iview/src/utils/calcTextareaHeight.js

// Thanks to
// https://github.com/andreypopp/react-textarea-autosize/

// let hiddenTextarea;
//
// const HIDDEN_STYLE = `
//     height:0 !important;
//     min-height:0 !important;
//     max-height:none !important;
//     visibility:hidden !important;
//     overflow:hidden !important;
//     position:absolute !important;
//     z-index:-1000 !important;
//     top:0 !important;
//     right:0 !important
// `;
//
// const CONTEXT_STYLE = [
//     'letter-spacing',
//     'line-height',
//     'padding-top',
//     'padding-bottom',
//     'font-family',
//     'font-weight',
//     'font-size',
//     'text-rendering',
//     'text-transform',
//     'width',
//     'text-indent',
//     'padding-left',
//     'padding-right',
//     'border-width',
//     'box-sizing'
// ];
//
// function calculateNodeStyling(node) {
//     const style = window.getComputedStyle(node);
//
//     const boxSizing = style.getPropertyValue('box-sizing');
//
//     const paddingSize = (
//         parseFloat(style.getPropertyValue('padding-bottom')) +
//         parseFloat(style.getPropertyValue('padding-top'))
//     );
//
//     const borderSize = (
//         parseFloat(style.getPropertyValue('border-bottom-width')) +
//         parseFloat(style.getPropertyValue('border-top-width'))
//     );
//
//     const contextStyle = CONTEXT_STYLE
//         .map(name => `${name}:${style.getPropertyValue(name)}`)
//         .join(';');
//
//     return {contextStyle, paddingSize, borderSize, boxSizing};
// }
//
// export default function calcTextareaHeight(targetNode, minRows = null, maxRows = null) {
//     if (!hiddenTextarea) {
//         hiddenTextarea = document.createElement('textarea');
//         document.body.appendChild(hiddenTextarea);
//     }
//
//     let {
//         paddingSize,
//         borderSize,
//         boxSizing,
//         contextStyle
//     } = calculateNodeStyling(targetNode);
//
//     hiddenTextarea.setAttribute('style', `${contextStyle};${HIDDEN_STYLE}`);
//     hiddenTextarea.value = targetNode.value || targetNode.placeholder || '';
//
//     let height = hiddenTextarea.scrollHeight;
//     let minHeight = -Infinity;
//     let maxHeight = Infinity;
//     let overflowY;
//
//     if (boxSizing === 'border-box') {
//         height = height + borderSize;
//     } else if (boxSizing === 'content-box') {
//         height = height - paddingSize;
//     }
//
//     hiddenTextarea.value = '';
//     let singleRowHeight = hiddenTextarea.scrollHeight - paddingSize;
//
//     if (minRows !== null) {
//         minHeight = singleRowHeight * minRows;
//         if (boxSizing === 'border-box') {
//             minHeight = minHeight + paddingSize + borderSize;
//         }
//         height = Math.max(minHeight, height);
//     }
//     if (maxRows !== null) {
//         maxHeight = singleRowHeight * maxRows;
//         if (boxSizing === 'border-box') {
//             maxHeight = maxHeight + paddingSize + borderSize;
//         }
//         overflowY = height > maxHeight ? '' : 'hidden';
//         height = Math.min(maxHeight, height);
//     }
//
//     if (!maxRows) {
//         overflowY = 'hidden';
//     }
//
//     return {
//         height: `${height}px`,
//         minHeight: `${minHeight}px`,
//         maxHeight: `${maxHeight}px`,
//         overflowY
//     };
// }

const HIDDEN_TEXTAREA_STYLE = `
  min-height:0 !important;
  max-height:none !important;
  height:0 !important;
  visibility:hidden !important;
  overflow:hidden !important;
  position:absolute !important;
  z-index:-1000 !important;
  top:0 !important;
  right:0 !important
`;

const SIZING_STYLE = [
    'letter-spacing',
    'line-height',
    'padding-top',
    'padding-bottom',
    'font-family',
    'font-weight',
    'font-size',
    'text-rendering',
    'text-transform',
    'width',
    'text-indent',
    'padding-left',
    'padding-right',
    'border-width',
    'box-sizing',
];

