MD History: Refactored design for displaying history information

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]);
-    }
-
-    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.
-   * @param {number} overallItemCount The number of items selected.
-   */
-  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)
-            return;
-        }
-      }
-    }
-  },
-
-  /**
-   * Remove all selected items from the overall array so that they are also
-   * removed from view. Make sure that the card length and positioning is
-   * updated accordingly.
-   * @param {number} overallItemCount The number of items selected.
-   */
-  removeDeletedHistory: function(overallItemCount) {
-    var infiniteList = /** @type {IronListElement} */(this.$['infinite-list']);
-    for (var i = 0; i < this.historyDataByDay_.length; i++) {
-      var items = this.historyDataByDay_[i].historyItems;
-      var itemDeletedFromCard = false;
-
-      for (var j = items.length - 1; j >= 0; j--) {
-        if (!items[j].selected)
-          continue;
-
-        this.splice('historyDataByDay_.' + i + '.historyItems', j, 1);
-        itemDeletedFromCard = true;
-        overallItemCount--;
-        if (overallItemCount == 0) {
-          this.removeEmptyCards_();
-          // If the last card has been removed don't try to update its size.
-          if (i < this.historyDataByDay_.length)
-            infiniteList.updateSizeForItem(i);
-          return;
-        }
-      }
-      if (itemDeletedFromCard)
-        infiniteList.updateSizeForItem(i);
-    }
-  },
-
-  /**
-   * If a day has had all the history it contains removed, remove this day from
-   * the array.
-   * @private
-   */
-  removeEmptyCards_: function() {
-    var historyCards = this.historyDataByDay_;
-    for (var i = historyCards.length - 1; i >= 0; i--) {
-      if (historyCards[i].historyItems.length == 0) {
-        this.splice('historyDataByDay_', i, 1);
-      }
-    }
-  },
-
-  /**
-   * 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
-      });
-    }
-  },
-
-  /**
-   * Based on which items are selected, collect an array of the info required
-   * for chrome.send('removeHistory', ...).
-   * @param {number} count The number of items that are selected.
-   * @return {Array<HistoryEntry>} toBeRemoved An array of objects which contain
-   * information on which history-items should be deleted.
-   */
-  getSelectedItems: function(count) {
-    var toBeRemoved = [];
-    for (var i = 0; i < this.historyDataByDay_.length; i++) {
-      var items = this.historyDataByDay_[i].historyItems;
-      for (var j = 0; j < items.length; j++) {
-        if (items[j].selected) {
-
-          toBeRemoved.push({
-            url: items[j].url,
-            timestamps: items[j].allTimestamps
-          });
-
-          count--;
-          if (count == 0)
-            return toBeRemoved;
-        }
-      }
-    }
-    return toBeRemoved;
-  },
-
-  /**
-   * Called when the card manager is scrolled.
-   * @private
-   */
-  scrollHandler_: function() {
-    // Close overflow menu on scroll.
-    this.closeMenu();
-
-    // Requests the next list of results when the scrollbar is near the bottom
-    // of the window.
-    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]);
-    }
-  }
-});