chamilo-lms2/main/inc/lib/javascript/ViewerJS/ui_utils.js

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* Copyright 2012 Mozilla Foundation
 *
 * 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.
 */

'use strict';

// optimised CSS custom property getter/setter
var CustomStyle = (function CustomStyleClosure() {

  // As noted on: http://www.zachstronaut.com/posts/2009/02/17/
  //              animate-css-transforms-firefox-webkit.html
  // in some versions of IE9 it is critical that ms appear in this list
  // before Moz
  var prefixes = ['ms', 'Moz', 'Webkit', 'O'];
  var _cache = { };

  function CustomStyle() {
  }

  CustomStyle.getProp = function get(propName, element) {
    // check cache only when no element is given
    if (arguments.length == 1 && typeof _cache[propName] == 'string') {
      return _cache[propName];
    }

    element = element || document.documentElement;
    var style = element.style, prefixed, uPropName;

    // test standard property first
    if (typeof style[propName] == 'string') {
      return (_cache[propName] = propName);
    }

    // capitalize
    uPropName = propName.charAt(0).toUpperCase() + propName.slice(1);

    // test vendor specific properties
    for (var i = 0, l = prefixes.length; i < l; i++) {
      prefixed = prefixes[i] + uPropName;
      if (typeof style[prefixed] == 'string') {
        return (_cache[propName] = prefixed);
      }
    }

    //if all fails then set to undefined
    return (_cache[propName] = 'undefined');
  };

  CustomStyle.setProp = function set(propName, element, str) {
    var prop = this.getProp(propName);
    if (prop != 'undefined')
      element.style[prop] = str;
  };

  return CustomStyle;
})();

function getFileName(url) {
  var anchor = url.indexOf('#');
  var query = url.indexOf('?');
  var end = Math.min(
    anchor > 0 ? anchor : url.length,
    query > 0 ? query : url.length);
  return url.substring(url.lastIndexOf('/', end) + 1, end);
}

/**
 * Returns scale factor for the canvas. It makes sense for the HiDPI displays.
 * @return {Object} The object with horizontal (sx) and vertical (sy)
                    scales. The scaled property is set to false if scaling is
                    not required, true otherwise.
 */
function getOutputScale(ctx) {
  var devicePixelRatio = window.devicePixelRatio || 1;
  var backingStoreRatio = ctx.webkitBackingStorePixelRatio ||
                          ctx.mozBackingStorePixelRatio ||
                          ctx.msBackingStorePixelRatio ||
                          ctx.oBackingStorePixelRatio ||
                          ctx.backingStorePixelRatio || 1;
  var pixelRatio = devicePixelRatio / backingStoreRatio;
  return {
    sx: pixelRatio,
    sy: pixelRatio,
    scaled: pixelRatio != 1
  };
}

/**
 * Scrolls specified element into view of its parent.
 * element {Object} The element to be visible.
 * spot {Object} An object with optional top and left properties,
 *               specifying the offset from the top left edge.
 */
function scrollIntoView(element, spot) {
  // Assuming offsetParent is available (it's not available when viewer is in
  // hidden iframe or object). We have to scroll: if the offsetParent is not set
  // producing the error. See also animationStartedClosure.
  var parent = element.offsetParent;
  var offsetY = element.offsetTop + element.clientTop;
  var offsetX = element.offsetLeft + element.clientLeft;
  if (!parent) {
    console.error('offsetParent is not set -- cannot scroll');
    return;
  }
  while (parent.clientHeight === parent.scrollHeight) {
    if (parent.dataset._scaleY) {
      offsetY /= parent.dataset._scaleY;
      offsetX /= parent.dataset._scaleX;
    }
    offsetY += parent.offsetTop;
    offsetX += parent.offsetLeft;
    parent = parent.offsetParent;
    if (!parent) {
      return; // no need to scroll
    }
  }
  if (spot) {
    if (spot.top !== undefined) {
      offsetY += spot.top;
    }
    if (spot.left !== undefined) {
      offsetX += spot.left;
      parent.scrollLeft = offsetX;
    }
  }
  parent.scrollTop = offsetY;
}

