Support theme provided by asciicast compatible (JSON) live stream parser

Author: ku1ik

lib/asciinema/colors.ex

@@ -1,7 +1,7 @@
 defmodule Asciinema.Colors do
   def mix(c1, c2, ratio) do
-    {r1, g1, b1} = parse_color(c1)
-    {r2, g2, b2} = parse_color(c2)
+    {r1, g1, b1} = parse(c1)
+    {r2, g2, b2} = parse(c2)
     r = hex(floor(r1 * ratio + r2 * (1 - ratio)))
     g = hex(floor(g1 * ratio + g2 * (1 - ratio)))
     b = hex(floor(b1 * ratio + b2 * (1 - ratio)))
@@ -19,11 +19,11 @@ defmodule Asciinema.Colors do
     |> String.downcase()
   end
 
-  defp parse_color(<<"#", r::binary-size(2), g::binary-size(2), b::binary-size(2)>>) do
+  def parse(<<"#", r::binary-size(2), g::binary-size(2), b::binary-size(2)>>) do
     {String.to_integer(r, 16), String.to_integer(g, 16), String.to_integer(b, 16)}
   end
 
-  defp parse_color("rgb(" <> rest) do
+  def parse("rgb(" <> rest) do
     rest
     |> String.slice(0, String.length(rest) - 1)
     |> String.split(",", parts: 3)

lib/asciinema/streaming/live_stream_server.ex

@@ -2,7 +2,7 @@ defmodule Asciinema.Streaming.LiveStreamServer do
   use GenServer, restart: :temporary
   alias Asciinema.Recordings.Snapshot
   alias Asciinema.Streaming.ViewerTracker
-  alias Asciinema.{Colors, PubSub, Streaming, Vt}
+  alias Asciinema.{PubSub, Streaming, Vt}
   require Logger
 
   defmodule Update do
@@ -295,13 +295,11 @@ defmodule Asciinema.Streaming.LiveStreamServer do
 
   defp theme_fields(nil), do: [theme_fg: nil, theme_bg: nil, theme_palette: nil]
 
-  defp theme_fields(theme) when byte_size(theme) == 18 * 3 do
-    colors = for <<r::8, g::8, b::8 <- theme>>, do: Colors.hex(r, g, b)
-
+  defp theme_fields(theme) do
     [
-      theme_fg: Enum.at(colors, 0),
-      theme_bg: Enum.at(colors, 1),
-      theme_palette: Enum.join(Enum.slice(colors, 2..-1), ":")
+      theme_fg: theme.fg,
+      theme_bg: theme.bg,
+      theme_palette: Enum.join(theme.palette, ":")
     ]
   end
 

lib/asciinema/streaming/parser/alis.ex

@@ -1,4 +1,6 @@
 defmodule Asciinema.Streaming.Parser.Alis do
+  alias Asciinema.Colors
+
   @behaviour Asciinema.Streaming.Parser
 
   @theme_absent 0x00
@@ -50,6 +52,8 @@ defmodule Asciinema.Streaming.Parser.Alis do
         %{status: status} = state
       )
       when status in [:init, :offline] do
+    theme = parse_theme(theme)
+
     {:ok, [reset: %{size: {cols, rows}, init: init, time: time, theme: theme}],
      %{state | status: :online}}
   end
@@ -91,4 +95,14 @@ defmodule Asciinema.Streaming.Parser.Alis do
   def parse({_type, _payload}, _state) do
     {:error, :message_invalid}
   end
+
+  defp parse_theme(theme) do
+    colors = for <<r::8, g::8, b::8 <- theme>>, do: Colors.hex(r, g, b)
+
+    %{
+      fg: Enum.at(colors, 0),
+      bg: Enum.at(colors, 1),
+      palette: Enum.slice(colors, 2..-1)
+    }
+  end
 end

lib/asciinema/streaming/parser/json.ex

@@ -17,14 +17,26 @@ defmodule Asciinema.Streaming.Parser.Json do
 
   def handle_message(%{"cols" => cols, "rows" => rows} = header, state)
       when is_integer(cols) and is_integer(rows) do
-    commands = [reset: %{size: {cols, rows}, init: header["init"], time: header["time"]}]
+    commands = [
+      reset: %{
+        size: {cols, rows},
+        init: header["init"],
+        time: header["time"],
+        theme: parse_theme(header["theme"])
+      }
+    ]
 
     {:ok, commands, %{state | first: false}}
   end
 
-  def handle_message(%{"width" => cols, "height" => rows}, state)
+  def handle_message(%{"width" => cols, "height" => rows} = header, state)
       when is_integer(cols) and is_integer(rows) do
-    commands = [reset: %{size: {cols, rows}}]
+    commands = [
+      reset: %{
+        size: {cols, rows},
+        theme: parse_theme(header["theme"])
+      }
+    ]
 
     {:ok, commands, %{state | first: false}}
   end
@@ -53,4 +65,14 @@ defmodule Asciinema.Streaming.Parser.Json do
   def handle_message(_message, _state) do
     {:error, :message_invalid}
   end
+
+  defp parse_theme(nil), do: nil
+
+  defp parse_theme(%{"fg" => fg, "bg" => bg, "palette" => palette}) do
+    %{
+      fg: fg,
+      bg: bg,
+      palette: String.split(palette, ":")
+    }
+  end
 end

lib/asciinema_web/live_stream_consumer_socket.ex

@@ -1,5 +1,5 @@
 defmodule AsciinemaWeb.LiveStreamConsumerSocket do
-  alias Asciinema.{Accounts, Authorization, Streaming}
+  alias Asciinema.{Accounts, Authorization, Colors, Streaming}
   alias Asciinema.Streaming.{LiveStreamServer, ViewerTracker}
   alias AsciinemaWeb.Endpoint
   require Logger
@@ -174,6 +174,7 @@ defmodule AsciinemaWeb.LiveStreamConsumerSocket do
   defp reset_message({vt_size, init, time, theme}) do
     {cols, rows} = vt_size
     theme_presence = 1
+    theme = encode_theme(theme)
     init = init || ""
     init_len = byte_size(init)
 
@@ -221,4 +222,12 @@ defmodule AsciinemaWeb.LiveStreamConsumerSocket do
   defp offline_message do
     {:binary, <<@msg_type_offline>>}
   end
+
+  defp encode_theme(%{fg: fg, bg: bg, palette: palette}) do
+    for color <- [fg, bg | palette], into: <<>> do
+      {r, g, b} = Colors.parse(color)
+
+      <<r::8, g::8, b::8>>
+    end
+  end
 end