React - skalowanie zawartości do rozmiaru kontenera (CSS transform scale)

// Uwaga: Odkomentuj poniższe linijki podczas pracy z kompilatorem JSX:

// import React from 'react';

// import ReactDOM from 'react-dom';

​

const AutoSizer = React.memo(({ interval, children, ...other }) => {

    const reference = React.useRef();

    const [size, setSize] = React.useState();

    React.useEffect(() => {

        let storedWidth = size?.width;

        let storedHeight = size?.height;

        const id = setInterval(() => {

            const element = reference.current;

            if (element) {

                const width = element.offsetWidth;

                const height = element.offsetHeight;

                if (width != storedWidth || height != storedHeight) {

                    storedWidth = width;

                    storedHeight = height;

                    setSize({ width, height });

                }

            }

        }, interval ?? 100);

        return () => {

            clearInterval(id);

        };

    }, [interval]);

    return (

      <div ref={reference} {...other}>

        {size && children && children(size.width, size.height)}

      </div>

    );

});

​

const ContentStretcher = ({sizerInterval, contentWidth, contentHeight, children, ...other}) => (

  <AutoSizer

    {...other}

    style={{

      ...other.style,

      position: 'relative',

      display: 'flex'

    }}

    interval={sizerInterval}

  >

    {(containerWidth, containerHeight) => {

        const contentScale =

              containerHeight * contentWidth < containerWidth * contentHeight

            ? containerHeight / contentHeight

            : containerWidth / contentWidth;

        return (

          <div

            style={{

              position: 'absolute',

              left: '50%',

              top: '50%',

              transform: `translate(-50%, -50%) scale(${contentScale})`,

              transformOrigin: '50% 50%',

            }}

          >

            {children}

          </div>

        );

    }}

  </AutoSizer>

);

​

// Przykład:

​

// Utworzymy element iframe z dirask.com, który zostanie przeskalowany do kontenera

// z zachowaniem proporcji treści.

​

const DiraskFrame = ({containerWidth, containerHeight, contentWidth, contentHeight}) => (

  <ContentStretcher

    style={{

        background: '#e1e1e1',

        width: `${containerWidth}px`,

        height: `${containerHeight}px`

    }}

    contentWidth={contentWidth}

    contentHeight={contentHeight}

  >

    <iframe

      src="https://dirask.com/about"

      style={{

        border: 'none',

        width: `${contentWidth}px`,

        height: `${contentHeight}px`

      }}

    />

  </ContentStretcher>

);

​

const App = () => (

  <div>

    <DiraskFrame

      containerWidth={100}

      containerHeight={100}

      contentWidth={200}

      contentHeight={200}

    />

    <br />

    <DiraskFrame

      containerWidth={300}

      containerHeight={300}

      contentWidth={200}

      contentHeight={200}

    />

    <br />

    <DiraskFrame

      containerWidth={300}

      containerHeight={200}

      contentWidth={150}

      contentHeight={150}

    />

    <br />

    <DiraskFrame

      containerWidth={200}

      containerHeight={300}

      contentWidth={150}

      contentHeight={150}

    />

  </div>

);

​

const root = document.querySelector('#root');

ReactDOM.render(<App />, root );