exercises/01 - JavaScript Drum Kit/index.html

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>JS Drum Kit</title>
  <link rel="stylesheet" href="style.css">
</head>

<body>


  <div class="keys">
    <div data-key="65" class="key">
      <kbd>A</kbd>
      <span class="sound">clap</span>
    </div>
    <div data-key="83" class="key">
      <kbd>S</kbd>
      <span class="sound">hihat</span>
    </div>
    <div data-key="68" class="key">
      <kbd>D</kbd>
      <span class="sound">kick</span>
    </div>
    <div data-key="70" class="key">
      <kbd>F</kbd>
      <span class="sound">openhat</span>
    </div>
    <div data-key="71" class="key">
      <kbd>G</kbd>
      <span class="sound">boom</span>
    </div>
    <div data-key="72" class="key">
      <kbd>H</kbd>
      <span class="sound">ride</span>
    </div>
    <div data-key="74" class="key">
      <kbd>J</kbd>
      <span class="sound">snare</span>
    </div>
    <div data-key="75" class="key">
      <kbd>K</kbd>
      <span class="sound">tom</span>
    </div>
    <div data-key="76" class="key">
      <kbd>L</kbd>
      <span class="sound">tink</span>
    </div>
  </div>

  <audio data-key="65" src="sounds/clap.wav"></audio>
  <audio data-key="83" src="sounds/hihat.wav"></audio>
  <audio data-key="68" src="sounds/kick.wav"></audio>
  <audio data-key="70" src="sounds/openhat.wav"></audio>
  <audio data-key="71" src="sounds/boom.wav"></audio>
  <audio data-key="72" src="sounds/ride.wav"></audio>
  <audio data-key="74" src="sounds/snare.wav"></audio>
  <audio data-key="75" src="sounds/tom.wav"></audio>
  <audio data-key="76" src="sounds/tink.wav"></audio>

  <script>
    /** GOAL: When a user opens this page and presses a key that corresponds with
      * one of our div elements, we should play the audio clip associated with
      * the keypress, add a class to the specific element that matches with the keypress,
      * and then remove that class in order to reset the element to it's original state.
      */

    (()=> {
      const playSound = (e) => {
        const soundclip = document.querySelector(`audio[data-key="${e.keyCode}"]`);
        const keyelement = document.querySelector(`.key[data-key="${e.keyCode}"]`);

        if (!soundclip) return undefined; // Stop function from running if key pressed doesn't match up with our elements

        keyelement.classList.add('playing');

        // Ensures that the sound clip always plays from the beginning. Otherwise,
        // if the 'a' key is pressed twice rapidly, the soundclip will only play through
        // once.
        soundclip.currentTime = 0;

        soundclip.play(); // Play sound
      }

      const removeTransition = (e) => {
        // skip if it's not a transform event
        if (e.propertyName !== 'transform') return undefined;
        e.target.classList.remove('playing');
      }

      // Find all elements in the document with a class 'key'
      const keys = document.querySelectorAll('.key');

      // Listen for any `keydown` events that occur on this browser window instance (this page)
      // When a `keydown` event is observered, trigger the `playSound` function, passing in the
      // `keydown` event as the argument (e)
      window.addEventListener('keydown', playSound);

      keys.forEach(key =>
        key.addEventListener(
          'transitionend',
          (e) => removeTransition.call(key, e)
        ));
    })();
  </script>

</body>

</html>