MD Bookmarks: Remove old bookmark data store

chrome/browser/resources/md_bookmarks/store.js

-// Copyright 2016 The Chromium Authors. All rights reserved.
+// Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-var BookmarksStore = Polymer({
-  is: 'bookmarks-store',
+/**
+ * @fileoverview A singleton datastore for the Bookmarks page. Page state is
+ * publicly readable, but can only be modified by dispatching an Action to
+ * the store.
+ */
 
-  properties: {
-    /** @type {BookmarkTreeNode} */
-    rootNode: {
-      type: Object,
-      notify: true,
+cr.define('bookmarks', function() {
+  /** @constructor */
+  function Store() {
+    /** @type {!BookmarksPageState} */
+    this.data_ = bookmarks.util.createEmptyState();
+    /** @type {boolean} */
+    this.initialized_ = false;
+    /** @type {!Array<!Action>} */
+    this.queuedActions_ = [];
+    /** @type {!Array<!StoreObserver>} */
+    this.observers_ = [];
+  }
+
+  Store.prototype = {
+    /**
+     * @param {!BookmarksPageState} initialState
+     */
+    init: function(initialState) {
+      this.data_ = initialState;
+
+      this.queuedActions_.forEach(function(action) {
+        this.reduce_(action);
+      }.bind(this));
+
+      this.initialized_ = true;
+      this.notifyObservers_(this.data_);
     },
 
-    /** @type {?string} */
-    selectedId: {
-      type: String,
-      observer: 'updateSelectedDisplay_',
-      notify: true,
+    /** @type {!BookmarksPageState} */
+    get data() {
+      return this.data_;
     },
 
-    searchTerm: {
-      type: String,
-      value: '',
-      observer: 'updateSearchDisplay_',
-      notify: true,
+    /** @return {boolean} */
+    isInitialized: function() {
+      return this.initialized_;
+    },
+
+    /** @param {!StoreObserver} observer */
+    addObserver: function(observer) {
+      this.observers_.push(observer);
+    },
+
+    /** @param {!StoreObserver} observer */
+    removeObserver: function(observer) {
+      var index = this.observers_.indexOf(observer);
+      this.observers_.splice(index, 1);
     },
 
     /**
-     * This updates to either the result of a search or the contents of the
-     * selected folder.
-     * @type {Array<BookmarkTreeNode>}
+     * Transition to a new UI state based on the supplied |action|, and notify
+     * observers of the change. If the Store has not yet been initialized, the
+     * action will be queued and performed upon initialization.
+     * @param {Action} action
      */
-    displayedList: {
-      type: Array,
-      notify: true,
-      readOnly: true,
+    handleAction: function(action) {
+      if (!this.initialized_) {
+        this.queuedActions_.push(action);
+        return;
+      }
+
+      this.reduce_(action);
+      this.notifyObservers_(this.data_);
     },
 
-    /** @type {Object<?string, !BookmarkTreeNode>} */
-    idToNodeMap_: Object,
+    /**
+     * @param {Action} action
+     * @private
+     */
+    reduce_: function(action) {
+      this.data_ = bookmarks.reduceAction(this.data_, action);
+    },
 
-    /** @type {?number} */
-    anchorIndex_: Number,
+    /**
+     * @param {!BookmarksPageState} state
+     * @private
+     */
+    notifyObservers_: function(state) {
+      this.observers_.forEach(function(o) {
+        o.onStateChanged(state);
+      });
+    },
+  };
 
-    /** @type {Set<string>} */
-    searchResultSet_: Object,
-  },
+  cr.addSingletonGetter(Store);
 
