Class: Postsvg::Svg::TransformList

Inherits:
Object
  • Object
show all
Defined in:
lib/postsvg/svg/transform_list.rb

Overview

Parsed SVG transform attribute. Produces a list of Postsvg::Matrix instances that, multiplied in order, give the composite CTM for the element.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(matrices = []) ⇒ TransformList

Returns a new instance of TransformList.



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# File 'lib/postsvg/svg/transform_list.rb', line 11

def initialize(matrices = [])
  @matrices = matrices.freeze
  freeze
end

Instance Attribute Details

#matrices ⇒ Object (readonly)

Returns the value of attribute matrices.



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# File 'lib/postsvg/svg/transform_list.rb', line 9

def matrices
  @matrices
end

Class Method Details

.parse(text) ⇒ Object 



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# File 'lib/postsvg/svg/transform_list.rb', line 26

def self.parse(text)
  return new if text.nil? || text.strip.empty?

  matrices = []
  text.scan(/(\w+)\s*\(([^)]*)\)/).each do |name, args|
    nums = args.split(/[\s,]+/).map(&:to_f)
    case name
    when "matrix"
      next unless nums.length == 6

      matrices << Matrix.new(a: nums[0], b: nums[1], c: nums[2],
                             d: nums[3], e: nums[4], f: nums[5])
    when "translate"
      tx = nums[0] || 0
      ty = nums[1] || 0
      matrices << Matrix.new(e: tx, f: ty)
    when "scale"
      sx = nums[0] || 1
      sy = nums.length > 1 ? nums[1] : sx
      matrices << Matrix.new(a: sx, d: sy)
    when "rotate"
      angle = nums[0] || 0
      matrices << Matrix.new.rotate(angle)
    when "skewX"
      matrices << Matrix.new.skew_x(nums[0] || 0)
    when "skewY"
      matrices << Matrix.new.skew_y(nums[0] || 0)
    end
  end
  new(matrices)
end

Instance Method Details

#composite ⇒ Object 



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# File 'lib/postsvg/svg/transform_list.rb', line 20

def composite
  return Matrix.new if @matrices.empty?

  @matrices.reduce(Matrix.new) { |acc, m| acc.multiply(m) }
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/postsvg/svg/transform_list.rb', line 16

def empty?
  @matrices.empty?
end