Class: Gruff::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/gruff/base.rb

Overview

A common base class inherited from class of drawing a graph.

Constant Summary collapse

LEGEND_MARGIN =

Space around text elements. Mostly used for vertical spacing.

TITLE_MARGIN = 20.0
LABEL_MARGIN =
15.0
DEFAULT_MARGIN =
20.0
DEFAULT_TARGET_WIDTH =
800.0

Instance Attribute Summary collapse

Instance Method Summary collapse

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').

Parameters:

  • target_width (Numeric, String) (defaults to: DEFAULT_TARGET_WIDTH)

    The graph image width.


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# File 'lib/gruff/base.rb', line 129

def initialize(target_width = DEFAULT_TARGET_WIDTH)
  if target_width.is_a?(String)
    @columns, @rows = target_width.split('x').map(&:to_f)
  else
    @columns = target_width.to_f
    @rows = target_width.to_f * 0.75
  end
  @columns.freeze
  @rows.freeze

  @has_left_labels = false
  @center_labels_over_point = true

  initialize_graph_scale
  initialize_attributes
  initialize_store

  self.theme = Themes::KEYNOTE
end

Instance Attribute Details

#bottom_margin=(value) ⇒ Object (writeonly)

Blank space below the graph. Default is 20.


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# File 'lib/gruff/base.rb', line 34

def bottom_margin=(value)
  @bottom_margin = value
end

#colorsObject

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 77

def colors
  @colors
end

#hide_legend=(value) ⇒ Object (writeonly)

Prevent drawing of the legend. Default is false.


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# File 'lib/gruff/base.rb', line 83

def hide_legend=(value)
  @hide_legend = value
end

#hide_line_markers=(value) ⇒ Object (writeonly)

Prevent drawing of line markers. Default is false.


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# File 'lib/gruff/base.rb', line 80

def hide_line_markers=(value)
  @hide_line_markers = value
end

#hide_line_numbers=(value) ⇒ Object (writeonly)

Prevent drawing of line numbers. Default is false.


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# File 'lib/gruff/base.rb', line 89

def hide_line_numbers=(value)
  @hide_line_numbers = value
end

#hide_title=(value) ⇒ Object (writeonly)

Prevent drawing of the title. Default is false.


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# File 'lib/gruff/base.rb', line 86

def hide_title=(value)
  @hide_title = value
end

#label_max_size=(value) ⇒ Object (writeonly)

Truncates labels if longer than max specified.


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# File 'lib/gruff/base.rb', line 49

def label_max_size=(value)
  @label_max_size = value
end

#label_truncation_style=(value) ⇒ Object (writeonly)

How truncated labels visually appear if they exceed #label_max_size=.

  • :absolute - does not show trailing dots to indicate truncation. This is the default.

  • :trailing_dots - shows trailing dots to indicate truncation (note that #label_max_size= must be greater than 3).


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# File 'lib/gruff/base.rb', line 56

def label_truncation_style=(value)
  @label_truncation_style = value
end

#left_margin=(value) ⇒ Object (writeonly)

Blank space to the left of the graph. Default is 20.


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# File 'lib/gruff/base.rb', line 40

def left_margin=(value)
  @left_margin = value
end

#legend_at_bottom=(value) ⇒ Object (writeonly)

Display the legend under the graph. Default is false.


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# File 'lib/gruff/base.rb', line 113

def legend_at_bottom=(value)
  @legend_at_bottom = value
end

#legend_box_size=(value) ⇒ Object (writeonly)

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 119

def legend_box_size=(value)
  @legend_box_size = value
end

#legend_margin=(value) ⇒ Object (writeonly)

Blank space below the legend. Default is 20.


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# File 'lib/gruff/base.rb', line 46

def legend_margin=(value)
  @legend_margin = value
end

#marker_color=(value) ⇒ Object (writeonly)

Set the color of the auxiliary lines.


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# File 'lib/gruff/base.rb', line 96

def marker_color=(value)
  @marker_color = value
end

#marker_count=(value) ⇒ Object

Set the number of horizontal lines shown for reference.


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# File 'lib/gruff/base.rb', line 102

def marker_count=(value)
  @marker_count = value
end

#marker_shadow_color=(value) ⇒ Object (writeonly)

Set the shadow color of the auxiliary lines.


