chrome/browser/resources/md_downloads/manager.js

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 cr.define('downloads', function() {
   6   var Manager = Polymer({
   7     is: 'downloads-manager',
   8
   9     created: function() {
  10       /** @private {!downloads.ActionService} */
  11       this.actionService_ = new downloads.ActionService;
  12     },
  13
  14     properties: {
  15       hasDownloads_: {
  16         type: Boolean,
  17         value: false,
  18       },
  19     },
  20
  21     ready: function() {
  22       window.addEventListener('resize', this.onResize_.bind(this));
  23       // onResize_() doesn't need to be called immediately here because it's
  24       // guaranteed to be called again shortly when items are received.
  25     },
  26
  27     /**
  28      * @return {number} A guess at how many items could be visible at once.
  29      * @private
  30      */
  31     guesstimateNumberOfVisibleItems_: function() {
  32       var toolbarHeight = this.$.toolbar.offsetHeight;
  33       return Math.floor((window.innerHeight - toolbarHeight) / 46) + 1;
  34     },
  35
  36     /**
  37      * @param {Event} e
  38      * @private
  39      */
  40     onCanExecute_: function(e) {
  41       e = /** @type {cr.ui.CanExecuteEvent} */(e);
  42       switch (e.command.id) {
  43         case 'undo-command':
  44           e.canExecute = this.$.toolbar.canUndo();
  45           break;
  46         case 'clear-all-command':
  47           e.canExecute = this.$.toolbar.canClearAll();
  48           break;
  49       }
  50     },
  51
  52     /**
  53      * @param {Event} e
  54      * @private
  55      */
  56     onCommand_: function(e) {
  57       if (e.command.id == 'clear-all-command')
  58         this.actionService_.clearAll();
  59       else if (e.command.id == 'undo-command')
  60         this.actionService_.undo();
  61     },
  62
  63     /** @private */
  64     onLoad_: function() {
  65       this.$.toolbar.setActionService(this.actionService_);
  66
  67       cr.ui.decorate('command', cr.ui.Command);
  68       document.addEventListener('canExecute', this.onCanExecute_.bind(this));
  69       document.addEventListener('command', this.onCommand_.bind(this));
  70
  71       // Shows all downloads.
  72       this.actionService_.search('');
  73     },
  74
  75     /** @private */
  76     onResize_: function() {
  77       // TODO(dbeam): expose <paper-header-panel>'s #mainContainer in Polymer.
  78       var container = this.$.panel.$.mainContainer;
  79       var scrollbarWidth = container.offsetWidth - container.clientWidth;
  80       this.items_.forEach(function(item) {
  81         item.scrollbarWidth = scrollbarWidth;
  82       });
  83     },
  84
  85     /**
  86      * @return {number} The number of downloads shown on the page.
  87      * @private
  88      */
  89     size_: function() {
  90       return this.items_.length;
  91     },
  92
  93     /**
  94      * Called when all items need to be updated.
  95      * @param {!Array<!downloads.Data>} list A list of new download data.
  96      * @private
  97      */
  98     updateAll_: function(list) {
  99       var oldIdMap = this.idMap_ || {};
 100
 101       /** @private {!Object<!downloads.Item>} */
 102       this.idMap_ = {};
 103
 104       /** @private {!Array<!downloads.Item>} */
 105       this.items_ = [];
 106
 107       if (!this.iconLoader_) {
 108         var guesstimate = Math.max(this.guesstimateNumberOfVisibleItems_(), 1);
 109         /** @private {downloads.ThrottledIconLoader} */
 110         this.iconLoader_ = new downloads.ThrottledIconLoader(guesstimate);
 111       }
 112
 113       for (var i = 0; i < list.length; ++i) {
 114         var data = list[i];
 115         var id = data.id;
 116
 117         // Re-use old items when possible (saves work, preserves focus).
 118         var item = oldIdMap[id] ||
 119             new downloads.Item(this.iconLoader_, this.actionService_);
 120
 121         this.idMap_[id] = item;  // Associated by ID for fast lookup.
 122         this.items_.push(item);  // Add to sorted list for order.
 123
 124         // Render |item| but don't actually add to the DOM yet. |this.items_|
 125         // must be fully created to be able to find the right spot to insert.
 126         item.update(data);
 127
 128         // Collapse redundant dates.
 129         var prev = list[i - 1];
 130         item.hideDate = !!prev && prev.date_string == data.date_string;
 131
 132         delete oldIdMap[id];
 133       }
 134
 135       // Remove stale, previously rendered items from the DOM.
 136       for (var id in oldIdMap) {
 137         if (oldIdMap[id].parentNode)
 138           oldIdMap[id].parentNode.removeChild(oldIdMap[id]);
 139         delete oldIdMap[id];
 140       }
 141
 142       for (var i = 0; i < this.items_.length; ++i) {
 143         var item = this.items_[i];
 144         if (item.parentNode)  // Already in the DOM; skip.
 145           continue;
 146
 147         var before = null;
 148         // Find the next rendered item after this one, and insert before it.
 149         for (var j = i + 1; !before && j < this.items_.length; ++j) {
 150           if (this.items_[j].parentNode)
 151             before = this.items_[j];
 152         }
 153         // If |before| is null, |item| will just get added at the end.
 154         this.$['downloads-list'].insertBefore(item, before);
 155       }
 156
 157       this.hasDownloads_ = this.size_() > 0;
 158
 159       if (loadTimeData.getBoolean('allowDeletingHistory'))
 160         this.$.toolbar.downloadsShowing = this.hasDownloads_;
 161
 162       this.onResize_();
 163     },
 164
 165     /**
 166      * @param {!downloads.Data} data
 167      * @private
 168      */
 169     updateItem_: function(data) {
 170       this.idMap_[data.id].update(data);
 171       this.onResize_();
 172     },
 173   });
 174
 175   Manager.size = function() {
 176     return document.querySelector('downloads-manager').size_();
 177   };
 178
 179   Manager.updateAll = function(list) {
 180     document.querySelector('downloads-manager').updateAll_(list);
 181   };
 182
 183   Manager.updateItem = function(item) {
 184     document.querySelector('downloads-manager').updateItem_(item);
 185   };
 186
 187   Manager.onLoad = function() {
 188     document.querySelector('downloads-manager').onLoad_();
 189   };
 190
 191   return {Manager: Manager};
 192 });
 193
 194 window.addEventListener('load', downloads.Manager.onLoad);