path: root/graphics/finomaton/finomaton.tcl

#!/bin/sh
# the next line restarts using wish \
exec wish "$0" "$@"

#   Finomaton - Draw Finite State Machines
#   Copyright (C) 2003, 2006, 2007 Markus Triska (triska@gmx.at)
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA


if {[info tclversion] < 8.3} {
    puts "This program requires Tcl >= 8.3. You have: [info tclversion]"
    exit
}

set PROGRAM      "Finomaton"
set VERSION      1.0
set PI           [expr atan(1)*4]
set windowtitle  $PROGRAM
set batchmode    0

set default_stateradius 20
set default_linelength  80
set default_cpradius     6
set magnetic_radius      7
set highlight           "#3078d8"
set metapost_scale_default 0.5
set metapost_scale      $metapost_scale_default

set selectedlist        {}
set dragobject          -1
set dragstart        "0 0"
set dragend          "0 0"
set dragrectangleid     -1
set currentcommand      ""
set anchormenu          ""
set needs_save           0
set currentfile         ""
set export_mp_file_default ""
set export_mp_file      $export_mp_file_default
set export_ps_file      ""
set filecomment_default ""
set filecomment         $filecomment_default
set ahangle_default     35
set ahangle             $ahangle_default
set ahlength_default     4
set ahlength            $ahlength_default
set fileauthor_default  ""
set fileauthor          $fileauthor_default
set verbatimtex_default ""
set verbatimtex         $verbatimtex_default
set graphstyle          "automaton"
set graphstyle_default  "automaton"
set modifiable_params   {metapost_scale ahangle ahlength filecomment \
			     export_mp_file fileauthor verbatimtex graphstyle}
array set objectinfo    {}


proc digraph {} {
    global graphstyle
    return [string equal $graphstyle "digraph"]
}

proc automaton {} {
    return [expr ![digraph]]
}

proc reset_parameter {param} {
    upvar #0 $param p
    upvar #0 ${param}_default pd
    set p $pd
}

proc reset_all_parameters {} {
    global modifiable_params
    foreach mp $modifiable_params { reset_parameter $mp }
}

proc is_numeric {s} {
    return [regexp {^[+-]?\d*\.?\d+$} $s]
}

proc check_parameters {} {
    global metapost_scale ahangle ahlength
    foreach numericparam {metapost_scale ahangle ahlength} {
	if {![is_numeric [subst $$numericparam]]} {
	    reset_parameter $numericparam
	}
    }
}

set unid 0
proc unique_id {} {
    # simulate behaviour of the canvas widget in batch mode
    global unid
    incr unid
    return $unid
}

proc get_objects_type {type} {
    global objectinfo
    set objlist ""
    foreach id [array names objectinfo {*-id}] {
	set id [string replace $id [string first "-" $id] end]
	if {$objectinfo($id-type) == $type} { lappend objlist $id }
    }
    return $objlist
}

proc set_command {command} {
    global currentcommand commandsframe
    if {$currentcommand != ""} {
	set path "$commandsframe.command_$currentcommand"
	$path configure -relief raised
    }

    set newpath "$commandsframe.command_$command"
    $newpath configure -relief sunken
    set currentcommand $command
}

proc dist {x1 y1 x2 y2} {
    set dx [expr {$x2 - $x1}]
    set dy [expr {$y2 - $y1}]
    return [expr hypot($dx, $dy)]
}

proc inside_object {X Y} {
    upvar #0 objectinfo oi

    # check control points first since they can be inside states
    foreach id [get_objects_type "controlpoint"] {
	if {[dist $oi($id-x) $oi($id-y) $X $Y] <= $oi($id-radius)} {
	    return $id
	}
    }

    foreach id [get_objects_type "state"] {
	if {[dist $oi($id-x) $oi($id-y) $X $Y] <= $oi($id-radius)} {
	    return $id
	}
    }
    return -1
}

proc correct_angle {angle a} {
    set corr 7
    if {($angle >= $a - $corr) && ($angle <= $a + $corr)} { return $a }
    return $angle
}

proc magnetic_anchor {X Y} {
    # pull control points to states (outline or center), return stateid
    # and angle to attach line (-1 for center), or -1 if no state found

    global magnetic_radius

    foreach id [get_objects_type "state"] {
	upvar #0 objectinfo oi
	set d [dist $X $Y $oi($id-x) $oi($id-y)]
	if {abs($d - $oi($id-radius)) <= $magnetic_radius} {
	    # pull to point on outline
	    set dx [expr {$X - $oi($id-x)}]
	    set cos [expr {$dx / $d}]
	    global PI
	    set angle [expr {(acos($cos)/$PI*180)}]
	    if {$Y > $oi($id-y)} { set angle [expr {360 - $angle}] }
	    foreach a {0 90 180 270 360} {
		# set angle [correct_angle $angle $a]
	    }
	    return "$id [expr round($angle)]"
	} elseif {$d <= $magnetic_radius} {
	    # pull to center
	    return "$id -1"
	}
    }
    return -1
}

proc anchor_coords {stateid angle} {
    global objectinfo PI
    set x $objectinfo($stateid-x)
    set y $objectinfo($stateid-y)
    if {$angle == -1} { return "$x $y" }

    set r $objectinfo($stateid-radius)
    set anchx [expr {$x + $r*cos($angle*$PI/180)}]
    set anchy [expr {$y - $r*sin($angle*$PI/180)}]
    return "$anchx $anchy"
}

proc create_state {X Y r} {
    global maincanvas objectinfo batchmode

    set id 0
    if {$batchmode} {
	set id [unique_id]
	set labelid [unique_id]
    } else {
	set id [$maincanvas create oval 0 0 0 0 -tags state]
	set labelid [$maincanvas create text $X $Y -text "s"]
    }
    set objectinfo($id-radius) $r
    set objectinfo($id-x) $X
    set objectinfo($id-y) $Y
    set objectinfo($id-id) $id
    set objectinfo($id-type) "state"
    set objectinfo($id-label) ""
    set objectinfo($id-tex) ""
    set objectinfo($id-accept) 0
    set objectinfo($id-acceptid) -1
    set objectinfo($id-start) 0
    set objectinfo($id-labelid) $labelid
    set objectinfo($labelid-type) "statelabel"

    update_object $id
    return $id
}

proc add_control_point {line X Y {interactive 1}} {
    global objectinfo maincanvas default_cpradius batchmode

    set id 0
    if {$batchmode} {
	set id [unique_id]
    } else {
	set id [$maincanvas create oval 0 0 0 0 -tags cp]
    }
    set objectinfo($id-x) $X
    set objectinfo($id-y) $Y
    set objectinfo($id-type) "controlpoint"
    set objectinfo($id-line) $line
    set objectinfo($id-id) $id

    set insertpos end
    if {$interactive} {
	set insertpos 1
	if {[llength $objectinfo($line-cplist)] == 3} {
	    # insert it depending on which endpoint is nearer
	    set ep1 [lindex $objectinfo($line-cplist) 0]
	    set ep2 [lindex $objectinfo($line-cplist) 2]
	    set d1 [dist $objectinfo($ep1-x) $objectinfo($ep1-y) $X $Y]
	    set d2 [dist $objectinfo($ep2-x) $objectinfo($ep2-y) $X $Y]
	    if {$d2 < $d1} { set insertpos 2 }
	}
    }

