Refactor print preview web ui

chrome/browser/resources/print_preview/preview_area.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';
-
-  /**
-   * Creates a PreviewArea object. It represents the area where the preview
-   * document is displayed.
-   * @constructor
-   */
-  function PreviewArea() {
-    // The embedded pdf plugin object.
-    this.pdfPlugin_ = null;
-
-    // @type {HTMLDivElement} A layer on top of |this.pdfPlugin_| used for
-    // displaying messages to the user.
-    this.overlayLayer = $('overlay-layer');
-    // @type {HTMLDivElement} Contains text displayed to the user followed by
-    // three animated dots.
-    this.customMessageWithDots_ = $('custom-message-with-dots');
-    // @type {HTMLDivElement} Contains text displayed to the user.
-    this.customMessage_ = $('custom-message');
-    // @type {HTMLInputElement} Button associated with a displayed error
-    // message.
-    this.errorButton = $('error-button');
-    // @type {HTMLDivElement} Contains three animated (dancing) dots.
-    this.dancingDotsText = $('dancing-dots-text');
-
-    // True if the pdf document is loaded in the preview area.
-    this.pdfLoaded_ = false;
-
-    // Contains the zoom level just before a new preview is requested so the
-    // same zoom level can be restored.
-    this.zoomLevel_ = null;
-    // @type {{x: number, y: number}} Contains the page offset values just
-    //     before a new preview is requested so that the scroll amount can be
-    //     restored later.
-    this.pageOffset_ = null;
-    // @type {print_preview.Rect} A rectangle describing the postion of the
-    // most visible page normalized with respect to the total height and width
-    // of the plugin.
-    this.pageLocationNormalized = null;
-
-    // @type {EventTracker} Used to keep track of certain event listeners.
-    this.eventTracker = new EventTracker();
-
-    this.addEventListeners_();
-  }
-
-  cr.addSingletonGetter(PreviewArea);
-
-  PreviewArea.prototype = {
-    /**
-     * The width of the plugin area in pixels, excluding any visible scrollbars,
-     * @type {number}
-     */
-    get width() {
-      return this.widthPercent * this.pdfPlugin_.offsetWidth;
-    },
-
-    /**
-     * The height of the plugin area in pixels, excluding any visible
-     *     scrollbars.
-     * @type {number}
-     */
-    get height() {
-      return this.heightPercent * this.pdfPlugin_.offsetHeight;
-    },
-
-    /**
-     * The width of the plugin area in percent, excluding any visible
-     *     scrollbars.
-     * @type {number}
-     */
-    get widthPercent() {
-      var width = this.pdfPlugin_.getWidth();
-      var scrollbarWidth = this.pdfPlugin_.getVerticalScrollbarThickness();
-      return (width - scrollbarWidth) / width;
-    },
-
-    /**
-     * The height of the plugin area in percent, excluding any visible
-     *     scrollbars.
-     * @type {number}
-     */
-    get heightPercent() {
-      var height = this.pdfPlugin_.getHeight();
-      var scrollbarHeight = this.pdfPlugin_.getHorizontalScrollbarThickness();
-      return (height - scrollbarHeight) / height;
-    },
-
-    get pdfPlugin() {
-      return this.pdfPlugin_;
-    },
-
-    get pdfLoaded() {
-      return this.pdfLoaded_;
-    },
-
-    set pdfLoaded(pdfLoaded) {
-      this.pdfLoaded_ = pdfLoaded;
-    },
-
-    /**
-     * Initializes the PDF plugin and places it on the page.
-     * @param {!string} srcURL The URL of the document to be loaded in the
-     *     plugin.
-     * @private
-     */
-    createPDFPlugin_: function(srcURL) {
-      this.pdfPlugin_ = document.createElement('embed');
-      this.pdfPlugin_.setAttribute('id', 'pdf-viewer');
-      this.pdfPlugin_.setAttribute(
-          'type', 'application/x-google-chrome-print-preview-pdf');
-      this.pdfPlugin_.setAttribute('src', srcURL);
-      this.pdfPlugin_.setAttribute('aria-live', 'polite');
-      this.pdfPlugin_.setAttribute('aria-atomic', 'true');
-      $('mainview').appendChild(this.pdfPlugin_);
-
-      this.pdfPlugin_.onload('onPDFLoad()');
-      this.pdfPlugin_.onScroll('onPreviewPositionChanged()');
-      this.pdfPlugin_.onPluginSizeChanged('onPreviewPositionChanged()');
-      this.pdfPlugin_.removePrintButton();
-      this.pdfPlugin_.grayscale(true);
-    },
-
-    /**
-     * Reloads the plugin with a new url.
-     * @param {string} srcURL The URL to load in the plugin.
-     * @private
-     */
-    reloadPDFPlugin_: function(srcURL) {
-      // Need to call this before the reload(), where the plugin resets its
-      // internal page count.
-      this.pdfPlugin_.goToPage('0');
-      this.pdfPlugin_.resetPrintPreviewUrl(srcURL);
-      this.pdfPlugin_.reload();
-      this.pdfPlugin_.grayscale(
-          colorSettings.colorMode == print_preview.ColorSettings.GRAY);
-    },
-
-    /**
-     * Creates the PDF plugin or reloads the existing one.
-     * @param {number} srcDataIndex Preview data source index.
