In Files

  • lib/gruff/base.rb
  • lib/gruff/mini/legend.rb
  • lib/gruff/stacked_mixin.rb

Gruff::Base

Constants

DATA_COLOR_INDEX
DATA_LABEL_INDEX

Used for navigating the array of data to plot

DATA_VALUES_INDEX
DEBUG

Draw extra lines showing where the margins and text centers are

DEFAULT_MARGIN
DEFAULT_TARGET_WIDTH
LABEL_MARGIN
LEGEND_MARGIN

Space around text elements. Mostly used for vertical spacing

THOUSAND_SEPARATOR

Attributes

additional_line_values[RW]

Experimental

bottom_margin[RW]

Blank space below the graph

center_labels_over_point[RW]

Used internally for spacing.

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

colors[RW]

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

font[R]

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.

font_color[RW]
has_left_labels[RW]

Used internally for horizontal graph types.

hide_legend[RW]

Prevent drawing of the legend

hide_line_markers[RW]

Prevent drawing of line markers

hide_line_numbers[RW]

Prevent drawing of line numbers

hide_title[RW]

Prevent drawing of the title

labels[RW]

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

left_margin[RW]

Blank space to the left of the graph

legend_box_size[RW]

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.

legend_font_size[RW]

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.

legend_margin[RW]

Blank space below the legend

marker_color[RW]

The color of the auxiliary lines

marker_count[RW]

The number of horizontal lines shown for reference

marker_font_size[RW]

The font size of the labels around the graph

maximum_value[RW]

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.

minimum_value[RW]

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.

no_data_message[RW]

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

right_margin[RW]

Blank space to the right of the graph

sort[RW]

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

stacked[RW]

Experimental

title[RW]

The large title of the graph displayed at the top

title_font_size[RW]

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

title_margin[RW]

Blank space below the title

top_margin[RW]

Blank space above the graph

x_axis_label[RW]

A label for the bottom of the graph

y_axis_increment[RW]

Manually set increment of the horizontal marking lines

y_axis_label[RW]

A label for the left side of the graph

Public Class Methods

new(target_width=DEFAULT_TARGET_WIDTH) click to toggle source

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.)

 
               # File lib/gruff/base.rb, line 182
def initialize(target_width=DEFAULT_TARGET_WIDTH)
  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

  initialize_ivars

  reset_themes
  theme_keynote
end
            

Public Instance Methods

add_color(colorname) click to toggle source

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

Example:

add_color('#c0e9d3')
 
               # File lib/gruff/base.rb, line 264
def add_color(colorname)
  @colors << colorname
end
            
data(name, data_points=[], color=nil) click to toggle source

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')
 
               # File lib/gruff/base.rb, line 457
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
            
font=(font_path) click to toggle source

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

 
               # File lib/gruff/base.rb, line 255
def font=(font_path)
  @font = font_path
  @d.font = @font
end
            
initialize_ivars() click to toggle source

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.

 
               # File lib/gruff/base.rb, line 204
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
  
  @top_margin = @bottom_margin = @left_margin = @right_margin = DEFAULT_MARGIN
  @legend_margin = LEGEND_MARGIN
  @title_margin = TITLE_MARGIN

  @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

  @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) click to toggle source

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

 
               # File lib/gruff/base.rb, line 250
def margins=(margin)
  @top_margin = @left_margin = @right_margin = @bottom_margin = margin
end
            
replace_colors(color_list=[]) click to toggle source

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, ‘increment_color’ 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.

Example:

replace_colors ['#cc99cc', '#d9e043', '#34d8a2']
 
               # File lib/gruff/base.rb, line 282
def replace_colors(color_list=[])
  @colors = color_list
  @color_index = 0
end
            
theme=(options) click to toggle source

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

graph.theme = {
  :colors => %w(orange purple green white red),
  :marker_color => 'blue',
  :background_colors => %w(black grey)
}

:background_image => ‘squirrel.png’ is also possible.

(Or hopefully something better looking than that.)

 
               # File lib/gruff/base.rb, line 300
def theme=(options)
  reset_themes()

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

  @colors = @theme_options[:colors]
  @marker_color = @theme_options[:marker_color]
  @font_color = @theme_options[:font_color] || @marker_color
  @additional_line_colors = @theme_options[:additional_line_colors]

  render_background
end
            
theme_37signals() click to toggle source

A color scheme plucked from the colors on the popular usability blog.