    set objectinfo($line-cplist) [linsert $objectinfo($line-cplist) \
				      $insertpos $id]
    set objectinfo($id-radius) $default_cpradius
    set objectinfo($id-attached) -1
    set objectinfo($id-angle) 0
    # don't use update_object here, because the line might not be finished yet
    update_oval $id
    return $id
}

proc create_line {X Y {interactive 1}} {
    global maincanvas default_linelength objectinfo batchmode
    # set control points
    set cp1x $X
    set cp2x [expr {$X + ($default_linelength / 2)}]
    set cp3x [expr {$X + $default_linelength}]
    set lid 0
    if {$batchmode} {
	set lid [unique_id]
    } else {
	set lid [$maincanvas create line $cp1x $Y $cp2x $Y $cp3x $Y \
		     -smooth 1 -arrow last -tags line]
    }
    set objectinfo($lid-type) "line"
    set objectinfo($lid-id) $lid
    set objectinfo($lid-tex) ""
    set objectinfo($lid-texpos) 0.5
    set objectinfo($lid-anchor) "top"
    set objectinfo($lid-cplist) ""
    set objectinfo($lid-bisect) 1
    # coordinates for lines are used to compute relative movement when
    # the line is being dragged. meaningless otherwise.
    set objectinfo($lid-x) 0
    set objectinfo($lid-y) 0

    if {$interactive} {
	foreach cp {cp1 cp2 cp3} {
	    set cpx [subst $${cp}x]
	    add_control_point $lid $cpx $Y 0
	}
	update_object $lid
    }
    return $lid
}

proc create_text {X Y} {
    global maincanvas objectinfo batchmode
    set id 0
    if {$batchmode} {
	set id [unique_id]
    } else {
	set id [$maincanvas create text $X $Y -text "text" -tags text]
    }
    set objectinfo($id-type) "text"
    set objectinfo($id-x) $X
    set objectinfo($id-y) $Y
    set objectinfo($id-label) "text"
    set objectinfo($id-tex) ""
    set objectinfo($id-id) $id
    return $id
}

proc remove_object {id {interactive 1}} {
    global objectinfo maincanvas

    if {$objectinfo($id-type) == "controlpoint"} {
	set lid $objectinfo($id-line)
	set cplist $objectinfo($lid-cplist)
	set i [lsearch $cplist $id]
	set objectinfo($lid-cplist) [lreplace $cplist $i $i]
	if {$interactive} {
	    # called by user, not when deleting whole line
	    if {[llength $objectinfo($lid-cplist)] <= 1} {
		remove_object $lid
	    } else {
		update_object $lid
	    }
	}
    } elseif {$objectinfo($id-type) == "line"} {
	foreach cp $objectinfo($id-cplist) { remove_object $cp 0 }
    } elseif {$objectinfo($id-type) == "state"} {
	remove_object $objectinfo($id-labelid)
	if {$objectinfo($id-accept)} {
	    remove_object $objectinfo($id-acceptid)
	}
	foreach cpid [get_objects_type "controlpoint"] {
	    if {$objectinfo($cpid-attached) == $id} {
		set objectinfo($cpid-attached) -1
	    }
	}
    }

    remove_select $id
    $maincanvas delete $id
    array unset objectinfo "$id-*"
}

proc update_oval {id} {
    global maincanvas batchmode objectinfo
    if {$batchmode} { return }

    set r $objectinfo($id-radius)
    set x1 [expr {$objectinfo($id-x) - $r}]
    set x2 [expr {$objectinfo($id-x) + $r}]
    set y1 [expr {$objectinfo($id-y) - $r}]
    set y2 [expr {$objectinfo($id-y) + $r}]
    $maincanvas coords $id $x1 $y1 $x2 $y2
}

proc update_object {id} {
    global objectinfo maincanvas batchmode
    if {$batchmode} { return }
    if {$objectinfo($id-type) == "line"} {
	set points ""
	foreach cp $objectinfo($id-cplist) {
	    set points [concat $points "$objectinfo($cp-x) $objectinfo($cp-y)"]
	}
	$maincanvas coords $id $points
    } elseif {$objectinfo($id-type) == "controlpoint"} {
	update_oval $id
	update_object $objectinfo($id-line)
    } elseif {$objectinfo($id-type) == "state"} {
	update_oval $id
	if {$objectinfo($id-start)} {
	    $maincanvas itemconfigure $id -width 3
	} else {
	    $maincanvas itemconfigure $id -width 1
	}

	if {$objectinfo($id-accept)} {
	    set accid $objectinfo($id-acceptid)
	    if {$accid == -1} {
		set accid [$maincanvas create oval 0 0 0 0]
		global default_stateradius
		set objectinfo($accid-radius) [expr {$default_stateradius - 4}]
		set objectinfo($accid-type) "acceptcircle"
		set objectinfo($id-acceptid) $accid
	    }
	    set objectinfo($accid-x) $objectinfo($id-x)
	    set objectinfo($accid-y) $objectinfo($id-y)
	    update_oval $accid
	} else {
	    if {$objectinfo($id-acceptid) != -1} {
		remove_object $objectinfo($id-acceptid)
		set objectinfo($id-acceptid) -1
	    }
	}
	$maincanvas itemconfigure $objectinfo($id-labelid) -text \
	    $objectinfo($id-label)
	$maincanvas coords $objectinfo($id-labelid) \
	    $objectinfo($id-x) $objectinfo($id-y)
	foreach cp [get_objects_type "controlpoint"] {
	    if {$objectinfo($cp-attached) == $id} {
		set c [anchor_coords $id $objectinfo($cp-angle)]
		set objectinfo($cp-x) [lindex $c 0]
		set objectinfo($cp-y) [lindex $c 1]
		update_object $cp
	    }
	}
    } elseif {$objectinfo($id-type) == "text"} {
	$maincanvas itemconfigure $id -text $objectinfo($id-label)
	$maincanvas coords $id $objectinfo($id-x) $objectinfo($id-y)
    }
}

proc move_delta {id dx dy} {
    global objectinfo
    set objectinfo($id-x) [expr {$objectinfo($id-x) + $dx}]
    set objectinfo($id-y) [expr {$objectinfo($id-y) + $dy}]
    if {$objectinfo($id-x) < 0} { set objectinfo($id-x) 0 }
    if {$objectinfo($id-y) < 0} { set objectinfo($id-y) 0 }
    update_object $id
}


proc move_objects {coords} {
    global selectedlist objectinfo dragobject
    if {$dragobject == -1} { return }

    set X [lindex $coords 0]
    set Y [lindex $coords 1]

    set newx $X
    set newy $Y

    # a control point might be moved to coordinates different from ($X/$Y)
    # because of magnetic states. so check this first.
    if {$objectinfo($dragobject-type) == "controlpoint"} {
	set magna [magnetic_anchor $X $Y]
	if {$magna != -1} {
	    set magid [lindex $magna 0]
	    set angle [lindex $magna 1]
	    set coords [anchor_coords $magid $angle]
	    set newx [lindex $coords 0]
	    set newy [lindex $coords 1]
	    set objectinfo($dragobject-attached) $magid
	    set objectinfo($dragobject-angle) $angle
	} else {
	    set objectinfo($dragobject-attached) -1
	    set objectinfo($dragobject-angle) 0
	}
    }

    # now compute the relative movement of the primarily dragged object
    set dx [expr {$newx - $objectinfo($dragobject-x)}]
    set dy [expr {$newy - $objectinfo($dragobject-y)}]

