add support for page margin initialization options as well as adding an option to worksheet initialization so we can do stuff like this:

workbook.add_worksheet(:page_margins => {:top=> 1.9})

and yielding the page_margins object off the worksheet for stuff like:
worksheet.page_margins do |pm|
  pm.left = 0.7
end

5 files changed, 86 insertions, 16 deletions

diff --git a/lib/axlsx/workbook/workbook.rb b/lib/axlsx/workbook/workbook.rb
index 47af692b..b3b10fac 100644
--- a/lib/axlsx/workbook/workbook.rb
+++ b/lib/axlsx/workbook/workbook.rb
@@ -136,6 +136,7 @@ require 'axlsx/workbook/shared_strings_table.rb'
     # Adds a worksheet to this workbook
     # @return [Worksheet]
     # @option options [String] name The name of the worksheet.
+    # @option options [Hash] page_margins The page margins for the worksheet.
     # @see Worksheet#initialize
     def add_worksheet(options={})
       worksheet = Worksheet.new(self, options)
diff --git a/lib/axlsx/workbook/worksheet/page_margins.rb b/lib/axlsx/workbook/worksheet/page_margins.rb
index cef6dcbf..ab67337b 100644
--- a/lib/axlsx/workbook/worksheet/page_margins.rb
+++ b/lib/axlsx/workbook/worksheet/page_margins.rb
@@ -5,7 +5,9 @@ module Axlsx
   # has been specified. Otherwise, it serializes to a PageMargin element specifying all 6 margin values
   # (using default values for margins that have not been specified explicitly).
   #
+  # @note The recommended way to manage page margins is via Worksheet#page_margins
   # @see Worksheet#page_margins
+  # @see Worksheet#initialize
   class PageMargins
 
     # Default left and right margin (in inches)
@@ -41,18 +43,29 @@ module Axlsx
     # @return [Float]
     attr_reader :footer
     
-    def initialize
+    # Creates a new PageMargins object
+    # @option options [Numeric] left The left margin in inches
+    # @option options [Numeric] right The right margin in inches
+    # @option options [Numeric] bottom The bottom margin in inches
+    # @option options [Numeric] top The top margin in inches
+    # @option options [Numeric] header The header margin in inches
+    # @option options [Numeric] footer The footer margin in inches
+    def initialize(options={})
       # Default values taken from MS Excel for Mac 2011
       @left = @right = DEFAULT_LEFT_RIGHT
       @top = @bottom = DEFAULT_TOP_BOTTOM
       @header = @footer = DEFAULT_HEADER_FOOTER
-      
-      @custom_margins_specified = false
+
+      options.each do |o|
+        self.send("#{o[0]}=", o[1]) if self.respond_to? "#{o[0]}="
+      end
     end
     
     # True if custom page margins have been specified.
     def custom_margins_specified?
-      @custom_margins_specified
+      !(@left == @right && @right == DEFAULT_LEFT_RIGHT &&
+      @top == @bottom && @bottom == DEFAULT_TOP_BOTTOM &&
+      @header == @footer && @footer == DEFAULT_HEADER_FOOTER)
     end
     
     # Set some or all margins at once.
@@ -65,17 +78,17 @@ module Axlsx
     end
     
     # @see left
-    def left=(v); Axlsx::validate_unsigned_numeric(v); @custom_margins_specified = true; @left = v end
+    def left=(v); Axlsx::validate_unsigned_numeric(v); @left = v end
     # @see right
-    def right=(v); Axlsx::validate_unsigned_numeric(v); @custom_margins_specified = true; @right = v end
+    def right=(v); Axlsx::validate_unsigned_numeric(v); @right = v end
     # @see top
-    def top=(v); Axlsx::validate_unsigned_numeric(v); @custom_margins_specified = true; @top = v end
+    def top=(v); Axlsx::validate_unsigned_numeric(v); @top = v end
     # @see bottom
-    def bottom=(v); Axlsx::validate_unsigned_numeric(v); @custom_margins_specified = true; @bottom = v end
+    def bottom=(v); Axlsx::validate_unsigned_numeric(v); @bottom = v end
     # @see header
-    def header=(v); Axlsx::validate_unsigned_numeric(v); @custom_margins_specified = true; @header = v end
+    def header=(v); Axlsx::validate_unsigned_numeric(v); @header = v end
     # @see footer
-    def footer=(v); Axlsx::validate_unsigned_numeric(v); @custom_margins_specified = true; @footer = v end
+    def footer=(v); Axlsx::validate_unsigned_numeric(v); @footer = v end
 
     # Serializes the page margins element
     # @note For compatibility, this is a noop unless custom margins have been specified.
@@ -86,4 +99,4 @@ module Axlsx
       xml.pageMargins :left => left, :right => right, :top => top, :bottom => bottom, :header => header, :footer => footer
     end
   end
-end
\ No newline at end of file
+end
diff --git a/lib/axlsx/workbook/worksheet/worksheet.rb b/lib/axlsx/workbook/worksheet/worksheet.rb
index ca2c51d6..3882b1db 100644
--- a/lib/axlsx/workbook/worksheet/worksheet.rb
+++ b/lib/axlsx/workbook/worksheet/worksheet.rb
@@ -36,13 +36,33 @@ module Axlsx
     attr_reader :auto_filter
     
