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<h1 ALIGN=
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</h1>
<dt> <h3>Name
</h3></dt><dd>
contains functions for handling colors and color schemes
</p><dt> <h3>Description
</h3></dt><dd>
This module is a set of functions for manipulating colors and for
modifying the color scheme of an application or a widget. Many of
the functions in this module take or return colors. These values
may represent colors in the following ways:
</p><dl><dt><strong>name
</strong></dt><dd>a standard color name, eg
<code>'orange'
</code> or
<code>'#ffa500'
</code><p></p>
<dt><strong>rgb
</strong></dt><dd>a
3-element sequence of red, green and blue intensities
each between
0.0 (dark) and
1.0 (light), eg
<code>[
1.0,
0.6,
0.0]
</code>.
<p></p><dt><strong>hsi
</strong></dt><dd>a
3-element sequence (
<em>hue
</em>,
<em>saturation
</em>,
<em>intensity
</em>). The value of
<em>hue
</em> is between
0.0 and
<strong>2pi
</strong>
(
6.28318) giving a range of colors covering, in order, red,
orange, yellow green, cyan, blue, magenta and back to red.
The value of
<em>saturation
</em> is between
0.0 (grey) and
1.0 (brilliant) and the value of
<em>intensity
</em> is between
0.0 (dark)
<p> As used in these functions, the
<strong>brightness
</strong> of a color is the
perceived grey level of the color as registered by the human eye.
For example, even though the colors red, blue and yellow have the
same intensity (
1.0), they have different brightnesses,
0.299,
0.114 and
0.886 respectively, reflecting the different way these
colors appear to the eye. The brightness of a color is a value
between
0.0 (dark) and
1.0 (bright).
</p><p> A
<strong>color scheme
</strong> is a set of colors defined for each of the
default color options in the Tk option database. Color schemes
can be used in two ways. Firstly, using
<code>Pmw.Color.setscheme()
</code>,
the Tk option database can be set to the values in the color
scheme. This will not have any effect on currently existing
widgets, but any new widgets created after setting the options
will have these colors as their defaults. Secondly, using
<code>Pmw.Color.changecolor()
</code> the color scheme can be used to change
the colors of a widget and all its child widgets.
</p><p> A color scheme is specified by defining one or more color options
(one of the defined options must be
<code>background
</code>). Not all
options need be specified - if any options are not defined, they
are calculated from the other colors. These are the options used
by a color scheme, together with their values if not specified:
</p><dl><dd><pre> background: (must be specified)
activeForeground: same as foreground
insertBackground: same as foreground
selectForeground: same as foreground
highlightColor: same as foreground
disabledForeground: between fg and bg but closer to bg
highlightBackground: same as background
activeBackground: a little lighter that bg
selectBackground: a little darker that bg
troughColor: a little darker that bg
selectColor: yellow
</pre></dd></dl><p> There are many functions in this module. As well as
<code>Pmw.Color.setscheme()
</code> and
<code>Pmw.Color.changecolor()
</code>, some of the
most useful are
<code>Pmw.Color.spectrum()
</code>,
<code>Pmw.Color.changebrightness()
</code> and
<code>Pmw.Color.getdefaultpalette()
</code>.
</p>
<dt> <h3>Functions
</h3></dt><dd>
The following functions are available.
<p></p><dt> <strong>Pmw.Color.average
</strong>(
<em>rgb1
</em>,
<em>rgb2
</em>,
<em>fraction
</em>)
</dt><dd>
Return an
<strong>rgb
</strong> color
<em>fraction
</em> of the way
"between" the colors
<em>rgb1
</em> and
<em>rgb2
</em>, where
<em>fraction
</em> must be between
<strong>0.0</strong> and
<strong>1.0</strong>. If
<em>fraction
</em> is close to
<strong>0.0</strong>, then the color returned
will be close to
<em>rgb1
</em>. If it is close to
<strong>1.0</strong>, then the color
returned will be close to
<em>rgb2
</em>. If it is near
<strong>0.5</strong>, then the
color returned will be half way between the two colors.
