Eskil

    # Add a dummy if it does not exist.
    proc addBalloon {args} {}
} else {
    namespace import -force psballoon::addBalloon
}

set debug 0
set diffver "Version 2.0.4+ 2004-08-17"
set diffver "Version 2.0.4+ 2004-08-18"
set thisScript [file join [pwd] [info script]]
set thisDir [file dirname $thisScript]

# Follow any link
set tmplink $thisScript
while {[file type $tmplink] eq "link"} {
    set tmplink [file readlink $tmplink]

proc resetEdit {top} {
    set ::diff($top,leftEdit) 0
    set ::diff($top,rightEdit) 0
    $top.mt.m entryconfigure "Edit Mode" -state normal

    $::widgets($top,wDiff1) tag configure padding -background {}
    $::widgets($top,wDiff2) tag configure padding -background {}

    $::widgets($top,wDiff1) edit reset
    $::widgets($top,wDiff1) configure -undo 0
    $::widgets($top,wDiff2) edit reset
    $::widgets($top,wDiff2) configure -undo 0
}

# Turn on editing on sides where it has not bew disallowed
proc allowEdit {top} {
    $top.mt.m entryconfigure "Edit Mode" -state disable
    if {$::diff($top,leftEdit) == 0} {
        set ::diff($top,leftEdit) 1
        $::widgets($top,wDiff1) tag configure padding -background \#f0f0f0
        $::widgets($top,wDiff1) configure -undo 1
    }
    if {$::diff($top,rightEdit) == 0} {
        set ::diff($top,rightEdit) 1
        $::widgets($top,wDiff2) tag configure padding -background \#f0f0f0
        $::widgets($top,wDiff2) configure -undo 1
    }
}

# Turn off editing on sides that do not correspond to a file
proc disallowEdit {top {side 0}} {
    if {$side == 0 || $side == 1} {
        set ::diff($top,leftEdit) -1

proc mayEdit {top side} {
    if {$side == 1} {
        return [expr {$::diff($top,leftEdit) == 1}]
    } else {
        return [expr {$::diff($top,rightEdit) == 1}]
    }
}

# Start an undo block in a bunch of text widgets
proc startUndoBlock {args} {
    foreach w $args {
        $w configure -autoseparators 0
    }
}

# End an undo block in a bunch of text widgets
proc endUndoBlock {args} {
    foreach w $args {
        $w configure -autoseparators 1
        $w edit separator
    }
}

proc copyBlock {top from first last} {
    set to [expr {3 - $from}]

    set wfrom $::widgets($top,wDiff$from)
    set wto   $::widgets($top,wDiff$to)

    set tags ""
    set dump [$wfrom dump -all $first.0 $last.end+1c]

    startUndoBlock $wfrom $wto

    $wfrom delete $first.0 $last.end+1c
    $wto   delete $first.0 $last.end+1c

    foreach {key value index} $dump {
        switch -- $key {
            text {

            tagoff {
                if {$value eq "padding"} {
                    set tags 0
                }
            }
        }
    }

    endUndoBlock $wfrom $wto
}

# Copy a row between text widgets
proc copyRow {top from row} {
    set to [expr {3 - $from}]

    set wfrom $::widgets($top,wDiff$from)
    set wto   $::widgets($top,wDiff$to)

    set text [$wfrom get $row.0 $row.end+1c]

    startUndoBlock $wfrom $wto

    $wto delete $row.0 $row.end+1c
    $wto insert $row.0 $text ""
    # Rewrite the source row to remove any tags
    $wfrom delete $row.0 $row.end+1c
    $wfrom insert $row.0 $text ""
}


    endUndoBlock $wfrom $wto
}

# Delete a row filling it with padding
proc deleteBlock {top side from {to {}}} {
    set w $::widgets($top,wDiff$side)

    if {$to eq ""} {set to $from}
    startUndoBlock $w
    $w delete $from.0 $to.end+1c
    $w insert $from.0 [string repeat \n [expr {$to - $from + 1}]] padding
    endUndoBlock $w
}

