QEvBwg

index.html

  <div id="app"></div>

<br/>
<label for="container-height">Height (px):</label>
<input name="container-height" size="10" id="container-height" type="text" value="80"/>
<button type="button" onClick="changeContainerHeight()">Adjust</button>

QEvBwg.markdown

QEvBwg

A Pen by Dave Atchley on CodePen.

License.

script.babel

/*
 * Utility functions
 */
const requestAnimationFrame = window.requestAnimationFrame || (fn=>setTimeout(fn,30));

function changeContainerHeight() {
  const cont = document.querySelector('.app-container');
  const input = document.querySelector('#container-height');
  cont.style.height = input.value + 'px';
}

/*
 * HOC to allow Components to receive their width/height as
 * props on render.
 */
const Responsive = (WrappedComponent) => class _Responsive extends React.Component {
  constructor(props) {
    super(props);
    this.state = { width: null, height: null };
    this.rafCallback = this.getUpdatedSize.bind(this);
  }
  
  getUpdatedSize() {
    const node = ReactDOM.findDOMNode(this._comp);
    let height = node.offsetHeight;
    let width = node.offsetWidth;
    if (height != this.state.height || width != this.state.width) {
      this.setState({
        height,
        width
      });
    }
    requestAnimationFrame(this.rafCallback);
  }
  
  componentDidMount() {
    requestAnimationFrame(this.rafCallback);
  }

  componentWillUnmount() {
    cancelInterval(this._interval);
  }

  render() {
    return <WrappedComponent ref={(ref) => this._comp = ref}  {...this.props} dimensions={{...this.state}} />;
  }
};

/*
 * Price Component, which should have responsive text sizing
 * based on it's container's height.
 */
@Responsive
class Price extends React.Component {
  render() {
    const { prefix, price, suffix, subtext, subtextPosition = "bottom" } = this.props;
    const [ dollars, cents = '00' ] = price.split('.');
    const subcls = ["subtext", subtextPosition].join(' ');
    
    return (
      <div ref={(ref)=>this._container = ref} className={"price"}>
        <div className={"price-container"}>
          <div className={"prefix"}>{ prefix }</div>
          <div className={"symbol"}>$</div>
          <span className={"dollars"}>{ dollars }</span>
          <div className={"cents"}>
            { cents }
            <span className={"suffix"}>{ suffix }</span>
          </div>
        </div>
        <div className={subcls}>{ subtext }</div>
      </div>
    );
  }
  
  componentDidUpdate() {
    this.resizeFont();
  }
  
  resizeFont() {
    window.requestAnimationFrame(() => {
      const { width, height } = this.props.dimensions;
      const factor = this.props.subtext && this.props.subtextPosition == 'bottom' ? .7 : .9;
      this._container.style.fontSize = (height * factor).toFixed(2) + 'px';
    });
  }
}



ReactDOM.render(
  <div className={"app-container"}>
    <Price prefix="from" 
         price="29.99" 
         suffix="/mo" 
         subtext="for 12 months when bundled"
         subtextPosition="right"/>
    </div>,
  document.getElementById('app')
);

scripts

<script src="https://fb.me/react-15.1.0.min.js"></script>
<script src="https://fb.me/react-dom-15.1.0.min.js"></script>

style.scss

.app-container {
  height: 80px;
  background-color: rgba(0,0,0,.2);
  overflow: hidden;
}


.price {
  width: auto;
  height: 100%;
  font-size: 85%;
  text-align: center;
}
.price-container {
  display: inline-block;
  position: relative;
  height: auto;
  text-align: center;
  -webkit-transition: font-size .3s ease;
  -moz-transition: font-size .3s ease;
  -o-transition: font-size .3s ease;
  transition: font-size .3s ease;
}
.prefix,
.symbol,
.cents {
  position: absolute;
  display: inline-block;
}
.symbol {
  left: -0.6em;
  top: .5em;
  opacity: .5;
  font-size: 30%;
}
.prefix {
  left: -2.2em;
  bottom: 0.6em;
  font-size: 30%;
  color: #999;
}
.cents {
  left: 100%;
  top: .4em;
  opacity: .5;
  font-size: 33%;
  
  .suffix {
    font-size: 80%;
  }
}
.subtext {
  text-align: center;
  font-size: 20%;
  opacity: .3;
  
  &.bottom {
    margin-top: -5px;
  }
  &.right {
    display: inline-block;
  }
  &.hidden {
    display: none;
  }
}
.dollars {
    font-size: 100%;
}