Added sensible defaults for color scale

You can now use Axlsx::ColorScale.three_tone or
Axlsx::ColorScale.two_tone to create pretty conditional formatting.

3 files changed, 30 insertions, 8 deletions

diff --git a/examples/example.rb b/examples/example.rb
index dc56b882..87678a2e 100755
--- a/examples/example.rb
+++ b/examples/example.rb
@@ -23,7 +23,7 @@ examples = []
 #examples << :data_types
 #examples << :hyperlinks
 #examples << :number_currency_format
-examples << :venezuela_currency
+#examples << :venezuela_currency
 #examples << :bar_chart
 #examples << :chart_gridlines
 #examples << :pie_chart
@@ -37,7 +37,7 @@ examples << :venezuela_currency
 #examples << :printing
 #examples << :comments
 #examples << :panes
-#examples << :conditional_formatting
+examples << :conditional_formatting
 #examples << :streaming
 #examples << :shared_strings
 #examples << :no_autowidth
@@ -604,8 +604,10 @@ if examples.include? :conditional_formatting
     offset.upto(rows + offset) do |i|
       ws.add_row ["Q#{i}", 10000*((rows/2-i) * (rows/2-i)), "=100*B#{i}/SUM(B3:B#{rows+offset})"], :style=>[nil, money, percent]
     end
-    # Apply conditional formatting to range B3:B100 in the worksheet
-    color_scale = Axlsx::ColorScale.new
+    # color scale has two_tone and three_tone class methods to setup the excel defaults (2011)
+    # alternatively, you can pass in {:type => [:min, :max, :percent], :val => [whatever], :color =>[Some RGB String] to create a customized color scale object
+
+    color_scale = Axlsx::ColorScale.three_tone
     ws.add_conditional_formatting("B3:B100", { :type => :colorScale, :operator => :greaterThan, :formula => "100000", :dxfId => profitable, :priority => 1, :color_scale => color_scale })
   end
 
diff --git a/lib/axlsx/workbook/worksheet/color_scale.rb b/lib/axlsx/workbook/worksheet/color_scale.rb
index cdeac099..9d1f47cf 100644
--- a/lib/axlsx/workbook/worksheet/color_scale.rb
+++ b/lib/axlsx/workbook/worksheet/color_scale.rb
@@ -9,8 +9,18 @@ module Axlsx
 
     class << self
       def default_cfvos
-        [{:type => :min, :val => 0, :color => 'FFFF0000'},
-         {:type => :max, :val => 0, :color => 'FF0000FF'}]
+        [{:type => :min, :val => 0, :color => 'FFFF7128'},
+         {:type => :max, :val => 0, :color => 'FFFFEF9C'}]
+      end
+
+      def two_tone
+        self.new(*self.default_cfvos)
+      end
+
+      def three_tone
+        self.new({:type => :min, :val => 0, :color => 'FFF8696B'},
+                 {:type => :percent, :val => '50', :color => 'FFFFEB84'},
+                 {:type => :max, :val => 0, :color => 'FF63BE7B'})
       end
     end
     # A simple typed list of cfvos
diff --git a/test/workbook/worksheet/tc_color_scale.rb b/test/workbook/worksheet/tc_color_scale.rb
index 9dde93ab..75e19cdb 100644
--- a/test/workbook/worksheet/tc_color_scale.rb
+++ b/test/workbook/worksheet/tc_color_scale.rb
@@ -5,15 +5,25 @@ class TestColorScale < Test::Unit::TestCase
     @color_scale = Axlsx::ColorScale.new
   end
 
+  def test_three_tone
+    color_scale = Axlsx::ColorScale.three_tone
+    assert_equal 3, color_scale.value_objects.size
+    assert_equal 3, color_scale.colors.size
+  end
 
+  def two_tone
+    color_scale = Axlsx::ColorScale.two_tone
+    assert_equal 2, color_scale.value_objects.size
+    assert_equal 2, color_scale.colors.size
+  end
   def test_default_cfvo
     first = Axlsx::ColorScale.default_cfvos.first
     second = Axlsx::ColorScale.default_cfvos.last
-    assert_equal 'FFFF0000', first[:color]
+    assert_equal 'FFFF7128', first[:color]
     assert_equal :min,first[:type]
     assert_equal 0, first[:val]
 
-    assert_equal 'FF0000FF', second[:color]
+    assert_equal 'FFFFEF9C', second[:color]
     assert_equal :max, second[:type]
     assert_equal 0, second[:val]
   end