 
               # File lib/gruff/base.rb, line 342
def theme_37signals
  # Colors
  @green = '#339933'
  @purple = '#cc99cc'
  @blue = '#336699'
  @yellow = '#FFF804'
  @red = '#ff0000'
  @orange = '#cf5910'
  @black = 'black'
  @colors = [@yellow, @blue, @green, @red, @purple, @orange, @black]

  self.theme = {
    :colors => @colors,
    :marker_color => 'black',
    :font_color => 'black',
    :background_colors => ['#d1edf5', 'white']
  }
end
            
theme_greyscale() click to toggle source

A greyscale theme

 
               # File lib/gruff/base.rb, line 424
def theme_greyscale
  # Colors
  @colors = [
             '#282828', #
             '#383838', #
             '#686868', #
             '#989898', #
             '#c8c8c8', #
             '#e8e8e8', #
            ]

  self.theme = {
    :colors => @colors,
    :marker_color => '#aea9a9', # Grey
    :font_color => 'black',
    :background_colors => 'white'
  }
end
            
theme_keynote() click to toggle source

A color scheme similar to the popular presentation software.

 
               # File lib/gruff/base.rb, line 322
def theme_keynote
  # Colors
  @blue = '#6886B4'
  @yellow = '#FDD84E'
  @green = '#72AE6E'
  @red = '#D1695E'
  @purple = '#8A6EAF'
  @orange = '#EFAA43'
  @white = 'white'
  @colors = [@yellow, @blue, @green, @red, @purple, @orange, @white]

  self.theme = {
    :colors => @colors,
    :marker_color => 'white',
    :font_color => 'white',
    :background_colors => ['black', '#4a465a']
  }
end
            
theme_odeo() click to toggle source

A color scheme similar to that used on the popular podcast site.

 
               # File lib/gruff/base.rb, line 383
def theme_odeo
  # Colors
  @grey = '#202020'
  @white = 'white'
  @dark_pink = '#a21764'
  @green = '#8ab438'
  @light_grey = '#999999'
  @dark_blue = '#3a5b87'
  @black = 'black'
  @colors = [@grey, @white, @dark_blue, @dark_pink, @green, @light_grey, @black]

  self.theme = {
    :colors => @colors,
    :marker_color => 'white',
    :font_color => 'white',
    :background_colors => ['#ff47a4', '#ff1f81']
  }
end
            
theme_pastel() click to toggle source

A pastel theme

 
               # File lib/gruff/base.rb, line 403
def theme_pastel
  # Colors
  @colors = [
             '#a9dada', # blue
             '#aedaa9', # green
             '#daaea9', # peach
             '#dadaa9', # yellow
             '#a9a9da', # dk purple
             '#daaeda', # purple
             '#dadada' # grey
            ]

  self.theme = {
    :colors => @colors,
    :marker_color => '#aea9a9', # Grey
    :font_color => 'black',
    :background_colors => 'white'
  }
end
            
theme_rails_keynote() click to toggle source

A color scheme from the colors used on the 2005 Rails keynote presentation at RubyConf.

 
               # File lib/gruff/base.rb, line 363
def theme_rails_keynote
  # Colors
  @green = '#00ff00'
  @grey = '#333333'
  @orange = '#ff5d00'
  @red = '#f61100'
  @white = 'white'
  @light_grey = '#999999'
  @black = 'black'
  @colors = [@green, @grey, @orange, @red, @white, @light_grey, @black]

  self.theme = {
    :colors => @colors,
    :marker_color => 'white',
    :font_color => 'white',
    :background_colors => ['#0083a3', '#0083a3']
  }
end
            
to_blob(fileformat='PNG') click to toggle source

Return the graph as a rendered binary blob.

 
               # File lib/gruff/base.rb, line 492
def to_blob(fileformat='PNG')
  draw()
  return @base_image.to_blob do
    self.format = fileformat
  end
end
            
write(filename="graph.png") click to toggle source

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

Example:

write('graphs/my_pretty_graph.png')
 
               # File lib/gruff/base.rb, line 486
def write(filename="graph.png")
  draw()
  @base_image.write(filename)
end
            

Protected Instance Methods

center(size) click to toggle source

Return a calculation of center

 
               # File lib/gruff/base.rb, line 756
def center(size)
  (@raw_columns - size) / 2
end
            
draw() click to toggle source

Overridden by subclasses to do the actual plotting of the graph.

