no display name and no $DISPLAY environment variable
    while executing
"load /enadisk/commun/linux/local/ActiveTcl-8.6.11/lib/libtk8.6.so Tk"
    ("package ifneeded Tk 8.6.11" script)
    invoked from within
"package require Tk 8"
    (in namespace eval "::request" script line 12)
    invoked from within
"namespace eval ::request $script"
    ("::try" body line 12)
OUTPUT BUFFER:
#==============================================================================
# Contains scaling-related utility procedures.
#
# Structure of the module:
#   - Namespace initialization
#   - Public utility procedures
#   - Private helper procedures
#
# Copyright (c) 2020  Csaba Nemethi (E-mail: csaba.nemethi@t-online.de)
#==============================================================================

package require Tk 8

#
# Namespace initialization
# ========================
#

namespace eval scaleutil {
    #
    # Public variables:
    #
    variable version	1.0
    variable library
    if {$::tcl_version >= 8.4} {
	set library	[file dirname [file normalize [info script]]]
    } else {
	set library	[file dirname [info script]] ;# no "file normalize" yet
    }

    #
    # Public procedures:
    #
    namespace export	scalingPercentage \
    			scaleBWidgetSpinBox scaleBWidgetComboBox \
			scaleIncrDateentry scaleIncrTimeentry \
			scaleIncrCombobox scaleOakleyComboboxArrow
}

#
# Public utility procedures
# =========================
#

#------------------------------------------------------------------------------
# scaleutil::scalingPercentage
#
# Returns the display's current scaling percentage (100, 125, 150, 175, or 200).
#------------------------------------------------------------------------------
proc scaleutil::scalingPercentage winSys {
    variable onX11 [expr {[string compare $winSys "x11"] == 0}]
    set pct [expr {[tk scaling] * 75}]

    if {$onX11} {
	set factor 1
	if {[catch {exec ps -e | grep xfce}] == 0} {			;# Xfce
	    if {[catch {exec xfconf-query -c xsettings \
		 -p /Gdk/WindowScalingFactor} result] == 0} {
		set factor $result
		set pct [expr {100 * $factor}]
	    }
	} elseif {[catch {exec ps -e | grep mate}] == 0} {		;# MATE
	    if {[catch {exec gsettings get org.mate.interface \
		 window-scaling-factor} result] == 0} {
		if {$result == 0} {			;# means: "Auto-detect"
		    #
		    # Try to get the scaling factor from the cursor size
		    #
		    if {[catch {exec xrdb -query | grep Xcursor.size} \
			 result] == 0 &&
			[catch {exec gsettings get org.mate.peripherals-mouse \
			 cursor-size} defCursorSize] == 0} {
			scan $result "%*s %d" cursorSize
			set factor [expr {($cursorSize + $defCursorSize - 1) /
					  $defCursorSize}]
			set pct [expr {100 * $factor}]
		    }
		} else {
		    set factor $result
		    set pct [expr {100 * $factor}]
		}
	    }
	} elseif {[catch {exec gsettings get \
		   org.gnome.settings-daemon.plugins.xsettings overrides} \
		   result] == 0 &&
		  [set idx \
		   [string first "'Gdk/WindowScalingFactor'" $result]] >= 0} {
	    scan [string range $result $idx end] "%*s <%d>" factor
	    set pct [expr {100 * $factor}]
	} elseif {[catch {exec xrdb -query | grep Xft.dpi} result] == 0} {
	    scan $result "%*s %f" dpi
	    set pct [expr {100 * $dpi / 96}]
	} elseif {$::tk_version >= 8.3 &&
		  [catch {exec ps -e | grep gnome}] == 0 &&
		  ![info exists ::env(WAYLAND_DISPLAY)] &&
		  [catch {exec xrandr | grep " connected"} result] == 0 &&
		  [catch {open $::env(HOME)/.config/monitors.xml} chan] == 0} {
	    #
	    # Update pct by scanning the file ~/.config/monitors.xml
	    #
	    scanMonitorsFile $chan pct
	}

	#
	# Conditionally correct and then scale the sizes of the standard fonts
	#
	if {$::tk_version >= 8.5} {
	    scaleX11Fonts $factor
	}
    }

    if {$pct < 100 + 12.5} {
	set pct 100
    } elseif {$pct < 125 + 12.5} {
	set pct 125 
    } elseif {$pct < 150 + 12.5} {
	set pct 150 
    } elseif {$pct < 175 + 12.5} {
	set pct 175 
    } else {
	set pct 200
    }

    if {$onX11} {
	tk scaling [expr {$pct / 75.0}]

	if {$pct > 100} {
	    #
	    # Scale the default scrollbar width
	    #
	    set helpScrlbar .__helpScrlbar
	    for {set n 2} {[winfo exists $helpScrlbar]} {incr n} {
		set helpScrlbar .__helpScrlbar$n
	    }
	    scrollbar $helpScrlbar
	    set defScrlbarWidth [lindex [$helpScrlbar configure -width] 3]
	    destroy $helpScrlbar
	    set scrlbarWidth [expr {$defScrlbarWidth * $pct / 100}]
	    option add *Scrollbar.width $scrlbarWidth userDefault
	}
    }

    if {$::tk_version >= 8.5} {
	#
	# Scale a few styles for the built-in themes
	# "alt", "clam", "classic", and "default"
	#
	scaleStyles $pct

	#
	# For the "xpnative" and "vista" themes work around a bug
	# related to the scaling of ttk::checkbutton and ttk::radiobutton
	# widgets in Tk releases no later than 8.6.10 and 8.7a3
	#
	if {$pct > 100 &&
	    ([package vcompare $::tk_patchLevel "8.6.10"] <= 0 ||
	     ($::tk_version == 8.7 &&
	      [package vcompare $::tk_patchLevel "8.7a3"] <= 0))} {
	    foreach theme {xpnative vista} {
		if {[lsearch -exact [ttk::style theme names] $theme] >= 0} {
		    patchWinTheme $theme $pct
		}
	    }
	}
    }

    return $pct
}

#------------------------------------------------------------------------------
# scaleutil::scaleBWidgetSpinBox
#
# Scales a BWidget SpinBox widget of the given path name.
#------------------------------------------------------------------------------
proc scaleutil::scaleBWidgetSpinBox {w pct} {
    #
    # Scale the width of the two arrows, which is set to 11
    #
    set arrWidth [expr {11 * $pct / 100}]
    $w.arrup configure -width $arrWidth
    $w.arrdn configure -width $arrWidth
}

#------------------------------------------------------------------------------
# scaleutil::scaleBWidgetComboBox
#
# Scales a BWidget ComboBox widget of the given path name.
#------------------------------------------------------------------------------
proc scaleutil::scaleBWidgetComboBox {w pct} {
    #
    # Scale the width of the arrow, which is set to 11 or 15
    #
    variable onX11
    set defaultWidth [expr {$onX11 ? 11 : 15}]
    set width [expr {$defaultWidth * $pct / 100}]
    $w.a configure -width $width

    #
    # Scale the width of the two scrollbars, which is set to 11 or 15
    #
    ComboBox::_create_popup $w
    if {![Widget::theme]} {
	bind $w.shell