pdfjs-dist/lib/web/ui_utils.js

/* Copyright 2017 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';

var pdfjsLib = require('./pdfjs.js');
var CSS_UNITS = 96.0 / 72.0;
var DEFAULT_SCALE_VALUE = 'auto';
var DEFAULT_SCALE = 1.0;
var MIN_SCALE = 0.25;
var MAX_SCALE = 10.0;
var UNKNOWN_SCALE = 0;
var MAX_AUTO_SCALE = 1.25;
var SCROLLBAR_PADDING = 40;
var VERTICAL_PADDING = 5;
var RendererType = {
  CANVAS: 'canvas',
  SVG: 'svg'
};
var mozL10n = document.mozL10n || document.webL10n;
var PDFJS = pdfjsLib.PDFJS;
PDFJS.disableFullscreen = PDFJS.disableFullscreen === undefined ? false : PDFJS.disableFullscreen;
PDFJS.useOnlyCssZoom = PDFJS.useOnlyCssZoom === undefined ? false : PDFJS.useOnlyCssZoom;
PDFJS.maxCanvasPixels = PDFJS.maxCanvasPixels === undefined ? 16777216 : PDFJS.maxCanvasPixels;
PDFJS.disableHistory = PDFJS.disableHistory === undefined ? false : PDFJS.disableHistory;
PDFJS.disableTextLayer = PDFJS.disableTextLayer === undefined ? false : PDFJS.disableTextLayer;
PDFJS.ignoreCurrentPositionOnZoom = PDFJS.ignoreCurrentPositionOnZoom === undefined ? false : PDFJS.ignoreCurrentPositionOnZoom;
PDFJS.locale = PDFJS.locale === undefined ? navigator.language : PDFJS.locale;
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
  };
}
function scrollIntoView(element, spot, skipOverflowHiddenElements) {
  var parent = element.offsetParent;
  if (!parent) {
    console.error('offsetParent is not set -- cannot scroll');
    return;
  }
  var checkOverflow = skipOverflowHiddenElements || false;
  var offsetY = element.offsetTop + element.clientTop;
  var offsetX = element.offsetLeft + element.clientLeft;
  while (parent.clientHeight === parent.scrollHeight || checkOverflow && getComputedStyle(parent).overflow === 'hidden') {
    if (parent.dataset._scaleY) {
      offsetY /= parent.dataset._scaleY;
      offsetX /= parent.dataset._scaleX;
    }
    offsetY += parent.offsetTop;
    offsetX += parent.offsetLeft;
    parent = parent.offsetParent;
    if (!parent) {
      return;
    }
  }
  if (spot) {
    if (spot.top !== undefined) {
      offsetY += spot.top;
    }
    if (spot.left !== undefined) {
      offsetX += spot.left;
      parent.scrollLeft = offsetX;
    }
  }
  parent.scrollTop = offsetY;
}
function watchScroll(viewAreaElement, callback) {
  var debounceScroll = function debounceScroll(evt) {
    if (rAF) {
      return;
    }
    rAF = window.requestAnimationFrame(function viewAreaElementScrolled() {
      rAF = null;
      var currentY = viewAreaElement.scrollTop;
      var lastY = state.lastY;
      if (currentY !== lastY) {
        state.down = currentY > lastY;
      }
      state.lastY = currentY;
      callback(state);
    });
  };
  var state = {
    down: true,
    lastY: viewAreaElement.scrollTop,
    _eventHandler: debounceScroll
  };
  var rAF = null;
  viewAreaElement.addEventListener('scroll', debounceScroll, true);
  return state;
}
function parseQueryString(query) {
  var parts = query.split('&');
  var params = {};
  for (var i = 0, ii = parts.length; i < ii; ++i) {
    var param = parts[i].split('=');
    var key = param[0].toLowerCase();
    var value = param.length > 1 ? param[1] : null;
    params[decodeURIComponent(key)] = decodeURIComponent(value);
  }
  return params;
}
function binarySearchFirstItem(items, condition) {
  var minIndex = 0;
  var maxIndex = items.length - 1;
  if (items.length === 0 || !condition(items[maxIndex])) {
    return items.length;
  }
  if (condition(items[minIndex])) {
    return minIndex;
  }
  while (minIndex < maxIndex) {
    var currentIndex = minIndex + maxIndex >> 1;
    var currentItem = items[currentIndex];
