Desktop: Resolves #11687: Plugins: Allow editor plugins to support multiple windows (#12041)

packages/lib/hooks/plugins/usePlugin.ts

@@ -0,0 +1,43 @@
+import PluginService from '../../services/plugins/PluginService';
+import Logger from '@joplin/utils/Logger';
+import shim from '../../shim';
+
+const logger = Logger.create('usePlugin');
+
+const usePlugin = (pluginId: string) => {
+	const React = shim.react();
+	const [pluginReloadCounter, setPluginReloadCounter] = React.useState(0);
+
+	const plugin = React.useMemo(() => {
+		if (!PluginService.instance().pluginIds.includes(pluginId)) {
+			return null;
+		}
+
+		if (pluginReloadCounter > 0) {
+			logger.debug('Reloading plugin', pluginId, 'because the set of loaded plugins changed.');
+		}
+
+		return PluginService.instance().pluginById(pluginId);
+		// The dependency on pluginReloadCounter is important -- it ensures that the plugin
+		// matches the one loaded in the PluginService.
+	}, [pluginId, pluginReloadCounter]);
+
+	const reloadCounterRef = React.useRef(0);
+	reloadCounterRef.current = pluginReloadCounter;
+
+	// The plugin may need to be re-fetched from the PluginService. When a plugin is reloaded,
+	// its Plugin object is replaced with a new one.
+	React.useEffect(() => {
+		const { remove } = PluginService.instance().addLoadedPluginsChangeListener(() => {
+			setPluginReloadCounter(reloadCounterRef.current + 1);
+		});
+
+		return () => {
+			remove();
+		};
+	}, []);
+
+	return plugin;
+};
+
+export default usePlugin;