    # move all selected objects accordingly (includes dragged object)
    foreach id $selectedlist {
	if {$id != $dragobject && $objectinfo($id-type) == "controlpoint"} {
	    # detach other control points if necessary
	    set s $objectinfo($id-attached)
	    if {$s != -1 && [lsearch $selectedlist $s] == -1} {
		set objectinfo($id-attached) -1
	    }
	}
	move_delta $id $dx $dy
    }
}

proc hide_control_points {} {
    global maincanvas
    $maincanvas itemconfigure cp -outline ""
}

proc add_select {id} {
    global selectedlist maincanvas objectinfo highlight
    if {[lsearch $selectedlist $id] == -1} {
	lappend selectedlist $id
    }

    if {$objectinfo($id-type) == "line" || $objectinfo($id-type) == "text"} {
	$maincanvas itemconfigure $id -fill $highlight
    } else {
	$maincanvas itemconfigure $id -outline $highlight
    }

    if {$objectinfo($id-type) == "line"} {
	foreach cp $objectinfo($id-cplist) { add_select $cp }
    }
}

proc remove_select {id} {
    global selectedlist objectinfo maincanvas
    set pos [lsearch $selectedlist $id]
    if {$pos != -1} {
	set selectedlist [lreplace $selectedlist $pos $pos]
	if {$objectinfo($id-type) == "line" || \
		$objectinfo($id-type) == "text"} {
	    $maincanvas itemconfigure $id -fill black
	} else {
	    $maincanvas itemconfigure $id -outline black
	}
    }
    global dragobject
    if {$dragobject == $id} {
	set dragobject -1
    }
}

proc toggle_item {id} {
    global selectedlist dragobject
    if {[lsearch $selectedlist $id] == -1} {
	add_select $id
	set dragobject $id
    } else {
	remove_select $id
    }
}

proc closest_item {coords} {
    global maincanvas objectinfo
    set X [lindex $coords 0]
    set Y [lindex $coords 1]

    set id [inside_object $X $Y]
    if {$id != -1} { return $id }

    set id [$maincanvas find closest $X $Y]
    if {$id != ""} {
	if {$objectinfo($id-type) == "line"} {
	    return $id
	} elseif {$objectinfo($id-type) == "text"} {
	    return $id
	}
    }
    return -1
}

proc toggle_select {coords} {
    global objectinfo
    set id [closest_item $coords]
    if {$id != -1} {
	toggle_item $id
	if {$objectinfo($id-type) == "line"} {
	    set objectinfo($id-x) [lindex $coords 0]
	    set objectinfo($id-y) [lindex $coords 1]
	}
    }
}


proc canvas_clicked {command coords} {
    global maincanvas objectinfo default_stateradius needs_save
    set X [lindex $coords 0]
    set Y [lindex $coords 1]
    if {$command == "newstate"} {
	create_state $X $Y $default_stateradius
	hide_control_points
	set needs_save 1
    } elseif {$command == "newline"} {
	create_line $X $Y
	set needs_save 1
    } elseif {$command == "newcp"} {
	set id [$maincanvas find closest $X $Y]
	if {$id == "" || $objectinfo($id-type) != "line"} { return }
	if {[llength $objectinfo($id-cplist)] < 4} {
	    add_control_point $id $X $Y
	    update_object $id
	    set needs_save 1
	}
    } elseif {$command == "newtext"} {
	create_text $X $Y
	set needs_save 1
    } elseif {$command == "select"} {
	global dragobject selectedlist
	set id [closest_item "$X $Y"]

	if {$id == -1 || [lsearch $selectedlist $id] == -1} {
	    foreach sid $selectedlist { remove_select $sid }
	}

	if {$id == -1} {
	    hide_control_points
	    set dragobject -1
	    global dragstart dragend dragrectangleid
	    set dragstart "$X $Y"
	    set dragend $dragstart
	    set dragrectangleid [$maincanvas create rectangle $X $Y $X $Y]
	    return
	}

	if {$objectinfo($id-type) == "state"} {
	    hide_control_points
	} elseif {$objectinfo($id-type) == "line"} {
	    # here, the line is assigned coordinates to compute
	    # relative movement when dragged
	    set objectinfo($id-x) $X
	    set objectinfo($id-y) $Y
	} elseif {$objectinfo($id-type) == "controlpoint"} {
	    set lid $objectinfo($id-line)
	    remove_select $lid
	    foreach cp $objectinfo($lid-cplist) {
		remove_select $cp
	    }
	}

	set dragobject $id
	add_select $id
    } elseif {$command == "remove"} {
	set id [closest_item "$X $Y"]
	if {$id != -1} {
	    remove_object $id
	    set needs_save 1
	}
    }
}

proc center_window {win} {
    set x [expr {[winfo rootx .] + [winfo reqwidth .]/2 \
		     - [winfo reqwidth $win]/2}]
    set y [expr {[winfo rooty .] + [winfo reqheight .]/2 \
		     - [winfo reqheight $win]/2}]
    wm geometry $win "+$x+$y"
}

proc set_geometry {win} {
    wm withdraw $win
    update idletasks
    center_window $win
    wm deiconify $win
    wm minsize $win [winfo reqwidth $win] [winfo reqheight $win]
}

proc transient_window {win title} {
    if {[winfo exists $win]} {
	center_window $win
	return -1
    }
    toplevel $win
    wm title $win $title
    wm transient $win .
    return $win
}

proc double_click {coords} {
    global objectinfo
    set id [closest_item $coords]
    if {$id == -1} { return }

    if {$objectinfo($id-type) == "text"} {
	edit_text $id
    } elseif {$objectinfo($id-type) == "line"} {
	edit_line $id
    } elseif {$objectinfo($id-type) == "state"} {
	edit_state $id
    }
}


proc edit_state {id} {
    set w [transient_window .editstate "Edit state"]
    if {$w == -1} { return }

    wm protocol $w WM_DELETE_WINDOW { set statebutton 0 }

    global objectinfo
    set f1 [frame $w.f1]
    label $f1.lab1 -text "Label:"
    entry $f1.ent1
    $f1.ent1 insert 0 $objectinfo($id-label)
    bind $f1.ent1 <Return> { set statebutton 1 }

    label $f1.lab2 -text "TeX:"
    entry $f1.ent2
    $f1.ent2 insert 0 $objectinfo($id-tex)
    bind $f1.ent2 <Return> { set statebutton 1 }

    label $f1.lab3 -text \
	"Tip for TeX: Include a \\strut to\nmake the circle bigger"

    grid $f1.lab1 $f1.ent1 -padx 5 -pady 5
    grid $f1.lab2 $f1.ent2 -padx 5 -pady 5
    grid $f1.lab3 -
    grid configure $f1.lab1 -sticky w
    grid configure $f1.lab2 -sticky w
    grid configure $f1.ent1 -sticky e
    grid configure $f1.ent2 -sticky nesw
    grid columnconfigure $f1 1 -weight 1
    pack $f1 -expand yes -fill both

    set f2 [frame $w.f2]
    label $f2.lab1 -text "X:"
    entry $f2.ent1 -width 6
    $f2.ent1 insert 0 $objectinfo($id-x)
    bind $f2.ent1 <Return> { set statebutton 1 }

    label $f2.lab2 -text "Y:"
    entry $f2.ent2 -width 6
    $f2.ent2 insert 0 $objectinfo($id-y)
    bind $f2.ent2 <Return> { set statebutton 1 }

