スケルトン切り替え制御

<%# Markup for the skeleton (skeleton toggle control) demo.
    Initially the skeleton is shown, the real content hidden, and aria-busy="true". On
    ready it swaps and sets aria-busy="false". The skeleton is decorative
    (aria-hidden="true"). A minimum display time prevents flicker.
    The Load / Reset buttons sit outside the busy card (so aria-busy stays scoped to the
    loading region, not the controls), so they drive it through events the controller
    listens for (see demo.js): Load fires content:ready — the same signal a consumer
    dispatches when their real content arrives — and Reset returns it to loading. A
    Stimulus data-action on the buttons would not bind, since actions only wire up
    within the controller's own element. %>
<div class="skeleton-demo">
  <div class="skeleton-demo__controls">
    <button
      class="demo-trigger"
      type="button"
      data-skeleton-load>
      <%= t("components.skeleton.demo.load") %>
    </button>
    <button
      class="demo-trigger"
      type="button"
      data-skeleton-reset>
      <%= t("components.skeleton.demo.reset") %>
    </button>
  </div>

  <div
    class="skeleton-card"
    data-controller="stimeo--skeleton"
    aria-busy="true"
    data-stimeo--skeleton-min-duration-value="400"
    data-action="content:ready->stimeo--skeleton#ready skeleton:reset->stimeo--skeleton#reset">
    <div
      class="skeleton"
      aria-hidden="true"
      data-stimeo--skeleton-target="placeholder">
      <span class="skeleton__line skeleton__line--title"></span>
      <span class="skeleton__line"></span>
      <span class="skeleton__line skeleton__line--short"></span>
    </div>

    <div class="skeleton-content" hidden data-stimeo--skeleton-target="content">
      <h3 class="skeleton-content__title"><%= t("components.skeleton.demo.title") %></h3>
      <p><%= t("components.skeleton.demo.body") %></p>
    </div>
  </div>
</div>

/*
 * Presentation-only styles for the skeleton demo.
 * This CSS owns the skeleton shapes and shimmer; the library only toggles
 * hidden / aria-busy / aria-hidden / data-state (loading / ready).
 */

.skeleton-demo {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 32rem;
}

.skeleton-demo__controls {
  display: flex;
  gap: 0.5rem;
}

.skeleton-card {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
}

.skeleton {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.skeleton__line {
  height: 0.75rem;
  border-radius: 0.25rem;
  background: linear-gradient(
    90deg,
    var(--surface-subtle) 25%,
    var(--surface-subtle) 50%,
    var(--surface-subtle) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.4s ease-in-out infinite;
}

.skeleton__line--title {
  height: 1.1rem;
  width: 55%;
}

.skeleton__line--short {
  width: 70%;
}

@keyframes skeleton-shimmer {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

.skeleton-content__title {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.skeleton-content p {
  margin: 0;
  color: var(--fg);
}

@media (prefers-reduced-motion: reduce) {
  .skeleton__line {
    animation: none;
  }
}

// skeleton external-control demo (consumer-side JS).
//
// The core controller (stimeo--skeleton) swaps the placeholder for the real
// content on ready and returns to loading on reset, syncing aria-busy on the card.
// The Load / Reset buttons sit outside that busy card (so aria-busy stays scoped to
// the loading region), where a Stimulus data-action would never bind — actions only
// wire up within the controller's own element. The card listens for content:ready
// (the signal a consumer fires when their real content has arrived) and skeleton:reset,
// so here Load dispatches content:ready and Reset dispatches skeleton:reset.
document.querySelectorAll(".skeleton-demo").forEach((root) => {
  const card = root.querySelector('.skeleton-card[data-controller~="stimeo--skeleton"]');
  const controls = root.querySelector(".skeleton-demo__controls");
  if (!card || !controls) return;

  controls.querySelector("[data-skeleton-load]")?.addEventListener("click", () => {
    card.dispatchEvent(new CustomEvent("content:ready"));
  });
  controls.querySelector("[data-skeleton-reset]")?.addEventListener("click", () => {
    card.dispatchEvent(new CustomEvent("skeleton:reset"));
  });
});