocus]
             if {[string is false $mode]} {
                 set delay [expr {[$menu cget -type] eq "menubar" ? 0 : 50}]
                 if {[$menu type $index] eq "cascade"} {
                     set Priv(menuActivatedTimer) \
                         [after $delay [list $menu postcascade active]]
                 } else {
                     set Priv(menuDeactivatedTimer) \
                         [after $delay [list $menu postcascade none]]
                 }
             }
         }
     }
 }
 
 # ::tk::MenuButtonDown --
 # Handles button presses in menus.  There are a couple of tricky things
 # here:
 # 1. Change the posted cascade entry (if any) to match the mouse position.
 # 2. If there is a posted menubutton, must grab to the menubutton;  this
 #    overrrides the implicit grab on button press, so that the menu
 #    button can track mouse motions over other menubuttons and change
 #    the posted menu.
 # 3. If there's no posted menubutton (e.g. because we're a torn-off menu
 #    or one of its descendants) must grab to the top-level menu so that
 #    we can track mouse motions across the entire menu hierarchy.
 #
 # Arguments:
 # menu -		The menu window.
 
 proc ::tk::MenuButtonDown menu {
     variable ::tk::Priv
 
     if {![winfo viewable $menu]} {
         return
     }
     if {[$menu index active] eq "none"} {
         if {[$menu cget -type] ne "menubar" } {
             set Priv(window) {}
         }
         return
     }
     $menu postcascade active
     if {$Priv(postedMb) ne "" && [winfo viewable $Priv(postedMb)]} {
 	grab -global $Priv(postedMb)
     } else {
 	while {[$menu cget -type] eq "normal" \
 		&& [winfo class [winfo parent $menu]] eq "Menu" \
 		&& [winfo ismapped [winfo parent $menu]]} {
 	    set menu [winfo parent $menu]
 	}
 
 	if {$Priv(menuBar) eq {}} {
 	    set Priv(menuBar) $menu
 	    if {$::tk_strictMotif} {
 		set Priv(cursor) [$menu cget -cursor]
 		$menu configure -cursor arrow
 	    }
 	    if {[$menu type active] eq "cascade"} {
 		set Priv(menuActivated) 1
 	    }
         }
 
 	# Don't update grab information if the grab window isn't changing.
 	# Otherwise, we'll get an error when we unpost the menus and
 	# restore the grab, since the old grab window will not be viewable
 	# anymore.
 
 	if {$menu ne [grab current $menu]} {
 	    SaveGrabInfo $menu
 	}
 
 	# Must re-grab even if the grab window hasn't changed, in order
 	# to release the implicit grab from the button press.
 
 	if {[tk windowingsystem] eq "x11"} {
 	    grab -global $menu
 	}
     }
 }
 
 # ::tk::MenuLeave --
 # This procedure is invoked to handle Leave events for a menu.  It
 # deactivates everything unless the active element is a cascade element
 # and the mouse is now over the submenu.
 #
 # Arguments:
 # menu -		The menu window.
 # rootx, rooty -	Root coordinates of mouse.
 # state -		Modifier state.
 
 proc ::tk::MenuLeave {menu rootx rooty state} {
     variable ::tk::Priv
     set Priv(window) {}
     if {[$menu index active] eq "none"} {
 	return
     }
     if {[$menu type active] eq "cascade" \
 	    && [winfo containing $rootx $rooty] eq \
 		[$menu entrycget active -menu]} {
 	return
     }
     $menu activate none
     GenerateMenuSelect $menu
 }
 
 # ::tk::MenuInvoke --
 # This procedure is invoked when button 1 is released over a menu.
 # It invokes the appropriate menu action and unposts the menu if
 # it came from a menubutton.
 #
 # Arguments:
 # w -			Name of the menu widget.
 # buttonRelease -	1 means this procedure is called because of
 #			a button release;  0 means because of keystroke.
 
 proc ::tk::MenuInvoke {w buttonRelease} {
     variable ::tk::Priv
 
     if {$buttonRelease && $Priv(window) eq ""} {
 	# Mouse was pressed over a menu without a menu button, then
 	# dragged off the menu (possibly with a cascade posted) and
 	# released.  Unpost everything and quit.
 