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# File 'lib/gruff/base.rb', line 99

def marker_shadow_color=(value)
  @marker_shadow_color = value
end

#maximum_valueObject

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 482

def maximum_value
  (@maximum_value || store.max).to_f
end

#minimum_valueObject

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 471

def minimum_value
  min = [0.0, store.min.to_f].min
  (@minimum_value || min).to_f
end

#no_data_message=(value) ⇒ Object (writeonly)

Set a 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 93

def no_data_message=(value)
  @no_data_message = value
end

#right_margin=(value) ⇒ Object (writeonly)

Blank space to the right of the graph. Default is 20.


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# File 'lib/gruff/base.rb', line 37

def right_margin=(value)
  @right_margin = value
end

#sort=(value) ⇒ Object (writeonly)

Set to true if you want the data sets sorted with largest avg values drawn first. Default is false.


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

def sort=(value)
  @sort = value
end

#sorted_drawing=(value) ⇒ Object (writeonly)

Set to true if you want the data sets drawn with largest avg values drawn first. This does not affect the legend. Default is false.


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# File 'lib/gruff/base.rb', line 110

def sorted_drawing=(value)
  @sorted_drawing = value
end

#title_margin=(value) ⇒ Object (writeonly)

Blank space below the title. Default is 20.


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# File 'lib/gruff/base.rb', line 43

def title_margin=(value)
  @title_margin = value
end

#top_margin=(value) ⇒ Object (writeonly)

Blank space above the graph. Default is 20.


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# File 'lib/gruff/base.rb', line 31

def top_margin=(value)
  @top_margin = value
end

#x_axis_increment=(value) ⇒ Object (writeonly)

Set increment of the vertical marking lines.


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# File 'lib/gruff/base.rb', line 71

def x_axis_increment=(value)
  @x_axis_increment = value
end

#x_axis_label=(value) ⇒ Object

Set a label for the bottom of the graph.


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# File 'lib/gruff/base.rb', line 59

def x_axis_label=(value)
  @x_axis_label = value
end

#x_axis_label_format=(value) ⇒ Object (writeonly)

Allow passing lambda to format labels for x axis.


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

def x_axis_label_format=(value)
  @x_axis_label_format = value
end

#y_axis_increment=(value) ⇒ Object (writeonly)

Set increment of the horizontal marking lines.


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# File 'lib/gruff/base.rb', line 74

def y_axis_increment=(value)
  @y_axis_increment = value
end

#y_axis_label=(value) ⇒ Object

Set a label for the left side of the graph.


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

def y_axis_label=(value)
  @y_axis_label = value
end

#y_axis_label_format=(value) ⇒ Object (writeonly)

Allow passing lambda to format labels for y axis.


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# File 'lib/gruff/base.rb', line 68

def y_axis_label_format=(value)
  @y_axis_label_format = value
end

Instance Method Details

#add_color(colorname) ⇒ Object

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

Examples:

add_color('#c0e9d3')

Parameters:

  • colorname (String)

    The color.


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# File 'lib/gruff/base.rb', line 343

def add_color(colorname)
  @colors << colorname
end

#bold_title=(value) ⇒ Object

Specifies whether to draw the title bolded or not. Default is true.

Parameters:

  • value (Boolean)

    specifies whether to draw the title bolded or not.


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# File 'lib/gruff/base.rb', line 323

def bold_title=(value)
  @title_font.bold = value
end

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

Note:

If you want to use a preset theme, you must set it before calling #data.

Input the data in the graph.

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.

Examples:

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

Parameters:

  • name (String, Symbol)

    The name of the dataset.

  • data_points (Array) (defaults to: [])

    The array of dataset.

  • color (String) (defaults to: nil)

    The color for drawing graph of dataset.


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# File 'lib/gruff/base.rb', line 463

def data(name, data_points = [], color = nil)
  store.add(name, data_points, color)
end

#drawObject

Draw a graph.


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# File 'lib/gruff/base.rb', line 531

def draw
  setup_data

  # Maybe should be done in one of the following functions for more granularity.
  unless data_given?
    draw_no_data
    return
  end

  setup_drawing

  draw_legend
  draw_line_markers
  draw_axis_labels
  draw_title
  draw_graph
end

#font=(font_path) ⇒ Object

Sets the font for graph text to the font at font_path.

