Get shopping cart details in Magento2

I figured this out by myself in the end:

<?php

$om =   \Magento\Framework\App\ObjectManager::getInstance();
$cartData = $om->create('Magento\Checkout\Model\Cart')->getQuote()->getAllVisibleItems();
$cartDataCount = count( $cartData );

?>
<div class="bagDrop" id="bagDrop">
    <h4><a href="<?php echo $block->getShoppingCartUrl(); ?>">Quote Basket</a></h4>
    <?php if( $cartDataCount > 1 ): ?>
        <a href="#" class="arr up off" id="bagDropScrollUp"></a>
    <?php endif; ?>
    <div class="bagDropWindow">
    <?php if( $cartDataCount > 0 ): ?>
        <div class="bagDropList" id="bagDropList">
            <?php foreach( $cartData as $item ): ?>
                <?php $product = $item->getProduct(); ?>
                <?php $image = $product['small_image'] == '' ? '/pub/static/frontend/Clear/usb2u/en_GB/images/default-category-image_1.png' : '/pub/media/catalog/product' . $product['small_image']; ?>
                <a href="<?php echo $product['request_path']; ?>" class="bagDropListItem">
                    <img src="<?php echo $image; ?>">
                    <p>
                        <span class="name"><?php echo $product['name']; ?></span><br>
                        <span class="qty">x <?php echo $item->getQty(); ?></span>
                    </p>
                </a>
            <?php endforeach; ?>
        </div>
    <?php else: ?>
        <div class="emptyList">No products in your basket.</div>
    <?php endif; ?>
    </div>
    <?php if( $cartDataCount > 1 ): ?>
        <a href="#" class="arr dn" id="bagDropScrollDown"></a>
    <?php endif; ?>
</div>

protected $_checkoutSession;

public function __construct (
    \Magento\Checkout\Model\Session $_checkoutSession
    ) {
    $this->_checkoutSession = $_checkoutSession;
}

public function execute(\Magento\Framework\Event\Observer $observer)
{
  $cartData = $this->_checkoutSession->getQuote()->getAllVisibleItems();
  $cartDataCount = count( $cartData );
}

you can get the quote data in observer