Refactor: Update Projection To Keep Track Of Past Projections

Why This Change Is Necessary
========================================================================

Previous projections are valuable information for some projectors and so
each projector needs to have the capability of tracking it if it so
chooses.

What These Changes Do To Address the Issue
========================================================================

Track the projection in a new variable.

Side Effects Caused By This Change
========================================================================

None expected.

Author: jfelchner

lib/ruby-progressbar/calculators/smoothed_average.rb

@@ -4,22 +4,33 @@ class   SmoothedAverage
   DEFAULT_STRENGTH = 0.1
 
   attr_accessor :strength
+  attr_reader   :projection
 
   def initialize(options = {})
-    self.strength = options[:strength] || DEFAULT_STRENGTH
+    self.projection = 0.0
+    self.strength   = options[:strength] || DEFAULT_STRENGTH
   end
 
-  def calculate(current_projection, new_value)
-    self.class.calculate(
-      current_projection,
-      new_value,
-      strength
-    )
+  def start(_options = {})
+    self.projection = 0.0
+  end
+
+  def calculate(new_value)
+    self.projection = \
+      self.class.calculate(
+        @projection,
+        new_value,
+        strength
+      )
   end
 
   def self.calculate(current_projection, new_value, rate)
     (new_value * (1.0 - rate)) + (current_projection * rate)
   end
+
+  protected
+
+  attr_writer :projection
 end
 end
 end

lib/ruby-progressbar/progress.rb

@@ -9,19 +9,18 @@ class   Progress
                             :progress
 
   attr_accessor             :starting_position,
-                            :running_average,
                             :running_average_calculator
 
   def initialize(options = {})
     self.total                      = options.fetch(:total, DEFAULT_TOTAL)
     self.running_average_calculator = options[:projector]
 
-    start :at => DEFAULT_BEGINNING_POSITION
+    start(:at => DEFAULT_BEGINNING_POSITION)
   end
 
   def start(options = {})
-    self.running_average   = 0
-    self.progress          = \
+    running_average_calculator.start
+    self.progress = \
       self.starting_position = options[:at] || progress
   end
 
@@ -54,7 +53,7 @@ def decrement
   end
 
   def reset
-    start :at => starting_position
+    start(:at => starting_position)
   end
 
   def progress=(new_progress)
@@ -64,9 +63,11 @@ def progress=(new_progress)
     end
 
     @progress = new_progress
+    running_average_calculator.calculate(absolute)
+  end
 
-    self.running_average = running_average_calculator.calculate(running_average,
-                                                                absolute)
+  def running_average
+    running_average_calculator.projection
   end
 
   def total=(new_total)

spec/lib/ruby-progressbar/calculators/smoothed_average_spec.rb

@@ -4,7 +4,7 @@
 class    ProgressBar
 module   Calculators
 describe SmoothedAverage do
-  it 'can properly calculate a projector' do
+  it 'can properly calculate a projection' do
     first_projection = SmoothedAverage.calculate(4.5,  12,  0.1)
     expect(first_projection).to be_within(0.001).of 11.25
 
@@ -15,6 +15,20 @@ module   Calculators
     expect(third_projection).to be_within(0.001).of 65.662
   end
 
+  describe '#start' do
+    it 'resets the projection' do
+      projector = SmoothedAverage.new
+      projector.start
+      projector.calculate(10)
+
+      expect(projector.projection).not_to be_zero
+
+      projector.start
+
+      expect(projector.projection).to be 0.0
+    end
+  end
+
   describe '#strength' do
     it 'allows the default strength to be overridden' do
       projector = SmoothedAverage.new(:strength => 0.3)

spec/lib/ruby-progressbar/progress_spec.rb

@@ -123,7 +123,7 @@ class    ProgressBar
     projector  = Calculators::SmoothedAverage.new
     progress   = Progress.new(:total => 50, :projector => projector)
 
-    progress.running_average = 10
+    projector.__send__(:projection=, 10)
     progress.start :at => 0
 
     expect(progress.running_average).to be_zero
@@ -137,7 +137,7 @@ class    ProgressBar
     projector  = Calculators::SmoothedAverage.new
     progress   = Progress.new(:total => 50, :projector => projector)
 
-    progress.running_average = 10
+    projector.__send__(:projection=, 10)
     progress.start :at => 0
 
     expect(progress.running_average).to be_zero