-  /** @private {Object} */
-  documentListeners_: null,
-
-  /** @override */
-  attached: function() {
-    this.documentListeners_ = {
-      'folder-open-changed': this.onFolderOpenChanged_.bind(this),
-      'search-term-changed': this.onSearchTermChanged_.bind(this),
-      'select-item': this.onItemSelected_.bind(this),
-      'selected-folder-changed': this.onSelectedFolderChanged_.bind(this),
-    };
-    for (var event in this.documentListeners_)
-      document.addEventListener(event, this.documentListeners_[event]);
-  },
-
-  /** @override */
-  detached: function() {
-    for (var event in this.documentListeners_)
-      document.removeEventListener(event, this.documentListeners_[event]);
-  },
-
-  /**
-   * Initializes the store with data from the bookmarks API.
-   * Called by app on attached.
-   */
-  initializeStore: function() {
-    chrome.bookmarks.getTree(function(results) {
-      this.setupStore_(results[0]);
-    }.bind(this));
-    // Attach bookmarks API listeners.
-    chrome.bookmarks.onRemoved.addListener(this.onBookmarkRemoved_.bind(this));
-    chrome.bookmarks.onChanged.addListener(this.onBookmarkChanged_.bind(this));
-    chrome.bookmarks.onImportBegan.addListener(this.onImportBegan_.bind(this));
-    chrome.bookmarks.onImportEnded.addListener(this.onImportEnded_.bind(this));
-  },
-
-  //////////////////////////////////////////////////////////////////////////////
-  // bookmarks-store, private:
-
-  /**
-   * @param {BookmarkTreeNode} rootNode
-   * @private
-   */
-  setupStore_: function(rootNode) {
-    this.rootNode = rootNode;
-    this.idToNodeMap_ = {};
-    this.rootNode.path = 'rootNode';
-    BookmarksStore.generatePaths(rootNode, 0);
-    BookmarksStore.initNodes(this.rootNode, this.idToNodeMap_);
-
-    // Initialize the store's fields from the router.
-    if (this.$.router.searchTerm)
-      this.searchTerm = this.$.router.searchTerm;
-    else
-      this.fire('selected-folder-changed', this.$.router.selectedId);
-  },
-
-  /** @private */
-  deselectFolders_: function() {
-    this.unlinkPaths('displayedList');
-    this.set(
-        this.idToNodeMap_[this.selectedId].path + '.isSelectedFolder', false);
-    this.selectedId = null;
-  },
-
-  /**
-   * @param {BookmarkTreeNode} folder
-   * @private
-   * @return {boolean}
-   */
-  isAncestorOfSelected_: function(folder) {
-    if (!this.selectedId)
-      return false;
-
-    var selectedNode = this.idToNodeMap_[this.selectedId];
-    return selectedNode.path.startsWith(folder.path);
-  },
-
-  /** @private */
-  updateSearchDisplay_: function() {
-    if (!this.rootNode)
-      return;
-
-    if (!this.searchTerm) {
-      this.fire('selected-folder-changed', this.rootNode.children[0].id);
-    } else {
-      chrome.bookmarks.search(this.searchTerm, function(results) {
-        this.anchorIndex_ = null;
-        this.clearSelectedItems_();
-        this.searchResultSet_ = new Set();
-
-        if (this.selectedId)
-          this.deselectFolders_();
-
-        this.setupSearchResults_(results);
-      }.bind(this));
-    }
-  },
-
-  /** @private */
-  updateSelectedDisplay_: function() {
-    // Don't change to the selected display if ID was cleared.
-    if (!this.selectedId)
-      return;
-
-    this.clearSelectedItems_();
-    this.anchorIndex_ = null;
-
-    var selectedNode = this.idToNodeMap_[this.selectedId];
-    this.linkPaths('displayedList', selectedNode.path + '.children');
-    this._setDisplayedList(
-        /** @type {Array<BookmarkTreeNode>} */ (selectedNode.children));
-  },
-
-  /**
-   * Remove all descendants of a given node from the map.
-   * @param {string} id
-   * @private
-   */
-  removeDescendantsFromMap_: function(id) {
-    var node = this.idToNodeMap_[id];
-    if (!node)
-      return;
-
-    if (node.children) {
-      for (var i = 0; i < node.children.length; i++)
-        this.removeDescendantsFromMap_(node.children[i].id);
-    }
-    delete this.idToNodeMap_[id];
-  },
-
-  /**
-   * Remove all selected items in the list.
-   * @private
-   */
-  clearSelectedItems_: function() {
-    if (!this.displayedList)
-      return;
-
-    for (var i = 0; i < this.displayedList.length; i++) {
-      if (!this.displayedList[i].isSelectedItem)
-        continue;
-
