downloads: break downloads.js into more classes/files.

chrome/browser/resources/downloads/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.
+
+cr.define('downloads', function() {
+  /**
+   * Class to own and manage download items.
+   * @constructor
+   */
+  function Manager() {}
+
+  cr.addSingletonGetter(Manager);
+
+  Manager.prototype = {
+    /** @private {string} */
+    searchText_: '',
+
+    /**
+     * Sets the search text, updates related UIs, and tells the browser.
+     * @param {string} searchText Text we're searching for.
+     */
+    setSearchText: function(searchText) {
+      this.searchText_ = searchText;
+
+      $('downloads-summary-text').textContent = this.searchText_ ?
+          loadTimeData.getStringF('searchresultsfor', this.searchText_) : '';
+
+      // Split quoted terms (e.g., 'The "lazy" dog' => ['The', 'lazy', 'dog']).
+      function trim(s) { return s.trim(); }
+      chrome.send('getDownloads', searchText.split(/"([^"]*)"/).map(trim));
+    },
+
+    /**
+     * Called when all items need to be updated.
+     * @param {!Array<!downloads.Data>} list A list of new download data.
+     */
+    updateAll: function(list) {
+      var oldIdMap = this.idMap_ || {};
+
+      /** @private {!Object<!downloads.Item>} */
+      this.idMap_ = {};
+
+      /** @private {!Array<!downloads.Item>} */
+      this.items_ = [];
+
+      for (var i = 0; i < list.length; ++i) {
+        var data = list[i];
+        var id = data.id;
+
+        // Re-use old items when possible (saves work, preserves focus).
+        var item = oldIdMap[id] || new downloads.Item;
+
+        this.idMap_[id] = item;  // Associated by ID for fast lookup.
+        this.items_.push(item);  // Add to sorted list for order.
+
+        // Render |item| but don't actually add to the DOM yet. |this.items_|
+        // must be fully created to be able to find the right spot to insert.
+        item.render(data);
+
+        // Collapse redundant dates.
+        var prev = list[i - 1];
+        item.view.dateContainer.hidden =
+            prev && prev.date_string == data.date_string;
+
+        delete oldIdMap[id];
+      }
+
+      // Remove stale, previously rendered items from the DOM.
+      for (var id in oldIdMap) {
+        oldIdMap[id].unrender();
+        delete oldIdMap[id];
+      }
+
+      for (var i = 0; i < this.items_.length; ++i) {
+        var item = this.items_[i];
+        if (item.view.node.parentNode)  // Already in the DOM; skip.
+          continue;
+
+        var before = null;
+        // Find the next rendered item after this one, and insert before it.
+        for (var j = i + 1; !before && j < this.items_.length; ++j) {
+          if (this.items_[j].view.node.parentNode)
+            before = this.items_[j].view.node;
+        }
+        // If |before| is null, |item| will just get added at the end.
+        this.node_.insertBefore(item.view.node, before);
+      }
+
+      var noDownloadsOrResults = $('no-downloads-or-results');
+      noDownloadsOrResults.textContent = loadTimeData.getString(
+          this.searchText_ ? 'no_search_results' : 'no_downloads');
+
+      var hasDownloads = this.size() > 0;
+      this.node_.hidden = !hasDownloads;
+      noDownloadsOrResults.hidden = hasDownloads;
+
+      if (loadTimeData.getBoolean('allow_deleting_history'))
+        $('clear-all').hidden = !hasDownloads || this.searchText_.length > 0;
+
+      this.rebuildFocusGrid_();
+    },
+
+    /** @param {!downloads.Data} data Info about the item to update. */
+    updateItem: function(data) {
+      this.idMap_[data.id].render(data);
+    },
+
+    /**
+     * Rebuild the focusGrid_ using the elements that each download will have.
+     * @private
+     */
+    rebuildFocusGrid_: function() {
+      var activeElement = document.activeElement;
+
+      /** @private {!cr.ui.FocusGrid} */
+      this.focusGrid_ = this.focusGrid_ || new cr.ui.FocusGrid();
+      this.focusGrid_.destroy();
+
+      this.items_.forEach(function(item) {
+        downloads.FocusRow.decorate(item.view.node, item.view, this.node_);
+        var focusRow = assertInstanceof(item.view.node, downloads.FocusRow);
+        this.focusGrid_.addRow(focusRow);
+
+        // Focus the equivalent element in the focusRow because the active
+        // element may no longer be visible.
+        if (focusRow.contains(activeElement))
+          focusRow.getEquivalentElement(activeElement).focus();
+      }, this);
+    },
+
+    /** @return {number} The number of downloads shown on the page. */
+    size: function() {
+      return this.items_.length;
+    },
+
+    clearAll: function() {
+      if (loadTimeData.getBoolean('allow_deleting_history')) {
+        chrome.send('clearAll');
+        this.setSearchText('');
+      }
+    },
+
+    onLoad: function() {
+      this.node_ = $('downloads-display');
+
+      $('clear-all').onclick = function() {
+        this.clearAll();
+      }.bind(this);
+
+      $('open-downloads-folder').onclick = function() {
+        chrome.send('openDownloadsFolder');
+      };
+
+      $('term').onsearch = function(e) {
+        this.setSearchText($('term').value);
+      }.bind(this);
+
+      cr.ui.decorate('command', cr.ui.Command);
+      document.addEventListener('canExecute', this.onCanExecute_.bind(this));
+      document.addEventListener('command', this.onCommand_.bind(this));
+
+      this.setSearchText('');
+
+      chrome.send('onPageLoaded');
+    },
+
+    /**
+     * @param {Event} e
+     * @private
+     */
+    onCanExecute_: function(e) {
+      e = /** @type {cr.ui.CanExecuteEvent} */(e);
+      e.canExecute = document.activeElement != $('term');
+    },
+
+    /**
+     * @param {Event} e
+     * @private
+     */
+    onCommand_: function(e) {
+      if (e.command.id == 'undo-command')
+        chrome.send('undo');
+      else if (e.command.id == 'clear-all-command')
+        this.clearAll();
+    },
+  };
+
+  Manager.updateAll = function(list) {
+    Manager.getInstance().updateAll(list);
+  };
+
+  Manager.updateItem = function(item) {
+    Manager.getInstance().updateItem(item);
+  };
+
+  Manager.setSearchText = function(searchText) {
+    Manager.getInstance().setSearchText(searchText);
+  };
+
+  Manager.onLoad = function() {
+    Manager.getInstance().onLoad();
+  };
+
+  Manager.size = function() {
+    return Manager.getInstance().size();
+  };
+
+  return {Manager: Manager};
+});
+
+window.addEventListener('DOMContentLoaded', downloads.Manager.onLoad);