    grid $f2.lab1 $f2.ent1 -padx 5 -pady 5
    grid $f2.lab2 $f2.ent2 -padx 5 -pady 5
    grid configure $f2.lab1 -sticky w
    grid configure $f2.lab2 -sticky w
    grid configure $f2.ent1 -sticky e
    grid configure $f2.ent2 -sticky e
    grid columnconfigure $f2 1 -weight 1
    pack $f2 -expand yes -fill both

    global acceptcheck startcheck

    set f3 [frame $w.f3]
    label $f3.lab -text "Accepting state:"
    pack $f3.lab -side left -padx 5 -pady 5
    pack [checkbutton $f3.acceptcheck] -side left -expand yes -anchor e
    set acceptcheck $objectinfo($id-accept)
    pack $f3 -expand yes -fill both

    set f4 [frame $w.f4]
    label $f4.lab -text "Starting state:"
    pack $f4.lab -side left -padx 5 -pady 5
    pack [checkbutton $f4.startcheck] -side left -expand yes -anchor e
    set startcheck $objectinfo($id-start)
    pack $f4 -expand yes -fill both


    global statebutton needs_save
    set statebutton ""
    set f5 [frame $w.f5]
    button $f5.ok -text "  OK  " -command { set statebutton 1 }
    pack $f5.ok -side left -padx 5 -pady 5
    button $f5.cancel -text " Cancel " -command { set statebutton 0 }
    pack $f5.cancel -side left -padx 5 -pady 5
    pack $f5 -padx 5 -pady 5

    set_geometry $w
    focus $f1.ent1
    tkwait variable statebutton
    if {$statebutton == 1} {
	set objectinfo($id-label) [$f1.ent1 get]
	set objectinfo($id-tex)   [$f1.ent2 get]
	set x [$f2.ent1 get]
	set y [$f2.ent2 get]
	if {[is_numeric $x] && $x >= 0} { set objectinfo($id-x) $x }
	if {[is_numeric $y] && $y >= 0} { set objectinfo($id-y) $y }
	set objectinfo($id-accept) $acceptcheck
	set objectinfo($id-start)  $startcheck
	set needs_save 1
	update_object $id
    }
    destroy $w
}

proc edit_text {id} {
    set w [transient_window .edittext "Edit text"]
    if {$w == -1} { return }

    wm protocol $w WM_DELETE_WINDOW { set textbutton 0 }

    global objectinfo
    set f1 [frame $w.f1]
    label $f1.lab -text "Label:"
    pack $f1.lab -side left -padx 5 -pady 5
    entry $f1.ent
    pack $f1.ent -side left -padx 5 -pady 5 -expand yes -fill x
    $f1.ent insert 0 $objectinfo($id-label)
    pack $f1 -padx 5 -pady 5 -fill both -expand yes -anchor e
    bind $f1.ent <Return> { set textbutton 1 }

    set f2 [frame $w.f2]
    label $f2.lab -text "TeX:"
    pack $f2.lab -side left -padx 5 -pady 5
    entry $f2.ent
    pack $f2.ent -side left -padx 5 -pady 5 -expand yes -fill x
    $f2.ent insert 0 $objectinfo($id-tex)
    pack $f2 -padx 5 -pady 5 -fill both -expand yes -anchor e
    bind $f2.ent <Return> { set textbutton 1 }

    global textbutton needs_save
    set textbutton ""
    set f3 [frame $w.f3]
    button $f3.ok -text "  OK  " -command { set textbutton 1 }
    pack $f3.ok -side left -padx 5 -pady 5
    button $f3.cancel -text " Cancel " -command { set textbutton 0 }
    pack $f3.cancel -side left -padx 5 -pady 5
    pack $f3 -padx 5 -pady 5

    set_geometry $w
    focus $f1.ent
    tkwait variable textbutton
    if {$textbutton == 1} {
	set objectinfo($id-label) [$f1.ent get]
	set objectinfo($id-tex)   [$f2.ent get]
	set needs_save 1
	update_object $id
    }
    destroy $w
}

proc edit_line {id} {
    set w [transient_window .editline "Edit line"]
    if {$w == -1} { return }

    wm protocol $w WM_DELETE_WINDOW { set linebutton 0 }

    global objectinfo
    set f1 [frame $w.f1]
    label $f1.lab -text "Label (TeX):"
    pack $f1.lab -side left -padx 5 -pady 5
    entry $f1.ent
    pack $f1.ent -side left -padx 5 -pady 5 -expand yes -fill x
    $f1.ent insert 0 $objectinfo($id-tex)
    pack $f1 -fill both -expand yes
    bind $f1.ent <Return> { set linebutton 1 }

    set f2 [frame $w.f2]
    label $f2.lab -text "How far along (percent):"
    pack $f2.lab -side left -padx 5 -pady 5
    scale $f2.pos -from 0 -to 100 -orient horizontal
    pack $f2.pos -side left -padx 5 -pady 5 -expand yes -fill x
    pack $f2 -fill both -expand yes
    $f2.pos set [expr {$objectinfo($id-texpos) * 100}]

    set f3 [frame $w.f3]
    label $f3.lab -text "Label position:"
    pack $f3.lab -side left -padx 5 -pady 5
    set mb [menubutton $f3.mbutton -menu $f3.mbutton.menu -relief raised]
    pack $mb -side left -padx 5 -pady 5

    global anchorpos
    set anchorpos $objectinfo($id-anchor)
    set m [menu $f3.mbutton.menu -tearoff 0]
    foreach {l p} {Top top Right rt Bottom bot Left lft "Upper right" urt \
		       "Lower right" lrt "Lower left" llft "Upper left" ulft} {
	if {$anchorpos == $p} { $mb configure -text $l }
	$m add command -label $l -command \
	    "set anchorpos $p; $mb configure -text [list $l]"
    }
    pack $f3 -fill both -expand yes

    global bisectcheck
    set f4 [frame $w.f4]
    label $f4.lab -text "Interpolate control points:"
    pack $f4.lab -side left -padx 5 -pady 5
    pack [checkbutton $f4.bisectcheck] -side left -expand yes -anchor e
    set bisectcheck $objectinfo($id-bisect)
    pack $f4 -expand yes -fill both

    global linebutton
    set linebutton ""
    set f5 [frame $w.f5]
    button $f5.ok -text "  OK  " -command { set linebutton 1 }
    pack $f5.ok -side left -padx 5 -pady 5
    button $f5.cancel -text " Cancel " -command { set linebutton 0 }
    pack $f5.cancel -side left -padx 5 -pady 5
    pack $f5 -padx 5 -pady 5

    set_geometry $w
    focus $f1.ent
    tkwait variable linebutton
    if {$linebutton == 1} {
	set objectinfo($id-tex) [$f1.ent get]
	set objectinfo($id-texpos) [expr {[$f2.pos get] / 100.0}]
	set objectinfo($id-anchor) $anchorpos
	set objectinfo($id-bisect) $bisectcheck
	global needs_save
	set needs_save 1
    }
    destroy $w
}

proc settings {} {
    global metapost_scale filecomment ahangle ahlength fileauthor
    global verbatimtex graphstyle
    set w [transient_window .settings "Settings for this file"]
    if {$w == -1} { return }