-      this.set('displayedList.#' + i + '.isSelectedItem', false);
-    }
-  },
-
-  /**
-   * Return the index in the search result of an item.
-   * @param {BookmarkTreeNode} item
-   * @return {number}
-   * @private
-   */
-  getIndexInList_: function(item) {
-    return this.searchTerm ? item.searchResultIndex : item.index;
-  },
-
-  /**
-   * @param {string} id
-   * @return {boolean}
-   * @private
-   */
-  isInDisplayedList_: function(id) {
-    return this.searchTerm ? this.searchResultSet_.has(id) :
-                             this.idToNodeMap_[id].parentId == this.selectedId;
-  },
-
-  /**
-   * Initializes the search results returned by the API as follows:
-   * - Populates |searchResultSet_| with a mapping of all result ids to
-   *   their corresponding result.
-   * - Sets up the |searchResultIndex|.
-   * @param {Array<BookmarkTreeNode>} results
-   * @private
-   */
-  setupSearchResults_: function(results) {
-    for (var i = 0; i < results.length; i++) {
-      results[i].searchResultIndex = i;
-      results[i].isSelectedItem = false;
-      this.searchResultSet_.add(results[i].id);
-    }
-
-    this._setDisplayedList(results);
-  },
-
-  /**
-   * Select multiple items based on |anchorIndex_| and the selected
-   * item. If |anchorIndex_| is not set, single select the item.
-   * @param {BookmarkTreeNode} item
-   * @private
-   */
-  selectRange_: function(item) {
-    var startIndex, endIndex;
-    if (this.anchorIndex_ == null) {
-      this.anchorIndex_ = this.getIndexInList_(item);
-      startIndex = this.anchorIndex_;
-      endIndex = this.anchorIndex_;
-    } else {
-      var selectedIndex = this.getIndexInList_(item);
-      startIndex = Math.min(this.anchorIndex_, selectedIndex);
-      endIndex = Math.max(this.anchorIndex_, selectedIndex);
-    }
-    for (var i = startIndex; i <= endIndex; i++)
-      this.set('displayedList.#' + i + '.isSelectedItem', true);
-  },
-
-  /**
-   * Selects a single item in the displayedList.
-   * @param {BookmarkTreeNode} item
-   * @private
-   */
-  selectItem_: function(item) {
-    this.anchorIndex_ = this.getIndexInList_(item);
-    this.set('displayedList.#' + this.anchorIndex_ + '.isSelectedItem', true);
-  },
-
-  //////////////////////////////////////////////////////////////////////////////
-  // bookmarks-store, bookmarks API event listeners:
-
-  /**
-   * Callback for when a bookmark node is removed.
-   * If a folder is selected or is an ancestor of a selected folder, the parent
-   * of the removed folder will be selected.
-   * @param {string} id The id of the removed bookmark node.
-   * @param {!{index: number,
-   *           parentId: string,
-   *           node: BookmarkTreeNode}} removeInfo
-   */
-  onBookmarkRemoved_: function(id, removeInfo) {
-    chrome.bookmarks.getSubTree(removeInfo.parentId, function(parentNodes) {
-      var parentNode = parentNodes[0];
-      var isAncestor = this.isAncestorOfSelected_(this.idToNodeMap_[id]);
-      var wasInDisplayedList = this.isInDisplayedList_(id);
-
-      // Refresh the parent node's data from the backend as its children's
-      // indexes will have changed and Polymer doesn't update them.
-      this.removeDescendantsFromMap_(id);
-      parentNode.path = this.idToNodeMap_[parentNode.id].path;
-      BookmarksStore.generatePaths(parentNode, 0);
-      BookmarksStore.initNodes(parentNode, this.idToNodeMap_);
-      this.set(parentNode.path, parentNode);
-
-      // Updates selectedId if the removed node is an ancestor of the current
-      // selected node.
-      if (isAncestor)
-        this.fire('selected-folder-changed', removeInfo.parentId);
-
-      // Only update the displayedList if the removed node is in the
-      // displayedList.
-      if (!wasInDisplayedList)
-        return;
-
-      this.anchorIndex_ = null;
-
-      // Update the currently displayed list.
-      if (this.searchTerm) {
-        this.updateSearchDisplay_();
-      } else {
-        if (!isAncestor)
-          this.fire('selected-folder-changed', this.selectedId);
-
-        this._setDisplayedList(parentNode.children);
-      }
-    }.bind(this));
-  },
-
-  /**
-   * Called when the title of a bookmark changes.
-   * @param {string} id The id of changed bookmark node.
-   * @param {!Object} changeInfo
-   */
