MD Bookmarks: Allow 'complex' actions to access the page state directly

chrome/browser/resources/md_bookmarks/complex_actions.js

+// 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.
+
+/**
+ * @fileoverview Module for functions which produce Action objects based on
+ * complex logic and/or relying on the page state.
+ *
+ * All functions in this file should have a counterpart in actions.js
+ * which does not depend on State (removeBookmark vs removeBookmarkSubtree).
+ * Functions in complex_actions.js should be unit tested, while functions in
+ * actions.js are suitable for use in other test files (eg, reducers_test.js).
+ */
+
+cr.define('bookmarks.actions', function() {
+  /** @return {BookmarksPageState} */
+  function getState() {
+    return bookmarks.Store.getInstance().data;
+  }
+
+  /**
+   * @param {string} id
+   * @param {string} parentId
+   * @param {number} index
+   */
+  function removeBookmark(id, parentId, index) {
+    var descendants = bookmarks.util.getDescendants(getState().nodes, id);
+    return bookmarks.actions.removeBookmarkSubtree(
+        id, parentId, index, descendants);
+  }
+
+  /**
+   * @param {string} id
+   * @param {boolean} add
+   * @param {boolean} range
+   * @return {!Action}
+   */
+  function selectItem(id, add, range) {
+    var anchor = getState().selection.anchor;
+    var toSelect = [];
+
+    // TODO(tsergeant): Make it possible to deselect items by ctrl-clicking them
+    // again.
+    if (range && anchor) {
+      var displayedList = bookmarks.util.getDisplayedList(getState());
+      var selectedIndex = displayedList.indexOf(id);
+      assert(selectedIndex != -1);
+      var anchorIndex = displayedList.indexOf(anchor);
+      if (anchorIndex == -1)
+        anchorIndex = selectedIndex;
+
+      var startIndex = Math.min(anchorIndex, selectedIndex);
+      var endIndex = Math.max(anchorIndex, selectedIndex);
+
+      for (var i = startIndex; i <= endIndex; i++)
+        toSelect.push(displayedList[i]);
+    } else {
+      toSelect.push(id);
+    }
+
+    return bookmarks.actions.selectItemSet(toSelect, id, add);
+  }
+
+  return {
+    removeBookmark: removeBookmark,
+    selectItem: selectItem,
+  };
+});