palette.tcl

# palette.tcl --
#
# This file contains procedures that change the color palette used
# by Tk.
#
# RCS: @(#) $Id: palette.tcl,v 1.5.4.1 2002/04/06 01:02:01 hobbs Exp $
#
# Copyright (c) 1995-1997 Sun Microsystems, Inc.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#

# ::tk_setPalette --
# Changes the default color scheme for a Tk application by setting
# default colors in the option database and by modifying all of the
# color options for existing widgets that have the default value.
#
# Arguments:
# The arguments consist of either a single color name, which
# will be used as the new background color (all other colors will
# be computed from this) or an even number of values consisting of
# option names and values.  The name for an option is the one used
# for the option database, such as activeForeground, not -activeforeground.

proc ::tk_setPalette {args} {
    if {[winfo depth .] == 1} {
	# Just return on monochrome displays, otherwise errors will occur
	return
    }

    # Create an array that has the complete new palette.  If some colors
    # aren't specified, compute them from other colors that are specified.

    if {[llength $args] == 1} {
	set new(background) [lindex $args 0]
    } else {
	array set new $args
    }
    if {![info exists new(background)]} {
	error "must specify a background color"
    }
    set bg [winfo rgb . $new(background)]
    if {![info exists new(foreground)]} {
	# Note that the range of each value in the triple returned by
	# [winfo rgb] is 0-65535, and your eyes are more sensitive to
	# green than to red, and more to red than to blue.
	foreach {r g b} $bg {break}
	if {$r+1.5*$g+0.5*$b > 100000} {
	    set new(foreground) black
	} else {
	    set new(foreground) white
	}
    }
    set fg [winfo rgb . $new(foreground)]
    set darkerBg [format #%02x%02x%02x [expr {(9*[lindex $bg 0])/2560}] \
	    [expr {(9*[lindex $bg 1])/2560}] [expr {(9*[lindex $bg 2])/2560}]]
    foreach i {activeForeground insertBackground selectForeground \
	    highlightColor} {
	if {![info exists new($i)]} {
	    set new($i) $new(foreground)
	}
    }
    if {![info exists new(disabledForeground)]} {
	set new(disabledForeground) [format #%02x%02x%02x \
		[expr {(3*[lindex $bg 0] + [lindex $fg 0])/1024}] \
		[expr {(3*[lindex $bg 1] + [lindex $fg 1])/1024}] \
		[expr {(3*[lindex $bg 2] + [lindex $fg 2])/1024}]]
    }
    if {![info exists new(highlightBackground)]} {
	set new(highlightBackground) $new(background)
    }
    if {![info exists new(activeBackground)]} {
	# Pick a default active background that islighter than the
	# normal background.  To do this, round each color component
	# up by 15% or 1/3 of the way to full white, whichever is
	# greater.

	foreach i {0 1 2} {
	    set light($i) [expr {[lindex $bg $i]/256}]
	    set inc1 [expr {($light($i)*15)/100}]
	    set inc2 [expr {(255-$light($i))/3}]
	    if {$inc1 > $inc2} {
		incr light($i) $inc1
	    } else {
		incr light($i) $inc2
	    }
	    if {$light($i) > 255} {
		set light($i) 255
	    }
	}
	set new(activeBackground) [format #%02x%02x%02x $light(0) \
		$light(1) $light(2)]
    }
    if {![info exists new(selectBackground)]} {
	set new(selectBackground) $darkerBg
    }
    if {![info exists new(troughColor)]} {
	set new(troughColor) $darkerBg
    }
    if {![info exists new(selectColor)]} {
	set new(selectColor) #b03060
    }

    # let's make one of each of the widgets so we know what the 
    # defaults are currently for this platform.
    toplevel .___tk_set_palette
    wm withdraw .___tk_set_palette
    foreach q {
	button canvas checkbutton entry frame label labelframe
	listbox menubutton menu message radiobutton scale scrollbar
	spinbox text
    } {
	$q .___tk_set_palette.$q
    }