 	$w postcascade none
 	$w activate none
 	event generate $w <<MenuSelect>>
 	MenuUnpost $w
 	return
     }
     if {[$w type active] eq "cascade"} {
 	$w postcascade active
 	set menu [$w entrycget active -menu]
 	MenuFirstEntry $menu
     } elseif {[$w type active] eq "tearoff"} {
 	::tk::TearOffMenu $w
 	MenuUnpost $w
     } elseif {[$w cget -type] eq "menubar"} {
 	$w postcascade none
 	set active [$w index active]
 	set isCascade [string equal [$w type $active] "cascade"]
 
 	# Only de-activate the active item if it's a cascade; this prevents
 	# the annoying "activation flicker" you otherwise get with
 	# checkbuttons/commands/etc. on menubars
 
 	if { $isCascade } {
 	    $w activate none
 	    event generate $w <<MenuSelect>>
 	}
 
 	MenuUnpost $w
 
 	# If the active item is not a cascade, invoke it.  This enables
 	# the use of checkbuttons/commands/etc. on menubars (which is legal,
 	# but not recommended)
 
 	if { !$isCascade } {
 	    uplevel #0 [list $w invoke $active]
 	}
     } else {
 	set active [$w index active]
 	if {$Priv(popup) eq "" || $active ne "none"} {
 	    MenuUnpost $w
 	}
 	uplevel #0 [list $w invoke active]
     }
 }
 
 # ::tk::MenuEscape --
 # This procedure is invoked for the Cancel (or Escape) key.  It unposts
 # the given menu and, if it is the top-level menu for a menu button,
 # unposts the menu button as well.
 #
 # Arguments:
 # menu -		Name of the menu window.
 
 proc ::tk::MenuEscape menu {
     set parent [winfo parent $menu]
     if {[winfo class $parent] ne "Menu"} {
 	MenuUnpost $menu
     } elseif {[$parent cget -type] eq "menubar"} {
 	MenuUnpost $menu
 	RestoreOldGrab
     } else {
 	MenuNextMenu $menu left
     }
 }
 
 # The following routines handle arrow keys. Arrow keys behave
 # differently depending on whether the menu is a menu bar or not.
 
 proc ::tk::MenuUpArrow {menu} {
     if {[$menu cget -type] eq "menubar"} {
 	MenuNextMenu $menu left
     } else {
 	MenuNextEntry $menu -1
     }
 }
 
 proc ::tk::MenuDownArrow {menu} {
     if {[$menu cget -type] eq "menubar"} {
 	MenuNextMenu $menu right
     } else {
 	MenuNextEntry $menu 1
     }
 }
 
 proc ::tk::MenuLeftArrow {menu} {
     if {[$menu cget -type] eq "menubar"} {
 	MenuNextEntry $menu -1
     } else {
 	MenuNextMenu $menu left
     }
 }
 
 proc ::tk::MenuRightArrow {menu} {
     if {[$menu cget -type] eq "menubar"} {
 	MenuNextEntry $menu 1
     } else {
 	MenuNextMenu $menu right
     }
 }
 
 # ::tk::MenuNextMenu --
 # This procedure is invoked to handle "left" and "right" traversal
 # motions in menus.  It traverses to the next menu in a menu bar,
 # or into or out of a cascaded menu.
 #
 # Arguments:
 # menu -		The menu that received the keyboard
 #			event.
 # direction -		Direction in which to move: "left" or "right"
 
 proc ::tk::MenuNextMenu {menu direction} {
     variable ::tk::Priv
 
     # First handle traversals into and out of cascaded menus.
 
     if {$direction eq "right"} {
 	set count 1
 	set parent [winfo parent $menu]
 	set class [winfo class $parent]
 	if {[$menu type active] eq "cascade"} {
 	    $menu postcascade active
 	    set m2 [$menu entrycget active -menu]
 	    if {$m2 ne ""} {
 		MenuFirstEntry $m2
 	    }
 	    return
 	} else {
 	    set parent [winfo parent $menu]
 	    while {$parent ne "."} {
 		if {[winfo class $parent] eq "Menu" \
 			&& [$parent cget -type] eq "menubar"} {
 		    tk_menuSetFocus $parent
 		    MenuNextEntry $parent 1
 		    return
 		}
 		set parent [winfo parent $parent]
 	    }
 	}
     } else {
 	set count -1
 	set m2 [winfo parent $menu]
 	if {[winfo class $m2] eq "Menu"} {
 	    $menu activate none
 	    GenerateMenuSelect $menu
 	    tk_menuSetFocus $m2
 
