[#14] I should be able to specify the tab's transposition.

examples/aimee-man-wise-up/aimee-man-wise-up.ly

@@ -151,9 +151,15 @@ vTwoScoreTabOneScoreOne = { \vTwoStanzaIntro \vTwoStanzaVerseOne \vTwoStanzaChor
 %-----------------------------------------------------------------------
 % Voices
 
-vOne = { \vOneScoreTabOneScoreOne }
+vOne = {
+  \transposition d''
+  \vOneScoreTabOneScoreOne
+}
 
-vTwo = { \vTwoScoreTabOneScoreOne }
+vTwo = {
+  \transposition d'
+  \vTwoScoreTabOneScoreOne
+}
 
 
 %-----------------------------------------------------------------------

examples/aimee-man-wise-up/aimee-man-wise-up.rb

@@ -5,6 +5,7 @@
   instrument "Guitar (capo on second fret)"
   midi_instrument "acoustic guitar (nylon)"
   tempo "4 = 75"
+  transposition "d"
 
   bar :BeforeYouSign do
     notes "r8 <d'/2>16( <c'/2>8.) <a/3>16 <c'/2>8. <d'/2>16 <e'/1>8. <g/3>8"

examples/tab.ly

@@ -61,9 +61,15 @@ vTwoScoreTabOneScoreOne = { \vTwoStanzaVerseOne }
 %-----------------------------------------------------------------------
 % Voices
 
-vOne = { \vOneScoreTabOneScoreOne }
+vOne = {
+  \transposition d''
+  \vOneScoreTabOneScoreOne
+}
 
-vTwo = { \vTwoScoreTabOneScoreOne }
+vTwo = {
+  \transposition d'
+  \vTwoScoreTabOneScoreOne
+}
 
 
 %-----------------------------------------------------------------------

examples/tab.rb

@@ -4,7 +4,7 @@
   arranger "Arranged by George Mendoza"
   instrument "Guitar (capo on second fret)"
   midi_instrument "acoustic guitar (nylon)"
-  #key "d"
+  transposition "d"
   tempo "4 = 75"
 
   bar :BeganIt do

lib/gitara/dsl.rb

@@ -9,10 +9,10 @@ class Dsl < Valuable
     can_add_property :arranger
     can_add_property :composer
     can_add_property :instrument
-    #can_add_property :key
     can_add_property :midi_instrument
     can_add_property :tempo
     can_add_property :title
+    can_add_property :transposition
 
     def add(child, &block)
       self.node.add child

lib/gitara/node/tab.rb

@@ -4,10 +4,10 @@ class Tab < Base
       has_value :arranger
       has_value :composer
       has_value :instrument
-      #has_value :key
       has_value :midi_instrument, :default => "acoustic guitar (nylon)"
       has_value :tempo
       has_value :title
+      has_value :transposition
 
       def self.parse(text)
         Transform.new.apply(Parser.new.parse(text))

lib/gitara/template/voice.erb

@@ -1 +1,6 @@
-<%= definition_name %> = { <%= parent.playable_child.voiced_as(self).call_name %> }
+<%= definition_name %> = {
+  <% if self.transposition %>
+  \transposition <%= self.transposition %>
+  <% end %>
+  <%= parent.playable_child.voiced_as(self).call_name %>
+}

lib/gitara/voice.rb

@@ -15,8 +15,16 @@ def id_as_word
       Utilities.id_as_word(id)
     end
 
+    def octave
+      (self.parent.max_number_of_voices - self.id) + 1
+    end
+
     def stem_type
       "\\voice#{id_as_word}"
     end
+
+    def transposition
+      "#{self.parent.transposition}#{"'" * self.octave}" if self.parent.transposition
+    end
   end
 end

spec/lib/gitara/dsl_spec.rb

@@ -203,7 +203,7 @@
       end
     end
 
-    [:title, :composer, :arranger, :instrument, :midi_instrument, :tempo].each do |property|
+    [:title, :composer, :arranger, :instrument, :midi_instrument, :tempo, :transposition].each do |property|
       describe "#{property}(value)" do
         it "should set the #{property} of the tab to value" do
           tab =Node::Tab.new

spec/lib/gitara/voice_spec.rb

@@ -28,4 +28,58 @@
       voice.stem_type.should == '\voiceOne'
     end
   end
+
+  describe "transposition" do
+    it "should be based on the tab's transposition and the voice's octave" do
+      tab = Node::Tab.new(
+        :transposition => 'd',
+        :children => [
+          Node::Bar.new(:children => [
+            Node::NoteSet.new,
+            Node::NoteSet.new
+          ])
+        ]
+      )
+      tab.max_number_of_voices.should == 2
+
+      voice = Voice.new(:parent => tab, :id => 1)
+      voice.transposition.should == "d''"
+
+      voice = Voice.new(:parent => tab, :id => 2)
+      voice.transposition.should == "d'"
+    end
+
+    it "should be blank if the tab has no transposition" do
+      tab = Node::Tab.new(
+        :children => [
+          Node::Bar.new(:children => [
+            Node::NoteSet.new,
+            Node::NoteSet.new
+          ])
+        ]
+      )
+      tab.max_number_of_voices.should == 2
+
+      voice = Voice.new(:parent => tab, :id => 1)
+      voice.transposition.should be_nil
+    end
+  end
+
+  describe "octave" do
+    it "should be based on the voice's position in the tab" do
+      tab = Node::Tab.new(:children => [
+        Node::Bar.new(:children => [
+          Node::NoteSet.new,
+          Node::NoteSet.new
+        ])
+      ])
+      tab.max_number_of_voices.should == 2
+
+      voice = Voice.new(:parent => tab, :id => 1)
+      voice.octave.should == 2
+
+      voice = Voice.new(:parent => tab, :id => 2)
+      voice.octave.should == 1
+    end
+  end
 end