    if (condition(currentItem)) {
      maxIndex = currentIndex;
    } else {
      minIndex = currentIndex + 1;
    }
  }
  return minIndex;
}
function approximateFraction(x) {
  if (Math.floor(x) === x) {
    return [x, 1];
  }
  var xinv = 1 / x;
  var limit = 8;
  if (xinv > limit) {
    return [1, limit];
  } else if (Math.floor(xinv) === xinv) {
    return [1, xinv];
  }
  var x_ = x > 1 ? xinv : x;
  var a = 0,
      b = 1,
      c = 1,
      d = 1;
  while (true) {
    var p = a + c,
        q = b + d;
    if (q > limit) {
      break;
    }
    if (x_ <= p / q) {
      c = p;
      d = q;
    } else {
      a = p;
      b = q;
    }
  }
  var result;
  if (x_ - a / b < c / d - x_) {
    result = x_ === x ? [a, b] : [b, a];
  } else {
    result = x_ === x ? [c, d] : [d, c];
  }
  return result;
}
function roundToDivide(x, div) {
  var r = x % div;
  return r === 0 ? x : Math.round(x - r + div);
}
function getVisibleElements(scrollEl, views, sortByVisibility) {
  var top = scrollEl.scrollTop,
      bottom = top + scrollEl.clientHeight;
  var left = scrollEl.scrollLeft,
      right = left + scrollEl.clientWidth;
  function isElementBottomBelowViewTop(view) {
    var element = view.div;
    var elementBottom = element.offsetTop + element.clientTop + element.clientHeight;
    return elementBottom > top;
  }
  var visible = [],
      view,
      element;
  var currentHeight, viewHeight, hiddenHeight, percentHeight;
  var currentWidth, viewWidth;
  var firstVisibleElementInd = views.length === 0 ? 0 : binarySearchFirstItem(views, isElementBottomBelowViewTop);
  for (var i = firstVisibleElementInd, ii = views.length; i < ii; i++) {
    view = views[i];
    element = view.div;
    currentHeight = element.offsetTop + element.clientTop;
    viewHeight = element.clientHeight;
    if (currentHeight > bottom) {
      break;
    }
    currentWidth = element.offsetLeft + element.clientLeft;
    viewWidth = element.clientWidth;
    if (currentWidth + viewWidth < left || currentWidth > right) {
      continue;
    }
    hiddenHeight = Math.max(0, top - currentHeight) + Math.max(0, currentHeight + viewHeight - bottom);
    percentHeight = (viewHeight - hiddenHeight) * 100 / viewHeight | 0;
    visible.push({
      id: view.id,
      x: currentWidth,
      y: currentHeight,
      view: view,
      percent: percentHeight
    });
  }
  var first = visible[0];
  var last = visible[visible.length - 1];
  if (sortByVisibility) {
    visible.sort(function (a, b) {
      var pc = a.percent - b.percent;
      if (Math.abs(pc) > 0.001) {
        return -pc;
      }
      return a.id - b.id;
    });
  }
  return {
    first: first,
    last: last,
    views: visible
  };
}
function noContextMenuHandler(e) {
  e.preventDefault();
}
function getPDFFileNameFromURL(url, defaultFilename) {
  if (typeof defaultFilename === 'undefined') {
    defaultFilename = 'document.pdf';
  }
  var reURI = /^(?:(?:[^:]+:)?\/\/[^\/]+)?([^?#]*)(\?[^#]*)?(#.*)?$/;
  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) {
      try {
        suggestedFilename = reFilename.exec(decodeURIComponent(suggestedFilename))[0];
      } catch (e) {}
    }
  }
  return suggestedFilename || defaultFilename;
}
function normalizeWheelEventDelta(evt) {
  var delta = Math.sqrt(evt.deltaX * evt.deltaX + evt.deltaY * evt.deltaY);
  var angle = Math.atan2(evt.deltaY, evt.deltaX);
  if (-0.25 * Math.PI < angle && angle < 0.75 * Math.PI) {
    delta = -delta;
  }
  var MOUSE_DOM_DELTA_PIXEL_MODE = 0;
  var MOUSE_DOM_DELTA_LINE_MODE = 1;
  var MOUSE_PIXELS_PER_LINE = 30;
  var MOUSE_LINES_PER_PAGE = 30;
