MultiCombobox: Add truncation behavior (#97691)

packages/grafana-ui/src/components/Combobox/MultiCombobox.internal.story.tsx

@@ -14,6 +14,8 @@ const commonArgs = {
     { label: 'Option 1', value: 'option1' },
     { label: 'Option 2', value: 'option2' },
     { label: 'Option 3', value: 'option3' },
+    { label: 'Option 4', value: 'option4' },
+    { label: 'Option 5', value: 'option5' },
   ],
   value: ['option2'],
   placeholder: 'Select multiple options...',

packages/grafana-ui/src/components/Combobox/MultiCombobox.test.tsx

@@ -86,13 +86,13 @@ describe('MultiCombobox', () => {
     expect(onChange).toHaveBeenNthCalledWith(3, [third]);
   });
 
-  it('should be able to render a valie that is not in the options', async () => {
+  it('should be able to render a value that is not in the options', async () => {
     const options = [
       { label: 'A', value: 'a' },
       { label: 'B', value: 'b' },
       { label: 'C', value: 'c' },
     ];
-    render(<MultiCombobox options={options} value={['a', 'd', 'c']} onChange={jest.fn()} />);
+    render(<MultiCombobox width={200} options={options} value={['a', 'd', 'c']} onChange={jest.fn()} />);
     await user.click(screen.getByRole('combobox'));
     expect(await screen.findByText('d')).toBeInTheDocument();
   });

packages/grafana-ui/src/components/Combobox/MultiCombobox.tsx

@@ -1,14 +1,19 @@
+import { cx } from '@emotion/css';
 import { useCombobox, useMultipleSelection } from 'downshift';
 import { useCallback, useMemo, useState } from 'react';
 
 import { useStyles2 } from '../../themes';
 import { Checkbox } from '../Forms/Checkbox';
+import { Box } from '../Layout/Box/Box';
 import { Portal } from '../Portal/Portal';
+import { Text } from '../Text/Text';
+import { Tooltip } from '../Tooltip';
 
 import { ComboboxOption, ComboboxBaseProps, AutoSizeConditionals, itemToString } from './Combobox';
 import { OptionListItem } from './OptionListItem';
 import { ValuePill } from './ValuePill';
 import { getMultiComboboxStyles } from './getMultiComboboxStyles';
+import { useMeasureMulti } from './useMeasureMulti';
 
 interface MultiComboboxBaseProps<T extends string | number> extends Omit<ComboboxBaseProps<T>, 'value' | 'onChange'> {
   value?: T[] | Array<ComboboxOption<T>>;
@@ -18,7 +23,7 @@ interface MultiComboboxBaseProps<T extends string | number> extends Omit<Combobo
 export type MultiComboboxProps<T extends string | number> = MultiComboboxBaseProps<T> & AutoSizeConditionals;
 
 export const MultiCombobox = <T extends string | number>(props: MultiComboboxProps<T>) => {
-  const { options, placeholder, onChange, value } = props;
+  const { options, placeholder, onChange, value, width } = props;
   const isAsync = typeof options === 'function';
 
   const selectedItems = useMemo(() => {
@@ -30,11 +35,13 @@ export const MultiCombobox = <T extends string | number>(props: MultiComboboxPro
     return getSelectedItemsFromValue<T>(value, options);
   }, [value, options, isAsync]);
 
-  const multiStyles = useStyles2(getMultiComboboxStyles);
-
   const [items, _baseSetItems] = useState(isAsync ? [] : options);
   const [isOpen, setIsOpen] = useState(false);
 
+  const multiStyles = useStyles2(getMultiComboboxStyles, isOpen);
+
+  const { measureRef, suffixMeasureRef, shownItems } = useMeasureMulti(selectedItems, width);
+
   const isOptionSelected = useCallback(
     (item: ComboboxOption<T>) => selectedItems.some((opt) => opt.value === item.value),
     [selectedItems]
@@ -114,25 +121,60 @@ export const MultiCombobox = <T extends string | number>(props: MultiComboboxPro
     },
   });
 
+  const visibleItems = isOpen ? selectedItems : selectedItems.slice(0, shownItems);
+
   return (
-    <div className={multiStyles.wrapper}>
-      <span className={multiStyles.pillWrapper}>
-        {selectedItems.map((item, index) => (
-          <ValuePill
-            onRemove={() => {
-              removeSelectedItem(item);
-            }}
-            key={`${item.value}${index}`}
-            {...getSelectedItemProps({ selectedItem: item, index })}
-          >
-            {itemToString(item)}
-          </ValuePill>
-        ))}
-      </span>
-      <input
-        className={multiStyles.input}
-        {...getInputProps(getDropdownProps({ preventKeyAction: isOpen, placeholder, onFocus: () => setIsOpen(true) }))}
-      />
+    <div>
+      <div
+        style={{ width: width === 'auto' ? undefined : width }}
+        className={multiStyles.wrapper}
+        ref={measureRef}
+        onClick={() => selectedItems.length > 0 && setIsOpen(!isOpen)}
+      >
+        <span className={multiStyles.pillWrapper}>
+          {visibleItems.map((item, index) => (
+            <ValuePill
+              onRemove={() => {
+                removeSelectedItem(item);
+              }}
+              key={`${item.value}${index}`}
+              {...getSelectedItemProps({ selectedItem: item, index })}
+            >
+              {itemToString(item)}
+            </ValuePill>
+          ))}
+          {selectedItems.length > shownItems && !isOpen && (
+            <Box display="flex" direction="row" marginLeft={0.5} gap={1} ref={suffixMeasureRef}>
+              {/* eslint-disable-next-line @grafana/no-untranslated-strings */}
+              <Text>...</Text>
+              <Tooltip
+                interactive
+                content={
+                  <>
+                    {selectedItems.slice(shownItems).map((item) => (
+                      <div key={item.value}>{itemToString(item)}</div>
+                    ))}
+                  </>
+                }
+              >
+                <div className={multiStyles.restNumber}>{selectedItems.length - shownItems}</div>
+              </Tooltip>
+            </Box>
+          )}
+          <input
+            className={cx(multiStyles.input, {
+              [multiStyles.inputClosed]: !isOpen && selectedItems.length > 0,
+            })}
+            {...getInputProps(
+              getDropdownProps({
+                preventKeyAction: isOpen,
+                placeholder: selectedItems.length > 0 ? undefined : placeholder,
+                onFocus: () => setIsOpen(true),
+              })
+            )}
+          />
+        </span>
+      </div>
       <div {...getMenuProps()}>
         <Portal>
           {isOpen && (