    # Walk the widget hierarchy, recoloring all existing windows.
    # The option database must be set according to what we do here, 
    # but it breaks things if we set things in the database while 
    # we are changing colors...so, ::tk::RecolorTree now returns the
    # option database changes that need to be made, and they
    # need to be evalled here to take effect.
    # We have to walk the whole widget tree instead of just 
    # relying on the widgets we've created above to do the work
    # because different extensions may provide other kinds
    # of widgets that we don't currently know about, so we'll
    # walk the whole hierarchy just in case.

    eval [tk::RecolorTree . new]

    catch {destroy .___tk_set_palette}

    # Change the option database so that future windows will get the
    # same colors.

    foreach option [array names new] {
	option add *$option $new($option) widgetDefault
    }

    # Save the options in the variable ::tk::Palette, for use the
    # next time we change the options.

    array set ::tk::Palette [array get new]
}

# ::tk::RecolorTree --
# This procedure changes the colors in a window and all of its
# descendants, according to information provided by the colors
# argument. This looks at the defaults provided by the option 
# database, if it exists, and if not, then it looks at the default
# value of the widget itself.
#
# Arguments:
# w -			The name of a window.  This window and all its
#			descendants are recolored.
# colors -		The name of an array variable in the caller,
#			which contains color information.  Each element
#			is named after a widget configuration option, and
#			each value is the value for that option.

proc ::tk::RecolorTree {w colors} {
    upvar $colors c
    set result {}
    set prototype .___tk_set_palette.[string tolower [winfo class $w]]
    if {![winfo exists $prototype]} {
	unset prototype
    }
    foreach dbOption [array names c] {
	set option -[string tolower $dbOption]
	set class [string replace $dbOption 0 0 [string toupper \
		[string index $dbOption 0]]]
	if {![catch {$w config $option} value]} {
	    # if the option database has a preference for this
	    # dbOption, then use it, otherwise use the defaults
	    # for the widget.
	    set defaultcolor [option get $w $dbOption $class]
	    if {[string match {} $defaultcolor] || \
		    ([info exists prototype] && \
		    [$prototype cget $option] ne "$defaultcolor")} {
		set defaultcolor [winfo rgb . [lindex $value 3]]
	    } else {
		set defaultcolor [winfo rgb . $defaultcolor]
	    }
	    set chosencolor [winfo rgb . [lindex $value 4]]
	    if {[string match $defaultcolor $chosencolor]} {
		# Change the option database so that future windows will get
		# the same colors.
		append result ";\noption add [list \
		    *[winfo class $w].$dbOption $c($dbOption) 60]"
		$w configure $option $c($dbOption)
	    }
	}
    }
    foreach child [winfo children $w] {
	append result ";\n[::tk::RecolorTree $child c]"
    }
    return $result
}

# ::tk::Darken --
# Given a color name, computes a new color value that darkens (or
# brightens) the given color by a given percent.
#
# Arguments:
# color -	Name of starting color.
# perecent -	Integer telling how much to brighten or darken as a
#		percent: 50 means darken by 50%, 110 means brighten
#		by 10%.

proc ::tk::Darken {color percent} {
    foreach {red green blue} [winfo rgb . $color] {
	set red [expr {($red/256)*$percent/100}]
	set green [expr {($green/256)*$percent/100}]
	set blue [expr {($blue/256)*$percent/100}]
	break
    }
    if {$red > 255} {
	set red 255
    }
    if {$green > 255} {
	set green 255
    }
    if {$blue > 255} {
	set blue 255
    }
    return [format "#%02x%02x%02x" $red $green $blue]
}

# ::tk_bisque --
# Reset the Tk color palette to the old "bisque" colors.
#
# Arguments:
# None.

proc ::tk_bisque {} {
    tk_setPalette activeBackground #e6ceb1 activeForeground black \
	    background #ffe4c4 disabledForeground #b0b0b0 foreground black \
	    highlightBackground #ffe4c4 highlightColor black \
	    insertBackground black selectColor #b03060 \
	    selectBackground #e6ceb1 selectForeground black \
	    troughColor #cdb79e
}