Refactor print preview web ui

chrome/browser/resources/print_preview/data/destination_store.js

+// Copyright (c) 2012 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('print_preview', function() {
+  'use strict';
+
+  /**
+   * A data store that stores destinations and dispatches events when the data
+   * store changes.
+   * @constructor
+   * @extends {cr.EventTarget}
+   */
+  function DestinationStore() {
+    cr.EventTarget.call(this);
+
+    /**
+     * Internal backing store for the data store.
+     * @type {!Array.<print_preview.Destination>}
+     * @private
+     */
+    this.destinations_ = [];
+
+    /**
+     * Currently selected destination.
+     * @type {print_preview.Destination}
+     * @private
+     */
+    this.selectedDestination_ = null;
+
+    /**
+     * Initial destination ID used to auto-select the first inserted destination
+     * that matches.
+     * @type {?string}
+     * @private
+     */
+    this.initialDestinationId_ = null;
+
+    /**
+     * Initial destination ID used to auto-select the first inserted destination
+     * that matches. This will be reset when match occurs.
+     * @type {?string}
+     * @private
+     */
+    this.autoSelectDestinationId_ = null;
+  };
+
+  /**
+   * Event types dispatched by the data store.
+   * @enum {string}
+   */
+  DestinationStore.EventType = {
+    DESTINATIONS_INSERTED:
+        'print_preview.DestinationStore.DESTINATIONS_INSERTED',
+    DESTINATION_SELECT: 'print_preview.DestinationStore.DESTINATION_SELECT'
+  };
+
+  DestinationStore.prototype = {
+    __proto__: cr.EventTarget.prototype,
+
+    /**
+     * @return {!Array.<!print_preview.Destination>} List of destinations in
+     *     the store.
+     */
+    get destinations() {
+      return this.destinations_.slice(0);
+    },
+
+    /**
+     * @return {print_preview.Destination} The currently selected destination or
+     *     {@code null} if none is selected.
+     */
+    get selectedDestination() {
+      return this.selectedDestination_;
+    },
+
+    /**
+     * Sets the initially selected destination. If any inserted destinations
+     * match this ID, that destination will be automatically selected. This
+     * occurs only once for every time this setter is called or if the store is
+     * cleared.
+     * @param {string} ID of the destination that should be selected
+     *     automatically when added to the store.
+     */
+    set initialDestinationId(initialDestinationId) {
+      this.initialDestinationId_ = initialDestinationId;
+      this.autoSelectDestinationId_ = initialDestinationId;
+    },
+
+    /** @param {!print_preview.Destination} Destination to select. */
+    selectDestination: function(destination) {
+      if (!destination) {
+        throw Error('Selected destination must not be null nor undefined');
+      }
+      this.selectedDestination_ = destination;
+      this.selectedDestination_.isRecent = true;
+      this.autoSelectDestinationId_ = null;
+      cr.dispatchSimpleEvent(
+          this, DestinationStore.EventType.DESTINATION_SELECT);
+    },
+
+    /**
+     * Inserts a print destination to the data store and dispatches a
+     * DESTINATIONS_INSERTED event. If the destination matches the initial
+     * destination ID, then the destination will be automatically selected.
+     * @param {!print_preview.Destination} destination Print destination to
+     *     insert.
+     */
+    insertDestination: function(destination) {
+      this.destinations_.push(destination);
+      cr.dispatchSimpleEvent(
+          this, DestinationStore.EventType.DESTINATIONS_INSERTED);
+      if (this.autoSelectDestinationId_ != null &&
+          destination.id == this.autoSelectDestinationId_) {
+        this.autoSelectDestinationId_ = null;
+        this.selectDestination(destination);
+      }
+    },
+
+    /**
+     * Inserts multiple print destinations to the data store and dispatches one
+     * DESTINATIONS_INSERTED event. If any of the destinations match the initial
+     * destination ID, then that destination will be automatically selected.
+     * @param {!Array.<print_preview.Destination>} destinations Print
+     *     destinations to insert.
+     */
+    insertDestinations: function(destinations) {
+      this.destinations_ = this.destinations_.concat(destinations);
+      cr.dispatchSimpleEvent(
+          this, DestinationStore.EventType.DESTINATIONS_INSERTED);
+      if (this.autoSelectDestinationId_ != null) {
+        for (var dest, i = 0; dest = destinations[i]; i++) {
+          if (dest.id == this.autoSelectDestinationId_) {
+            this.autoSelectDestinationId_ = null;
+            this.selectDestination(dest);
+            break;
+          }
+        }
+      }
+    },
+
+    /**
+     * Updates an existing print destination with capabilities information.
+     * @param {!print_preview.Destination} destination Destination to update.
+     * @return {!print_preview.Destination} The existing destination that was
+     *     updated.
+     */
+    updateDestination: function(destination) {
+      var existingDestination = null;
+      for (var d, i = 0; d = this.destinations_[i]; i++) {
+        if (destination.id == d.id) {
+          existingDestination = d;
+          break;
+        }
+      }
+      if (existingDestination) {
+        existingDestination.capabilities = destination.capabilities;
+        return existingDestination;
+      } else {
+        throw Error('Print destination not found: ' + destination.id);
+      }
+    },
+
+    /** Clears all print destinations. */
+    clear: function() {
+      this.destinations_ = [];
+      this.selectedDestination_ = null;
+      this.autoSelectDestinationId_ = this.initialDestinationId_;
+    }
+  };
+
+  // Export
+  return {
+    DestinationStore: DestinationStore
+  };
+});