Fix for column/bar gap/overlap on y2 axis.

  jmcnamara/excel-writer-xlsx#113

lib/write_xlsx/chart.rb

@@ -241,9 +241,27 @@ def add_series(params)
 
       @series << Series.new(self, params)
 
+      # Set the secondary axis properties.
+      x2_axis = params[:x2_axis]
+      y2_axis = params[:y2_axis]
+
       # Set the gap and overlap for Bar/Column charts.
-      @series_gap     = params[:gap]     if params[:gap]
-      @series_overlap = params[:overlap] if params[:overlap]
+      if params[:gap]
+        if ptrue?(y2_axis)
+          @series_gap_2 = params[:gap]
+        else
+          @series_gap_1 = params[:gap]
+        end
+      end
+
+      # Set the overlap for Bar/Column charts.
+      if params[:overlap]
+        if ptrue?(y2_axis)
+          @series_overlap_2 = params[:overlap]
+        else
+          @series_overlap_1 = params[:overlap]
+        end
+      end
     end
 
     #
@@ -428,7 +446,7 @@ def write_bar_chart(params)   # :nodoc:
 
       # Set a default overlap for stacked charts.
       if @subtype =~ /stacked/
-        @series_overlap = 100 unless @series_overlap
+        @series_overlap_1 = 100 unless @series_overlap_1
       end
 
       @writer.tag_elements('c:barChart') do
@@ -442,8 +460,17 @@ def write_bar_chart(params)   # :nodoc:
         # write the c:marker element.
         write_marker_value
 
-        # Write the c:gapWidth element.
-        write_gap_width(@series_gap)
+        if ptrue?(params[:primary_axes])
+          # Write the c:gapWidth element.
+          write_gap_width(@series_gap_1)
+          # Write the c:overlap element.
+          write_overlap(@series_overlap_1)
+        else
+          # Write the c:gapWidth element.
+          write_gap_width(@series_gap_2)
+          # Write the c:overlap element.
+          write_overlap(@series_overlap_2)
+        end
 
         # write the c:overlap element.
         write_overlap(@series_overlap)

test/regression/test_chart_gap04.rb

@@ -0,0 +1,54 @@
+# -*- coding: utf-8 -*-
+require 'helper'
+
+class TestRegressionChartGap04 < Test::Unit::TestCase
+  def setup
+    setup_dir_var
+  end
+
+  def teardown
+    File.delete(@xlsx) if File.exist?(@xlsx)
+  end
+
+  def test_chart_gap04
+    @xlsx = 'chart_gap04.xlsx'
+    workbook  = WriteXLSX.new(@xlsx)
+    worksheet = workbook.add_worksheet
+    chart     = workbook.add_chart(:type => 'column', :embedded => 1)
+
+    # For testing, copy the randomly generated axis ids in the target xlsx file.
+    chart.instance_variable_set(:@axis_ids,  [45938176, 59715584])
+    chart.instance_variable_set(:@axis2_ids, [62526208, 59718272])
+
+    data = [
+            [1, 2, 3,  4,  5],
+            [6, 8, 6,  4,  2]
+           ]
+
+    worksheet.write('A1', data)
+
+    chart.add_series(
+                     :values     => '=Sheet1!$A$1:$A$5',
+                     :gap        => 51,
+                     :overlap    => 12
+                     )
+
+    chart.add_series(
+                     :values     => '=Sheet1!$B$1:$B$5',
+                     :y2_axis    => 1,
+                     :gap        => 251,
+                     :overlap    => -27
+                     )
+
+    worksheet.insert_chart('E9', chart)
+
+    workbook.close
+    compare_xlsx_for_regression(File.join(@regression_output, @xlsx), @xlsx,
+                                [],
+                                {
+                                  'xl/charts/chart1.xml' => ['<c:pageMargins'],
+                                  'xl/workbook.xml'      => [ '<fileVersion' ]
+                                }
+                                )
+  end
+end

test/regression/test_chart_gap05.rb

@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+require 'helper'
+
+class TestRegressionChartGap05 < Test::Unit::TestCase
+  def setup
+    setup_dir_var
+  end
+
+  def teardown
+    File.delete(@xlsx) if File.exist?(@xlsx)
+  end
+
+  def test_chart_gap05
+    @xlsx = 'chart_gap05.xlsx'
+    workbook  = WriteXLSX.new(@xlsx)
+    worksheet = workbook.add_worksheet
+    chart     = workbook.add_chart(:type => 'bar', :embedded => 1)
+
+    # For testing, copy the randomly generated axis ids in the target xlsx file.
+    chart.instance_variable_set(:@axis_ids,  [45938176, 59715584])
+    chart.instance_variable_set(:@axis2_ids, [70848512, 54519680])
+
+    data = [
+            [1, 2, 3,  4,  5],
+            [6, 8, 6,  4,  2]
+           ]
+
+    worksheet.write('A1', data)
+
+    chart.add_series(
+                     :values     => '=Sheet1!$A$1:$A$5',
+                     :gap        => 51,
+                     :overlap    => 12
+                     )
+
+    chart.add_series(
+                     :values     => '=Sheet1!$B$1:$B$5',
+                     :y2_axis    => 1,
+                     :gap        => 251,
+                     :overlap    => -27
+                     )
+
+    chart.set_x2_axis(:label_position => 'next_to')
+
+    worksheet.insert_chart('E9', chart)
+
+    workbook.close
+    compare_xlsx_for_regression(File.join(@regression_output, @xlsx), @xlsx,
+                                [],
+                                {
+                                  'xl/charts/chart1.xml' => ['<c:pageMargins'],
+                                  'xl/workbook.xml'      => [ '<fileVersion' ]
+                                }
+                                )
+  end
+end