     # Page margins for printing the worksheet.
+    # @example
+    #      wb = Axlsx::Package.new.workbook
+    #      # using options when creating the worksheet.
+    #      ws = wb.add_worksheet :page_margins => {:left => 1.9, :header => 0.1}
+    #      
+    #      # use the set method of the page_margins object
+    #      ws.page_margins.set(:bottom => 3, :footer => 0.7)
+    #      
+    #      # set page margins in a block
+    #      ws.page_margins do |margins|
+    #        margins.right = 6
+    #        margins.top = 0.2
+    #      end
+    # @see PageMargins#initialize
     # @return [PageMargins]
-    attr_reader :page_margins
+    # @yeilds self
+    def page_margins
+      @page_margins ||= PageMargins.new
+      yield @page_margins if block_given?
+      @page_margins
+    end
     
     # Creates a new worksheet.
     # @note the recommended way to manage worksheets is Workbook#add_worksheet
     # @see Workbook#add_worksheet
-    # @option options [String] name The name of this sheet.
+    # @option options [String] name The name of this worksheet.
+    # @option options [Hash] page_margins A hash containing page margins for this worksheet. @see PageMargins
     def initialize(wb, options={})
       @drawing = nil
       @auto_filter = nil
@@ -51,10 +71,12 @@ module Axlsx
       @workbook.worksheets << self
       @auto_fit_data = []
       self.name = options[:name] || "Sheet" + (index+1).to_s
+
       @magick_draw = Magick::Draw.new
       @cols = SimpleTypedList.new Cell
       @merged_cells = []
-      @page_margins = PageMargins.new
+      
+      @page_margins = PageMargins.new options[:page_margins] if options[:page_margins]
     end
 
     # convinience method to access all cells in this worksheet
@@ -326,7 +348,7 @@ module Axlsx
           }
           xml.autoFilter :ref=>@auto_filter if @auto_filter
           xml.mergeCells(:count=>@merged_cells.size) { @merged_cells.each { | mc | xml.mergeCell(:ref=>mc) } } unless @merged_cells.empty?
-          @page_margins.to_xml(xml)
+          page_margins.to_xml(xml)
           xml.drawing :"r:id"=>"rId1" if @drawing          
         }
       end
diff --git a/test/workbook/worksheet/tc_page_margins.rb b/test/workbook/worksheet/tc_page_margins.rb
index 6f2e6fdb..ed3d90d8 100644
--- a/test/workbook/worksheet/tc_page_margins.rb
+++ b/test/workbook/worksheet/tc_page_margins.rb
@@ -18,7 +18,18 @@ class TestPageMargins < Test::Unit::TestCase
     assert_equal(Axlsx::PageMargins::DEFAULT_HEADER_FOOTER, @pm.header)
     assert_equal(Axlsx::PageMargins::DEFAULT_HEADER_FOOTER, @pm.footer)
   end
-  
+
+  def test_initialize_with_options
+    optioned = Axlsx::PageMargins.new(:left => 2, :right => 3, :top => 2, :bottom => 1, :header => 0.1, :footer => 0.1)
+    assert_equal(true, optioned.custom_margins_specified?)
+    assert_equal(2, optioned.left)
+    assert_equal(3, optioned.right)
+    assert_equal(2, optioned.top)
+    assert_equal(1, optioned.bottom)
+    assert_equal(0.1, optioned.header)
+    assert_equal(0.1, optioned.footer)    
+  end
+
   def test_custom_margins_specified
     @pm.left = 0.5
     assert(@pm.custom_margins_specified?)
diff --git a/test/workbook/worksheet/tc_worksheet.rb b/test/workbook/worksheet/tc_worksheet.rb
index c2444820..d7e52f73 100644
--- a/test/workbook/worksheet/tc_worksheet.rb
+++ b/test/workbook/worksheet/tc_worksheet.rb
@@ -13,6 +13,29 @@ class TestWorksheet < Test::Unit::TestCase
     assert_equal(ws.pn, "worksheets/sheet2.xml")
   end
 
+  def test_page_margins
+    assert(@ws.page_margins.is_a? Axlsx::PageMargins)    
+  end
+
+  def test_page_margins_yeild
+    @ws.page_margins do |pm|
+      assert(pm.is_a? Axlsx::PageMargins)
+      assert(@ws.page_margins == pm)
+    end
+  end
+
+  def test_initialization_options
+    page_margins = {:left => 2, :right => 2, :bottom => 2, :top => 2, :header => 2, :footer => 2}
+    optioned = @ws.workbook.add_worksheet(:name => 'bob', :page_margins => page_margins)
+    assert_equal(optioned.page_margins.left, page_margins[:left])
+    assert_equal(optioned.page_margins.right, page_margins[:right])
+    assert_equal(optioned.page_margins.top, page_margins[:top])
+    assert_equal(optioned.page_margins.bottom, page_margins[:bottom])
+    assert_equal(optioned.page_margins.header, page_margins[:header])
+    assert_equal(optioned.page_margins.footer, page_margins[:footer])
+    assert_equal(optioned.name, 'bob')
+  end
+
   def test_rels_pn
     assert_equal(@ws.rels_pn, "worksheets/_rels/sheet1.xml.rels")
     ws = @ws.workbook.add_worksheet