Merge pull request #74 from joekain/wide

Wide

2 files changed, 43 insertions, 3 deletions

diff --git a/lib/axlsx.rb b/lib/axlsx.rb
index dd628562..46d1c9bf 100644
--- a/lib/axlsx.rb
+++ b/lib/axlsx.rb
@@ -57,7 +57,7 @@ module Axlsx
   def self.name_to_indices(name)
     raise ArgumentError, 'invalid cell name' unless name.size > 1
     v = name[/[A-Z]+/].reverse.chars.reduce({:base=>1, :i=>0}) do  |val, c|
-      val[:i] += ((c.bytes.first - 65) + val[:base]); val[:base] *= 26; val
+      val[:i] += ((c.bytes.first - 64) * val[:base]); val[:base] *= 26; val
     end
 
     [v[:i]-1, ((name[/[1-9][0-9]*/]).to_i)-1]
@@ -71,9 +71,9 @@ module Axlsx
     chars = []
     while index >= 26 do
       chars << ((index % 26) + 65).chr
-      index /= 26
+      index = index / 26 - 1
     end
-    chars << ((chars.empty? ? index : index-1) + 65).chr
+    chars << (index + 65).chr
     chars.reverse.join
   end
 
diff --git a/test/workbook/worksheet/tc_cell.rb b/test/workbook/worksheet/tc_cell.rb
index 4db0c7be..c35e62bc 100644
--- a/test/workbook/worksheet/tc_cell.rb
+++ b/test/workbook/worksheet/tc_cell.rb
@@ -13,6 +13,30 @@ class TestCell < Test::Unit::TestCase
     @cAA = @ws["AA2"]
   end
 
+  def setup_wide
+    # The wide row makes the test take a long time.  Add it only
+    # in test_large as adding it in setup make all the tests take
+    # longer.
+    # 
+    # For even more, but slower, testing use the 20000 cell row and
+    # uncomment the ABCD3 element below.
+    data = (0..1000).map { |index| index }
+    #data = (0..20000).map { |index| index }
+    @ws.add_row data
+
+    @wide_test_points = { "A3" =>      0,
+      "Z3"    =>                      25,
+      "B3"    =>                       1,
+      "AA3"   =>             1 * 26 +  0,
+      "AAA3"  => 1 * 26**2 + 1 * 26 +  0,
+      "AAZ3"  => 1 * 26**2 + 1 * 26 + 25,
+      "ABA3"  => 1 * 26**2 + 2 * 26 +  0,
+
+      # For additional testing, uncomment this line and uncomment the 20000 cell row above
+      #"ABCD3" => 1 * 26**3 + 2 * 26**2 + 3 * 26 + 3
+    }
+  end
+
   def test_initialize
     assert_equal(@row.cells.last, @c, "the cell was added to the row")
     assert_equal(@c.type, :float, "type option is applied")
@@ -41,6 +65,22 @@ class TestCell < Test::Unit::TestCase
     assert_equal(@c.r, "A1", "calculate cell reference")
   end
 
+  def test_wide_index
+    setup_wide
+    @wide_test_points.each_pair do |ref, index|
+      c = @ws[ref]
+      assert_equal(c.index, index, "calculate cell index for cell #{ref}")
+    end
+  end
+
+  def test_wide_r
+    setup_wide
+    @wide_test_points.each_pair do |ref, index|
+      c = @ws[ref]
+      assert_equal(c.r, ref, "calculate cell reference for cell at index #{index}")
+    end
+  end
+
   def test_r_abs
     assert_equal(@c.r_abs,"$A$1", "calculate absolute cell reference")
     assert_equal(@cAA.r_abs,"$AA$2", "needs to accept multi-digit columns")