 	    $m2 postcascade none
 
 	    if {[$m2 cget -type] ne "menubar"} {
 		return
 	    }
 	}
     }
 
     # Can't traverse into or out of a cascaded menu. Go to the next
     # or previous menubutton, if that makes sense.
 
     set m2 [winfo parent $menu]
     if {[winfo class $m2] eq "Menu" && [$m2 cget -type] eq "menubar"} {
 	tk_menuSetFocus $m2
 	MenuNextEntry $m2 -1
 	return
     }
 
     set w $Priv(postedMb)
     if {$w eq ""} {
 	return
     }
     set buttons [winfo children [winfo parent $w]]
     set length [llength $buttons]
     set i [expr {[lsearch -exact $buttons $w] + $count}]
     while {1} {
 	while {$i < 0} {
 	    incr i $length
 	}
 	while {$i >= $length} {
 	    incr i -$length
 	}
 	set mb [lindex $buttons $i]
 	if {[winfo class $mb] eq "Menubutton" \
 		&& [$mb cget -state] ne "disabled" \
 		&& [$mb cget -menu] ne "" \
 		&& [[$mb cget -menu] index last] ne "none"} {
 	    break
 	}
 	if {$mb eq $w} {
 	    return
 	}
 	incr i $count
     }
     MbPost $mb
     MenuFirstEntry [$mb cget -menu]
 }
 
 # ::tk::MenuNextEntry --
 # Activate the next higher or lower entry in the posted menu,
 # wrapping around at the ends.  Disabled entries are skipped.
 #
 # Arguments:
 # menu -			Menu window that received the keystroke.
 # count -			1 means go to the next lower entry,
 #				-1 means go to the next higher entry.
 
 proc ::tk::MenuNextEntry {menu count} {
     if {[$menu index last] eq "none"} {
 	return
     }
     set length [expr {[$menu index last]+1}]
     set quitAfter $length
     set active [$menu index active]
     if {$active eq "none"} {
 	set i 0
     } else {
 	set i [expr {$active + $count}]
     }
     while {1} {
 	if {$quitAfter <= 0} {
 	    # We've tried every entry in the menu.  Either there are
 	    # none, or they're all disabled.  Just give up.
 
 	    return
 	}
 	while {$i < 0} {
 	    incr i $length
 	}
 	while {$i >= $length} {
 	    incr i -$length
 	}
 	if {[catch {$menu entrycget $i -state} state] == 0} {
 	    if {$state ne "disabled" && \
 		    ($i!=0 || [$menu cget -type] ne "tearoff" \
 		    || [$menu type 0] ne "tearoff")} {
 		break
 	    }
 	}
 	if {$i == $active} {
 	    return
 	}
 	incr i $count
 	incr quitAfter -1
     }
     $menu activate $i
     GenerateMenuSelect $menu
 
     if {[$menu type $i] eq "cascade" && [$menu cget -type] eq "menubar"} {
 	set cascade [$menu entrycget $i -menu]
 	if {$cascade ne ""} {
 	    # Here we auto-post a cascade.  This is necessary when
 	    # we traverse left/right in the menubar, but undesirable when
 	    # we traverse up/down in a menu.
 	    $menu postcascade $i
 	    MenuFirstEntry $cascade
 	}
     }
 }
 
 # ::tk::MenuFind --
 # This procedure searches the entire window hierarchy under w for
 # a menubutton that isn't disabled and whose underlined character
 # is "char" or an entry in a menubar that isn't disabled and whose
 # underlined character is "char".
 # It returns the name of that window, if found, or an
 # empty string if no matching window was found.  If "char" is an
 # empty string then the procedure returns the name of the first
 # menubutton found that isn't disabled.
 #
 # Arguments:
 # w -				Name of window where key was typed.
 # char -			Underlined character to search for;
 #				may be either upper or lower case, and
 #				will match either upper or lower case.
 