-  onBookmarkChanged_: function(id, changeInfo) {
-    if (changeInfo.title)
-      this.set(this.idToNodeMap_[id].path + '.title', changeInfo.title);
-    if (changeInfo.url)
-      this.set(this.idToNodeMap_[id].path + '.url', changeInfo.url);
-
-    if (this.searchTerm)
-      this.updateSearchDisplay_();
-  },
-
-  /**
-   * Called when importing bookmark is started.
-   */
-  onImportBegan_: function() {
-    // TODO(rongjie): pause onCreated once this event is used.
-  },
-
-  /**
-   * Called when importing bookmark node is finished.
-   */
-  onImportEnded_: function() {
-    chrome.bookmarks.getTree(function(results) {
-      this.setupStore_(results[0]);
-      this.updateSelectedDisplay_();
-    }.bind(this));
-  },
-
-  //////////////////////////////////////////////////////////////////////////////
-  // bookmarks-store, bookmarks app event listeners:
-
-  /**
-   * @param {Event} e
-   * @private
-   */
-  onSearchTermChanged_: function(e) {
-    this.searchTerm = /** @type {string} */ (e.detail);
-  },
-
-  /**
-   * Selects the folder specified by the event and deselects the previously
-   * selected folder.
-   * @param {CustomEvent} e
-   * @private
-   */
-  onSelectedFolderChanged_: function(e) {
-    if (this.searchTerm)
-      this.searchTerm = '';
-
-    // Deselect the old folder if defined.
-    if (this.selectedId && this.idToNodeMap_[this.selectedId])
-      this.set(
-          this.idToNodeMap_[this.selectedId].path + '.isSelectedFolder', false);
-
-    // Check if the selected id is that of a defined folder.
-    var id = /** @type {string} */ (e.detail);
-    if (!this.idToNodeMap_[id] || this.idToNodeMap_[id].url)
-      id = this.rootNode.children[0].id;
-
-    var folder = this.idToNodeMap_[id];
-    this.set(folder.path + '.isSelectedFolder', true);
-    this.selectedId = id;
-
-    if (folder.id == this.rootNode.id)
-      return;
-
-    var parent = this.idToNodeMap_[/** @type {?string} */ (folder.parentId)];
-    while (parent) {
-      if (!parent.isOpen) {
-        this.fire('folder-open-changed', {
-          id: parent.id,
-          open: true,
-        });
-      }
-
-      parent = this.idToNodeMap_[/** @type {?string} */ (parent.parentId)];
-    }
-  },
-
-  /**
-   * Handles events that open and close folders.
-   * @param {CustomEvent} e
-   * @private
-   */
-  onFolderOpenChanged_: function(e) {
-    var folder = this.idToNodeMap_[e.detail.id];
-    this.set(folder.path + '.isOpen', e.detail.open);
-    if (!folder.isOpen && this.isAncestorOfSelected_(folder))
-      this.fire('selected-folder-changed', folder.id);
-  },
-
-  /**
-   * Selects items according to keyboard behaviours.
-   * @param {CustomEvent} e
-   * @private
-   */
-  onItemSelected_: function(e) {
-    if (!e.detail.add)
-      this.clearSelectedItems_();
-
-    if (e.detail.range)
-      this.selectRange_(e.detail.item);
-    else
-      this.selectItem_(e.detail.item);
-  },
+  return {
+    Store: Store,
+  };
 });
-
-////////////////////////////////////////////////////////////////////////////////
-// bookmarks-store, static methods:
-
-/**
- * Stores the path from the store to a node inside the node.
- * @param {BookmarkTreeNode} bookmarkNode
- * @param {number} startIndex
- */
-BookmarksStore.generatePaths = function(bookmarkNode, startIndex) {
-  if (!bookmarkNode.children)
-    return;
-
-  for (var i = startIndex; i < bookmarkNode.children.length; i++) {
-    bookmarkNode.children[i].path = bookmarkNode.path + '.children.#' + i;
-    BookmarksStore.generatePaths(bookmarkNode.children[i], 0);
-  }
-};
-
-/**
- * Initializes the nodes in the bookmarks tree as follows:
- * - Populates |idToNodeMap_| with a mapping of all node ids to their
- *   corresponding BookmarkTreeNode.
- * - Sets all the nodes to not selected and open by default.
- * @param {BookmarkTreeNode} bookmarkNode
- * @param {Object=} idToNodeMap
- */
-BookmarksStore.initNodes = function(bookmarkNode, idToNodeMap) {
-  bookmarkNode.isSelectedItem = false;
-  if (idToNodeMap)
-    idToNodeMap[bookmarkNode.id] = bookmarkNode;
-
-  if (bookmarkNode.url)
-    return;
-
-  bookmarkNode.isSelectedFolder = false;
-  bookmarkNode.isOpen = true;
-  for (var i = 0; i < bookmarkNode.children.length; i++)
-    BookmarksStore.initNodes(bookmarkNode.children[i], idToNodeMap);
-};