Subclasses should start by calling super() for this method.

 
               # File lib/gruff/base.rb, line 506
def draw
  make_stacked if @stacked
  setup_drawing

  debug {
    # Outer margin
    @d.rectangle( @left_margin, @top_margin,
                  @raw_columns - @right_margin, @raw_rows - @bottom_margin)
    # Graph area box
    @d.rectangle( @graph_left, @graph_top, @graph_right, @graph_bottom)
  }
end
            
draw_axis_labels() click to toggle source

Draw the optional labels for the x axis and y axis.

 
               # File lib/gruff/base.rb, line 630
def draw_axis_labels
  unless @x_axis_label.nil?
    # X Axis
    # Centered vertically and horizontally by setting the
    # height to 1.0 and the width to the width of the graph.
    x_axis_label_y_coordinate = @graph_bottom + LABEL_MARGIN * 2 + @marker_caps_height

    # TODO Center between graph area
    @d.fill = @font_color
    @d.font = @font if @font
    @d.stroke('transparent')
    @d.pointsize = scale_fontsize(@marker_font_size)
    @d.gravity = NorthGravity
    @d = @d.annotate_scaled( @base_image,
                             @raw_columns, 1.0,
                             0.0, x_axis_label_y_coordinate,
                             @x_axis_label, @scale)
    debug { @d.line 0.0, x_axis_label_y_coordinate, @raw_columns, x_axis_label_y_coordinate }
  end

  unless @y_axis_label.nil?
    # Y Axis, rotated vertically
    @d.rotation = 90.0
    @d.gravity = CenterGravity
    @d = @d.annotate_scaled( @base_image,
                             1.0, @raw_rows,
                             @left_margin + @marker_caps_height / 2.0, 0.0,
                             @y_axis_label, @scale)
    @d.rotation = -90.0
  end
end
            
draw_label(x_offset, index) click to toggle source

Draws column labels below graph, centered over x_offset

 
               # File lib/gruff/base.rb, line 857
def draw_label(x_offset, index)
  return if @hide_line_markers

  if !@labels[index].nil? && @labels_seen[index].nil?
    y_offset = @graph_bottom + LABEL_MARGIN

    @d.fill = @font_color
    @d.font = @font if @font
    @d.stroke('transparent')
    @d.font_weight = NormalWeight
    @d.pointsize = scale_fontsize(@marker_font_size)
    @d.gravity = NorthGravity
    @d = @d.annotate_scaled(@base_image,
                            1.0, 1.0,
                            x_offset, y_offset,
                            @labels[index], @scale)
    @labels_seen[index] = 1
    debug { @d.line 0.0, y_offset, @raw_columns, y_offset }
  end
end
            
draw_legend() click to toggle source

Draws a legend with the names of the datasets matched to the colors used to draw them.

 
               # File lib/gruff/base.rb, line 764
def draw_legend
  return if @hide_legend

  @legend_labels = @data.collect {|item| item[DATA_LABEL_INDEX] }

  legend_square_width = @legend_box_size # small square with color of this item

  # May fix legend drawing problem at small sizes
  @d.font = @font if @font
  @d.pointsize = @legend_font_size

  label_widths = [[]] # Used to calculate line wrap
  @legend_labels.each do |label|
    metrics = @d.get_type_metrics(@base_image, label.to_s)
    label_width = metrics.width + legend_square_width * 2.7
    label_widths.last.push label_width

    if sum(label_widths.last) > (@raw_columns * 0.9)
      label_widths.push [label_widths.last.pop]
    end
  end

  current_x_offset = center(sum(label_widths.first))
  current_y_offset =  @hide_title ?
  @top_margin + title_margin :
    @top_margin + title_margin + @title_caps_height

  @legend_labels.each_with_index do |legend_label, index|

    # Draw label
    @d.fill = @font_color
    @d.font = @font if @font
    @d.pointsize = scale_fontsize(@legend_font_size)
    @d.stroke('transparent')
    @d.font_weight = NormalWeight
    @d.gravity = WestGravity
    @d = @d.annotate_scaled( @base_image,
                             @raw_columns, 1.0,
                             current_x_offset + (legend_square_width * 1.7), current_y_offset,
                             legend_label.to_s, @scale)