</p><dt> <strong>Pmw.Color.bhi2saturation
</strong>(
<em>brightness
</em>,
<em>hue
</em>,
<em>intensity
</em>)
</dt><dd>
Return the saturation of the color represented by
<em>brightness
</em>,
<em>hue
</em> and
<em>intensity
</em>.
</p>
<dt> <strong>Pmw.Color.bordercolors
</strong>(
<em>root
</em>,
<em>colorName
</em>)
</dt><dd>
Return a tuple
<code>(light, dark)
</code> of color names that can be used as
the light and dark border shadows on a widget where the background
is
<em>colorName
</em>. This is the same method that Tk uses for shadows
when drawing reliefs on widget borders. The
<em>root
</em> argument is
only used to query Tk for the
<strong>rgb
</strong> values of
<em>colorName
</em>.
</p><dt> <strong>Pmw.Color.changebrightness
</strong>(
<em>root
</em>,
<em>colorName
</em>,
<em>brightness
</em>)
</dt><dd>
Find the hue of the color
<em>colorName
</em> and return a color of this
hue with the required
<em>brightness
</em>. If
<em>brightness
</em> is
<strong>None
</strong>,
return the name of color with the given hue and with saturation
and intensity both
<strong>1.0</strong>. The
<em>root
</em> argument is only used to
query Tk for the
<strong>rgb
</strong> values of
<em>colorName
</em>.
</p><dt> <strong>Pmw.Color.changecolor
</strong>(
<em>widget
</em>,
<em>background
</em> =
<strong>None
</strong>, **
<em>kw
</em>)
</dt><dd>
Change the color of
<em>widget
</em> and all its child widgets according
to the color scheme specified by the other arguments. This is done
by modifying all of the color options of existing widgets that
have the default value. The color options are the lower case
versions of those described in the
<strong>color scheme
</strong> section. Any
options which are different to the previous color scheme (or the
defaults, if this is the first call) are not changed.
</p><p> For example to change a widget to have a red color scheme with a
<dl><dd><pre> Pmw.Color.changecolor(widget,
background = 'red3', foreground = 'white')
</pre></dd></dl><p> The colors of widgets created after this call will not be
<p> Note that
<em>widget
</em> must be a Tk widget or toplevel. To change the
color of a Pmw megawidget, use it's
<strong>hull
</strong> component. For example:
</p><dl><dd><pre> widget = megawidget.component('hull')
Pmw.Color.changecolor(widget, background = 'red3')
</pre></dd></dl><dt> <strong>Pmw.Color.correct
</strong>(
<em>rgb
</em>,
<em>correction
</em>)
</dt><dd>
Return the
"corrected" value of
<em>rgb
</em>. This can be used to
correct for dull monitors. If
<em>correction
</em> is less than
<strong>1.0</strong>,
the color is dulled. If
<em>correction
</em> is greater than
<strong>1.0</strong>, the
<dt> <strong>Pmw.Color.getdefaultpalette
</strong>(
<em>root
</em>)
</dt><dd>
Return a dictionary of the default values of the color options
described in the
<strong>color scheme
</strong> section.
</p><p> To do this, a few widgets are created as children of
<em>root
</em>, their
defaults are queried, and then the widgets are destroyed. (Tk
supplies no other way to get widget default values.)
</p><p> Note that
<em>root
</em> must be a Tk widget or toplevel. To use a Pmw
megawidget as the root, use it's
<strong>hull
</strong> component. For example:
</p><dl><dd><pre> root = megawidget.component('hull')
Pmw.Color.getdefaultpalette(root)
</pre></dd></dl><dt> <strong>Pmw.Color.hsi2rgb
</strong>(
<em>hue
</em>,
<em>saturation
</em>,
<em>intensity
</em>)
</dt><dd>
Return the
<strong>rgb
</strong> representation of the color represented by
<em>hue
</em>,
<em>saturation
</em> and
<em>intensity
</em>.
