Class: Gruff::Base

Inherits:
Object
  • Object
show all
Includes:
Deprecated, Magick
Defined in:
lib/gruff/base.rb

Direct Known Subclasses

Area, Bar, Bullet, Line, Net, PhotoBar, Pie, Scene, SideBar, Spider, StackedArea, StackedBar

Defined Under Namespace

Modules: StackedMixin

Constant Summary collapse

DEBUG =

Draw extra lines showing where the margins and text centers are

false
DATA_LABEL_INDEX =

Used for navigating the array of data to plot

0
DATA_VALUES_INDEX = 
1
DATA_COLOR_INDEX = 
2
DATA_ATTRS_INDEX = 
3
LEGEND_MARGIN =

Space around text elements. Mostly used for vertical spacing

TITLE_MARGIN = LABEL_MARGIN = 10.0
DEFAULT_TARGET_WIDTH = 
800

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Deprecated

#graph_height, #graph_left, #graph_top, #graph_width, #scale_measurements, #total_height

Constructor Details

#initialize(target_width = DEFAULT_TARGET_WIDTH) ⇒ Base

If one numerical argument is given, the graph is drawn at 4/3 ratio according to the given width (800 results in 800x600, 400 gives 400x300, etc.).

Or, send a geometry string for other ratios (‘800x400’, ‘400x225’).

Looks for Bitstream Vera as the default font. Expects an environment var of MAGICK_FONT_PATH to be set. (Uses RMagick’s default font otherwise.)



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# File 'lib/gruff/base.rb', line 176

def initialize(target_width=DEFAULT_TARGET_WIDTH)
  @top_margin = @bottom_margin = @left_margin = @right_margin = 20.0

  if not Numeric === target_width
    geometric_width, geometric_height = target_width.split('x')
    @columns = geometric_width.to_f
    @rows = geometric_height.to_f
  else
    @columns = target_width.to_f
    @rows = target_width.to_f * 0.75
  end

  # Call any other initializers -- open-ended to allow for
  # subclass extensions
  self.class.instance_methods.
	select{|m| m.to_s =~ /^initialize_/o}.each do |initializer|
	self.send(initializer)
  end

  reset_themes
  theme_keynote
end

Instance Attribute Details

#additional_line_values ⇒ Object

Experimental



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# File 'lib/gruff/base.rb', line 157

def additional_line_values
  @additional_line_values
end

#bottom_margin ⇒ Object

Blank space below the graph



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# File 'lib/gruff/base.rb', line 48

def bottom_margin
  @bottom_margin
end

#center_labels_over_point ⇒ Object

Used internally for spacing.

By default, labels are centered over the point they represent.



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# File 'lib/gruff/base.rb', line 70

def center_labels_over_point
  @center_labels_over_point
end

#colors ⇒ Object

Get or set the list of colors that will be used to draw the bars or lines.



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# File 'lib/gruff/base.rb', line 87

def colors
  @colors
end

#font ⇒ Object

Font used for titles, labels, etc. Works best if you provide the full path to the TTF font file. RMagick must be built with the Freetype libraries for this to work properly.

Tries to find Bitstream Vera (Vera.ttf) in the location specified by ENV. Uses default RMagick font otherwise.

The font= method below fulfills the role of the writer, so we only need a reader here.



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# File 'lib/gruff/base.rb', line 101

def font
  @font
end

#font_color ⇒ Object

Returns the value of attribute font_color.



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# File 'lib/gruff/base.rb', line 103

def font_color
  @font_color
end

#has_left_labels ⇒ Object

Used internally for horizontal graph types.



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# File 'lib/gruff/base.rb', line 73

def has_left_labels
  @has_left_labels
end

#hide_legend ⇒ Object

Prevent drawing of the legend



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# File 'lib/gruff/base.rb', line 109

def hide_legend
  @hide_legend
end

#hide_line_markers ⇒ Object

Prevent drawing of line markers



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# File 'lib/gruff/base.rb', line 106

def hide_line_markers
  @hide_line_markers
end

#hide_line_numbers ⇒ Object

Prevent drawing of line numbers



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# File 'lib/gruff/base.rb', line 115

def hide_line_numbers
  @hide_line_numbers
end

#hide_title ⇒ Object

Prevent drawing of the title



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# File 'lib/gruff/base.rb', line 112

def hide_title
  @hide_title
end

#label_rotation ⇒ Object

Labels can be rotated from 0-90 degrees



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# File 'lib/gruff/base.rb', line 65

def label_rotation
  @label_rotation
end

#labels ⇒ Object

A hash of names for the individual columns, where the key is the array index for the column this label represents.