    # Now draw box with color of this dataset
    @d = @d.stroke('transparent')
    @d = @d.fill @data[index][DATA_COLOR_INDEX]
    @d = @d.rectangle(current_x_offset,
                      current_y_offset - legend_square_width / 2.0,
                      current_x_offset + legend_square_width,
                      current_y_offset + legend_square_width / 2.0)

    @d.pointsize = @legend_font_size
    metrics = @d.get_type_metrics(@base_image, legend_label.to_s)
    current_string_offset = metrics.width + (legend_square_width * 2.7)

    # Handle wrapping
    label_widths.first.shift
    if label_widths.first.empty?
      debug { @d.line 0.0, current_y_offset, @raw_columns, current_y_offset }

      label_widths.shift
      current_x_offset = center(sum(label_widths.first)) unless label_widths.empty?
      line_height = [@legend_caps_height, legend_square_width].max + legend_margin
      if label_widths.length > 0
        # Wrap to next line and shrink available graph dimensions
        current_y_offset += line_height
        @graph_top += line_height
        @graph_height = @graph_bottom - @graph_top
      end
    else
      current_x_offset += current_string_offset
    end
  end
  @color_index = 0
end
            
draw_line_markers() click to toggle source

Draws horizontal background lines and labels

 
               # File lib/gruff/base.rb, line 663
def draw_line_markers
  return if @hide_line_markers

  @d = @d.stroke_antialias false

  if @y_axis_increment.nil?
    # Try to use a number of horizontal lines that will come out even.
    #
    # TODO Do the same for larger numbers...100, 75, 50, 25
    if @marker_count.nil?
      (3..7).each do |lines|
        if @spread % lines == 0.0
          @marker_count = lines
          break
        end
      end
      @marker_count ||= 4
    end
    @increment = (@spread > 0) ? significant(@spread / @marker_count) : 1
  else
    # TODO Make this work for negative values
    @maximum_value = [@maximum_value.ceil, @y_axis_increment].max
    @minimum_value = @minimum_value.floor
    calculate_spread
    normalize(true)

    @marker_count = (@spread / @y_axis_increment).to_i
    @increment = @y_axis_increment
  end
  @increment_scaled = @graph_height.to_f / (@spread / @increment)

  # Draw horizontal line markers and annotate with numbers
  (0..@marker_count).each do |index|
    y = @graph_top + @graph_height - index.to_f * @increment_scaled

    @d = @d.fill(@marker_color)
    @d = @d.line(@graph_left, y, @graph_right, y)

    marker_label = index * @increment + @minimum_value.to_f

    unless @hide_line_numbers
      @d.fill = @font_color
      @d.font = @font if @font
      @d.stroke('transparent')
      @d.pointsize = scale_fontsize(@marker_font_size)
      @d.gravity = EastGravity

      # Vertically center with 1.0 for the height
      @d = @d.annotate_scaled( @base_image,
                               @graph_left - LABEL_MARGIN, 1.0,
                               0.0, y,
                               label(marker_label), @scale)
    end
  end

  # # Submitted by a contibutor...the utility escapes me
  # i = 0
  # @additional_line_values.each do |value|
  #   @increment_scaled = @graph_height.to_f / (@maximum_value.to_f / value)
  #
  #   y = @graph_top + @graph_height - @increment_scaled
  #
  #   @d = @d.stroke(@additional_line_colors[i])
  #   @d = @d.line(@graph_left, y, @graph_right, y)
  #
  #
  #   @d.fill = @additional_line_colors[i]
  #   @d.font = @font if @font
  #   @d.stroke('transparent')
  #   @d.pointsize = scale_fontsize(@marker_font_size)
  #   @d.gravity = EastGravity
  #   @d = @d.annotate_scaled( @base_image,
  #                     100, 20,
  #                     -10, y - (@marker_font_size/2.0),
  #                     "", @scale)
  #   i += 1
  # end

  @d = @d.stroke_antialias true
end
            
draw_no_data() click to toggle source

Shows an error message because you have no data.

