Function onscrolltop

src/lib/editorManager.js:2693–2708

* Handles the scroll top event. * Updates the vertical scroll value and renders the vertical scrollbar.

()

	 * Updates the vertical scroll value and renders the vertical scrollbar.
	 */
	function onscrolltop() {
		const scroller = editor?.scrollDOM;
		if (!scroller) return;
		const maxScroll = Math.max(
			scroller.scrollHeight - scroller.clientHeight,
			0,
		);
		if (maxScroll <= 0) {
			$vScrollbar.hide();
			lastScrollTop = 0;
			$vScrollbar.value = 0;
			return;
		}
		setVScrollValue();
		$vScrollbar.render();
	}

	function clamp01(value) {
		if (value <= 0) return 0;