Parameters:

  • font_path (String)

    The path to font.


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# File 'lib/gruff/base.rb', line 278

def font=(font_path)
  @title_font.path = font_path unless @title_font.path
  @marker_font.path = font_path
  @legend_font.path = font_path
end

#font_color=(value) ⇒ Object

Specifies the text color.

Parameters:

  • value (String)

    color


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# File 'lib/gruff/base.rb', line 331

def font_color=(value)
  @title_font.color = value
  @marker_font.color = value
  @legend_font.color = value
end

#label_rotation=(rotation) ⇒ Object

Set a rotation for labels. You can use Default is 0. You can use a rotation between 0.0 and 45.0, or between 0.0 and -45.0.

Parameters:

  • rotation (Numeric)

    the rotation.

Raises:

  • (ArgumentError)

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# File 'lib/gruff/base.rb', line 234

def label_rotation=(rotation)
  raise ArgumentError, 'rotation must be between 0.0 and 45.0 or between 0.0 and -45.0' if rotation > 45.0 || rotation < -45.0

  @label_rotation = rotation.to_f
end

#label_stagger_height=(_value) ⇒ Object

Deprecated.

Height of staggering between labels.


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# File 'lib/gruff/base.rb', line 242

def label_stagger_height=(_value)
  warn '#label_stagger_height= is deprecated. It is no longer effective.'
end

#labels=(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 with hash.

Or, an array corresponding to the data values.

Examples:

g = Gruff::Bar.new
g.labels = { 0 => 2005, 3 => 2006, 5 => 2007, 7 => 2008 }

g = Gruff::Bar.new
g.labels = ['2005', nil, nil, '2006', nil, nil, '2007', nil, nil, '2008'] # same labels for columns

Parameters:

  • labels (Hash, Array)

    the labels.


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# File 'lib/gruff/base.rb', line 219

def labels=(labels)
  if labels.is_a?(Array)
    labels = labels.each_with_index.each_with_object({}) do |(label, index), hash|
      hash[index] = label
    end
  end

  @labels = labels
end

#legend_font_size=(value) ⇒ Object

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

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

Parameters:

  • value (Numeric)

    legend font size


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# File 'lib/gruff/base.rb', line 315

def legend_font_size=(value)
  @legend_font.size = value
end

#margins=(margin) ⇒ Object

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

Parameters:

  • margin (Numeric)

    The margin size.


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# File 'lib/gruff/base.rb', line 270

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

#marker_font_size=(value) ⇒ Object

The font size of the labels around the graph. Default is 21.

Parameters:

  • value (Numeric)

    marker font size


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# File 'lib/gruff/base.rb', line 304

def marker_font_size=(value)
  @marker_font.size = value
end

#replace_colors(color_list = []) ⇒ Object

Replace the entire color list with a new array of colors. Also aliased as the #colors= setter method.

If you specify fewer colors than the number of datasets you intend to draw, it will cycle through the array, reusing colors as needed.

Note that (as with the #theme= method), you should set up your color list before you send your data (via the #data method). Calls to the #data method made prior to this call will use whatever color scheme was in place at the time data was called.

Examples:

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

Parameters:

  • color_list (Array) (defaults to: [])

    The array of colors.


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# File 'lib/gruff/base.rb', line 362

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

#theme=(options) ⇒ Object

You can set a theme manually. Assign a hash to this method before you send your data.

g = Gruff::Bar.new
g.theme = {
  colors: %w(orange purple green white red),
  marker_color: 'blue',
  background_colors: ['black', 'grey'],
  background_direction: :top_bottom
}

background_image: 'squirrel.png' is also possible.

background_direction accepts one of following parameters.

  • :top_bottom

  • :bottom_top

  • :left_right

  • :right_left

  • :topleft_bottomright

  • :topright_bottomleft

(Or hopefully something better looking than that.)

