1 files changed, 69 insertions, 0 deletions
diff --git a/frontend/src/components/DeckyToasterState.tsx b/frontend/src/components/DeckyToasterState.tsx
new file mode 100644
index 00000000..8732d7f8
--- /dev/null
+++ b/frontend/src/components/DeckyToasterState.tsx
@@ -0,0 +1,69 @@
+import { ToastData } from 'decky-frontend-lib';
+import { FC, createContext, useContext, useEffect, useState } from 'react';
+
+interface PublicDeckyToasterState {
+  toasts: Set<ToastData>;
+}
+
+export class DeckyToasterState {
+  // TODO a set would be better
+  private _toasts: Set<ToastData> = new Set();
+
+  public eventBus = new EventTarget();
+
+  publicState(): PublicDeckyToasterState {
+    return { toasts: this._toasts };
+  }
+
+  addToast(toast: ToastData) {
+    this._toasts.add(toast);
+    this.notifyUpdate();
+  }
+
+  removeToast(toast: ToastData) {
+    this._toasts.delete(toast);
+    this.notifyUpdate();
+  }
+
+  private notifyUpdate() {
+    this.eventBus.dispatchEvent(new Event('update'));
+  }
+}
+
+interface DeckyToasterContext extends PublicDeckyToasterState {
+  addToast(toast: ToastData): void;
+  removeToast(toast: ToastData): void;
+}
+
+const DeckyToasterContext = createContext<DeckyToasterContext>(null as any);
+
+export const useDeckyToasterState = () => useContext(DeckyToasterContext);
+
+interface Props {
+  deckyToasterState: DeckyToasterState;
+}
+
+export const DeckyToasterStateContextProvider: FC<Props> = ({ children, deckyToasterState }) => {
+  const [publicDeckyToasterState, setPublicDeckyToasterState] = useState<PublicDeckyToasterState>({
+    ...deckyToasterState.publicState(),
+  });
+
+  useEffect(() => {
+    function onUpdate() {
+      setPublicDeckyToasterState({ ...deckyToasterState.publicState() });
+    }
+
+    deckyToasterState.eventBus.addEventListener('update', onUpdate);
+
+    return () => deckyToasterState.eventBus.removeEventListener('update', onUpdate);
+  }, []);
+
+  const addToast = deckyToasterState.addToast.bind(deckyToasterState);
+  const removeToast = deckyToasterState.removeToast.bind(deckyToasterState);
+
+  return (
+    <DeckyToasterContext.Provider value={{ ...publicDeckyToasterState, addToast, removeToast }}>
+      {children}
+    </DeckyToasterContext.Provider>
+  );
+};