Composite chart Bar & Line and other features

README.md

@@ -1,3 +1,20 @@
+(new features)
+- format string for marker label
+- add secondary y axis
+- add property to specify space between data column (not bars)
+- add composite chart of bar and line
+- `bar n line` chart can use reference lines from line chart
+- colored boxes for legends can be vary sized (through `legend_box_sizes` property)
+
+(fixes)
+- legend at bottom
+
+v0.7.1b: fix pre normalize for secondary y axis
+
+v0.7.2:
+- add `x_axis_on_top`, if true, x axis markers will be drawn on top instead of bottom
+- fix `marker_format` not working for `side bar` chart
+
 # Gruff Graphs
 
 [![Build Status](https://travis-ci.org/topfunky/gruff.svg?branch=master)](https://travis-ci.org/topfunky/gruff)

lib/gruff.rb

@@ -4,9 +4,11 @@
 
 %w(
   themes
+  axis
   base
   area
   bar
+  bar_n_line
   bezier
   bullet
   dot

lib/gruff/axis.rb

@@ -0,0 +1,61 @@
+##
+# Original Author: Hoang Nguyen Minh
+#
+# This class contains data for secondary y axis
+#
+class Gruff::Axis
+  attr_accessor :label
+
+  attr_accessor :label_color
+
+  attr_accessor :label_font
+
+  attr_accessor :line_color
+
+  attr_accessor :shadow_color
+
+  attr_accessor :font_size
+
+  attr_accessor :maximum_value
+
+  attr_accessor :minimum_value
+
+  attr_accessor :count
+
+  attr_accessor :increment
+
+  attr_accessor :format
+
+  attr_accessor :skip_lines
+
+  attr_accessor :stroke_dash
+
+  attr_accessor :stroke_opacity
+
+  attr_accessor :m_increment
+
+  attr_accessor :m_spread
+
+  attr_accessor :m_offset
+
+  def initialize
+    @label = nil
+    @label_color = 'black'
+    @label_font = nil
+    @line_color = 'black'
+    @shadow_color = nil
+    @font_size = 21
+    @maximum_value = nil
+    @minimum_value = nil
+    @count = nil
+    @increment = nil
+    @format = nil
+    @stroke_dash = nil
+    @stroke_opacity = 1
+    @skip_lines = nil
+    @m_increment = nil
+    @m_spread = 1
+    @m_offset = 0
+  end
+
+end

lib/gruff/bar.rb

@@ -6,9 +6,14 @@ class Gruff::Bar < Gruff::Base
   # Spacing factor applied between bars
   attr_accessor :bar_spacing
 
+  # Spacing factor applied between column of data,
+  # formula: percent of total with * <this value> / (number of data columns - 1)
+  attr_accessor :data_column_spacing
+
   def initialize(*args)
     super
     @spacing_factor = 0.9
+    @data_column_spacing = 0
   end
 
   def draw
@@ -40,9 +45,11 @@ def draw_bars
     # Setup spacing.
     #
     # Columns sit side-by-side.
+    col_space = @data_column_spacing * @graph_width
     @bar_spacing ||= @spacing_factor # space between the bars
-    @bar_width = @graph_width / (@column_count * @data.length).to_f
+    @bar_width = (@graph_width - col_space) / (@column_count * @data.length).to_f
     padding = (@bar_width * (1 - @bar_spacing)) / 2
+    margin = [col_space / (@column_count - 1), 0].max
 
     @d = @d.stroke_opacity 0.0
 
@@ -74,7 +81,7 @@ def draw_bars
       data_row[DATA_VALUES_INDEX].each_with_index do |data_point, point_index|
         # Use incremented x and scaled y
         # x
-        left_x = @graph_left + (@bar_width * (row_index + point_index + ((@data.length - 1) * point_index))) + padding
+        left_x = @graph_left + (@bar_width * (row_index + point_index + ((@data.length - 1) * point_index))) + padding + point_index * margin
         right_x = left_x + @bar_width * @bar_spacing
         # y
         conv = []
@@ -87,7 +94,8 @@ def draw_bars
         # Calculate center based on bar_width and current row
         label_center = @graph_left + 
                       (@data.length * @bar_width * point_index) + 
-                      (@data.length * @bar_width / 2.0)
+                      (@data.length * @bar_width / 2.0) +
+                      point_index * margin
 
         # Subtract half a bar width to center left if requested
         draw_label(label_center - (@center_labels_over_point ? @bar_width / 2.0 : 0.0), point_index)