Class: String

Inherits:
Object
  • Object
show all
Defined in:
lib/string_dot_gradient/gradient.rb

Instance Method Summary collapse

Instance Method Details

#gradient(*arg_colours, bg: false) ⇒ Object

gradient(*arg_colours, bg: false) # => string or nil

Prettifies your string by adding gradient colours

This method accept a lot of colours. For example:

  1. puts “Hello”.gradient(‘#f55’, ‘#55f’)

This will add #f55 (red) to #55f (blue) gradient colours to your texts.

  1. puts “HellonWorld”.gradient(‘#f55’, ‘#55f’)

This will add #f55 (red) to #55f (blue) gradient colours to your texts, spanning multiple lines.

  1. puts “HellonWorld!nColoursnarenrotated here”.gradient(‘f55’,‘55f’, ‘3eb’ ‘ff5’)

This will add #ff5555 (red) to #5555ff (blue) gradient colours to the first line, 5555ff to 33eebb colour to the 2nd line, 33eebb to ffff55 to the third line And then back to ffff55 to ff5555 to the fourth line, And it will continue to rotate between these colours.

To stop rotating, just don’t give more than two arguments to this method.

Passing blocks is also optional, and is handy for animating text. For example:

"Hello\nWorld!\nColours\nare\nrotated here".gradient('f55','55f', '3eb' 'ff5', bg:true) { |x| print x ; sleep 0.05 }

This will pass the values to the block itself, and will draw the colourful text slowly. Passing block will return nil from the method because the values will be passed to the block variable instead.

Adding the option bg will change the background colour, but will keep the foreground colour defined in the terminal settings.

Raises:

  • (ArgumentError) 


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# File 'lib/string_dot_gradient/gradient.rb', line 32

def gradient(*arg_colours, bg: false)
  colours, line_length = [], -1
  temp = ''
  flatten_colours = arg_colours.flatten

  raise ArgumentError, "Wrong numeber of colours (given #{flatten_colours.length}, expected minimum 2)" if flatten_colours.length < 2
  raise ArgumentError, "Given argument for colour is neither a String nor an Integer" if flatten_colours.any? { |x| !(x.is_a?(String) || x.is_a?(Integer)) }

  all_rgbs = flatten_colours.map!(&method(:hex_to_rgb))

  block_given = block_given?

  r, g, b = all_rgbs[0]
  r2, g2, b2 = all_rgbs[1]
  rotate = all_rgbs.length > 2

  init = bg ? 48 : 38

  each_line do |c|
    _r, _g, _b = r, g, b
    n = c.length

    r_max, r_min = r > r2 ? [r, r2] : [r2, r]
    g_max, g_min = g > g2 ? [g, g2] : [g2, g]
    b_max, b_min = b > b2 ? [b, b2] : [b2, b]

    r_meth = r == r2 ? :itself : r2 > r ? [:+, r2.fdiv(n)] : [:-, r.fdiv(n)]
    g_meth = g == g2 ? :itself : g2 > g ? [:+, g2.fdiv(n)] : [:-, g.fdiv(n)]
    b_meth = b == b2 ? :itself : b2 > b ? [:+, b2.fdiv(n)] : [:-, b.fdiv(n)]

    if line_length != n || rotate
      line_length = n
      colours.clear

      i = -1
      while (i += 1) < n
        _r = _r.send(*r_meth) unless _r > r_max || _r < r_min
        _g = _g.send(*g_meth) unless _g > g_max || _g < g_min
        _b = _b.send(*b_meth) unless _b > b_max || _b < b_min

        r_to_i = _r.to_i
        g_to_i = _g.to_i
        b_to_i = _b.to_i

        colours << [
          r_to_i < 0 ? 0 : r_to_i > 255 ? 255 : r_to_i,
          g_to_i < 0 ? 0 : g_to_i > 255 ? 255 : g_to_i,
          b_to_i < 0 ? 0 : b_to_i > 255 ? 255 : b_to_i,
        ]
      end
    end

    i = -1
    while (i += 1) < n
      if block_given
        yield "\e[#{init};2;#{colours[i][0]};#{colours[i][1]};#{colours[i][2]}m#{c[i]}"
      else
        temp.concat(
          "\e[#{init};2;#{colours[i][0]};#{colours[i][1]};#{colours[i][2]}m#{c[i]}"
        )
      end
    end

    if block_given
      yield "\e[0m".freeze
    else
      temp << "\e[0m".freeze
    end

    if rotate
      all_rgbs.rotate!
      r, g, b = all_rgbs[0]
      r2, g2, b2 = all_rgbs[1]
    end
  end

  block_given ? nil : temp
end