 proc ::tk::MenuFind {w char} {
     set char [string tolower $char]
     set windowlist [winfo child $w]
 
     foreach child $windowlist {
 	# Don't descend into other toplevels.
         if {[winfo toplevel $w] ne [winfo toplevel $child]} {
 	    continue
 	}
 	if {[winfo class $child] eq "Menu" && \
 		[$child cget -type] eq "menubar"} {
 	    if {$char eq ""} {
 		return $child
 	    }
 	    set last [$child index last]
 	    for {set i [$child cget -tearoff]} {$i <= $last} {incr i} {
 		if {[$child type $i] eq "separator"} {
 		    continue
 		}
 		set char2 [string index [$child entrycget $i -label] \
 			[$child entrycget $i -underline]]
 		if {$char eq [string tolower $char2] || $char eq ""} {
 		    if {[$child entrycget $i -state] ne "disabled"} {
 			return $child
 		    }
 		}
 	    }
 	}
     }
 
     foreach child $windowlist {
 	# Don't descend into other toplevels.
         if {[winfo toplevel $w] ne [winfo toplevel $child]} {
 	    continue
 	}
 	switch -- [winfo class $child] {
 	    Menubutton {
 		set char2 [string index [$child cget -text] \
 			[$child cget -underline]]
 		if {$char eq [string tolower $char2] || $char eq ""} {
 		    if {[$child cget -state] ne "disabled"} {
 			return $child
 		    }
 		}
 	    }
 
 	    default {
 		set match [MenuFind $child $char]
 		if {$match ne ""} {
 		    return $match
 		}
 	    }
 	}
     }
     return {}
 }
 
 # ::tk::TraverseToMenu --
 # This procedure implements keyboard traversal of menus.  Given an
 # ASCII character "char", it looks for a menubutton with that character
 # underlined.  If one is found, it posts the menubutton's menu
 #
 # Arguments:
 # w -				Window in which the key was typed (selects
 #				a toplevel window).
 # char -			Character that selects a menu.  The case
 #				is ignored.  If an empty string, nothing
 #				happens.
 
 proc ::tk::TraverseToMenu {w char} {
     variable ::tk::Priv
     if {![winfo exists $w] || $char eq ""} {
 	return
     }
     while {[winfo class $w] eq "Menu"} {
 	if {[$w cget -type] eq "menubar"} {
 	    break
 	} elseif {$Priv(postedMb) eq ""} {
 	    return
 	}
 	set w [winfo parent $w]
     }
     set w [MenuFind [winfo toplevel $w] $char]
     if {$w ne ""} {
 	if {[winfo class $w] eq "Menu"} {
 	    tk_menuSetFocus $w
 	    set Priv(window) $w
 	    SaveGrabInfo $w
 	    grab -global $w
 	    TraverseWithinMenu $w $char
 	} else {
 	    MbPost $w
 	    MenuFirstEntry [$w cget -menu]
 	}
     }
 }
 
 # ::tk::FirstMenu --
 # This procedure traverses to the first menubutton in the toplevel
 # for a given window, and posts that menubutton's menu.
 #
 # Arguments:
 # w -				Name of a window.  Selects which toplevel
 #				to search for menubuttons.
 
 proc ::tk::FirstMenu w {
     variable ::tk::Priv
     set w [MenuFind [winfo toplevel $w] ""]
     if {$w ne ""} {
 	if {[winfo class $w] eq "Menu"} {
 	    tk_menuSetFocus $w
 	    set Priv(window) $w
 	    SaveGrabInfo $w
 	    grab -global $w
 	    MenuFirstEntry $w
 	} else {
 	    MbPost $w
 	    MenuFirstEntry [$w cget -menu]
 	}
     }
 }
 
 # ::tk::TraverseWithinMenu
 # This procedure implements keyboard traversal within a menu.  It
 # searches for an entry in the menu that has "char" underlined.  If
 # such an entry is found, it is invoked and the menu is unposted.
 #
 # Arguments:
 # w -				The name of the menu widget.
 # char -			The character to look for;  case is
 #				ignored.  If the string is empty then
 #				nothing happens.
 