-     */
-    createOrReloadPDFPlugin: function(srcDataIndex) {
-      var srcURL = getPageSrcURL(currentPreviewUid, srcDataIndex);
-      this.pdfPlugin_ ? this.reloadPDFPlugin_(srcURL) :
-          this.createPDFPlugin_(srcURL);
-    },
-
-    /**
-     * Queries the plugin for the location of the most visible page and updates
-     * |this.pageLocationNormalized|.
-     */
-    update: function() {
-      if (!this.pdfLoaded_)
-        return;
-      var pluginLocation =
-          this.pdfPlugin_.getPageLocationNormalized().split(';');
-      this.pageLocationNormalized = new print_preview.Rect(
-          parseFloat(pluginLocation[0]),
-          parseFloat(pluginLocation[1]),
-          parseFloat(pluginLocation[2]),
-          parseFloat(pluginLocation[3]));
-    },
-
-    /**
-     * Resets the state variables of |this|.
-     */
-    resetState: function() {
-      if (this.pdfPlugin_) {
-        this.zoomLevel_ = this.pdfPlugin_.getZoomLevel();
-        this.pageOffset_ = {
-            x: this.pdfPlugin_.pageXOffset(),
-            y: this.pdfPlugin_.pageYOffset()
-        };
-      }
-      this.pdfLoaded_ = false;
-    },
-
-    /**
-     * Adds event listeners for various events.
-     * @private
-     */
-    addEventListeners_: function() {
-      document.addEventListener(customEvents.PDF_LOADED,
-                                this.onPDFLoaded_.bind(this));
-    },
-
-    /**
-     * Listener executing when a |customEvents.PDF_LOADED| event occurs.
-     * @private
-     */
-    onPDFLoaded_: function() {
-      this.pdfPlugin_ = $('pdf-viewer');
-      this.pdfLoaded_ = true;
-      if (this.zoomLevel_ != null && this.pageOffset_ != null) {
-        this.pdfPlugin_.setZoomLevel(this.zoomLevel_);
-        this.pdfPlugin_.setPageXOffset(this.pageOffset_.x);
-        this.pdfPlugin_.setPageYOffset(this.pageOffset_.y);
-      } else {
-        this.pdfPlugin_.fitToHeight();
-      }
-    },
-
-    /**
-     * Hides the |this.overlayLayer| and any messages currently displayed.
-     */
-    hideOverlayLayer: function() {
-      this.eventTracker.add(this.overlayLayer, 'webkitTransitionEnd',
-          this.hideOverlayLayerCleanup_.bind(this), false);
-      if (this.pdfPlugin_)
-        this.pdfPlugin_.classList.remove('invisible');
-      this.overlayLayer.classList.add('invisible');
-    },
-
-    /**
-     * Displays the "Preview loading..." animation.
-     */
-    showLoadingAnimation: function() {
-      this.showCustomMessage(localStrings.getString('loading'));
-    },
-
-    /**
-     * Necessary cleanup so that the dancing dots animation is not being
-     * rendered in the background when not displayed.
-     */
-    hideOverlayLayerCleanup_: function() {
-      this.customMessageWithDots_.hidden = true;
-      this.eventTracker.remove(this.overlayLayer, 'webkitTransitionEnd');
-    },
-
-    /**
-     * Displays |message| followed by three dancing dots animation.
-     * @param {string} message The message to be displayed.
-     */
-    showCustomMessage: function(message) {
-      this.customMessageWithDots_.innerHTML = message +
-          this.dancingDotsText.innerHTML;
-      this.customMessageWithDots_.hidden = false;
-      if (this.pdfPlugin_)
-        this.pdfPlugin_.classList.add('invisible');
-      this.overlayLayer.classList.remove('invisible');
-    },
-
-    /**
-     * Clears the custom message with dots animation.
-     */
-    clearCustomMessageWithDots: function() {
-      this.customMessageWithDots_.innerHTML = '';
-      this.customMessageWithDots_.hidden = true;
-    },
-
-    /**
-     * Display an error message in the center of the preview area.
-     * @param {string} errorMessage The error message to be displayed.
-     */
-    displayErrorMessageAndNotify: function(errorMessage) {
-      this.overlayLayer.classList.remove('invisible');
-      this.customMessage_.textContent = errorMessage;
-      this.customMessage_.hidden = false;
-      this.customMessageWithDots_.innerHTML = '';
-      this.customMessageWithDots_.hidden = true;
-      if (this.pdfPlugin_) {
-        $('mainview').removeChild(this.pdfPlugin_);
-        this.pdfPlugin_ = null;
-      }
-      cr.dispatchSimpleEvent(document, customEvents.PDF_GENERATION_ERROR);
-    },
-
-    /**
-     * Display an error message in the center of the preview area followed by a
-     * button.
-     * @param {string} errorMessage The error message to be displayed.
-     * @param {string} buttonText The text to be displayed within the button.
-     * @param {string} buttonListener The listener to be executed when the
-     *     button is clicked.
-     */
-    displayErrorMessageWithButtonAndNotify: function(
-        errorMessage, buttonText, buttonListener) {
-      this.errorButton.disabled = false;
-      this.errorButton.textContent = buttonText;
-      this.errorButton.onclick = buttonListener;
-      this.errorButton.hidden = false;
-      $('system-dialog-throbber').hidden = true;
-      $('native-print-dialog-throbber').hidden = true;
-      if (cr.isMac)
-        $('open-preview-app-throbber').hidden = true;
-      this.displayErrorMessageAndNotify(errorMessage);
-    }
-  };
-
-  return {
-    PreviewArea: PreviewArea
-  };
-});