mindoc/static/element-ui/lib/utils/resize-event.js

'use strict';

exports.__esModule = true;
/* Modified from https://github.com/sdecima/javascript-detect-element-resize
 * version: 0.5.3
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013 Sebastián Décima
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */
var isServer = typeof window === 'undefined';

/* istanbul ignore next */
var requestFrame = function () {
  if (isServer) return;
  var raf = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || function (fn) {
    return window.setTimeout(fn, 20);
  };
  return function (fn) {
    return raf(fn);
  };
}();

/* istanbul ignore next */
var cancelFrame = function () {
  if (isServer) return;
  var cancel = window.cancelAnimationFrame || window.mozCancelAnimationFrame || window.webkitCancelAnimationFrame || window.clearTimeout;
  return function (id) {
    return cancel(id);
  };
}();

/* istanbul ignore next */
var resetTrigger = function resetTrigger(element) {
  var trigger = element.__resizeTrigger__;
  var expand = trigger.firstElementChild;
  var contract = trigger.lastElementChild;
  var expandChild = expand.firstElementChild;

  contract.scrollLeft = contract.scrollWidth;
  contract.scrollTop = contract.scrollHeight;
  expandChild.style.width = expand.offsetWidth + 1 + 'px';
  expandChild.style.height = expand.offsetHeight + 1 + 'px';
  expand.scrollLeft = expand.scrollWidth;
  expand.scrollTop = expand.scrollHeight;
};

/* istanbul ignore next */
var checkTriggers = function checkTriggers(element) {
  return element.offsetWidth !== element.__resizeLast__.width || element.offsetHeight !== element.__resizeLast__.height;
};

/* istanbul ignore next */
var scrollListener = function scrollListener(event) {
  var _this = this;

  resetTrigger(this);
  if (this.__resizeRAF__) cancelFrame(this.__resizeRAF__);
  this.__resizeRAF__ = requestFrame(function () {
    if (checkTriggers(_this)) {
      _this.__resizeLast__.width = _this.offsetWidth;
      _this.__resizeLast__.height = _this.offsetHeight;
      _this.__resizeListeners__.forEach(function (fn) {
        fn.call(_this, event);
      });
    }
  });
};

/* Detect CSS Animations support to detect element display/re-attach */
var attachEvent = isServer ? {} : document.attachEvent;
var DOM_PREFIXES = 'Webkit Moz O ms'.split(' ');
var START_EVENTS = 'webkitAnimationStart animationstart oAnimationStart MSAnimationStart'.split(' ');
var RESIZE_ANIMATION_NAME = 'resizeanim';
var animation = false;
var keyFramePrefix = '';
var animationStartEvent = 'animationstart';

/* istanbul ignore next */
if (!attachEvent && !isServer) {
  var testElement = document.createElement('fakeelement');
  if (testElement.style.animationName !== undefined) {
    animation = true;
  }

  if (animation === false) {
    var prefix = '';
    for (var i = 0; i < DOM_PREFIXES.length; i++) {
      if (testElement.style[DOM_PREFIXES[i] + 'AnimationName'] !== undefined) {
        prefix = DOM_PREFIXES[i];
        keyFramePrefix = '-' + prefix.toLowerCase() + '-';
        animationStartEvent = START_EVENTS[i];
        animation = true;
        break;
      }
    }
  }
}

var stylesCreated = false;
/* istanbul ignore next */
var createStyles = function createStyles() {
  if (!stylesCreated && !isServer) {
    var animationKeyframes = '@' + keyFramePrefix + 'keyframes ' + RESIZE_ANIMATION_NAME + ' { from { opacity: 0; } to { opacity: 0; } } ';
    var animationStyle = keyFramePrefix + 'animation: 1ms ' + RESIZE_ANIMATION_NAME + ';';

    // opacity: 0 works around a chrome bug https://code.google.com/p/chromium/issues/detail?id=286360
    var css = animationKeyframes + '\n      .resize-triggers { ' + animationStyle + ' visibility: hidden; opacity: 0; }\n      .resize-triggers, .resize-triggers > div, .contract-trigger:before { content: " "; display: block; position: absolute; top: 0; left: 0; height: 100%; width: 100%; overflow: hidden; }\n      .resize-triggers > div { background: #eee; overflow: auto; }\n      .contract-trigger:before { width: 200%; height: 200%; }';

    var head = document.head || document.getElementsByTagName('head')[0];
    var style = document.createElement('style');

    style.type = 'text/css';
    if (style.styleSheet) {
      style.styleSheet.cssText = css;
    } else {
      style.appendChild(document.createTextNode(css));
    }

    head.appendChild(style);
    stylesCreated = true;
  }
};

/* istanbul ignore next */
var addResizeListener = exports.addResizeListener = function addResizeListener(element, fn) {
  if (isServer) return;
  if (attachEvent) {
    element.attachEvent('onresize', fn);
  } else {
    if (!element.__resizeTrigger__) {
      if (getComputedStyle(element).position === 'static') {
        element.style.position = 'relative';
      }
      createStyles();
      element.__resizeLast__ = {};
      element.__resizeListeners__ = [];

      var resizeTrigger = element.__resizeTrigger__ = document.createElement('div');
      resizeTrigger.className = 'resize-triggers';
      resizeTrigger.innerHTML = '<div class="expand-trigger"><div></div></div><div class="contract-trigger"></div>';
      element.appendChild(resizeTrigger);

      resetTrigger(element);
      element.addEventListener('scroll', scrollListener, true);

      /* Listen for a css animation to detect element display/re-attach */
      if (animationStartEvent) {
        resizeTrigger.addEventListener(animationStartEvent, function (event) {
          if (event.animationName === RESIZE_ANIMATION_NAME) {
            resetTrigger(element);
          }
        });
      }
    }
    element.__resizeListeners__.push(fn);
  }
};

/* istanbul ignore next */
var removeResizeListener = exports.removeResizeListener = function removeResizeListener(element, fn) {
  if (attachEvent) {
    element.detachEvent('onresize', fn);
  } else {
    element.__resizeListeners__.splice(element.__resizeListeners__.indexOf(fn), 1);
    if (!element.__resizeListeners__.length) {
      element.removeEventListener('scroll', scrollListener);
      element.__resizeTrigger__ = !element.removeChild(element.__resizeTrigger__);
    }
  }
};