lib/lilygraph.rb in lilygraph-0.2.5 vs lib/lilygraph.rb in lilygraph-0.3.0

@@ -2,11 +2,11 @@
 #
 # Author:: Christopher Giroir <[e-mail]>
 
 require 'color'
 
-# This is the main graph to use if you want to create a graph!
+# This is the main class to use if you want to create a graph!
 #
 #   graph = Lilygraph.new(:title => "My Awesome Graph")
 #   graph.data = [1,2,3]
 #   graph.labels = ['One','Two','Three']
 #   graph.render
@@ -37,10 +37,32 @@
   # For a simple bar graph:
   #   graph.data=[1,2,3]
   # For a grouped bar graph:
   #   graph.data=[[1,10],[2,20],[3,30]]
   attr_accessor :data
+
+  # This allows you to set colors for the bars.
+  #
+  # If you just want a single color:
+  #   graph.colors='#0000aa'
+  # If you want to make each bar (or bar group) different colors:
+  #   graph.colors=['#aa0000','#00aa00','#0000aa']
+  # If you want every bar group to be the same, but each bar in the groups to have a different color
+  #   graph.colors=[['#aa0000','#00aa00','#0000aa']]
+  # If you want to set every bar group color:
+  #   graph.colors=[['#aa0000','#00aa00','#0000aa'],['#bb0000','#00bb00','#0000bb']]
+  # Last but not least you can set the color value to any object that responds to call (like a Proc). The proc takes four arguments.
+  # data_index: The index of the current bar (or group)
+  # number_index: The index of the current bar INSIDE of the current bar group (always 0 if you don't have grouped bars)
+  # data_size: total number of bar or groups.
+  # number_size: total number of bars in the current group (always 1 if you don't have bar groups)
+  # 
+  # The default proc looks like:
+  #   graph.colors=Proc.new do |data_index, number_index, data_size, number_size|
+  #     Color::HSL.from_fraction(Float(data_index) / Float(data_size), 1.0, 0.4 + (Float(number_index) / Float(number_size) * 0.4)).to_rgb.html
+  #   end
+  attr_accessor :colors
   
   # Returns a new graph creator with some default options specified via a hash:
   # height:: String to use as height parameter on the svg tag. Default is <tt>'100%'</tt>.
   # width:: String to use as width parameter on the svg tag. Default is <tt>'100%'</tt>.
   # indent:: Indent option to the XmlMarkup object. Defaults to <tt>2</tt>.
@@ -54,10 +76,14 @@
   #   graph = Lilygraph.new(:title => 'Testing a title', :indent => 4)
   def initialize(options = {})
     @options = DEFAULT_OPTIONS.merge(options)
     @data = []
     @labels = []
+
+    @colors = Proc.new do |data_index, number_index, data_size, number_size|
+      Color::HSL.from_fraction(Float(data_index) / Float(data_size), 1.0, 0.4 + (Float(number_index) / Float(number_size) * 0.4)).html
+    end
   end
 
   # Updates the graph options with items from the passed in hash. Please refer
   # to new for a description of available options.
   def update_options(options = {})
@@ -140,16 +166,29 @@
 
               x = (@options[:margin][:left] + (dx * data_index)).round
 
               # Rectangles
               data.each_with_index do |number, number_index|
-                color = Color::HSL.from_fraction(data_index * (1.0 / @data.size),1.0, 0.4 + (number_index * 0.2)).to_rgb
+                color = if @colors.respond_to? :call
+                          @colors.call(data_index, number_index, @data.size, data.size)
+                        elsif @colors.class == Array
+                          first = @colors[data_index % (@colors.size)]
+
+                          if first.class == Array
+                            first[number_index % (first.size)]
+                          else
+                            first
+                          end
+                        else
+                          @colors
+                        end
+
                 height = ((dy / 10.0) * number).round
 
                 bar_x = (x + ((dx - width) / 2.0) + (number_index * bar_width)).round
                 bar_y = @options[:viewbox][:height] - @options[:margin][:bottom] - height
 
-                xml.rect :fill => color.html, :stroke => color.html, 'stroke-width' => 0, :x => bar_x, :width => bar_width, :y => bar_y, :height => height - 1
+                xml.rect :fill => color, :stroke => color, 'stroke-width' => 0, :x => bar_x, :width => bar_width, :y => bar_y, :height => height - 1
               end
 
               # Text
               if @options[:bar_text]
                 data.each_with_index do |number, number_index|