overscroll/lib/handlers.js

scroll

'use strict';

exports.__esModule = true;
exports.handleInit = exports.handleScroll = exports.handleAfterScroll = exports.handleBeforeScroll = exports.handleDestroy = undefined;
exports.handler = handler;

var _object = require('object.pick');

var _object2 = _interopRequireDefault(_object);

var _compose = require('./utils/compose');

var _compose2 = _interopRequireDefault(_compose);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { 'default': obj }; }

var noop = function noop() {};

function handler(name) {
  return function (scope) {
    var mode = scope.mode;

    var wrap = function wrap(func) {
      return function () {
        func.call(scope.target, (0, _object2['default'])(scope.overscroll, ['scrollTop', 'scrollLeft', 'scrollHeight', 'scrollWidth', 'clientHeight', 'clientWidth'].concat(mode === 'scroll' ? [] : ['section', 'positions'])));
      };
    };
    scope.handleCache = scope.handleCache || {};
    scope.handleCache[name] = noop;
    var initialHandler = scope[name] ? scope[name] : noop;
    scope[name] = function () {
      scope.handleCache[name]();
      wrap(initialHandler)();
    };
    return (0, _compose2['default'])(function (callback) {
      scope.handleCache[name] = scope.handleCache[name] !== noop ? (0, _compose2['default'])(callback, scope.handleCache[name]) : callback;
    }, wrap);
  };
}

var handleDestroy = exports.handleDestroy = handler('onDestroy');
var handleBeforeScroll = exports.handleBeforeScroll = handler('onBeforeScroll');
var handleAfterScroll = exports.handleAfterScroll = handler('onAfterScroll');
var handleScroll = exports.handleScroll = handler('onScroll');
var handleInit = exports.handleInit = handler('onInit');