Wrapping with hidden counter

Wrapping with hidden counter

by Csaba Hellinger

HTML

<div class="layout">
  <div class="container"></div>
  <div class="remaining"></div>
</div>

<small>Change the window width to test the wrapping behaviour</small>

CSS

.layout {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-rows: 1fr;
  padding: 1px;
  background: white;
}

.container {
  background: dimgrey;
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  position: relative;
  overflow-y: clip;
}

.item {
  flex-shrink: 0;
  background: navy;
}

.remaining {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 50px;
  background: green;
}
.remaining.hidden {
  display: none;
}

.layout, .container, .item, .remaining {
  height: 50px;
  max-height: 50px;
}

/* ------------------- */

body {
  background: #333;
  color: #ddd;
  font-family: sans-serif;
  margin: 1rem;
}

JavaScript

const container = document.querySelector('.container');
const remaining = document.querySelector('.remaining');

const items = Array(8).fill(0).map((_,index) => {
  console.log(index);
  const item = document.createElement('div');
  item.className = 'item';
  item.style.width = Math.round(1 + Math.random() * 2) * 30 + 'px';
  item.textContent = index;
  container.appendChild(item);
  return item;
});

const resizeObserver = new ResizeObserver((entries) => {
  const visibleCount = items.filter((item,index) => item.offsetTop < container.clientHeight).length;
  const hiddenCount = items.length - visibleCount;
  remaining.classList[hiddenCount === 0 ? 'add' : 'remove']('hidden');
  remaining.textContent = `+ ${hiddenCount}`;    
});

resizeObserver.observe(container);