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, exclude_spaces: true) ⇒ Object

gradient(*arg_colours, bg: false, exclude_spaces: true) # => 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.

The option exclude_spaces, is expected to set either true or false. By default it’s set to true. Enabling this option will not waste colours on white-spaces. White spaces only include: s, t

Please do note that u0000 and r in the middle of the string will not be counted as a white space, but as a character instead. This is because r wipes out the previous characters, and using u0000 in a string is uncommon, and developers are requested to delete u0000 from string if such situations arise.

Raises:

  • (ArgumentError) 


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# File 'lib/string_dot_gradient/gradient.rb', line 43

def gradient(*arg_colours, bg: false, exclude_spaces: true)
  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 => starting r, g, b
  # r2, g2, b2 => stopping r, g, b
  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
    chomped = !!c.chomp!(''.freeze)

    len = c.length
    n_variable = exclude_spaces ? c.delete("\t\s".freeze).length : len
    n_variable -= 1
    n_variable = 1 if n_variable < 1

    # colour operator, colour value
    r_op = r_val  = nil
    g_op = g_val = nil
    b_op = b_val = nil

    if r2 > r
      r_op, r_val = :+, r2.-(r).fdiv(n_variable)
    elsif r2 < r
      r_op, r_val = :-, r.-(r2).fdiv(n_variable)
    end

    if g2 > g
      g_op, g_val = :+, g2.-(g).fdiv(n_variable)
    elsif g2 < g
      g_op, g_val = :-, g.-(g2).fdiv(n_variable)
    end

    if b2 > b
      b_op, b_val = :+, b2.-(b).fdiv(n_variable)
    elsif b2 < b
      b_op, b_val = :-, b.-(b2).fdiv(n_variable)
    end

    # To avoid the value getting adding | subtracted from the initial character
    _r = _r.send(r_op, r_val * -1) if r_op
    _g = _g.send(g_op, g_val * -1) if g_op
    _b = _b.send(b_op, b_val * -1) if b_op

    i = -1
    while (i += 1) < len
      _c = c[i]

      if !exclude_spaces || (exclude_spaces && !(_c == ?\s.freeze || _c == ?\t.freeze))
        _r = _r.send(r_op, r_val) if r_op
        _g = _g.send(g_op, g_val) if g_op
        _b = _b.send(b_op, b_val) if b_op
      end

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

      f_r = r_to_i < 0 ? 0 : r_to_i > 255 ? 255 : r_to_i
      f_g = g_to_i < 0 ? 0 : g_to_i > 255 ? 255 : g_to_i
      f_b = b_to_i < 0 ? 0 : b_to_i > 255 ? 255 : b_to_i

      ret = "\e[#{init};2;#{f_r};#{f_g};#{f_b}m#{_c}"

      if block_given
        yield ret
      else
        temp << ret
      end
    end

    ret = if !c.empty?
      chomped ? "\e[0m\n".freeze : "\e[0m".freeze
    elsif chomped
      ?\n.freeze
    end

    if block_given
      yield ret
    else
      temp << ret
    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