# Get the lines involved in the display
proc getLinesFromRange {w range} {
    set from [lindex $range 0]
    set to   [lindex $range 1]
    foreach {fromr fromi} [split $from "."] break
    foreach {tor   toi}   [split $to   "."] break

proc editMenu {m top n hl x y} {

    if {![mayEdit $top $n]} {return 1}

    # Only copy when in a change block
    if {$hl ne ""} {
        set o [expr {3 - $n}]
        set editOther [mayEdit $top $o]

        set w $::widgets($top,wLine$n)
        set wo $::widgets($top,wLine$o)

        # Get the row that was clicked
        set index [$w index @$x,$y]
        set row [lindex [split $index "."] 0]

        set line  [regexp -inline {\d+} [$w  get $row.0 $row.end]]
        set lineo [regexp -inline {\d+} [$wo get $row.0 $row.end]]

        # Row copy
        if {$lineo ne ""} {
            $m add command -label "Copy Row from other side" \
                    -command [list copyRow $top $o $row]
        } else {
            $m add command -label "Delete Row" \
                    -command [list deleteBlock $top $n $row]
        }
        if {$line ne ""} {
        if {$line ne "" && $editOther} {
            $m add command -label "Copy Row to other side" \
                    -command [list copyRow $top $n $row]
        }

        # Get ranges for the change block
        set range  [$w tag ranges hl$hl]
        set rangeo [$wo tag ranges hl$hl]

        # Get the lines involved in the block
        foreach {from  to  froml  tol}  [getLinesFromRange $w  $range ] break
        foreach {fromo too fromlo tolo} [getLinesFromRange $wo $rangeo] break

        # More than one line in the block?
        set thisSize 0
        set otherSize 0
        if {($froml  ne "" && $tol  ne "" && $froml  < $tol) ||
            ($fromlo ne "" && $tolo ne "" && $fromlo < $tolo)} {
            $m add command -label "Copy Block to other side" \
                    -command [list copyBlock $top $n $from $to]
            $m add command -label "Copy Block from other side" \
                    -command [list copyBlock $top $o $fromo $too]
        if {$froml ne "" && $tol ne ""} {
            set thisSize [expr {$tol - $froml + 1}]
        }
        if {$fromlo ne "" && $tolo ne ""} {
            set otherSize [expr {$tolo - $fromlo + 1}]
        }
        if {$thisSize > 1 || $otherSize > 1} {
            if {$otherSize > 0} {
                $m add command -label "Copy Block from other side" \
                        -command [list copyBlock $top $o $fromo $too]
            } else {
                $m add command -label "Delete Block" \
                        -command [list deleteBlock $top $n $from $to]
            }
            if {$editOther && $thisSize > 0} {
                $m add command -label "Copy Block to other side" \
                        -command [list copyBlock $top $n $from $to]
            }
        }
    }

    $m add command -label "Save File" -command [list saveFile $top $n]

    return 0
}

}

proc hlPopup {top n hl X Y x y} {
    if {[info exists ::diff($top,nopopup)] && $::diff($top,nopopup)} return
    destroy .lpm
    menu .lpm

    editMenu .lpm $top $n $hl $x $y
    if {![editMenu .lpm $top $n $hl $x $y]} {
        .lpm add separator
    }

    if {$hl != ""} {
        .lpm add command -label "Select" \
                -command [list hlSelect $top $hl]
    }

    set other [expr {$n == 1 ? 2 : 1}]

proc rowPopup {w X Y x y} {
    set top [winfo toplevel $w]
    if {[info exists ::diff($top,nopopup)] && $::diff($top,nopopup)} return
    destroy .lpm
    menu .lpm

    regexp {(\d+)\D*$} $w -> n
    set tmp1 [editMenu  .lpm $top $n "" $x $y]
    if {!$tmp1} {.lpm add separator}
    if {[editMenu .lpm $top $n "" $x $y] && [alignMenu .lpm $top $n $x $y]} {
    set tmp2 [alignMenu .lpm $top $n $x $y]
    if {$tmp1 && $tmp2} {
        # Nothing in the menu
        return
    }
    if {!$tmp1 && $tmp2} {.lpm delete last}

    set ::diff($top,nopopup) 1
    tk_popup .lpm $X $Y
    after idle [list after 1 [list set ::diff($top,nopopup) 0]]
}

proc bindHighlight {top} {