// Copyright 2008 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/**
 * @fileoverview Detects the Adobe Reader PDF browser plugin.
 *
 * @author chrisn@google.com (Chris Nokleberg)
 * @see ../demos/useragent.html
 */

/** @suppress {extraProvide} */
goog.provide('goog.userAgent.adobeReader');

goog.require('goog.string');
goog.require('goog.userAgent');


(function() {
  var version = '';
  if (goog.userAgent.IE) {
    var detectOnIe = function(classId) {
      /** @preserveTry */
      try {
        new ActiveXObject(classId);
        return true;
      } catch (ex) {
        return false;
      }
    };
    if (detectOnIe('AcroPDF.PDF.1')) {
      version = '7';
    } else if (detectOnIe('PDF.PdfCtrl.6')) {
      version = '6';
    }
    // TODO(chrisn): Add detection for previous versions if anyone needs them.
  } else {
    if (navigator.mimeTypes && navigator.mimeTypes.length > 0) {
      var mimeType = navigator.mimeTypes['application/pdf'];
      if (mimeType && mimeType.enabledPlugin) {
        var description = mimeType.enabledPlugin.description;
        if (description && description.indexOf('Adobe') != -1) {
          // Newer plugins do not include the version in the description, so we
          // default to 7.
          version = description.indexOf('Version') != -1 ?
              description.split('Version')[1] :
              '7';
        }
      }
    }
  }

  /**
   * Whether we detect the user has the Adobe Reader browser plugin installed.
   * @type {boolean}
   */
  goog.userAgent.adobeReader.HAS_READER = !!version;


  /**
   * The version of the installed Adobe Reader plugin. Versions after 7
   * will all be reported as '7'.
   * @type {string}
   */
  goog.userAgent.adobeReader.VERSION = version;


  /**
   * On certain combinations of platform/browser/plugin, a print dialog
   * can be shown for PDF files without a download dialog or making the
   * PDF visible to the user, by loading the PDF into a hidden iframe.
   *
   * Currently this variable is true if Adobe Reader version 6 or later
   * is detected on Windows.
   *
   * @type {boolean}
   */
  goog.userAgent.adobeReader.SILENT_PRINT =
      goog.userAgent.WINDOWS && goog.string.compareVersions(version, '6') >= 0;

})();
