draggable tables

static/css/markdown.css

@@ -91,10 +91,26 @@
 	border-radius: 4px;
 }
 
+.markdown .table-wrapper {
+	width: 100%;
+	overflow-x: auto;
+	margin: 16px 0;
+	cursor: grab;
+	touch-action: pan-y;
+}
+
+.markdown .table-wrapper:not(.overflowing) {
+	cursor: default;
+	overflow-x: hidden;
+}
+
+.markdown .table-wrapper.dragging {
+	cursor: grabbing;
+}
+
 .markdown table {
 	width: 100%;
 	border-collapse: collapse;
-	margin: 16px 0;
 	font-size: 14px;
 }
 

static/js/markdown.js

@@ -1,5 +1,12 @@
 (() => {
-	const timeouts = new WeakMap();
+	const timeouts = new WeakMap(),
+		scrollState = {
+			el: null,
+			startX: 0,
+			scrollLeft: 0,
+			pointerId: null,
+			moved: false,
+		};
 
 	marked.use({
 		async: false,
@@ -7,13 +14,13 @@
 		gfm: true,
 		pedantic: false,
 
-		walkTokens: (token) => {
+		walkTokens: token => {
 			const { type, text } = token;
 
 			if (type === "html") {
-				token.text = token.text.replace(/&/g, "&")
-				token.text = token.text.replace(/</g, "&lt;")
-				token.text = token.text.replace(/>/g, "&gt;")
+				token.text = token.text.replace(/&/g, "&amp;");
+				token.text = token.text.replace(/</g, "&lt;");
+				token.text = token.text.replace(/>/g, "&gt;");
 
 				return;
 			} else if (type !== "code") {
@@ -48,9 +55,18 @@
 				return `<a href="${link.href}" target="_blank">${escapeHtml(link.text || link.href)}</a>`;
 			},
 		},
+
+		hooks: {
+			postprocess: html => {
+				html = html.replace(/<table>/g, `<div class="table-wrapper"><table>`);
+				html = html.replace(/<\/ ?table>/g, `</table></div>`);
+
+				return html;
+			},
+		},
 	});
 
-	document.body.addEventListener("click", (event) => {
+	addEventListener("click", event => {
 		const button = event.target,
 			header = button.closest(".pre-header"),
 			pre = header?.closest("pre"),
@@ -70,11 +86,76 @@
 			pre,
 			setTimeout(() => {
 				button.classList.remove("copied");
-			}, 1000),
+			}, 1000)
 		);
 	});
 
-	window.render = (markdown) => {
+	addEventListener("pointerover", event => {
+		if (event.pointerType !== "mouse") {
+			return;
+		}
+
+		const el = event.target.closest(".table-wrapper");
+
+		if (!el) {
+			return;
+		}
+
+		el.classList.toggle("overflowing", el.scrollWidth - el.clientWidth > 1);
+	});
+
+	addEventListener("pointerdown", event => {
+		if (event.button !== 0) {
+			return;
+		}
+
+		const el = event.target.closest(".table-wrapper");
+
+		if (!el) {
+			return;
+		}
+
+		scrollState.el = el;
+		scrollState.pointerId = event.pointerId;
+		scrollState.startX = event.clientX;
+		scrollState.scrollLeft = el.scrollLeft;
+		scrollState.moved = false;
+
+		el.classList.add("dragging");
+		el.setPointerCapture?.(event.pointerId);
+
+		event.preventDefault();
+	});
+
+	addEventListener("pointermove", event => {
+		if (!scrollState.el || event.pointerId !== scrollState.pointerId) {
+			return;
+		}
+
+		const dx = event.clientX - scrollState.startX;
+
+		if (Math.abs(dx) > 3) {
+			scrollState.moved = true;
+		}
+
+		scrollState.el.scrollLeft = scrollState.scrollLeft - dx;
+	});
+
+	function endScroll(event) {
+		if (!scrollState.el || (event && event.pointerId !== scrollState.pointerId)) {
+			return;
+		}
+
+		scrollState.el.classList.remove("dragging");
+		scrollState.el.releasePointerCapture?.(scrollState.pointerId);
+		scrollState.el = null;
+		scrollState.pointerId = null;
+	}
+
+	addEventListener("pointerup", endScroll);
+	addEventListener("pointercancel", endScroll);
+
+	window.render = markdown => {
 		return marked.parse(markdown);
 	};
 })();