let computedStyleCache = {};
let hiddenTextarea;

function calculateNodeStyling(node, useCache = false) {
    const nodeRef = (
            node.getAttribute('id') ||
            node.getAttribute('data-reactid') ||
            node.getAttribute('name'));

    if (useCache && computedStyleCache[nodeRef]) {
        return computedStyleCache[nodeRef];
    }

    const style = window.getComputedStyle(node);

    const boxSizing = (
        style.getPropertyValue('box-sizing') ||
        style.getPropertyValue('-moz-box-sizing') ||
        style.getPropertyValue('-webkit-box-sizing')
    );

    const paddingSize = (
        parseFloat(style.getPropertyValue('padding-bottom')) +
        parseFloat(style.getPropertyValue('padding-top'))
    );

    const borderSize = (
        parseFloat(style.getPropertyValue('border-bottom-width')) +
        parseFloat(style.getPropertyValue('border-top-width'))
    );

    const sizingStyle = SIZING_STYLE
        .map(name => `${name}:${style.getPropertyValue(name)}`)
        .join(';');

    const nodeInfo = {
        sizingStyle,
        paddingSize,
        borderSize,
        boxSizing,
    };

    if (useCache && nodeRef) {
        computedStyleCache[nodeRef] = nodeInfo;
    }

    return nodeInfo;
}

export default function calcTextareaHeight(uiTextNode, minRows = null, maxRows = null, useCache = false) {
    if (!hiddenTextarea) {
        hiddenTextarea = document.createElement('textarea');
        document.body.appendChild(hiddenTextarea);
    }

    // Fix wrap="off" issue
    // https://github.com/ant-design/ant-design/issues/6577
    if (uiTextNode.getAttribute('wrap')) {
        hiddenTextarea.setAttribute('wrap', uiTextNode.getAttribute('wrap'));
    } else {
        hiddenTextarea.removeAttribute('wrap');
    }

    // Copy all CSS properties that have an impact on the height of the content in
    // the textbox
    let {
        paddingSize, borderSize,
        boxSizing, sizingStyle,
    } = calculateNodeStyling(uiTextNode, useCache);

    // Need to have the overflow attribute to hide the scrollbar otherwise
    // text-lines will not calculated properly as the shadow will technically be
    // narrower for content
    hiddenTextarea.setAttribute('style', `${sizingStyle};${HIDDEN_TEXTAREA_STYLE}`);
    hiddenTextarea.value = uiTextNode.value || uiTextNode.placeholder || '';

    let minHeight = Number.MIN_SAFE_INTEGER;
    let maxHeight = Number.MAX_SAFE_INTEGER;
    let height = hiddenTextarea.scrollHeight;
    let overflowY;

    if (boxSizing === 'border-box') {
        // border-box: add border, since height = content + padding + border
        height = height + borderSize;
    } else if (boxSizing === 'content-box') {
        // remove padding, since height = content
        height = height - paddingSize;
    }

    if (minRows !== null || maxRows !== null) {
        // measure height of a textarea with a single row
        hiddenTextarea.value = ' ';
        let singleRowHeight = hiddenTextarea.scrollHeight - paddingSize;
        if (minRows !== null) {
            minHeight = singleRowHeight * minRows;
            if (boxSizing === 'border-box') {
                minHeight = minHeight + paddingSize + borderSize;
            }
            height = Math.max(minHeight, height);
        }
        if (maxRows !== null) {
            maxHeight = singleRowHeight * maxRows;
            if (boxSizing === 'border-box') {
                maxHeight = maxHeight + paddingSize + borderSize;
            }
            overflowY = height > maxHeight ? '' : 'hidden';
            height = Math.min(maxHeight, height);
        }
    }
    // Remove scroll bar flash when autosize without maxRows
    if (!maxRows) {
        overflowY = 'hidden';
    }

    return {
        height: `${height}px`,
        minHeight: `${minHeight}px`,
        maxHeight: `${maxHeight}px`,
        overflowY
    };
}