@upleveled/code-surfer/dist/scroller.js

React component for scrolling, zooming and highlighting code.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.Element = exports.Content = exports.Container = undefined;

var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

var _react = require("react");

var _react2 = _interopRequireDefault(_react);

var _tween = require("./tween");

var _tween2 = _interopRequireDefault(_tween);

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

function _objectWithoutProperties(obj, keys) { var target = {}; for (var i in obj) { if (keys.indexOf(i) >= 0) continue; if (!Object.prototype.hasOwnProperty.call(obj, i)) continue; target[i] = obj[i]; } return target; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

var getNewCenter = function getNewCenter(container, content, firstSelected, lastSelected) {
  var parentHeight = container.parentElement.offsetHeight;
  container.style.padding = parentHeight / 2 + "px 0";
  container.style.height = 0;

  firstSelected = firstSelected || content;
  lastSelected = lastSelected || firstSelected;
  var contentTop = content.offsetTop;
  var contentHeight = content.offsetHeight;

  var top = firstSelected.offsetTop;
  var bottom = lastSelected.offsetTop + lastSelected.offsetHeight;
  var selectedHeight = bottom - top;
  var middle = Math.floor((top + bottom) / 2);
  var containerHeight = container.offsetHeight;

  var scale = 1;
  if (selectedHeight > containerHeight) {
    scale = containerHeight / selectedHeight;
    var minScale = 0.2;
    scale = scale < minScale ? minScale : scale;
  }

  // center in the middle of the selected element
  var center = middle;

  var scaledContentHeight = contentHeight * scale;
  var scaledSelectedHeight = selectedHeight * scale;
  var contentMargin = (contentHeight - scaledContentHeight) / 2;

  var halfContent = contentHeight / 2;
  if (scale !== 1) {
    center = (middle - halfContent) * scale + halfContent;
  }

  // console.log("top", top);
  // console.log("bottom", bottom);
  // console.log("containerHeight", containerHeight);
  // console.log("selectedHeight", selectedHeight);
  // console.log("scaledSelectedHeight", scaledSelectedHeight);
  // console.log("contentHeight", contentHeight);
  // console.log("scaledContentHeight", scaledContentHeight);

  if (containerHeight >= scaledContentHeight) {
    // center in the middle of the content
    center = contentHeight / 2;
  } else if (containerHeight >= scaledSelectedHeight) {
    var minScroll = contentMargin + containerHeight / 2;
    var maxScroll = contentHeight - contentMargin - containerHeight / 2;
    center = center < minScroll ? minScroll : center;
    center = center > maxScroll ? maxScroll : center;
  } else {
    // console.log("Bigger selected than container");
    center = (top - halfContent) * scale + halfContent + containerHeight / 2;
  }

  // console.log(center);
  return { center: center, scale: scale };
};

var scrollTo = function scrollTo(container, content, center, scale, duration) {
  var startY = container.scrollTop;

  var containerScale = container.getBoundingClientRect().height / container.offsetHeight;

  // TODO browser support?
  var startScale = content.getBoundingClientRect().height / content.offsetHeight / containerScale;

  var endY = center;

  var step = { top: startY, scale: startScale };
  var shouldAnimate = true;

  var tween = new _tween2.default.Tween(step).to({ top: endY, scale: scale }, duration).easing(_tween2.default.Easing.Circular.Out).onUpdate(function () {
    container.scrollTop = step.top | 0;
    content.style.transform = "scale(" + step.scale + ")";
  }).onComplete(function () {
    shouldAnimate = false;
  }).start();

  function animate(time) {
    if (!shouldAnimate) return;
    requestAnimationFrame(animate);
    _tween2.default.update(time);
  }
  requestAnimationFrame(animate);
};

var contentClassName = "scroll-content";
var selectedClassName = "scroll-selected";

var Container = exports.Container = function (_React$Component) {
  _inherits(Container, _React$Component);

  function Container(props) {
    _classCallCheck(this, Container);

    var _this = _possibleConstructorReturn(this, (Container.__proto__ || Object.getPrototypeOf(Container)).call(this, props));

    _this.containerRef = _react2.default.createRef();
    return _this;
  }

  _createClass(Container, [{
    key: "animate",
    value: function animate(duration) {
      var container = this.containerRef.current;
      var content = container.querySelector("." + contentClassName);
      var allSelected = container.querySelectorAll("." + selectedClassName);
      var firstSelected = allSelected.length ? allSelected[0] : content;
      var lastSelected = allSelected.length ? allSelected[allSelected.length - 1] : content;

      var _getNewCenter = getNewCenter(container, content, firstSelected, lastSelected),
          center = _getNewCenter.center,
          scale = _getNewCenter.scale;

      scrollTo(container, content, center, scale, duration);
    }
  }, {
    key: "componentDidMount",
    value: function componentDidMount() {
      this.animate(1);
    }
  }, {
    key: "componentDidUpdate",
    value: function componentDidUpdate() {
      this.animate(400);
    }
  }, {
    key: "render",
    value: function render() {
      var _props = this.props,
          type = _props.type,
          height = _props.height,
          children = _props.children,
          style = _props.style,
          rest = _objectWithoutProperties(_props, ["type", "height", "children", "style"]);

      return _react2.default.createElement(type || "div", _extends({
        ref: this.containerRef,
        style: Object.assign({}, {
          // height: 0,
          margin: 0,
          overflow: "hidden",
          textAlign: "center",
          position: "relative"
        }, style)
      }, rest), _react2.default.createElement(
        "div",
        { style: { position: "relative" } },
        children
      ));
    }
  }]);

  return Container;
}(_react2.default.Component);

var Content = exports.Content = function (_React$Component2) {
  _inherits(Content, _React$Component2);

  function Content() {
    _classCallCheck(this, Content);

    return _possibleConstructorReturn(this, (Content.__proto__ || Object.getPrototypeOf(Content)).apply(this, arguments));
  }

  _createClass(Content, [{
    key: "render",
    value: function render() {
      var _props2 = this.props,
          type = _props2.type,
          children = _props2.children,
          style = _props2.style,
          className = _props2.className,
          rest = _objectWithoutProperties(_props2, ["type", "children", "style", "className"]);

      return _react2.default.createElement(type || "div", _extends({
        className: contentClassName + " " + className,
        style: Object.assign({}, { display: "inline-block", textAlign: "left", width: "100%" }, style)
      }, rest), children);
    }
  }]);

  return Content;
}(_react2.default.Component);

var Element = exports.Element = function (_React$Component3) {
  _inherits(Element, _React$Component3);

  function Element() {
    _classCallCheck(this, Element);

    return _possibleConstructorReturn(this, (Element.__proto__ || Object.getPrototypeOf(Element)).apply(this, arguments));
  }

  _createClass(Element, [{
    key: "render",
    value: function render() {
      var _props3 = this.props,
          type = _props3.type,
          selected = _props3.selected,
          children = _props3.children,
          className = _props3.className,
          rest = _objectWithoutProperties(_props3, ["type", "selected", "children", "className"]);

      return _react2.default.createElement(type || "div", _extends({
        className: selected ? selectedClassName + " " + className : className
      }, rest), children);
    }
  }]);

  return Element;
}(_react2.default.Component);