lib/squid/graph.rb
require 'active_support'
require 'active_support/core_ext/string/inflections' # for singularize
require 'squid/axis'
require 'squid/axis_label'
require 'squid/gridline'
require 'squid/plotter'
require 'squid/point'
require 'squid/settings'
module Squid
# @private
class Graph
extend Settings
has_settings :baseline, :border, :chart, :colors, :every, :formats, :height
has_settings :legend, :line_widths, :steps, :ticks, :type, :labels
def initialize(document, data = {}, settings = {})
@data, @settings = data, settings
@plot = Plotter.new document, bottom: bottom
@plot.paddings = {left: left.width, right: right.width} if @data.any?
end
def draw
@plot.box(h: height, border: border) { draw_graph if @data.any? }
end
private
def draw_graph
draw_legend if legend
draw_gridlines
draw_axis_labels
draw_charts if chart
draw_categories if baseline
end
def draw_legend
labels = @data.keys.reverse.map{|key| key.to_s}
right = legend.is_a?(Hash) ? legend.fetch(:right, 0) : 0
@plot.legend labels, right: right, colors: colors, height: legend_height
end
def draw_gridlines
options = {height: grid_height, count: steps, skip_baseline: baseline}
Gridline.for(**options).each do |line|
@plot.horizontal_line line.y, line_width: 0.5, transparency: 0.25
end
end
def draw_axis_labels
@plot.axis_labels AxisLabel.for(left, align: :right, height: grid_height)
@plot.axis_labels AxisLabel.for(right, align: :left, height: grid_height)
end
def draw_categories
labels = @data.values.first.keys.map{|key| key.to_s}
@plot.categories labels, every: every, ticks: ticks
@plot.horizontal_line 0.0
end
def draw_charts
draw_chart right, second_axis: true
draw_chart left
end
def draw_chart(axis, second_axis: false)
args = {minmax: axis.minmax, height: grid_height, stack: stack?}
args[:labels] = items_of labels, skip_first_if: second_axis
args[:formats] = items_of formats, skip_first_if: second_axis
points = Point.for axis.data, **args
options = {colors: colors, starting_at: (second_axis ? 1: 0)}
case (second_axis ? :column : type)
when :point then @plot.points points, options
when :line, :two_axis then @plot.lines points, options.merge(line_widths: line_widths)
when :column then @plot.columns points, options
when :stack then @plot.stacks points, options
end
end
def items_of(array, skip_first_if:)
if skip_first_if
array.empty? ? [] : array[1..-1]
else
array
end
end
def left
@left ||= axis first: 0, last: (two_axis? ? 1 : @data.size)
end
def right
@right ||= axis first: 1, last: (two_axis? ? @data.size : 0)
end
def axis(first:, last:)
series = @data.values[first, last].map(&:values)
options = {steps: steps, stack: stack?, format: formats[first]}
Axis.new(series, **options) {|label| @plot.width_of label}
end
def bottom
baseline ? 20 : 0
end
def legend_height
legend ? 15 : 0
end
def legend_bottom
legend.is_a?(Hash) ? legend.fetch(:bottom, 15) : 15
end
def grid_height
height - bottom - legend_height - legend_bottom
end
def stack?
type == :stack
end
def two_axis?
type == :two_axis
end
end
end