feat: Add long press functionality to AutoresizeArea component

src/ts/gui/longtouch.ts

@@ -0,0 +1,27 @@
+export function longpress(node:HTMLElement, callback:(e:MouseEvent)=>void) {
+	const TIME_MS = 500;
+	let timeoutPtr: number;
+	function handleMouseDown(e:MouseEvent) {
+		window.addEventListener('mousemove', handleMoveBeforeLong);
+		timeoutPtr = window.setTimeout(() => {
+			window.removeEventListener('mousemove', handleMoveBeforeLong);
+			callback(e);
+		}, TIME_MS);
+	}
+	function handleMoveBeforeLong(e:MouseEvent) {
+		window.clearTimeout(timeoutPtr); 
+		window.removeEventListener('mousemove', handleMoveBeforeLong);
+	}
+	function handleMouseUp(e:MouseEvent) {
+		window.clearTimeout(timeoutPtr); 
+		window.removeEventListener('mousemove', handleMoveBeforeLong);
+	}
+	node.addEventListener('mousedown', handleMouseDown);
+	node.addEventListener('mouseup', handleMouseUp);
+	return {
+		destroy: () => {
+			node.removeEventListener('mousedown', handleMouseDown);
+			node.removeEventListener('mouseup', handleMouseUp);
+		}
+	};
+}