Add an option to loop Morse code sequences

This provides an easy way to workaround the end of the Morse code
message being clipped when the `:hz` setting is incorrect. What happens
in this situation is that Linux's rounds its timers up, Delux doesn't
know about it, and then Delux calculates the entire sequences duration
incorrectly and cuts it off early. Some people may also want their Morse
code messages to loop anyway.

Author: Frank Hunleth

lib/delux/morse.ex

@@ -63,7 +63,7 @@ defmodule Delux.Morse do
     ?@ => ".--.-."
   }
 
-  @type options() :: [words_per_minute: number()]
+  @type options() :: [words_per_minute: number(), loop?: boolean()]
 
   @doc """
   Convert a text string to Morse code
@@ -76,12 +76,14 @@ defmodule Delux.Morse do
   Options:
 
   * `:words_per_minute` - the rate at which to send the message
+  * `:loop?` - set to `true` to repeat the message (defaults to `false`)
   """
   @spec encode(RGB.color(), String.t(), options()) :: Program.t()
   def encode(c, string, options \\ []) do
     {r, g, b} = RGB.new(c)
 
     words_per_minute = options[:words_per_minute] || @default_words_per_minute
+    loop? = options[:loop?] || false
 
     if words_per_minute < 1 or words_per_minute > 100 do
       raise ArgumentError, "Invalid :words_per_minute"
@@ -90,13 +92,14 @@ defmodule Delux.Morse do
     up_string = String.upcase(string, :ascii)
     base_elements = morse(up_string, words_per_minute)
     duration = duration_elements(base_elements)
+    mode = if loop?, do: :simple_loop, else: :one_shot
 
     %Program{
       red: elements(r, base_elements, duration),
       green: elements(g, base_elements, duration),
       blue: elements(b, base_elements, duration),
       description: "Morse code: #{up_string}",
-      mode: :one_shot
+      mode: mode
     }
   end
 

test/delux/morse_test.exs

@@ -70,4 +70,22 @@ defmodule Delux.MorseTest do
     assert p.mode == :one_shot
     assert Program.text_description(p) == "Morse code: E E E"
   end
+
+  test "looping a message" do
+    p = Morse.encode(:red, "T", words_per_minute: 20, loop?: true)
+
+    # -
+    assert p.red == [
+             {1, 180},
+             {1, 0},
+             {0, 420},
+             {0, 0}
+           ]
+
+    assert p.green == [{0, 600}, {0, 0}]
+    assert p.blue == [{0, 600}, {0, 0}]
+
+    assert p.mode == :simple_loop
+    assert Program.text_description(p) == "Morse code: T"
+  end
 end