Implement Store for ordering tags in the tag panel

src/stores/TagOrderStore.js

@@ -0,0 +1,80 @@
+/*
+Copyright 2017 Vector Creations Ltd
+
+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
+
+    http://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 {Store} from 'flux/utils';
+import dis from '../dispatcher';
+// import Analytics from '../Analytics';
+import SettingsStore from "../settings/SettingsStore";
+
+const INITIAL_STATE = {
+    orderedTags: null,
+};
+
+/**
+ * A class for storing application state for ordering tags in the TagPanel.
+ */
+class TagOrderStore extends Store {
+    constructor() {
+        super(dis);
+
+        // Initialise state
+        this._state = INITIAL_STATE;
+    }
+
+    _setState(newState) {
+        this._state = Object.assign(this._state, newState);
+        this.__emitChange();
+    }
+
+    __onDispatch(payload) {
+        switch (payload.action) {
+            case 'sync_state':
+                // Get ordering from account data, once the client has synced
+                if (payload.prevState === "PREPARED" && payload.state === "SYNCING") {
+                    this._setState({
+                        orderedTags: SettingsStore.getValue("TagOrderStore.orderedTags"),
+                    });
+                }
+            break;
+            case 'all_tags':
+                // Initialise the state with all known tags displayed in the TagPanel
+                this._setState({allTags: payload.tags});
+            break;
+            case 'order_tag': {
+                // Puts payload.tag below payload.prevTag in the orderedTags state
+                const tags = SettingsStore.getValue("TagOrderStore.orderedTags") || this._state.allTags;
+                let orderedTags = tags.filter((t) => t !== payload.tag);
+                const tagPrevIx = orderedTags.indexOf(payload.prevTag);
+                orderedTags = [
+                    ...orderedTags.slice(0, tagPrevIx + 1),
+                    payload.tag,
+                    ...orderedTags.slice(tagPrevIx + 1),
+                ];
+                this._setState({orderedTags});
+                SettingsStore.setValue("TagOrderStore.orderedTags", null, "account", orderedTags);
+            }
+            break;
+        }
+    }
+
+    getOrderedTags() {
+        return this._state.orderedTags || SettingsStore.getValue("TagOrderStore.orderedTags");
+    }
+}
+
+if (global.singletonTagOrderStore === undefined) {
+    global.singletonTagOrderStore = new TagOrderStore();
+}
+export default global.singletonTagOrderStore;