MD History: Add basic material design history cards and history items

chrome/browser/resources/md_history/history_card_manager.js

+// Copyright 2015 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-card-manager',
+
+  properties: {
+    // An array of objects sorted in reverse chronological order.
+    // Each object has a date and the history items belonging to that date.
+    historyDataByDay_: {
+      type: Array,
+      value: function() { return []; }
+    },
+
+    // The time of access of the last element of historyDataByDay_.
+    lastVisitedTime: {
+      type: Number,
+      value: 0
+    },
+
+    menuOpen: {
+      type: Boolean,
+      value: false,
+      reflectToAttribute: true
+    },
+
+    menuIdentifier: {
+      type: Number,
+      value: 0
+    }
+  },
+
+  /** @const @private */
+  X_OFFSET_: 30,
+
+  listeners: {
+    'tap': 'closeMenu',
+    'toggle-menu': 'toggleMenu_'
+  },
+
+  /**
+   * Closes the overflow menu.
+   */
+  closeMenu: function() {
+    this.menuOpen = false;
+  },
+
+  /**
+   * Opens the overflow menu unless the menu is already open and the same button
+   * is pressed.
+   * @param {Event} e The event with details of the menu item that was clicked.
+   * @private
+   */
+  toggleMenu_: function(e) {
+    var menu = this.$['overflow-menu'];
+
+    // Menu closes if the same button is clicked.
+    if (this.menuOpen && this.menuIdentifier == e.detail.accessTime) {
+      this.closeMenu();
+    } else {
+      this.menuOpen = true;
+      this.menuIdentifier = e.detail.accessTime;
+
+      cr.ui.positionPopupAtPoint(e.detail.x + this.X_OFFSET_, e.detail.y, menu,
+          cr.ui.AnchorType.BEFORE);
+
+      menu.focus();
+    }
+  },
+
+  /**
+   * Split the newly updated history results into history items sorted via day
+   * accessed.
+   * @param {!Array<!HistoryEntry>} results The new history results.
+   */
+  addNewResults: function(results) {
+    if (results.length == 0)
+      return;
+
+    var dateSortedData = [];
+    var historyItems = [];
+    var currentDate = results[0].dateRelativeDay;
+
+    for (var i = 0; i < results.length; i++) {
+      if (!currentDate)
+        continue;
+
+      results[i].selected = false;
+      if (results[i].dateRelativeDay != currentDate) {
+        this.appendHistoryData_(currentDate, historyItems);
+        currentDate = results[i].dateRelativeDay;
+        historyItems = [];
+      }
+      historyItems.push(results[i]);
+    }

[Dan Beam, 2016/01/27 18:20:07]

nit: \n

[yingran, 2016/01/28 00:51:01]

Done.

+    if (currentDate)
+      this.appendHistoryData_(currentDate, historyItems);
+
+    this.lastVisitedTime = historyItems[historyItems.length - 1].time;
+  },
+
+  /**
+   * Cycle through each entry in historyDataByDay_ and set all items to be
+   * unselected.
+   */
+  unselectAllItems: function(overallItemCount) {
+    var historyCardData = this.historyDataByDay_;
+
+    for (var i = 0; i < historyCardData.length; i++) {
+      var items = historyCardData[i].historyItems;
+      for (var j = 0; j < items.length; j++) {
+        if (items[j].selected) {
+          this.set('historyDataByDay_.' + i + '.historyItems.' + j +
+              '.selected', false);
+          overallItemCount--;
+          if (overallItemCount == 0)
+            break;
+        }
+      }
+    }
+  },
+
+  /**
+   * Adds the given items into historyDataByDay_. Adds items to the last
+   * existing day if the date matches, creates a new element otherwise.
+   * @param {string} date The date of the history items.
+   * @param {!Array<!HistoryEntry>} historyItems The list of history items for
+   * the current date.
+   * @private
+   */
+  appendHistoryData_: function(date, historyItems) {
+    var lastDay = this.historyDataByDay_.length - 1;
+    if (lastDay > 0 && date == this.historyDataByDay_[lastDay].date) {
+      this.set('historyDataByDay_.' + lastDay + '.historyItems',
+          this.historyDataByDay_[lastDay].historyItems.concat(historyItems));
+    } else {
+      this.push('historyDataByDay_', {
+        date: date,
+        historyItems: historyItems
+      });
+    }
+  },
+
+  /**
+   * Called when the card manager is scrolled.
+   * @private
+   */
+  scrollHandler_: function() {
+    // Close overflow menu on scroll.
+    this.closeMenu();
+
+    this.loadMoreIfAtEnd_();

[Dan Beam, 2016/01/27 18:20:07]

is loadMoreIfAtEnd_ only called from here?  if so, can we just inline it here
and remove the extra method name?

[yingran, 2016/01/28 00:51:01]

Done.

+  },
+
+  /**
+   * Requests the next list of results when the scrollbar is near the bottom
+   * of the window.
+   * @private
+   */
+  loadMoreIfAtEnd_: function() {
+    var scrollOffset = 10;
+    var scrollElem = this.$['infinite-list'];
+
+    if (scrollElem.scrollHeight <=
+        scrollElem.scrollTop + scrollElem.clientHeight + scrollOffset) {
+      chrome.send('queryHistory',
+          ['', 0, 0, this.lastVisitedTime, RESULTS_PER_PAGE]);
+    }
+  }
+});