 
               # File lib/gruff/base.rb, line 879
def draw_no_data
  @d.fill = @font_color
  @d.font = @font if @font
  @d.stroke('transparent')
  @d.font_weight = NormalWeight
  @d.pointsize = scale_fontsize(80)
  @d.gravity = CenterGravity
  @d = @d.annotate_scaled( @base_image,
                           @raw_columns, @raw_rows/2.0,
                           0, 10,
                           @no_data_message, @scale)
end
            
draw_title() click to toggle source

Draws a title on the graph.

 
               # File lib/gruff/base.rb, line 839
def draw_title
  return if (@hide_title || @title.nil?)

  @d.fill = @font_color
  @d.font = @font if @font
  @d.stroke('transparent')
  @d.pointsize = scale_fontsize(@title_font_size)
  @d.font_weight = BoldWeight
  @d.gravity = NorthGravity
  @d = @d.annotate_scaled( @base_image,
                           @raw_columns, 1.0,
                           0, @top_margin,
                           @title, @scale)
end
            
get_maximum_by_stack() click to toggle source

Used by StackedBar and child classes.

May need to be moved to the StackedBar class.

 
               # File lib/gruff/base.rb, line 1016
def get_maximum_by_stack
  # Get sum of each stack
  max_hash = {}
  @data.each do |data_set|
    data_set[DATA_VALUES_INDEX].each_with_index do |data_point, i|
      max_hash[i] = 0.0 unless max_hash[i]
      max_hash[i] += data_point.to_f
    end
  end

  # @maximum_value = 0
  max_hash.keys.each do |key|
    @maximum_value = max_hash[key] if max_hash[key] > @maximum_value
  end
  @minimum_value = 0
end
            
normalize(force=false) click to toggle source

Make copy of data with values scaled between 0-100

 
               # File lib/gruff/base.rb, line 542
def normalize(force=false)
  if @norm_data.nil? || force
    @norm_data = []
    return unless @has_data

    calculate_spread

    @data.each do |data_row|
      norm_data_points = []
      data_row[DATA_VALUES_INDEX].each do |data_point|
        if data_point.nil?
          norm_data_points << nil
        else
          norm_data_points << ((data_point.to_f - @minimum_value.to_f ) / @spread)
        end
      end
      @norm_data << [data_row[DATA_LABEL_INDEX], norm_data_points, data_row[DATA_COLOR_INDEX]]
    end
  end
end
            
render_background() click to toggle source

Finds the best background to render based on the provided theme options.

Creates a @base_image to draw on.

 
               # File lib/gruff/base.rb, line 895
def render_background
  case @theme_options[:background_colors]
  when Array
    @base_image = render_gradiated_background(*@theme_options[:background_colors])
  when String
    @base_image = render_solid_background(@theme_options[:background_colors])
  else
    @base_image = render_image_background(*@theme_options[:background_image])
  end
end
            
render_gradiated_background(top_color, bottom_color) click to toggle source

Use with a theme definition method to draw a gradiated background.

 
               # File lib/gruff/base.rb, line 914
def render_gradiated_background(top_color, bottom_color)
  Image.new(@columns, @rows,
            GradientFill.new(0, 0, 100, 0, top_color, bottom_color))
end
            
render_image_background(image_path) click to toggle source

Use with a theme to use an image (800x600 original) background.

 
               # File lib/gruff/base.rb, line 920
def render_image_background(image_path)
  image = Image.read(image_path)
  if @scale != 1.0
    image[0].resize!(@scale) # TODO Resize with new scale (crop if necessary for wide graph)
  end
  image[0]
end
            
render_solid_background(color) click to toggle source

Make a new image at the current size with a solid color.

 
               # File lib/gruff/base.rb, line 907
def render_solid_background(color)
  Image.new(@columns, @rows) {
    self.background_color = color
  }
end
            
render_transparent_background() click to toggle source

Use with a theme to make a transparent background

 
               # File lib/gruff/base.rb, line 929
def render_transparent_background
  Image.new(@columns, @rows) do
    self.background_color = 'transparent'
  end
end
            
reset_themes() click to toggle source

Resets everything to defaults (except data).