  if (evt.deltaMode === MOUSE_DOM_DELTA_PIXEL_MODE) {
    delta /= MOUSE_PIXELS_PER_LINE * MOUSE_LINES_PER_PAGE;
  } else if (evt.deltaMode === MOUSE_DOM_DELTA_LINE_MODE) {
    delta /= MOUSE_LINES_PER_PAGE;
  }
  return delta;
}
var animationStarted = new Promise(function (resolve) {
  window.requestAnimationFrame(resolve);
});
var localized = new Promise(function (resolve, reject) {
  if (!mozL10n) {
    resolve();
    return;
  }
  if (mozL10n.getReadyState() !== 'loading') {
    resolve();
    return;
  }
  window.addEventListener('localized', function localized(evt) {
    resolve();
  });
});
var EventBus = function EventBusClosure() {
  function EventBus() {
    this._listeners = Object.create(null);
  }
  EventBus.prototype = {
    on: function EventBus_on(eventName, listener) {
      var eventListeners = this._listeners[eventName];
      if (!eventListeners) {
        eventListeners = [];
        this._listeners[eventName] = eventListeners;
      }
      eventListeners.push(listener);
    },
    off: function EventBus_on(eventName, listener) {
      var eventListeners = this._listeners[eventName];
      var i;
      if (!eventListeners || (i = eventListeners.indexOf(listener)) < 0) {
        return;
      }
      eventListeners.splice(i, 1);
    },
    dispatch: function EventBus_dispath(eventName) {
      var eventListeners = this._listeners[eventName];
      if (!eventListeners || eventListeners.length === 0) {
        return;
      }
      var args = Array.prototype.slice.call(arguments, 1);
      eventListeners.slice(0).forEach(function (listener) {
        listener.apply(null, args);
      });
    }
  };
  return EventBus;
}();
var ProgressBar = function ProgressBarClosure() {
  function clamp(v, min, max) {
    return Math.min(Math.max(v, min), max);
  }
  function ProgressBar(id, opts) {
    this.visible = true;
    this.div = document.querySelector(id + ' .progress');
    this.bar = this.div.parentNode;
    this.height = opts.height || 100;
    this.width = opts.width || 100;
    this.units = opts.units || '%';
    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() {
      if (!this.visible) {
        return;
      }
      this.visible = false;
      this.bar.classList.add('hidden');
      document.body.classList.remove('loadingInProgress');
    },
    show: function ProgressBar_show() {
      if (this.visible) {
        return;
      }
      this.visible = true;
      document.body.classList.add('loadingInProgress');
      this.bar.classList.remove('hidden');
    }
  };
  return ProgressBar;
}();
exports.CSS_UNITS = CSS_UNITS;
exports.DEFAULT_SCALE_VALUE = DEFAULT_SCALE_VALUE;
exports.DEFAULT_SCALE = DEFAULT_SCALE;
exports.MIN_SCALE = MIN_SCALE;
exports.MAX_SCALE = MAX_SCALE;
exports.UNKNOWN_SCALE = UNKNOWN_SCALE;
exports.MAX_AUTO_SCALE = MAX_AUTO_SCALE;
exports.SCROLLBAR_PADDING = SCROLLBAR_PADDING;
exports.VERTICAL_PADDING = VERTICAL_PADDING;
exports.RendererType = RendererType;
exports.mozL10n = mozL10n;
exports.EventBus = EventBus;
exports.ProgressBar = ProgressBar;
exports.getPDFFileNameFromURL = getPDFFileNameFromURL;
exports.noContextMenuHandler = noContextMenuHandler;
exports.parseQueryString = parseQueryString;
exports.getVisibleElements = getVisibleElements;
exports.roundToDivide = roundToDivide;
exports.approximateFraction = approximateFraction;
exports.getOutputScale = getOutputScale;
exports.scrollIntoView = scrollIntoView;
exports.watchScroll = watchScroll;
exports.binarySearchFirstItem = binarySearchFirstItem;
exports.normalizeWheelEventDelta = normalizeWheelEventDelta;
exports.animationStarted = animationStarted;
exports.localized = localized;