Merge pull request #134 from blockscout/text-cut

page description cut

ui/shared/AccountPageDescription.tsx

-import { Text } from '@chakra-ui/react';
-import React from 'react';
+import { Box, Text, useColorModeValue } from '@chakra-ui/react';
+import _debounce from 'lodash/debounce';
+import React, { useRef, useEffect, useState, useCallback } from 'react';
+
+const CUT_HEIGHT = 144;
 
 const AccountPageDescription = ({ children }: {children: React.ReactNode}) => {
+  const ref = useRef<HTMLParagraphElement>(null);
+
+  const [ needCut, setNeedCut ] = useState(false);
+  const [ expanded, setExpanded ] = useState(false);
+
+  const calculateCut = useCallback(() => {
+    const textHeight = ref.current?.offsetHeight;
+    if (!needCut && textHeight && textHeight > CUT_HEIGHT) {
+      setNeedCut(true);
+    } else if (needCut && textHeight && textHeight < CUT_HEIGHT) {
+      setNeedCut(false);
+    }
+  }, [ needCut ]);
+
+  useEffect(() => {
+    calculateCut();
+    const resizeHandler = _debounce(calculateCut, 300);
+    window.addEventListener('resize', resizeHandler);
+    return function cleanup() {
+      window.removeEventListener('resize', resizeHandler);
+    };
+  }, [ calculateCut ]);
+
+  const expand = useCallback(() => {
+    setExpanded(true);
+  }, []);
+
+  const gradient = useColorModeValue(
+    'linear-gradient(360deg, rgba(255, 255, 255, 0.8) 38.1%, rgba(255, 255, 255, 0) 166.67%)',
+    'linear-gradient(360deg, rgba(16, 17, 18, 0.8) 38.1%, rgba(16, 17, 18, 0) 166.67%)',
+  );
+
   return (
-    <Text marginBottom={{ base: 6, lg: 12 }}>
-      { children }
-    </Text>
+    <Box position="relative" marginBottom={{ base: 6, lg: 12 }}>
+      <Text
+        ref={ ref }
+        maxHeight={ needCut && !expanded ? `${ CUT_HEIGHT }px` : 'auto' }
+        overflow="hidden"
+
+        style={ needCut && !expanded ? { WebkitLineClamp: '6', WebkitBoxOrient: 'vertical', display: '-webkit-box' } : {} }
+      >
+        { children }
+      </Text>
+      { needCut && !expanded && (
+        <Box
+          position="absolute"
+          bottom="-16px"
+          left={ 0 }
+          width="100%"
+          height="63px"
+          style={{ background: gradient }}
+          onClick={ expand }
+        >
+        </Box>
+      ) }
+    </Box>
   );
 };