    wm protocol $w WM_DELETE_WINDOW { set settingsbutton 0 }

    set f1 [frame $w.f1]
    label $f1.lab -text "MetaPost scale factor:"
    pack $f1.lab -side left -padx 5 -pady 5
    entry $f1.ent -width 3
    $f1.ent insert 0 $metapost_scale
    pack $f1.ent -side left -padx 5 -pady 5 -expand yes -anchor e
    pack $f1 -fill x

    set f2 [frame $w.f2]
    label $f2.lab -text "Arrowhead breadth:"
    pack $f2.lab -side left -padx 5 -pady 5
    entry $f2.ent -width 3
    pack $f2.ent -side left -padx 5 -pady 5 -expand yes -anchor e
    $f2.ent insert 0 $ahangle
    pack $f2 -fill x

    set f3 [frame $w.f3]
    label $f3.lab -text "Arrowhead length (bp):"
    pack $f3.lab -side left -padx 5 -pady 5
    entry $f3.ent -width 3
    pack $f3.ent -side left -padx 5 -pady 5 -expand yes -anchor e
    $f3.ent insert 0 $ahlength
    pack $f3 -fill x

    set f4 [frame $w.f4]
    label $f4.lab -text "Export style:"
    pack $f4.lab -side left -padx 5 -pady 5
    set mb [menubutton $f4.mbutton -menu $f4.mbutton.menu \
		-text $graphstyle -relief raised]
    pack $mb -side left -padx 5 -pady 5

    set m [menu $f4.mbutton.menu -tearoff 0]
    foreach gs {automaton digraph} {
	$m add command -label $gs -command "$mb configure -text $gs"
    }
    pack $f4 -fill x

    set tp [frame $w.textparent]

    label $tp.authorlab -text "Author:"
    entry $tp.authorent -width 20
    $tp.authorent insert 0 $fileauthor

    label $tp.commentlab -text "File comment:"
    text $tp.commentent -width 40 -height 5
    $tp.commentent insert end $filecomment

    label $tp.verbatimlab -text "TeX macros:"
    text $tp.verbatiment -width 40 -height 7
    $tp.verbatiment insert end $verbatimtex

    grid $tp.authorlab $tp.authorent -padx 5 -pady 5
    grid $tp.commentlab $tp.commentent -padx 5 -pady 5
    grid $tp.verbatimlab $tp.verbatiment -padx 5 -pady 5
    grid configure $tp.authorent -sticky w
    grid configure $tp.commentent -sticky nesw
    grid configure $tp.verbatiment -sticky nesw
    grid columnconfigure $tp 1 -weight 1
    grid rowconfigure $tp 1 -weight 1
    grid rowconfigure $tp 2 -weight 1
    pack $tp -expand yes -fill both

    global settingsbutton needs_save
    set settingsbutton ""

    set f5 [frame $w.f5]
    button $f5.ok -text "  OK  " -command { set settingsbutton 1 }
    pack $f5.ok -side left -padx 5 -pady 5
    button $f5.cancel -text " Cancel " -command { set settingsbutton 0 }
    pack $f5.cancel -side left -padx 5 -pady 5
    pack $f5 -padx 5 -pady 5

    set_geometry $w
    focus $f1.ent

    tkwait variable settingsbutton
    if {$settingsbutton == 1} {
	set needs_save 1
	set metapost_scale [$f1.ent get]
	set ahangle [$f2.ent get]
	set ahlength [$f3.ent get]
	set graphstyle [$f4.mbutton cget -text]
	set fileauthor [$tp.authorent get]
	set filecomment [string trim [$tp.commentent get 1.0 end]]
	set verbatimtex [string trim [$tp.verbatiment get 1.0 end]]
	check_parameters
    }
    destroy $w
}

proc about {} {
    global PROGRAM VERSION
    set aboutwin [transient_window .aboutwin "About $PROGRAM"]
    if {$aboutwin == ""} { return }
    label $aboutwin.copyright -text \
	"$PROGRAM $VERSION - Draw Finite State Machines\n\n\
		$PROGRAM comes with ABSOLUTELY NO WARRANTY. This is\n\
		free software, and you are welcome to distribute it\n\
		under certain conditions. Read the file COPYING for\n\
		more information.\n\n\
		Copyright (C) 2003, 2006, 2007 Markus Triska triska@gmx.at"
    button $aboutwin.ok -text "OK" -command { destroy .aboutwin }
    pack $aboutwin.copyright -pady 10 -padx 20
    pack $aboutwin.ok -pady 4
    set_geometry $aboutwin
    focus $aboutwin.ok
}


# The rest is about loading, saving and exporting.


proc mpost_scale {coord} {
    global metapost_scale
    set newcoord [expr {$metapost_scale * $coord}]
    return $newcoord
}

proc mpost_coords {id} {
    global objectinfo
    if {$objectinfo($id-type) == "controlpoint"} {
	set attid $objectinfo($id-attached)
	if {$attid != -1} {
	    return "(s$attid.c)"
	}
    }

    # MetaPost y coordinate is reversed (from our standpoint)
    set y [expr {- $objectinfo($id-y)}]
    return "([mpost_scale $objectinfo($id-x)], [mpost_scale $y])"
}

proc mpost_line {id} {
    # approximate the given line in MetaPost syntax
    global objectinfo
    set firstid [lindex $objectinfo($id-cplist) 0]
    set lastid [lindex $objectinfo($id-cplist) end]
    set numcp [llength $objectinfo($id-cplist)]
    set coord1 [mpost_coords $firstid]
    set coord2 [mpost_coords [lindex $objectinfo($id-cplist) 1]]

    set coords ""
    set loop 0
    if {$numcp == 2} {
	set coords "$coord1--$coord2"
    } elseif {$numcp == 3} {
	set coord3 [mpost_coords $lastid]
	if {$objectinfo($firstid-attached) != -1 && \
		$objectinfo($firstid-attached) == $objectinfo($lastid-attached)} {
	    # state points to itself, use angles
	    set loop 1
	    set point "s$objectinfo($firstid-attached)"
	    set startangle $objectinfo($firstid-angle)
	    set endangle [expr {$objectinfo($lastid-angle) + 180}]
	    if {[automaton]} {
		set coords "directionpoint dir [expr {$startangle + 90}] of bpath $point..controls $coord2 and $coord2..directionpoint dir [expr {$endangle - 90}] of bpath $point"
	    } else {
		set coords "$point.c..controls $coord2 and $coord2..$point.c"
	    }
	} else {
	    if {$objectinfo($id-bisect)} {
		# interpolate the two control points by bisecting the
		# lines from the endpoints to the single control point
		set coords "$coord1..controls .5\[$coord1,$coord2\] and .5\[$coord2,$coord3\]..$coord3"
	    } else {
		# use the endpoint as second control point
		set coords "$coord1..controls $coord2 and $coord3..$coord3"
	    }
	}
    } elseif {$numcp == 4} {
	if {$objectinfo($firstid-attached) != -1 && \
		$objectinfo($firstid-attached) == $objectinfo($lastid-attached)} {
	    # state points to itself, use angles
	    set loop 1
	    set coord3 [mpost_coords [lindex $objectinfo($id-cplist) 2]]
	    set startangle $objectinfo($firstid-angle)
	    set endangle [expr {$objectinfo($lastid-angle) + 180}]
	    set point "s$objectinfo($firstid-attached)"
	    if {[automaton]} {
		set coords "directionpoint dir [expr {$startangle + 90}] of bpath $point..controls $coord2 and $coord3..directionpoint dir [expr {$endangle - 90}] of bpath $point"
	    } else {
		set coords "$point.c..controls $coord2 and $coord3..$point.c"
	    }
	} else {
	    set coord3 [mpost_coords [lindex $objectinfo($id-cplist) 2]]
	    set coord4 [mpost_coords $lastid]
	    set coords "$coord1..controls $coord2 and $coord3..$coord4"
	}
    }