/**
 * Event handler to suppress context menu.
 */
function noContextMenuHandler(e) {
  e.preventDefault();
}

/**
 * Returns the filename or guessed filename from the url (see issue 3455).
 * url {String} The original PDF location.
 * @return {String} Guessed PDF file name.
 */
function getPDFFileNameFromURL(url) {
  var reURI = /^(?:([^:]+:)?\/\/[^\/]+)?([^?#]*)(\?[^#]*)?(#.*)?$/;
  //            SCHEME      HOST         1.PATH  2.QUERY   3.REF
  // Pattern to get last matching NAME.pdf
  var reFilename = /[^\/?#=]+\.pdf\b(?!.*\.pdf\b)/i;
  var splitURI = reURI.exec(url);
  var suggestedFilename = reFilename.exec(splitURI[1]) ||
                           reFilename.exec(splitURI[2]) ||
                           reFilename.exec(splitURI[3]);
  if (suggestedFilename) {
    suggestedFilename = suggestedFilename[0];
    if (suggestedFilename.indexOf('%') != -1) {
      // URL-encoded %2Fpath%2Fto%2Ffile.pdf should be file.pdf
      try {
        suggestedFilename =
          reFilename.exec(decodeURIComponent(suggestedFilename))[0];
      } catch(e) { // Possible (extremely rare) errors:
        // URIError "Malformed URI", e.g. for "%AA.pdf"
        // TypeError "null has no properties", e.g. for "%2F.pdf"
      }
    }
  }
  return suggestedFilename || 'document.pdf';
}

var ProgressBar = (function ProgressBarClosure() {

  function clamp(v, min, max) {
    return Math.min(Math.max(v, min), max);
  }

  function ProgressBar(id, opts) {

    // Fetch the sub-elements for later.
    this.div = document.querySelector(id + ' .progress');

    // Get the loading bar element, so it can be resized to fit the viewer.
    this.bar = this.div.parentNode;

    // Get options, with sensible defaults.
    this.height = opts.height || 100;
    this.width = opts.width || 100;
    this.units = opts.units || '%';

    // Initialize heights.
    this.div.style.height = this.height + this.units;
    this.percent = 0;
  }

  ProgressBar.prototype = {

    updateBar: function ProgressBar_updateBar() {
      if (this._indeterminate) {
        this.div.classList.add('indeterminate');
        this.div.style.width = this.width + this.units;
        return;
      }

      this.div.classList.remove('indeterminate');
      var progressSize = this.width * this._percent / 100;
      this.div.style.width = progressSize + this.units;
    },

    get percent() {
      return this._percent;
    },

    set percent(val) {
      this._indeterminate = isNaN(val);
      this._percent = clamp(val, 0, 100);
      this.updateBar();
    },

    setWidth: function ProgressBar_setWidth(viewer) {
      if (viewer) {
        var container = viewer.parentNode;
        var scrollbarWidth = container.offsetWidth - viewer.offsetWidth;
        if (scrollbarWidth > 0) {
          this.bar.setAttribute('style', 'width: calc(100% - ' +
                                         scrollbarWidth + 'px);');
        }
      }
    },

    hide: function ProgressBar_hide() {
      this.bar.classList.add('hidden');
      this.bar.removeAttribute('style');
    }
  };

  return ProgressBar;
})();

var Cache = function cacheCache(size) {
  var data = [];
  this.push = function cachePush(view) {
    var i = data.indexOf(view);
    if (i >= 0)
      data.splice(i);
    data.push(view);
    if (data.length > size)
      data.shift().destroy();
  };
};

//#if !(FIREFOX || MOZCENTRAL || B2G)
var isLocalStorageEnabled = (function isLocalStorageEnabledClosure() {
  // Feature test as per http://diveintohtml5.info/storage.html
  // The additional localStorage call is to get around a FF quirk, see
  // bug #495747 in bugzilla
  try {
    return ('localStorage' in window && window['localStorage'] !== null &&
            localStorage);
  } catch (e) {
    return false;
  }
})();
//#endif