</p>
<dt> <strong>Pmw.Color.hue2name
</strong>(
<em>hue
</em>,
<em>brightness
</em> =
<strong>None
</strong>)
</dt><dd>
Return the name of the color with the specified
<em>hue
</em> and
<em>brightness
</em>. If
<em>hue
</em> is
<strong>None
</strong>, return a grey of the requested
brightness. Otherwise, the value of
<em>hue
</em> should be as described
above. If
<em>brightness
</em> is
<strong>None
</strong>, return the name of color with
the given hue and with saturation and intensity both
<strong>1.0</strong>.
</p><dt> <strong>Pmw.Color.name2rgb
</strong>(
<em>root
</em>,
<em>colorName
</em>,
<em>asInt
</em> =
<strong>0</strong>)
</dt><dd>
Return
<em>colorName
</em> as an
<strong>rgb
</strong> value. If
<em>asInt
</em> is true, then
the elements of the return sequence are in the range
<strong>0</strong> to
<strong>65535</strong> rather than
<strong>0.0</strong> to
<strong>1.0</strong>. The
<em>root
</em> argument is only
used to query Tk for the
<strong>rgb
</strong> values of
<em>colorName
</em>.
</p><dt> <strong>Pmw.Color.rgb2brightness
</strong>(
<em>rgb
</em>)
</dt><dd>
Return the brightness of the color represented by
<em>rgb
</em>.
</p><dt> <strong>Pmw.Color.rgb2hsi
</strong>(
<em>rgb
</em>)
</dt><dd>
Return a tuple (
<em>hue
</em>,
<em>saturation
</em>,
<em>intensity
</em>) corresponding to
the color specified by the
<em>rgb
</em> sequence.
</p><dt> <strong>Pmw.Color.rgb2name
</strong>(
<em>rgb
</em>)
</dt><dd>
Return the name of the color represented by
<em>rgb
</em> as a string of
the form
<code>'#RRGGBB'
</code> suitable for use with Tk color functions.
</p><dt> <strong>Pmw.Color.setscheme
</strong>(
<em>root
</em>,
<em>background
</em> =
<strong>None
</strong>, **
<em>kw
</em>)
</dt><dd>
Set the color scheme for the application by setting default colors
(in the Tk option database of the root window of
<em>root
</em>) according
to the color scheme specified by the other arguments. This will
affect the initial colours of all widgets created after the call
<p> For example to initialise an application to have a red color
scheme with a white foreground:
</p><dl><dd><pre> Pmw.Color.setscheme(root,
background = 'red3', foreground = 'white')
</pre></dd></dl><p> This function does not modify the colors of already existing
widgets. Use
<strong>Pmw.Color.changecolor()
</strong> to do this.
</p><p> Note that
<em>root
</em> must be a Tk widget or toplevel. To use the Tk
option database of the root window of a Pmw megawidget, use the
megawidget's
<strong>hull
</strong> component. For example:
</p><dl><dd><pre> root = megawidget.component('hull')
Pmw.Color.setscheme(root, background = 'red3')
</pre></dd></dl><dt> <strong>Pmw.Color.spectrum
</strong>(
<em>numColors
</em>,
<em>correction
</em> =
<strong>1.0</strong>,
<em>saturation
</em> =
<strong>1.0</strong>,
<em>intensity
</em> =
<strong>1.0</strong>,
<em>extraOrange
</em> =
<strong>1</strong>,
<em>returnHues
</em> =
<strong>0</strong>)
</dt><dd>
Return a list of
<em>numColors
</em> different colors making up a
<em>spectrum
</em>. If
<em>extraOrange
</em> is false, the colors are evenly
spaced by hue from one end of the spectrum (red) to the other
(magenta). If
<em>extraOrange
</em> is true, the hues are not quite
evenly spaced - the hues around orange are emphasised, thus
preventing the spectrum from appearing to have to many
<em>cool
</em><p> If
<em>returnHues
</em> is false, the return values are the names of the
colors represented by the hues together with
<em>saturation
</em> and
<em>intensity
</em> and corrected by
<em>correction
</em>.
</p>
<p> If
<em>returnHues
</em> is true, the return values are hues.
</p>
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