Eskil

        set lw [font measure $font $line]
        if {$lw > $len} {
            set len $lw
        }
    }
    return $len
}

# Returns a list of minX maxX for each screen.
# maxX are exclusive and normally equal to the next minX
proc psballoon::FigureOutScreenWidths {W} {
    set screens {}
    # Range of X over multiple windows
    set minX [winfo vrootx $W]
    set maxX [expr {$minX + [winfo vrootwidth $W]}]
    set sW [winfo screenwidth $W]

    # Guess: If minX is negative, there is a screen from minX to 0
    if {$minX < 0} {
	lappend screens $minX 0
    }
    # Guess: Main screen is in the middle if three

    # Main screen is 0 to screenWidth
    lappend screens 0 $sW

    # Guess: If maxX is larger than screen width (main screen), there
    # is one more screen to the right
    if {$maxX > $sW} {
	lappend screens $sW $maxX
    }
    return $screens
}

proc psballoon::createBalloon {W mx my} {
    variable balloon
    if {![winfo exists $W]} {
        return
    }
    if {$balloon(created) == 0} {
        # Figure out widget's font
        if {[catch {set font [$W cget -font]}]} {
            set font [ttk::style lookup [winfo class $W] -font]
        }
        # Fallback to something reasonable if font fails.
        if {$font eq ""} {
            set font TkDefaultFont
        }
        set ww [winfo width $W]
        set ih [winfo height $W]
        if {[winfo class $W] in {TLabelframe Labelframe}} {
            # Put it below the label, not the entire widget.

                set msg [subst -novariables -nobackslashes $msg]
            }
	    set iw [Measure $font $msg]
	}
	if {$create} {
            set x [expr {[winfo rootx $W] + $ix}]
            set y [expr {[winfo rooty $W] + $iy + $ih + 2}]
            # Limits of current screen.
            foreach {minX maxX} [FigureOutScreenWidths $W] {
                if {$minX <= $x && $x < $maxX} break
            }

            # Move it to the left as needed to fit on screen
            if {$x + $iw + 8 > $maxX} {
                set x [expr {$maxX - $iw - 8}]
            }
            # TBD, option to use a frame in parent instead?
            toplevel .balloon -bg black
            wm overrideredirect .balloon 1
            label .balloon.l \
                    -text $msg -relief flat -font $font -justify left \
                    -bg #ffffaa -fg black -padx 2 -pady 0 -anchor "w"
            pack .balloon.l -side left -padx 1 -pady 1
            wm geometry .balloon +${x}+${y}
            set balloon(created) 1
        }
    }
}