 proc ::tk::TraverseWithinMenu {w char} {
     if {$char eq ""} {
 	return
     }
     set char [string tolower $char]
     set last [$w index last]
     if {$last eq "none"} {
 	return
     }
     for {set i 0} {$i <= $last} {incr i} {
 	if {[catch {set char2 [string index \
 		[$w entrycget $i -label] [$w entrycget $i -underline]]}]} {
 	    continue
 	}
 	if {$char eq [string tolower $char2]} {
 	    if {[$w type $i] eq "cascade"} {
 		$w activate $i
 		$w postcascade active
 		event generate $w <<MenuSelect>>
 		set m2 [$w entrycget $i -menu]
 		if {$m2 ne ""} {
 		    MenuFirstEntry $m2
 		}
 	    } else {
 		MenuUnpost $w
 		uplevel #0 [list $w invoke $i]
 	    }
 	    return
 	}
     }
 }
 
 # ::tk::MenuFirstEntry --
 # Given a menu, this procedure finds the first entry that isn't
 # disabled or a tear-off or separator, and activates that entry.
 # However, if there is already an active entry in the menu (e.g.,
 # because of a previous call to tk::PostOverPoint) then the active
 # entry isn't changed.  This procedure also sets the input focus
 # to the menu.
 #
 # Arguments:
 # menu -		Name of the menu window (possibly empty).
 
 proc ::tk::MenuFirstEntry menu {
     if {$menu eq ""} {
 	return
     }
     tk_menuSetFocus $menu
     if {[$menu index active] ne "none"} {
 	return
     }
     set last [$menu index last]
     if {$last eq "none"} {
 	return
     }
     for {set i 0} {$i <= $last} {incr i} {
 	if {([catch {set state [$menu entrycget $i -state]}] == 0) \
 		&& $state ne "disabled" && [$menu type $i] ne "tearoff"} {
 	    $menu activate $i
 	    GenerateMenuSelect $menu
 	    # Only post the cascade if the current menu is a menubar;
 	    # otherwise, if the first entry of the cascade is a cascade,
 	    # we can get an annoying cascading effect resulting in a bunch of
 	    # menus getting posted (bug 676)
 	    if {[$menu type $i] eq "cascade" && [$menu cget -type] eq "menubar"} {
 		set cascade [$menu entrycget $i -menu]
 		if {$cascade ne ""} {
 		    $menu postcascade $i
 		    MenuFirstEntry $cascade
 		}
 	    }
 	    return
 	}
     }
 }
 
 # ::tk::MenuFindName --
 # Given a menu and a text string, return the index of the menu entry
 # that displays the string as its label.  If there is no such entry,
 # return an empty string.  This procedure is tricky because some names
 # like "active" have a special meaning in menu commands, so we can't
 # always use the "index" widget command.
 #
 # Arguments:
 # menu -		Name of the menu widget.
 # s -			String to look for.
 
 proc ::tk::MenuFindName {menu s} {
     set i ""
     if {![regexp {^active$|^last$|^none$|^[0-9]|^@} $s]} {
 	catch {set i [$menu index $s]}
 	return $i
     }
     set last [$menu index last]
     if {$last eq "none"} {
 	return
     }
     for {set i 0} {$i <= $last} {incr i} {
 	if {![catch {$menu entrycget $i -label} label]} {
 	    if {$label eq $s} {
 		return $i
 	    }
 	}
     }
     return ""
 }
 
 # ::tk::PostOverPoint --
 # This procedure posts a given menu such that a given entry in the
 # menu is centered over a given point in the root window.  It also
 # activates the given entry.
 #
 # Arguments:
 # menu -		Menu to post.
 # x, y -		Root coordinates of point.
 # entry -		Index of entry within menu to center over (x,y).
 #			If omitted or specified as {}, then the menu's
 #			upper-left corner goes at (x,y).
 
 proc ::tk::PostOverPoint {menu x y {entry {}}}  {
     if {$entry ne ""} {
 	if {$entry == [$menu index last]} {
 	    incr y [expr {-([$menu yposition $entry] \
 		    + [winfo reqheight $menu])/2}]
 	} else {
 	    incr y [expr {-([$menu yposition $entry] \
 		    + [$menu yposition [expr {$entry+1}]])/2}]
 	}
 	incr x [expr {-[winfo reqwidth $menu]/2}]
     }
 
     if {[tk windowingsystem] eq "win32"} {
 	# osVersion is not available in safe interps
 	set ver 5
 	if {[info exists ::tcl_platform(osVersion)]} {
 	    scan $::tcl_platform(osVersion) %d ver
 	}
 