Not all columns need to be named.

Example: 0 => 2005, 3 => 2006, 5 => 2007, 7 => 2008



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# File 'lib/gruff/base.rb', line 62

def labels
  @labels
end

#left_margin ⇒ Object

Blank space to the left of the graph



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# File 'lib/gruff/base.rb', line 54

def left_margin
  @left_margin
end

#legend_box_size ⇒ Object

Optionally set the size of the colored box by each item in the legend. Default is 20.0

Will be scaled down if graph is smaller than 800px wide.



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# File 'lib/gruff/base.rb', line 166

def legend_box_size
  @legend_box_size
end

#legend_font_size ⇒ Object

Optionally set the size of the font. Based on an 800x600px graph. Default is 20.

Will be scaled down if graph is smaller than 800px wide.



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# File 'lib/gruff/base.rb', line 128

def legend_font_size
  @legend_font_size
end

#marker_color ⇒ Object

The color of the auxiliary lines



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# File 'lib/gruff/base.rb', line 134

def marker_color
  @marker_color
end

#marker_count ⇒ Object

The number of horizontal lines shown for reference



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# File 'lib/gruff/base.rb', line 137

def marker_count
  @marker_count
end

#marker_font_size ⇒ Object

The font size of the labels around the graph



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# File 'lib/gruff/base.rb', line 131

def marker_font_size
  @marker_font_size
end

#maximum_value ⇒ Object

You can manually set a maximum value, such as a percentage-based graph that always goes to 100.

If you use this, you must set it after you have given all your data to the graph object.



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# File 'lib/gruff/base.rb', line 150

def maximum_value
  @maximum_value
end

#minimum_value ⇒ Object

You can manually set a minimum value instead of having the values guessed for you.

Set it after you have given all your data to the graph object.



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# File 'lib/gruff/base.rb', line 143

def minimum_value
  @minimum_value
end

#no_data_message ⇒ Object

Message shown when there is no data. Fits up to 20 characters. Defaults to “No Data.”



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# File 'lib/gruff/base.rb', line 119

def no_data_message
  @no_data_message
end

#right_margin ⇒ Object

Blank space to the right of the graph



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# File 'lib/gruff/base.rb', line 51

def right_margin
  @right_margin
end

#sort ⇒ Object

Set to false if you don’t want the data to be sorted with largest avg values at the back.



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# File 'lib/gruff/base.rb', line 154

def sort
  @sort
end

#stacked ⇒ Object

Experimental



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# File 'lib/gruff/base.rb', line 160

def stacked
  @stacked
end

#title ⇒ Object

The large title of the graph displayed at the top



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# File 'lib/gruff/base.rb', line 90

def title
  @title
end

#title_font_size ⇒ Object

The font size of the large title at the top of the graph



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# File 'lib/gruff/base.rb', line 122

def title_font_size
  @title_font_size
end

#top_margin ⇒ Object

Blank space above the graph



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# File 'lib/gruff/base.rb', line 45

def top_margin
  @top_margin
end

#x_axis_label ⇒ Object

A label for the bottom of the graph



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# File 'lib/gruff/base.rb', line 76

def x_axis_label
  @x_axis_label
end

#y_axis_increment ⇒ Object

Manually set increment of the horizontal marking lines



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# File 'lib/gruff/base.rb', line 84

def y_axis_increment
  @y_axis_increment
end

#y_axis_label ⇒ Object

A label for the left side of the graph



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# File 'lib/gruff/base.rb', line 79

def y_axis_label
  @y_axis_label
end

Instance Method Details

#add_color(colorname) ⇒ Object

Add a color to the list of available colors for lines.