    if {[automaton] && !$loop} {
	if {$objectinfo($firstid-attached) != -1} {
	    set coords "$coords cutbefore bpath s$objectinfo($firstid-attached)"
	}

	if {$objectinfo($lastid-attached) != -1} {
	    set coords "$coords cutafter bpath s$objectinfo($lastid-attached)"
	}
    }

    return $coords;
}

proc save_metapost {file} {
    global PROGRAM VERSION objectinfo ahangle ahlength filecomment
    global fileauthor verbatimtex

    set fid [open $file w]
    puts $fid "% Creator: $PROGRAM $VERSION"
    puts $fid "% Creation-Date: [clock format [clock seconds]]"
    if {$fileauthor != ""} { puts $fid "% Author: $fileauthor" }
    regsub -all {\n} $filecomment "\n%    " exportcomment
    if {$exportcomment != ""} { puts $fid "% Comment: $exportcomment" }

    if {$verbatimtex != ""} { puts $fid "verbatimtex $verbatimtex etex" }
    puts $fid ""
    puts $fid "input boxes"
    puts $fid "% Breadth of arrowheads (MetaPost default is 45)"
    puts $fid "ahangle := $ahangle;"
    puts $fid "% Length of arrowheads (MetaPost default is 4bp)"
    puts $fid "ahlength := $ahlength;"
    puts $fid "beginfig(1);"
    puts $fid "% for temporary paths (might be unused)"
    puts $fid {path p[];}
    puts $fid ""
    puts $fid "% First, define and draw all the states"

    if {[digraph]} { puts $fid {pair s[].c;} }

    foreach id [lsort -integer [get_objects_type "state"]] {
	set lbl "\"$objectinfo($id-label)\""
	if {$objectinfo($id-tex) != ""} {
	    set lbl "btex $objectinfo($id-tex) etex"
	}

	if {[automaton]} {
	    puts $fid "circleit.s${id}($lbl);"
	    puts $fid "s$id.c = [mpost_coords $id];"
	    if {$objectinfo($id-start)} {
		puts $fid "pickup pencircle scaled 1.2bp;"
		puts $fid "drawboxed(s$id);"
		puts $fid "pickup defaultpen;"
	    } else {
		puts $fid "drawboxed(s$id);"
	    }
	    if {$objectinfo($id-accept)} {
		puts $fid "draw fullcircle scaled 0.85(ypart s$id.n - ypart s$id.s) shifted s$id.c;"
	    }
	} elseif {[digraph]} {
	    puts $fid "s$id.c = [mpost_coords $id];"
	    puts $fid "draw s$id.c withpen pencircle scaled 5pt;"
	}
	puts $fid ""
    }


    puts $fid "\n% Next, draw the lines"
    foreach id [lsort -integer [get_objects_type "line"]] {
	set coords [mpost_line $id]
	if {$objectinfo($id-tex) != ""} {
	    puts $fid "p$id = $coords;"
	    if {[automaton]} {
		puts $fid "drawarrow p$id;"
	    } else {
		puts $fid "drawarrow subpath (0,0.86) of p$id;"
	    }
	    puts $fid "label.$objectinfo($id-anchor)(btex $objectinfo($id-tex) etex, point $objectinfo($id-texpos) of p$id);"
	} else {
	    if {[automaton]} {
		puts $fid "drawarrow $coords;"
	    } else {
		set numcp [llength $objectinfo($id-cplist)]
		if {$numcp == 2} {
		    puts $fid "drawarrow subpath (0,0.92) of ($coords);"
		} else {
		    puts $fid "drawarrow subpath (0,0.82) of ($coords);"
		}
	    }
	}
	puts $fid ""
    }

    puts $fid "\n% Finally, create labels"
    foreach id [lsort -integer [get_objects_type "text"]] {
	set x [mpost_scale $objectinfo($id-x)]
	set y [mpost_scale [expr {-$objectinfo($id-y)}]]
	set lbl "\"$objectinfo($id-label)\""
	if {$objectinfo($id-tex) != ""} {
	    set lbl "btex $objectinfo($id-tex) etex"
	}
	puts $fid "label($lbl, ($x, $y));"
    }

    puts $fid "\nendfig;\nend"
    close $fid
}

proc export_metapost {{choose 0}} {
    global export_mp_file batchmode currentfile
    if {$batchmode} {
	if {[regexp "\.fin$" $currentfile]} {
	    regsub {fin$} $currentfile {mp} export_mp_file
	} else {
	    set export_mp_file "${currentfile}.mp"
	}
	puts "Exporting to $export_mp_file."
    } else {
	if {$export_mp_file == "" || $choose} {
	    set ifile "[file rootname [file tail $currentfile]].mp"
	    set export_mp_file [tk_getSaveFile -defaultextension ".mp" -initialfile $ifile -filetypes {{MetaPost .mp} {All *}}]
	    if {$export_mp_file == ""} { return -1 }
	    global needs_save
	    set needs_save 1
	}
    }

    if {[catch [list save_metapost $export_mp_file]]} {
	set msg "Could not write to $export_mp_file."
	if {$batchmode} {
	    puts "Error: $msg"
	} else {
	    tk_messageBox -icon error -message $msg
	}
	return -1
    }

    return 0
}


proc save_native {file} {
    global VERSION PROGRAM
    upvar #0 objectinfo oi

    set fid [open $file w]
    puts $fid "# Creator: $PROGRAM $VERSION"
    puts $fid "# Creation-Date: [clock format [clock seconds]]"

    # internal IDs of states are normalised to 1...n to avoid
    # introducing differences by saving an unchanged file

    array set statemap {}
    set stateid 0

    foreach id [lsort -integer [get_objects_type "state"]] {
	set lblstring "label [list $oi($id-label)]"
	set texstring "tex [list $oi($id-tex)]"
	incr stateid
	set statemap($id) $stateid
	puts $fid "object state id $stateid x $oi($id-x) y $oi($id-y) radius $oi($id-radius) $lblstring $texstring accept $oi($id-accept) start $oi($id-start)"
    }

    foreach id [lsort -integer [get_objects_type "line"]] {
	puts -nonewline $fid "object line"
	set cpnum 0
	foreach cp $oi($id-cplist) {
	    incr cpnum
	    if {$oi($cp-attached) == -1} {
		puts -nonewline $fid " cp${cpnum}attached -1 cp${cpnum}x $oi($cp-x) cp${cpnum}y $oi($cp-y)"
	    } else {
		puts -nonewline $fid " cp${cpnum}attached $statemap($oi($cp-attached)) cp${cpnum}angle $oi($cp-angle)"
	    }
	}
	set texstring "tex [list $oi($id-tex)] texpos $oi($id-texpos) anchor $oi($id-anchor)"
	puts $fid " cpnum $cpnum $texstring bisect $oi($id-bisect)"
    }

    foreach id [lsort -integer [get_objects_type "text"]] {
	set lblstring "label [list $oi($id-label)]"
	set texstring "tex [list $oi($id-tex)]"