 
               # File lib/gruff/base.rb, line 936
def reset_themes
  @color_index = 0
  @labels_seen = {}
  @theme_options = {}

  @d = Draw.new
  # Scale down from 800x600 used to calculate drawing.
  @d = @d.scale(@scale, @scale)
end
            
scale_fontsize(value) click to toggle source

Return a comparable fontsize for the current graph.

 
               # File lib/gruff/base.rb, line 951
def scale_fontsize(value)
  new_fontsize = value * @scale
  # return new_fontsize < 10.0 ? 10.0 : new_fontsize
  return new_fontsize
end
            
setup_drawing() click to toggle source

Calculates size of drawable area and draws the decorations.

  • line markers

  • legend

  • title

 
               # File lib/gruff/base.rb, line 524
def setup_drawing
  # Maybe should be done in one of the following functions for more granularity.
  unless @has_data
    draw_no_data()
    return
  end

  normalize()
  setup_graph_measurements()
  sort_norm_data() if @sort # Sort norm_data with avg largest values set first (for display)

  draw_legend()
  draw_line_markers()
  draw_axis_labels()
  draw_title
end
            
setup_graph_measurements() click to toggle source

Calculates size of drawable area, general font dimensions, etc.

 
               # File lib/gruff/base.rb, line 571
def setup_graph_measurements
  @marker_caps_height = @hide_line_markers ? 0 :
    calculate_caps_height(@marker_font_size)
  @title_caps_height = @hide_title ? 0 :
    calculate_caps_height(@title_font_size)
  @legend_caps_height = @hide_legend ? 0 :
    calculate_caps_height(@legend_font_size)

  if @hide_line_markers
    (@graph_left,
     @graph_right_margin,
     @graph_bottom_margin) = [@left_margin, @right_margin, @bottom_margin]
  else
    longest_left_label_width = 0
    if @has_left_labels
      longest_left_label_width =  calculate_width(@marker_font_size,
                                                  labels.values.inject('') { |value, memo| (value.to_s.length > memo.to_s.length) ? value : memo }) * 1.25
    else
      longest_left_label_width = calculate_width(@marker_font_size,
                                                 label(@maximum_value.to_f))
    end

    # Shift graph if left line numbers are hidden
    line_number_width = @hide_line_numbers && !@has_left_labels ?
    0.0 :
      (longest_left_label_width + LABEL_MARGIN * 2)

    @graph_left = @left_margin +
      line_number_width +
      (@y_axis_label.nil? ? 0.0 : @marker_caps_height + LABEL_MARGIN * 2)

    # Make space for half the width of the rightmost column label.
    # Might be greater than the number of columns if between-style bar markers are used.
    last_label = @labels.keys.sort.last.to_i
    extra_room_for_long_label = (last_label >= (@column_count-1) && @center_labels_over_point) ?
    calculate_width(@marker_font_size, @labels[last_label]) / 2.0 :
      0
    @graph_right_margin = @right_margin + extra_room_for_long_label

    @graph_bottom_margin = @bottom_margin +
      @marker_caps_height + LABEL_MARGIN
  end

  @graph_right = @raw_columns - @graph_right_margin
  @graph_width = @raw_columns - @graph_left - @graph_right_margin

  # When @hide title, leave a title_margin space for aesthetics.
  # Same with @hide_legend
  @graph_top = @top_margin +
    (@hide_title  ? title_margin  : @title_caps_height  + title_margin ) +
    (@hide_legend ? legend_margin : @legend_caps_height + legend_margin)

  x_axis_label_height = @x_axis_label.nil? ? 0.0 :
    @marker_caps_height + LABEL_MARGIN
  @graph_bottom = @raw_rows - @graph_bottom_margin - x_axis_label_height
  @graph_height = @graph_bottom - @graph_top
end
            
sort_norm_data() click to toggle source

Sort with largest overall summed value at front of array so it shows up correctly in the drawn graph.

 
               # File lib/gruff/base.rb, line 1003
def sort_norm_data
  @norm_data.sort! { |a,b| sums(b[DATA_VALUES_INDEX]) <=> sums(a[DATA_VALUES_INDEX]) }
end
            
sum(arr) click to toggle source

Return the sum of values in an array.

Duplicated to not conflict with active_support in Rails.

 
               # File lib/gruff/base.rb, line 749
def sum(arr)
  arr.inject(0) { |i, m| m + i }
end