Parameters:

  • options (Hash)

    The optional setting for theme


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# File 'lib/gruff/base.rb', line 391

def theme=(options)
  reset_themes

  defaults = {
    colors: %w[black white],
    marker_color: 'white',
    marker_shadow_color: nil,
    font_color: 'black',
    background_colors: nil,
    background_image: nil
  }
  @theme_options = defaults.merge options

  self.marker_color = @theme_options[:marker_color]
  self.font_color = @theme_options[:font_color] || @marker_color

  @colors = @theme_options[:colors].dup
  @marker_shadow_color = @theme_options[:marker_shadow_color]

  @renderer = Gruff::Renderer.new(@columns, @rows, @scale, @theme_options)
end

#theme_37signalsObject

Apply 37signals theme.


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# File 'lib/gruff/base.rb', line 419

def theme_37signals
  self.theme = Themes::THIRTYSEVEN_SIGNALS
end

#theme_greyscaleObject

Apply greyscale theme.


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# File 'lib/gruff/base.rb', line 439

def theme_greyscale
  self.theme = Themes::GREYSCALE
end

#theme_keynoteObject

Apply Apple's keynote theme.


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# File 'lib/gruff/base.rb', line 414

def theme_keynote
  self.theme = Themes::KEYNOTE
end

#theme_odeoObject

Apply Odeo theme.


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# File 'lib/gruff/base.rb', line 429

def theme_odeo
  self.theme = Themes::ODEO
end

#theme_pastelObject

Apply pastel theme.


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# File 'lib/gruff/base.rb', line 434

def theme_pastel
  self.theme = Themes::PASTEL
end

#theme_rails_keynoteObject

Apply Rails theme.


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# File 'lib/gruff/base.rb', line 424

def theme_rails_keynote
  self.theme = Themes::RAILS_KEYNOTE
end

#title=(title) ⇒ Object

Set the large title of the graph displayed at the top. You can draw a multi-line title by putting a line break in the string or by setting an array as argument.

Examples:

g = Gruff::Bar.new
g.title = "The graph title"

g = Gruff::Bar.new
g.title = ['The first line of title', 'The second line of title']

Parameters:

  • title (String, Array)

    the title.


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# File 'lib/gruff/base.rb', line 258

def title=(title)
  if title.is_a?(Array)
    title = title.join("\n")
  end

  @title = title
end

#title_font=(font_path) ⇒ Object

Same as #font= but for the title.

Parameters:

  • font_path (String)

    The path to font.


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# File 'lib/gruff/base.rb', line 288

def title_font=(font_path)
  @title_font.path = font_path
end

#title_font_size=(value) ⇒ Object

Set the font size of the large title at the top of the graph. Default is 36.

Parameters:

  • value (Numeric)

    title font size


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# File 'lib/gruff/base.rb', line 296

def title_font_size=(value)
  @title_font.size = value
end

#to_blob(image_format = 'PNG') ⇒ Object

Deprecated.

Please use to_image.to_blob instead.

Return the graph as a rendered binary blob.

Parameters:

  • image_format (String) (defaults to: 'PNG')

    The image format of binary blob.


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# File 'lib/gruff/base.rb', line 523

def to_blob(image_format = 'PNG')
  warn '#to_blob is deprecated. Please use `to_image.to_blob` instead'
  to_image.to_blob do
    self.format = image_format
  end
end

#to_imageMagick::Image

Return a rendered graph image. This can use RMagick's methods to adjust the image before saving.

Examples:

g = Gruff::Line.new
g.data :Jimmy, [25, 36, 86, 39, 25, 31, 79, 88]
g.data :Charles, [80, 54, 67, 54, 68, 70, 90, 95]
image = g.to_image
image = image.resize(400, 300).quantize(128, Magick::RGBColorspace)
image.write('test.png')

Returns:

  • (Magick::Image)

    The rendered image.


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# File 'lib/gruff/base.rb', line 510

def to_image
  @to_image ||= begin
    draw
    renderer.finish
    renderer.image
  end
end

#write(file_name = 'graph.png') ⇒ Object

Writes the graph to a file. Defaults to 'graph.png'

Examples:

write('graphs/my_pretty_graph.png')

Parameters:

  • file_name (String) (defaults to: 'graph.png')

    The file name of output image.


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# File 'lib/gruff/base.rb', line 493

def write(file_name = 'graph.png')
  to_image.write(file_name)
end