MD History: Move queryState to be managed by history-router

chrome/browser/resources/md_history/query_manager.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.
+
+Polymer({
+  is: 'history-query-manager',
+
+  properties: {
+    /** @type {QueryState} */
+    queryState: {
+      type: Object,
+      notify: true,
+    },
+
+    groupedRange_: {
+      type: Number,
+      // Use a computed property to be able to compare old and new values.
+      computed: 'computeGroupedRange_(queryState.range)',
+    },
+
+    /** @type {QueryResult} */
+    queryResult: Object,
+  },
+
+  observers: [
+    'searchTermChanged_(queryState.searchTerm)',
+    'groupedOffsetChanged_(queryState.groupedOffset)',
+  ],
+
+  /** @private {?function(!Event)} */
+  boundOnQueryHistory_: null,
+
+  /** @override */
+  attached: function() {
+    this.boundOnQueryHistory_ = this.onQueryHistory_.bind(this);
+    document.addEventListener('query-history', this.boundOnQueryHistory_);
+  },
+
+  /** @override */
+  detached: function() {
+    document.removeEventListener('query-history', this.boundOnQueryHistory_);
+  },
+
+  /**
+   * @param {boolean} incremental
+   * @private
+   */
+  queryHistory_: function(incremental) {
+    var queryState = this.queryState;
+    // Disable querying until the first set of results have been returned. If
+    // there is a search, query immediately to support search query params from
+    // the URL.
+    var noResults = !this.queryResult || this.queryResult.results == null;
+    if (queryState.queryingDisabled ||
+        (!this.queryState.searchTerm && noResults)) {
+      return;
+    }
+
+    this.set('queryState.querying', true);
+    this.set('queryState.incremental', incremental);
+
+    var lastVisitTime = 0;
+    if (incremental) {
+      var lastVisit = this.queryResult.results.slice(-1)[0];
+      lastVisitTime = lastVisit ? Math.floor(lastVisit.time) : 0;
+    }
+
+    var maxResults =
+        this.queryState.range == HistoryRange.ALL_TIME ? RESULTS_PER_PAGE : 0;
+
+    chrome.send('queryHistory', [
+      queryState.searchTerm,
+      queryState.groupedOffset,
+      queryState.range,
+      lastVisitTime,
+      maxResults,
+    ]);
+  },
+
+  /**
+   * @param {!Event} e
+   * @private
+   */
+  onQueryHistory_: function(e) {
+    this.queryHistory_(/** @type {boolean} */ e.detail);
+    return false;
+  },
+
+  /** @private */
+  groupedOffsetChanged_: function() {
+    this.queryHistory_(false);
+  },
+
+  /**
+   * @param {HistoryRange} range
+   * @return {HistoryRange}
+   * @private
+   */
+  computeGroupedRange_: function(range) {
+    if (this.groupedRange_ != undefined) {
+      this.set('queryState.groupedOffset', 0);
+
+      this.queryHistory_(false);
+      this.fire('history-view-changed');
+    }
+
+    return range;
+  },
+
+  /** @private */
+  searchTermChanged_: function() {
+    this.queryHistory_(false);
+    // TODO(tsergeant): Ignore incremental searches in this metric.
+    if (this.queryState.searchTerm)
+      md_history.BrowserService.getInstance().recordAction('Search');
+  },
+});