Add programmatic play and pause to Kino.Audio (#458)

Co-authored-by: Jonatan Kłosko <[email protected]>

lib/assets/audio/main.js

@@ -4,6 +4,16 @@ export function init(ctx, [{ type, opts }, content]) {
       <audio ${opts} src="${createDataUrl(content, type)}" style="height: 150px"/>
     </div>
   `;
+
+  const audioEl = ctx.root.querySelector("audio");
+
+  ctx.handleEvent("play", () => {
+    audioEl.play();
+  });
+
+  ctx.handleEvent("pause", () => {
+    audioEl.pause();
+  });
 }
 
 function bufferToBase64(buffer) {

lib/kino/audio.ex

@@ -58,6 +58,24 @@ defmodule Kino.Audio do
     })
   end
 
+  @doc """
+  Makes a given kino play the audio.
+
+  Play has no effect if the audio is already playing.
+  """
+  @spec play(t()) :: :ok
+  def play(kino) do
+    Kino.JS.Live.cast(kino, :play)
+  end
+
+  @doc """
+  Makes a given kino stop playing the audio.
+  """
+  @spec pause(t()) :: :ok
+  def pause(kino) do
+    Kino.JS.Live.cast(kino, :pause)
+  end
+
   @impl true
   def init(assigns, ctx) do
     {:ok, assign(ctx, assigns)}
@@ -69,6 +87,17 @@ defmodule Kino.Audio do
     {:ok, payload, ctx}
   end
 
+  @impl true
+  def handle_cast(:play, ctx) do
+    broadcast_event(ctx, "play", %{})
+    {:noreply, ctx}
+  end
+
+  def handle_cast(:pause, ctx) do
+    broadcast_event(ctx, "pause", %{})
+    {:noreply, ctx}
+  end
+
   defp mime_type!(:wav), do: "audio/wav"
   defp mime_type!(:mp3), do: "audio/mpeg"
   defp mime_type!(:mpeg), do: "audio/mpeg"

test/kino/audio_test.exs

@@ -27,5 +27,17 @@ defmodule Kino.AudioTest do
       kino = Kino.Audio.new(<<>>, "audio/mp2", loop: true)
       assert {:binary, %{type: "audio/mp2", opts: "controls loop"}, <<>>} == connect(kino)
     end
+
+    test "supports playing" do
+      kino = Kino.Audio.new(<<>>, :wav)
+      Kino.Audio.play(kino)
+      assert_broadcast_event(kino, "play", %{})
+    end
+
+    test "supports pausing" do
+      kino = Kino.Audio.new(<<>>, :wav)
+      Kino.Audio.pause(kino)
+      assert_broadcast_event(kino, "pause", %{})
+    end
   end
 end