1 files changed, 30 insertions, 0 deletions
diff --git a/devtools/client/application/src/reducers/ui-state.js b/devtools/client/application/src/reducers/ui-state.js
new file mode 100644
index 0000000000..81a57c8086
--- /dev/null
+++ b/devtools/client/application/src/reducers/ui-state.js
@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const {
+  DEFAULT_PAGE,
+  UPDATE_SELECTED_PAGE,
+} = require("resource://devtools/client/application/src/constants.js");
+
+function UiState() {
+  return {
+    selectedPage: DEFAULT_PAGE,
+  };
+}
+
+function uiReducer(state = UiState(), action) {
+  switch (action.type) {
+    case UPDATE_SELECTED_PAGE:
+      return Object.assign({}, state, { selectedPage: action.selectedPage });
+    default:
+      return state;
+  }
+}
+
+module.exports = {
+  UiState,
+  uiReducer,
+};