view: add simple input handlers

1 files changed, 12 insertions, 0 deletions

diff --git a/src/util.ts b/src/util.ts
index 453966e..7129b2b 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -33,3 +33,15 @@ export function nextPowerOf2(n: number): number {
 
 	return i;
 }
+
+export class Listenable<T extends any[]> {
+	private readonly listeners: Array<(...args: T) => void> = [];
+
+	public addListener(listener: (...args: T) => void): void {
+		this.listeners.push(listener);
+	}
+
+	protected runListeners(...args: T): void {
+		this.listeners.forEach((l) => l(...args));
+	}
+}