1 files changed, 42 insertions, 0 deletions
diff --git a/pw_web/log-viewer/src/shared/state.ts b/pw_web/log-viewer/src/shared/state.ts
new file mode 100644
index 000000000..87a379f87
--- /dev/null
+++ b/pw_web/log-viewer/src/shared/state.ts
@@ -0,0 +1,42 @@
+// Copyright 2023 The Pigweed Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+import { State } from './interfaces';
+
+/**
+ * Abstract Class for StateStore.
+ */
+export abstract class StateStore {
+  abstract getState(): State;
+  abstract setState(state: State): void;
+}
+
+/**
+ * LocalStorage version of StateStore
+ */
+export class LocalStorageState extends StateStore {
+  getState(): State {
+    try {
+      const state = localStorage.getItem('logState') as string;
+      return state == null ? { logViewConfig: [] } : JSON.parse(state);
+    } catch (e) {
+      console.error(e);
+      return { logViewConfig: [] };
+    }
+  }
+
+  setState(state: State): void {
+    localStorage.setItem('logState', JSON.stringify(state));
+  }
+}