	puts $fid "object text x $oi($id-x) y $oi($id-y) $lblstring $texstring"
    }

    global modifiable_params
    foreach mp $modifiable_params {
	if {[uplevel #0 "string compare $$mp $${mp}_default"]} {
	    global $mp
	    set val [list [subst $$mp]]
	    puts $fid "object setting variable $mp value $val"
	}
    }

    close $fid
}

proc clear_all {} {
    global objectinfo maincanvas selectedlist needs_save batchmode
    if {!$batchmode} { $maincanvas delete all }
    array unset objectinfo
    set selectedlist ""
    set needs_save 0
    reset_all_parameters
}

proc save_file {{choose 0}} {
    global currentfile needs_save
    set oldcurrentfile $currentfile
    if {$currentfile == "" || $choose} {
	set currentfile [tk_getSaveFile -defaultextension ".fin" -filetypes {{Finomaton .fin} {All *}}]
	if {$currentfile == ""} { return -1 }
    }

    if {[catch [list save_native $currentfile]]} {
	tk_messageBox -icon error -message "Could not write to $currentfile."
	set currentfile $oldcurrentfile
	return -1
    }

    set needs_save 0
    set_window_title
    return 0
}


proc load_native {file} {
    global objectinfo modifiable_params

    array set statemap {}
    set fid [open $file r]
    set wholeobject ""
    while {![eof $fid]} {
	gets $fid oneline
	if {[eof $fid]} { break }
	if {$wholeobject == "" && [regexp {^#} $oneline]} { continue }
	append wholeobject $oneline
	if {![info complete $wholeobject]} {
	    append wholeobject "\n"
	    continue
	}

	eval "array set object {$wholeobject}"
	set wholeobject ""

	if {$object(object) == "setting"} {
	    set var $object(variable)
	    if {[lsearch $modifiable_params $var] == -1} {
		continue
	    }
	    uplevel #0 [list set $var $object(value)]
	    array unset object
	    continue
	}

	set id -1
	if {$object(object) == "state"} {
	    set id [create_state $object(x) $object(y) $object(radius)]
	    set statemap($object(id)) $id
	    set objectinfo($id-label) $object(label)
	    set objectinfo($id-tex) $object(tex)
	    set objectinfo($id-accept) $object(accept)
	    set objectinfo($id-start) $object(start)
	} elseif {$object(object) == "line"} {
	    set id [create_line 0 0 0]
	    set objectinfo($id-tex) $object(tex)
	    set objectinfo($id-texpos) $object(texpos)
	    set objectinfo($id-anchor) $object(anchor)
	    set objectinfo($id-bisect) \
		[expr [info exists object(bisect)] ? {$object(bisect)} : 0]

	    for {set i 1} {$i <= $object(cpnum)} {incr i} {
		set cp [add_control_point $id 0 0 0]
		if {$object(cp${i}attached) != -1} {
		    set attachedto $statemap($object(cp${i}attached))
		    set objectinfo($cp-attached) $attachedto
		    set objectinfo($cp-angle) $object(cp${i}angle)
		    set coords [anchor_coords $attachedto $objectinfo($cp-angle)]
		    set objectinfo($cp-x) [lindex $coords 0]
		    set objectinfo($cp-y) [lindex $coords 1]
		} else {
		    set objectinfo($cp-x) $object(cp${i}x)
		    set objectinfo($cp-y) $object(cp${i}y)
		}
		# don't use update_object, since the line might not be complete
		update_oval $cp
	    }
	} elseif {$object(object) == "text"} {
	    set id [create_text $object(x) $object(y)]
	    set objectinfo($id-label) $object(label)
	    set objectinfo($id-tex) $object(tex)
	}
	update_object $id
	array unset object
    }

    if {$wholeobject != ""} { error "premature end of file"	}
    close $fid
    check_parameters
}

proc ask_save {title} {
    set response [tk_messageBox -icon question -type yesnocancel -title $title -message "File modified. Save changes?"]
    return $response
}

proc needs_save {} {
    global needs_save
    return $needs_save
}

proc exit_yesno {} {
    global PROGRAM
    if {[needs_save]} {
	set response [ask_save "Exit"]
	if {$response == "cancel"} {
	    return
	} elseif {$response == "yes"} {
	    if {[save_file] == -1} {
		return
	    }
	}
	exit
    } else {
	set response [tk_messageBox -icon question -type yesno -title "Exit" -message "Really exit $PROGRAM?"]
	if {$response} { exit }
    }
}

proc set_window_title {} {
    global windowtitle currentfile
    if {$currentfile == ""} {
	wm title . $windowtitle
    } else {
	wm title . "$windowtitle - $currentfile"
    }
}

proc new_file {} {
    if {[needs_save]} {
	set response [ask_save "New"]
	if {$response == "yes"} {
	    if {[save_file] == -1} {
		return
	    }
	} elseif {$response == "cancel"} {
	    return
	}
    }
    global currentfile
    set currentfile ""
    set_window_title
    clear_all
}

proc load_file {file} {
    global PROGRAM batchmode
    if {![file exists $file] || ![file readable $file]} {
	set msg "File $file does not exist or is not readable."
	if {$batchmode} {
	    puts "Error: $msg"
	} else {
	    tk_messageBox -icon error -message $msg
	}
	return -1
    }

    clear_all
    if {[catch [list load_native $file]]} {
	set msg "File $file contains no or corrupted graph, or your version of $PROGRAM is outdated."
	if {$batchmode} {
	    puts "Error: $msg"
	} else {
	    tk_messageBox -icon error -message $msg
	}
	clear_all
	return -1
    } else {
	global currentfile
	set currentfile $file

	if {!$batchmode} {
	    set_window_title
	    hide_control_points
	}
    }
    return 0
}

proc open_file {} {
    if {[needs_save]} {
	set response [ask_save "Open"]
	if {$response == "cancel"} {
	    return
	} elseif {$response == "yes"} {
	    if {[save_file] == -1} {
		return
	    }
	}
    }
    set file [tk_getOpenFile -defaultextension ".fin" -filetypes {{Finomaton .fin} {All *}}]
    if {$file == ""} { return }
    load_file $file
}

# Execution entry point. Batch-process or set up the main window.


if {[llength $argv] > 0 && [lindex $argv 0] == "-exportmp"} {
    set filelist [lreplace $argv 0 0]
    if {[llength $filelist] > 0} {
	set batchmode 1
	foreach file $filelist {
	    set unid 0
	    if {[load_file $file] != -1} {
		puts "Processing $file..."
		export_metapost
	    }
	}
	exit
    }
}

frame .themenu
menubutton .themenu.file -text "File" -menu .themenu.file.m
set m [menu .themenu.file.m]
$m add command -label "New" -command new_file
$m add command -label "Open... (C-o)" -command open_file
$m add command -label "Save (C-s)" -command save_file
$m add command -label "Save as..." -command "save_file 1"
$m add command -label "Settings..." -command settings
$m add command -label "Export MetaPost... (C-m)" -command "export_metapost 1"

