class Cairo::Paper - cairo-1.14.6 Documentation

# class Cairo::Paper

### Attributes

height[W]
name[RW]
unit[R]
width[W]

### Public Class Methods

default_unit() click to toggle source

    # File lib/cairo/paper.rb, line 52
    def default_unit
      @@default_unit
    end

default_unit=(unit) click to toggle source

    # File lib/cairo/paper.rb, line 56
    def default_unit=(unit)
      @@default_unit = unit
    end

new(width, height, unit=nil, name=nil) click to toggle source

    # File lib/cairo/paper.rb, line 128
    def initialize(width, height, unit=nil, name=nil)
      @width = width
      @height = height
      @unit = unit
      @name = name
    end

parse(paper_description, robust=false) click to toggle source

    # File lib/cairo/paper.rb, line 31
    def parse(paper_description, robust=false)
      case paper_description
      when Paper
        return paper_description.dup
      when Symbol
        paper = resolve_constant(paper_description)
        return paper.dup if paper
        raise UnknownPaperName.new(paper_description)
      when String
        paper = resolve_constant(paper_description)
        paper ||= parse_size(paper_description)
        return paper.dup if paper
      when Array
        return new(*paper_description)
      end

      raise UnrecognizedPaperDescription.new(paper_description) if robust
      nil
    end

register_unit_resolver(from_units, to_units, &resolver) click to toggle source

    # File lib/cairo/paper.rb, line 61
    def register_unit_resolver(from_units, to_units, &resolver)
      from_units = [from_units] unless from_units.is_a?(Array)
      to_units = [to_units] unless to_units.is_a?(Array)
      from_units.each do |from_unit|
        @@unit_resolvers[from_unit] ||= []
        to_units.each do |unit|
          @@unit_resolvers[from_unit] << [unit, resolver]
        end
      end
    end

resolve_unit(size, from_unit, to_unit) click to toggle source

    # File lib/cairo/paper.rb, line 72
    def resolve_unit(size, from_unit, to_unit)
      from_unit ||= default_unit
      return size if from_unit == to_unit
      from_units = @@unit_resolvers[from_unit] || []
      raise UnknownUnit.new(from_unit) if from_units.empty?
      from_units.each do |unit, resolver|
        return resolver.call(size) if to_unit == unit
      end
      raise UnknownUnit.new(to_unit)
    end

### Private Class Methods

parse_size(size) click to toggle source

    # File lib/cairo/paper.rb, line 93
    def parse_size(size)
      size_re = /(\d+(\.\d*)?)/
      unit_re = /([a-zA-Z]+?)/
      if /\A#{size_re}#{unit_re}?x#{size_re}#{unit_re}?(?:#(.*))?\z/ !~ size
        return nil
      end

      width = $1
      width_fractional = $2
      width_unit = $3
      height = $4
      height_fractional = $5
      height_unit = $6
      name = $7
      width = width_fractional ? Float(width) : Integer(width)
      height = height_fractional ?  Float(height) : Integer(height)
      new(resolve_unit(width, width_unit, "pt"),
          resolve_unit(height, height_unit, "pt"),
          nil, name)
    end

resolve_constant(name) click to toggle source

    # File lib/cairo/paper.rb, line 84
    def resolve_constant(name)
      name = name.to_s.upcase.gsub(/\s+|-/, '_')
      if /\A[A-Z]/ =~ name and const_defined?(name)
        const_get(name)
      else
        nil
      end
    end

### Public Instance Methods

==(other) click to toggle source

    # File lib/cairo/paper.rb, line 157
    def ==(other)
      other.is_a?(self.class) and @name == other.name and
        width_in_delta?(other.width(@unit)) and
        height_in_delta?(other.height(@unit))
    end

height(unit=nil) click to toggle source

    # File lib/cairo/paper.rb, line 148
    def height(unit=nil)
      return @height if unit.nil?
      self.class.resolve_unit(@height, @unit, unit)
    end

size(unit=nil) click to toggle source

    # File lib/cairo/paper.rb, line 153
    def size(unit=nil)
      [width(unit), height(unit)]
    end

to_s() click to toggle source

    # File lib/cairo/paper.rb, line 163
    def to_s
      string = "#{@width}#{@unit}x#{@height}#{@unit}"
      string << "\##{@name}" if @name
      string
    end

unit=(unit) click to toggle source

    # File lib/cairo/paper.rb, line 135
    def unit=(unit)
      if @unit != unit
        @width = self.class.resolve_unit(width, @unit, unit)
        @height = self.class.resolve_unit(height, @unit, unit)
      end
      @unit = unit
    end

width(unit=nil) click to toggle source

    # File lib/cairo/paper.rb, line 143
    def width(unit=nil)
      return @width if unit.nil?
      self.class.resolve_unit(@width, @unit, unit)
    end

### Private Instance Methods

height_in_delta?(value, delta=nil) click to toggle source

    # File lib/cairo/paper.rb, line 174
    def height_in_delta?(value, delta=nil)
      in_delta?(@height, delta, value)
    end

in_delta?(value, delta, other) click to toggle source

    # File lib/cairo/paper.rb, line 178
    def in_delta?(value, delta, other)
      delta ||= 0.001
      value - delta < other and other < value + delta
    end

width_in_delta?(value, delta=nil) click to toggle source

    # File lib/cairo/paper.rb, line 170
    def width_in_delta?(value, delta=nil)
      in_delta?(@width, delta, value)
    end