Pointer Drag

<%# pointer-drag: the primitive normalizes the drag lifecycle (threshold, axis
    lock, pointer capture, touch-action, cancel) and adds a keyboard alternative.
    With the opt-in follow value it also moves the card itself — translate on
    move, committed on drop, restored on cancel — so the consumer JS below only
    mirrors the signal into the status line. The card can travel out of the
    dashed area, which the area clips; the reset action brings it back, since
    follow's committed offset is internal state a consumer cannot clear. The
    button sits outside the controller element, so its click reaches the action
    as a custom event the element's own data-action maps. %>
<div class="pointer-drag-demo">
  <p class="pointer-drag-demo__hint"><%= t("components.pointer_drag.demo.hint") %></p>
  <div class="pointer-drag-demo__area">
    <button type="button" class="pointer-drag-demo__card" id="pointer-drag-card"
            data-controller="stimeo--pointer-drag"
            data-stimeo--pointer-drag-follow-value="true"
            data-action="demo:reset->stimeo--pointer-drag#reset">
      <svg class="demo-icon" viewBox="0 0 24 24" fill="currentColor" stroke="none"
           aria-hidden="true">
        <circle cx="9" cy="6" r="1.5"></circle><circle cx="15" cy="6" r="1.5"></circle>
        <circle cx="9" cy="12" r="1.5"></circle><circle cx="15" cy="12" r="1.5"></circle>
        <circle cx="9" cy="18" r="1.5"></circle><circle cx="15" cy="18" r="1.5"></circle>
      </svg>
      <%= t("components.pointer_drag.demo.card_label") %>
    </button>
  </div>
  <p class="pointer-drag-demo__actions">
    <button type="button" class="demo-trigger" data-pointer-drag-reset>
      <%= t("components.pointer_drag.demo.reset_label") %>
    </button>
  </p>
  <p class="pointer-drag-demo__status" data-pointer-drag-status aria-live="polite"
     data-moved-template="<%= t("components.pointer_drag.demo.moved_template") %>"
     data-idle-text="<%= t("components.pointer_drag.demo.idle_text") %>"></p>
</div>

/*
 * Presentation-only styles for the pointer-drag demo. The library emits the drag
 * signal and flips data-dragging / data-grabbed; demo.js applies the transform.
 * This CSS draws the play area and highlights the card while a session is live.
 */

.pointer-drag-demo {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: flex-start;
}

.pointer-drag-demo__hint {
  margin: 0;
  color: var(--muted);
}

.pointer-drag-demo__area {
  width: 100%;
  min-height: 10rem;
  padding: 1rem;
  border: 1px dashed var(--border);
  border-radius: 0.5rem;
  /* The card translates freely; keep the play area its clipping context. */
  overflow: hidden;
}

.pointer-drag-demo__actions {
  margin: 0;
}

.pointer-drag-demo__card {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--border-strong);
  border-radius: 0.375rem;
  background: var(--bg);
  color: var(--fg);
  font-size: 1rem;
  cursor: grab;
  transition: border-color 0.15s ease, color 0.15s ease;
}

.pointer-drag-demo__card:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Live session: pointer drag (data-dragging) or keyboard grab (data-grabbed). */
.pointer-drag-demo__card[data-dragging],
.pointer-drag-demo__card[data-grabbed] {
  border-color: var(--accent);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  cursor: grabbing;
}

.pointer-drag-demo__card .demo-icon {
  width: 1rem;
  height: 1rem;
  color: var(--muted);
}

.pointer-drag-demo__status {
  margin: 0;
  min-height: 1.25rem;
  font-size: 0.9rem;
  color: var(--muted);
}

// pointer-drag emits the normalized signal (cumulative dx/dy from the origin —
// pointer drags and keyboard arrows alike) and, with the opt-in follow value,
// already moves the card: translate on move, committed on drop, snapped back on
// cancel. No positioning JS is left to write — this consumer only mirrors the
// live deltas into the status line and hands the reset button to the action.
// Status copy comes from the localized data-* templates (values only, never
// words).
const card = document.getElementById("pointer-drag-card");
const status = document.querySelector("[data-pointer-drag-status]");
const resetButton = document.querySelector("[data-pointer-drag-reset]");
const template = status?.dataset.movedTemplate || "{dx}, {dy}";
const idleText = status?.dataset.idleText || "";

const idle = () => {
  if (status) status.textContent = idleText;
};
idle();

card?.addEventListener("stimeo--pointer-drag:move", (event) => {
  const { dx, dy } = event.detail;
  if (status) {
    status.textContent = template.replace("{dx}", String(dx)).replace("{dy}", String(dy));
  }
});

card?.addEventListener("stimeo--pointer-drag:end", idle);
card?.addEventListener("stimeo--pointer-drag:cancel", idle);

// The button sits outside the controller element, where a data-action cannot
// reach it. Dispatching on the element lets its own data-action run the reset.
resetButton?.addEventListener("click", () => {
  card?.dispatchEvent(new CustomEvent("demo:reset"));
});