 	# We need to fix some problems with menu posting on Windows,
 	# where, if the menu would overlap top or bottom of screen,
 	# Windows puts it in the wrong place for us.  We must also
 	# subtract an extra amount for half the height of the current
 	# entry.  To be safe we subtract an extra 10.
 	# NOTE: this issue appears to have been resolved in the Window
 	# manager provided with Vista and Windows 7.
 	if {$ver < 6} {
 	    set yoffset [expr {[winfo screenheight $menu] \
 		    - $y - [winfo reqheight $menu] - 10}]
 	    if {$yoffset < [winfo vrooty $menu]} {
 		# The bottom of the menu is offscreen, so adjust upwards
 		incr y [expr {$yoffset - [winfo vrooty $menu]}]
 	    }
 	    # If we're off the top of the screen (either because we were
 	    # originally or because we just adjusted too far upwards),
 	    # then make the menu popup on the top edge.
 	    if {$y < [winfo vrooty $menu]} {
 		set y [winfo vrooty $menu]
 	    }
 	}
     }
     $menu post $x $y
     if {$entry ne "" && [$menu entrycget $entry -state] ne "disabled"} {
 	$menu activate $entry
 	GenerateMenuSelect $menu
     }
 }
 
 # ::tk::SaveGrabInfo --
 # Sets the variables tk::Priv(oldGrab) and tk::Priv(grabStatus) to record
 # the state of any existing grab on the w's display.
 #
 # Arguments:
 # w -			Name of a window;  used to select the display
 #			whose grab information is to be recorded.
 
 proc tk::SaveGrabInfo w {
     variable ::tk::Priv
     set Priv(oldGrab) [grab current $w]
     if {$Priv(oldGrab) ne ""} {
 	set Priv(grabStatus) [grab status $Priv(oldGrab)]
     }
 }
 
 # ::tk::RestoreOldGrab --
 # Restores the grab to what it was before TkSaveGrabInfo was called.
 #
 
 proc ::tk::RestoreOldGrab {} {
     variable ::tk::Priv
 
     if {$Priv(oldGrab) ne ""} {
 	# Be careful restoring the old grab, since it's window may not
 	# be visible anymore.
 
 	catch {
 	    if {$Priv(grabStatus) eq "global"} {
 		grab set -global $Priv(oldGrab)
 	    } else {
 		grab set $Priv(oldGrab)
 	    }
 	}
 	set Priv(oldGrab) ""
     }
 }
 
 proc ::tk_menuSetFocus {menu} {
     variable ::tk::Priv
     if {![info exists Priv(focus)] || $Priv(focus) eq ""} {
 	set Priv(focus) [focus]
     }
     focus $menu
 }
 
 proc ::tk::GenerateMenuSelect {menu} {
     variable ::tk::Priv
 
     if {$Priv(activeMenu) eq $menu \
 	    && $Priv(activeItem) eq [$menu index active]} {
 	return
     }
 
     set Priv(activeMenu) $menu
     set Priv(activeItem) [$menu index active]
     event generate $menu <<MenuSelect>>
 }
 
 # ::tk_popup --
 # This procedure pops up a menu and sets things up for traversing
 # the menu and its submenus.
 #
 # Arguments:
 # menu -		Name of the menu to be popped up.
 # x, y -		Root coordinates at which to pop up the
 #			menu.
 # entry -		Index of a menu entry to center over (x,y).
 #			If omitted or specified as {}, then menu's
 #			upper-left corner goes at (x,y).
 
 proc ::tk_popup {menu x y {entry {}}} {
     variable ::tk::Priv
     if {$Priv(popup) ne "" || $Priv(postedMb) ne ""} {
 	tk::MenuUnpost {}
     }
     tk::PostOverPoint $menu $x $y $entry
     if {[tk windowingsystem] eq "x11" && [winfo viewable $menu]} {
         tk::SaveGrabInfo $menu
 	grab -global $menu
 	set Priv(popup) $menu
 	set Priv(window) $menu
 	set Priv(menuActivated) 1
 	tk_menuSetFocus $menu
     }
 }