Class: DynamicImageSources::ColorSource

Inherits:
SourceFactory show all
Defined in:
lib/sources/color_source.rb

Overview

Source providing solid color to use as source.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(color, alpha) ⇒ ColorSource

Creates source object from Cairo::Color::RGB object and alpha as Float value.



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# File 'lib/sources/color_source.rb', line 7

def initialize(color, alpha)
  alpha = nil unless alpha.class == Float
  @red = color.red
  @green = color.green
  @blue = color.blue
  @alpha = alpha || 1
end

Instance Attribute Details

#alpha ⇒ Object (readonly)

Gets color component



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# File 'lib/sources/color_source.rb', line 16

def alpha
  @alpha
end

#blue ⇒ Object (readonly)

Gets color component



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# File 'lib/sources/color_source.rb', line 16

def blue
  @blue
end

#green ⇒ Object (readonly)

Gets color component



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# File 'lib/sources/color_source.rb', line 16

def green
  @green
end

#red ⇒ Object (readonly)

Gets color component



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# File 'lib/sources/color_source.rb', line 16

def red
  @red
end

Class Method Details

.named_colors ⇒ Object

Gives Array of all known named colors. See cairo.rubyforge.org/doc/en/cairo-color.html#label-5



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# File 'lib/sources/color_source.rb', line 19

def self.named_colors
  @@named_colors ||= (Cairo::Color.constants.sort - %w{ RGB CMYK HSV X11 Base HEX_RE } - %w{ RGB CMYK HSV X11 Base HEX_RE }.map(&:to_sym)).map(&:to_s)
end

.parse(source) ⇒ Object

Returns source object or nil if it can’t parse it.

Supported syntax

All values can be given as Array or String separated by space chars.

To make color transparent add number value at the end of Array or String.

For any number value are valid values are 0 - 255 or 0.0 - 1.0

Name of color

Use one of ColorSource.named_colors.

RGB

Use separated number values for red, green and blue.

CMYK

Use :cmyk key as first value followed by separated number values for cyan, magenta, yellow and black.

HSV

Use :hsv key as first value followed by separated number values for hue, saturation and value.

HEX

Use String starting with # char followed by 6 or 3 hex numbers. Hex numbers are doubled if only 3 hex numbers are given. Color #AABBCC is same as #ABC.

Example

  • :red is same as "red" and [:red]

  • [255, 0, 0] and "#FF0000" makes red color

  • [255, 0, 0, 64] and ["#F00", 64] makes red color with 75% transparency

  • [1.0, 0, 0, 0.25] and "#F00 0.25" makes red color with 75% transparency

  • [:cmyk, 0, 0, 1.0, 0] makes yellow color

  • [:cmyk, 0, 0, 255, 0, 0.5] makes yellow color with 50% transparency



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# File 'lib/sources/color_source.rb', line 51

def self.parse(source)
  return source if source.is_a? SourceFactory
  if source[0].to_s =~ /^#([0-9a-f]{3}|[0-9a-f]{6})$/i
    hex = ($1.size == 6 ? $1 : $1.unpack('AXAAXAAXA').join).unpack("A2A2A2")
    source.shift
    hex.reverse.each {|h| source.unshift h.to_i(16) }
  end
  if is_all_nums(source, 0..2)
    treat_numbers source
    new Cairo::Color::RGB.new(*source[0..2]), source[3]
  elsif source[0] == "cmyk" && is_all_nums(source, 1..4)
    treat_numbers source
    new Cairo::Color::CMYK.new(*source[1..4]).to_rgb, source[5]
  elsif source[0] == "hsv" && is_all_nums(source, 1..3)
    treat_numbers source
    new Cairo::Color::HSV.new(*source[1..3]).to_rgb, source[4]
  elsif named_colors.include? source[0].to_s.upcase
    treat_numbers source
    new Cairo::Color.parse(source[0].to_s.upcase), source[1]
  end
end

Instance Method Details

#set_source(context, x, y, w, h) ⇒ Object

Sets color as source to given context



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# File 'lib/sources/color_source.rb', line 93

def set_source(context, x, y, w, h)
  context.set_source_rgba @red, @green, @blue, @alpha
end