Example:

add_color('#c0e9d3')



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# File 'lib/gruff/base.rb', line 264

def add_color(colorname)
  @colors << colorname
end

#data(name, data_points = [], color = nil) ⇒ Object

Parameters are an array where the first element is the name of the dataset and the value is an array of values to plot.

Can be called multiple times with different datasets for a multi-valued graph.

If the color argument is nil, the next color from the default theme will be used.

NOTE: If you want to use a preset theme, you must set it before calling data().

Example:

data("Bart S.", [95, 45, 78, 89, 88, 76], '#ffcc00')



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# File 'lib/gruff/base.rb', line 292

def data(name, data_points=[], color=nil)
  data_points = Array(data_points) # make sure it's an array
  @data << [name, data_points, (color || increment_color)]
  # Set column count if this is larger than previous counts
  @column_count = (data_points.length > @column_count) ? data_points.length : @column_count

  # Pre-normalize
  data_points.each_with_index do |data_point, index|
    next if data_point.nil?

    # Setup max/min so spread starts at the low end of the data points
    if @maximum_value.nil? && @minimum_value.nil?
      @maximum_value = @minimum_value = data_point
    end

    # TODO Doesn't work with stacked bar graphs
    # Original: @maximum_value = larger_than_max?(data_point, index) ? max(data_point, index) : @maximum_value
    @maximum_value = larger_than_max?(data_point) ? data_point : @maximum_value
    @has_data = true if @maximum_value > 0

    @minimum_value = less_than_min?(data_point) ? data_point : @minimum_value
    @has_data = true if @minimum_value < 0
  end
end

#initialize_ivars ⇒ Object

Set instance variables for this object.

Subclasses can override this, call super, then set values separately.

This makes it possible to set defaults in a subclass but still allow developers to change this values in their program.



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# File 'lib/gruff/base.rb', line 205

def initialize_ivars
  # Internal for calculations
  @raw_columns = 800.0
  @raw_rows = 800.0 * (@rows/@columns)
  @column_count = 0
  @marker_count = nil
  @maximum_value = @minimum_value = nil
  @has_data = false
  @data = Array.new
  @labels = Hash.new
  @labels_seen = Hash.new
  @sort = true
  @title = nil

  @scale = @columns / @raw_columns

  vera_font_path = File.expand_path('Vera.ttf', ENV['MAGICK_FONT_PATH'])
  @font = File.exists?(vera_font_path) ? vera_font_path : nil

  @marker_font_size = 21.0
  @legend_font_size = 20.0
  @title_font_size = 36.0

  @legend_box_size = 20.0

  @no_data_message = "No Data"

  @hide_line_markers = @hide_legend = @hide_title = @hide_line_numbers = false
  @center_labels_over_point = true
  @has_left_labels = false

  @label_rotation = 0

  @additional_line_values = []      
  @additional_line_colors = []
  @theme_options = {}

  @x_axis_label = @y_axis_label = nil
  @y_axis_increment = nil
  @stacked = nil
  @norm_data = nil

end

#margins=(margin) ⇒ Object

Sets the top, bottom, left and right margins to margin.



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# File 'lib/gruff/base.rb', line 250

def margins=(margin)
  @top_margin = @left_margin = @right_margin = @bottom_margin = margin
end

#replace_colors(color_list = []) ⇒ Object

Replace the entire color list with a new array of colors. You need to have one more color than the number of datasets you intend to draw. Also aliased as the colors= setter method.

Example:

replace_colors ['#cc99cc', '#d9e043', '#34d8a2']



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# File 'lib/gruff/base.rb', line 274

def replace_colors(color_list=[])
  @colors = color_list
end

#to_blob(fileformat = 'PNG') ⇒ Object

Return the graph as a rendered binary blob.



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# File 'lib/gruff/base.rb', line 327

def to_blob(fileformat='PNG')
  draw()
  return @base_image.to_blob do
    self.format = fileformat
  end
end

#write(filename = "graph.png") ⇒ Object

Writes the graph to a file. Defaults to ‘graph.png’

Example:

write('graphs/my_pretty_graph.png')



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# File 'lib/gruff/base.rb', line 321

def write(filename="graph.png")
  draw()
  @base_image.write(filename)
end