Class: GChart::Axis

Inherits:
Object
  • Object
show all
Defined in:
lib/gchart/axis.rb

Direct Known Subclasses

HorizontalAxis, VerticalAxis

Constant Summary collapse

AXIS_TYPES = 
[ :top, :right, :bottom, :left ]
TEXT_ALIGNMENT =

Defaults: :left for RightAxis, :center for TopAxis and for BottomAxis, and :right for LeftAxis.

{ :left => -1, :center => 0, :right => 1 }

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Axis

Returns a new instance of Axis.



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# File 'lib/gchart/axis.rb', line 59

def initialize
  @labels          = []
  @label_positions = []
  @range_markers   = []
end

Instance Attribute Details

#font_size ⇒ Object

Size of font in pixels. To set font_size, text_color is also required.



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# File 'lib/gchart/axis.rb', line 23

def font_size
  @font_size
end

#label_positions ⇒ Object

Array of float positions for labels. Without labels, the label_positions are self-labeling.



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# File 'lib/gchart/axis.rb', line 10

def label_positions
  @label_positions
end

#labels ⇒ Object

Array of axis labels. Can be exactly placed along the axis with label_positions, otherwise are evenly spaced.



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# File 'lib/gchart/axis.rb', line 6

def labels
  @labels
end

#range ⇒ Object

Takes a Range of float values. With labels, defines labels context, meaning the labels will be spaced at their proper location within the range. Without labels, smart-labeling occurs for range.



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# File 'lib/gchart/axis.rb', line 16

def range
  @range
end

#range_markers ⇒ Object

Array of 2-element sub-arrays such that the 1st element in each sub-array is a Range of float values which describe the start and end points of the range marker, and the 2nd element in each sub-array is an rrggbb color for the range marker. For :top and :bottom AXIS_TYPES, markers are vertical. For :right and :left AXIS_TYPES, markers are horizontal.



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# File 'lib/gchart/axis.rb', line 36

def range_markers
  @range_markers
end

#text_alignment ⇒ Object

TEXT_ALIGNMENT property for axis labeling. To set text_alignment, both text_color and font_size must also be set.



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# File 'lib/gchart/axis.rb', line 28

def text_alignment
  @text_alignment
end

#text_color ⇒ Object

An rrggbb color for axis text.



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# File 'lib/gchart/axis.rb', line 19

def text_color
  @text_color
end

Class Method Details

.create(axis_type) {|axis| ... } ⇒ Object

Instantiates the proper GChart::Axis subclass based on the axis_type.

Yields:

  • (axis)

Raises:

  • (ArgumentError) 


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# File 'lib/gchart/axis.rb', line 47

def create(axis_type, &block)
  raise ArgumentError.new("Invalid axis type '#{axis_type}'") unless AXIS_TYPES.include?(axis_type)

  axis = Object.module_eval("GChart::#{axis_type.to_s.capitalize}Axis").new

  yield(axis) if block_given?
  axis
end

Instance Method Details

#axis_type_label ⇒ Object

Returns a one-character label of the axis according to its type.

Raises:

  • (NotImplementedError) 


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# File 'lib/gchart/axis.rb', line 66

def axis_type_label
  raise NotImplementedError.new("Method must be overridden in a subclass of this abstract base class.")
end

#range_marker_type_label ⇒ Object

Returns a one-character label to indicate whether ranger_markers are vertical or horizontal.

Raises:

  • (NotImplementedError) 


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# File 'lib/gchart/axis.rb', line 72

def range_marker_type_label
  raise NotImplementedError.new("Method must be overridden in a subclass of this abstract base class.")
end

#validate! ⇒ Object

Ensures that all combinations of attributes which have been set will work with each other. Raises ArgumentError otherwise.



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# File 'lib/gchart/axis.rb', line 78

def validate!
  if labels.size > 0 and label_positions.size > 0 and labels.size != label_positions.size
    raise ArgumentError.new(
      "Both labels and label_positions have been specified, but their " +
      "respective counts do not match (labels.size = '#{labels.size}' " +
      "and label_positions.size = '#{label_positions.size}')"
    )
  end

  unless label_positions.all? { |pos| pos.is_a?(Numeric) }
    raise ArgumentError.new(
      "The label_positions attribute requires numeric values for each position specified"
    )
  end

  if range
    unless range.is_a?(Range)
      raise ArgumentError.new("The range attribute has been specified with a non-Range class")
    end

    unless range.first.is_a?(Numeric)
      raise ArgumentError.new("The range attribute has been specified with non-numeric range values")
    end
  end

  if font_size and not text_color
    raise ArgumentError.new("To specify a font_size, a text_color must also be specified")
  end

  if text_alignment and not (text_color and font_size)
    raise ArgumentError.new(
      "To specify a text_alignment, both text_color and font_size must also be specified"
    )
  end

  if text_color and not GChart.valid_color?(text_color)
    raise ArgumentError.new("The text_color attribute has been specified with an invalid color")
  end

  if font_size and not font_size.is_a?(Numeric)
    raise ArgumentError.new("The font_size must have a numeric value")
  end

  if text_alignment and not TEXT_ALIGNMENT[text_alignment]
    raise ArgumentError.new(
      "The text_alignment attribute has been specified with a non-TEXT_ALIGNMENT"
    )
  end

  if not range_markers.all? { |array| array.is_a?(Array) and array.size == 2 and
                                      array[0].is_a?(Range) and array[0].first.is_a?(Numeric) and
                                      GChart.valid_color?(array[1]) }
    raise ArgumentError.new(
      "The range_markers attribute must be an array of 2-element sub-arrays such that " +
      "the first element in each sub-array is a Range of numeric values and the second " +
      "element in each sub-array is a valid color"
    )
  end
end