Add hide_labels attribute in Gruff::Dot

lib/gruff/dot.rb

@@ -14,6 +14,9 @@
 #   g.write('dot.png')
 #
 class Gruff::Dot < Gruff::Base
+  # Prevent drawing of column labels below a stacked bar graph.  Default is +false+.
+  attr_writer :hide_labels
+
   def initialize(*)
     super
     @has_left_labels = true
@@ -22,6 +25,23 @@ def initialize(*)
 
 private
 
+  def initialize_attributes
+    super
+    @hide_labels = false
+  end
+
+  def hide_labels?
+    @hide_labels
+  end
+
+  def hide_left_label_area?
+    hide_labels? && @y_axis_label.nil?
+  end
+
+  def hide_bottom_label_area?
+    @hide_line_markers && @x_axis_label.nil? && @legend_at_bottom == false
+  end
+
   def draw_graph
     # Setup spacing.
     #

test/test_dot.rb

@@ -49,6 +49,15 @@ def test_dot_graph_small
     assert_same_image('test/expected/dot_small.png', 'test/output/dot_small.png')
   end
 
+  def test_no_labels
+    g = setup_basic_graph(400)
+    g.title = 'No Labels'
+    g.hide_labels = true
+    g.write('test/output/dot_no_labels.png')
+
+    assert_same_image('test/expected/dot_no_labels.png', 'test/output/dot_no_labels.png')
+  end
+
   def test_no_line_markers
     g = setup_basic_graph(400)
     g.title = 'No Line Markers'