$m add separator
$m add command -label Exit -command exit_yesno

menubutton .themenu.help -text "Help" -menu .themenu.help.m
set m [menu .themenu.help.m]
$m add command -label "About..." -command about
pack .themenu.file -side left -padx 5 -pady 5
pack .themenu.help -side right -padx 5 -pady 5
pack .themenu -fill x


set commandsframe [frame .commands]
# these variable names must equal the respective button's name
set command_select \
    [button $commandsframe.command_select -text "Select" -underline 1]
set command_newstate \
    [button $commandsframe.command_newstate -text "New state" -underline 4]
set command_newline \
    [button $commandsframe.command_newline -text "New line" -underline 4]
set command_newtext \
    [button $commandsframe.command_newtext -text "New text" -underline 4]
set command_newcp \
    [button $commandsframe.command_newcp -text "Control point" -underline 0]
set command_remove \
    [button $commandsframe.command_remove -text "Remove" -underline 0]
set command_balancex \
    [button $commandsframe.command_balancex -text "|   x" -underline 4]
set command_balancey \
    [button $commandsframe.command_balancey -text "--  y" -underline 4]

foreach b {select newstate newline newtext newcp remove balancex balancey} {
    set path [subst "\$command_$b"]
    pack $path -side top -fill both -expand yes -padx 5 -pady 5
    bind $path <ButtonPress-1> "set_command $b ; break"
}

set coordslabel [label $commandsframe.corodslabel]
pack $coordslabel -side bottom -expand yes -padx 5 -pady 5

proc balance {which} {
    global selectedlist objectinfo

    set first [lindex $selectedlist 0]
    foreach id $selectedlist {
	set objectinfo($id-$which) $objectinfo($first-$which)
	update_object $id
    }
}

bind $commandsframe.command_balancex <ButtonPress-1> "balance x"
bind $commandsframe.command_balancey <ButtonPress-1> "balance y"

set canvasframe [frame .canvasframe]
set border [frame $canvasframe.border -relief ridge -borderwidth 5]
set maincanvas [canvas $border.maincanvas -width 320 -height 300 \
		    -xscrollcommand "$canvasframe.xbar set" \
		    -yscrollcommand "$canvasframe.ybar set" -scrollregion "0 0 800 640"]
pack $maincanvas -expand yes -fill both

set xbar [scrollbar $canvasframe.xbar -orient horizontal \
	      -command "$maincanvas xview"]
set ybar [scrollbar $canvasframe.ybar -orient vertical \
	      -command "$maincanvas yview"]
grid $border $ybar
grid $xbar x
grid configure $border -sticky nesw
grid configure $xbar -sticky ew
grid configure $ybar -sticky ns
grid columnconfigure $canvasframe 0 -weight 1
grid rowconfigure $canvasframe 0 -weight 1

pack $commandsframe -side left -padx 5 -pady 5
pack $canvasframe -side left -padx 5 -pady 5 -expand yes -fill both

proc canvascoords {x y} {
    global maincanvas
    return "[$maincanvas canvasx $x] [$maincanvas canvasy $y]"
}

proc spread {which} {
    global selectedlist objectinfo

    if {[llength $selectedlist] <= 1} { return }
    set min ""
    set max ""
    set objs {}
    foreach id $selectedlist {
	set obj $objectinfo($id-$which)
	lappend objs [list $obj $id]
	if {$min == "" || $obj < $min} { set min $obj }
	if {$max == "" || $obj > $max} { set max $obj }
    }

    set range [expr {$max - $min}]
    if {$range == 0} { return }

    set increment [expr double($range) / ([llength $selectedlist] - 1)]

    set curr $min
    foreach e [lsort -real -index 0 $objs] {
	set id [lindex $e 1]
	set objectinfo($id-$which) $curr
	update_object $id
	set curr [expr {$curr + $increment}]
    }
}

bind $maincanvas <h> "spread x"
bind $maincanvas <v> "spread y"

bind $maincanvas <x> "balance x"
bind $maincanvas <y> "balance y"

bind $maincanvas <l> "set_command newline"
bind $maincanvas <c> "set_command newcp"
bind $maincanvas <r> "set_command remove"
bind $maincanvas <s> "set_command newstate"
bind $maincanvas <t> "set_command newtext"
bind $maincanvas <e> "set_command select"

bind $maincanvas <ButtonPress-1> {
    canvas_clicked $currentcommand [canvascoords %x %y]
}

bind $maincanvas <Motion> {
    $coordslabel configure -text [canvascoords %x %y]
}

bind $maincanvas <B1-Motion> {
    set coords [canvascoords %x %y]
    $coordslabel configure -text $coords
    if {$dragobject == -1} {
	set dragend $coords
	eval $maincanvas coords $dragrectangleid $dragstart $dragend
    } else {
	if {$currentcommand == "select"} {
	    set needs_save 1
	    move_objects [canvascoords %x %y]
	}
    }
}

bind $maincanvas <ButtonRelease-1> {
    if {$dragobject == -1 && $currentcommand == "select"} {
	if {$dragrectangleid != -1} {
	    $maincanvas delete $dragrectangleid
	}
	set dragrectangleid -1
	set x [lsort -real "[lindex $dragstart 0] [lindex $dragend 0]"]
	set y [lsort -real "[lindex $dragstart 1] [lindex $dragend 1]"]
	set items [$maincanvas find enclosed [lindex $x 0] \
		       [lindex $y 0] [lindex $x 1] [lindex $y 1]]
	foreach i $items {
	    if {$objectinfo($i-type) == "statelabel" || \
		    $objectinfo($i-type) == "acceptcircle"} {
		continue
	    }
	    add_select $i
	}
    }
}


bind $maincanvas <Control-B1-Motion> {
    set needs_save 1
    set coords [canvascoords %x %y]
    $coordslabel configure -text $coords
    if {$currentcommand == "select"} { move_objects $coords }
}

bind $maincanvas <Control-ButtonRelease-1> {
    if {$dragrectangleid != -1} {
	$maincanvas delete $dragrectangleid
	set dragrectangleid -1
    }
}

bind $maincanvas <Control-ButtonPress-1> { toggle_select [canvascoords %x %y] }
bind $maincanvas <Double-Button-1> { double_click [canvascoords %x %y] }
bind $maincanvas <Control-o> { open_file; break }
bind $maincanvas <Control-s> { save_file; break }
bind $maincanvas <Control-m> { export_metapost; break }
bind $maincanvas <Alt-x>     { exit_yesno; break }
bind $maincanvas <Delete>    {
    while {[llength $selectedlist] > 0} {
	remove_object [lindex $selectedlist 0]
    }
}

proc move_all_delta {dx dy} {
    # this differs from move_objects in that magnetic states are ignored
    global selectedlist objectinfo needs_save
    set needs_save 1
    foreach id $selectedlist {
	if {$objectinfo($id-type) == "controlpoint"} {
	    set objectinfo($id-attached) -1
	}
	move_delta $id $dx $dy
    }
}

bind $maincanvas <Up>    { move_all_delta  0 -1 }
bind $maincanvas <Right> { move_all_delta  1  0 }
bind $maincanvas <Down>  { move_all_delta  0  1 }
bind $maincanvas <Left>  { move_all_delta -1  0 }

wm title . $windowtitle
wm protocol . WM_DELETE_WINDOW { exit_yesno }

set win .
wm withdraw $win
update idletasks
set x [expr {[winfo screenwidth $win]/2 - [winfo reqwidth $win]/2}]
set y [expr {[winfo screenheight $win]/2 - [winfo reqheight $win]/2}]
wm geometry $win "+$x+$y"
wm deiconify $win
wm minsize $win [winfo reqwidth $win] [winfo reqheight $win]

set_command select

if {$argc > 0} { load_file [lindex $argv 0] }

focus $maincanvas