packages/grafana-ui/src/components/Combobox/ValuePill.tsx

@@ -15,7 +15,7 @@ export const ValuePill = forwardRef<HTMLSpanElement, ValuePillProps>(({ children
   const styles = useStyles2(getValuePillStyles);
   return (
     <span className={styles.wrapper} {...rest} ref={ref}>
-      {children}
+      <span className={styles.text}>{children}</span>
       <span className={styles.separator} />
       <IconButton
         name="times"
@@ -39,6 +39,18 @@ const getValuePillStyles = (theme: GrafanaTheme2) => ({
     background: theme.colors.background.secondary,
     padding: theme.spacing(0.25),
     fontSize: theme.typography.bodySmall.fontSize,
+    flexShrink: 0,
+    minWidth: '50px',
+
+    '&:first-child:has(+ div)': {
+      flexShrink: 1,
+    },
+  }),
+
+  text: css({
+    whiteSpace: 'nowrap',
+    overflow: 'hidden',
+    textOverflow: 'ellipsis',
   }),
 
   separator: css({

packages/grafana-ui/src/components/Combobox/getMultiComboboxStyles.ts

@@ -5,7 +5,7 @@ import { GrafanaTheme2 } from '@grafana/data';
 import { getFocusStyles } from '../../themes/mixins';
 import { getInputStyles } from '../Input/Input';
 
-export const getMultiComboboxStyles = (theme: GrafanaTheme2) => {
+export const getMultiComboboxStyles = (theme: GrafanaTheme2, isOpen: boolean) => {
   const inputStyles = getInputStyles({ theme });
   const focusStyles = getFocusStyles(theme);
 
@@ -34,10 +34,30 @@ export const getMultiComboboxStyles = (theme: GrafanaTheme2) => {
         outline: 'none',
       },
     }),
+    inputClosed: css({
+      width: 0,
+      flexGrow: 0,
+      paddingLeft: 0,
+      paddingRight: 0,
+    }),
     pillWrapper: css({
       display: 'inline-flex',
-      flexWrap: 'wrap',
+      flexWrap: isOpen ? 'wrap' : 'nowrap',
+      flexGrow: 1,
+      minWidth: '50px',
       gap: theme.spacing(0.5),
     }),
+    restNumber: css({
+      display: 'inline-flex',
+      alignItems: 'center',
+      justifyContent: 'center',
+      padding: theme.spacing(0, 1),
+      borderRadius: theme.shape.radius.default,
+      backgroundColor: theme.colors.background.secondary,
+      cursor: 'pointer',
+      '&:hover': {
+        backgroundColor: theme.colors.action.hover,
+      },
+    }),
   };
 };

packages/grafana-ui/src/components/Combobox/useMeasureMulti.ts

@@ -0,0 +1,44 @@
+import { useEffect, useState } from 'react';
+import { useMeasure } from 'react-use';
+
+import { measureText } from '../../utils';
+
+import { ComboboxOption } from './Combobox';
+
+const FONT_SIZE = 12;
+const EXTRA_PILL_SIZE = 50;
+
+/**
+ * Updates the number of shown items in the multi combobox based on the available width.
+ */
+export function useMeasureMulti<T extends string | number>(
+  selectedItems: Array<ComboboxOption<T>>,
+  width?: number | 'auto'
+) {
+  const [shownItems, setShownItems] = useState<number>(selectedItems.length);
+  const [measureRef, { width: containerWidth }] = useMeasure<HTMLDivElement>();
+  const [suffixMeasureRef, { width: suffixWidth }] = useMeasure<HTMLDivElement>();
+
+  const finalWidth = width && width !== 'auto' ? width : containerWidth;
+
+  useEffect(() => {
+    const maxWidth = finalWidth - suffixWidth;
+    let currWidth = 0;
+    for (let i = 0; i < selectedItems.length; i++) {
+      // Measure text width and add size of padding, separator and close button
+      currWidth += measureText(selectedItems[i].label || '', FONT_SIZE).width + EXTRA_PILL_SIZE;
+      if (currWidth > maxWidth) {
+        // If there is no space for that item, show the current number of items,
+        // but always show at least 1 item
+        setShownItems(i || 1);
+        break;
+      }
+      if (i === selectedItems.length - 1) {
+        // If it is the last item, show all items
+        setShownItems(selectedItems.length);
+      }
+    }
+  }, [finalWidth, suffixWidth, selectedItems, setShownItems]);
+
+  return { measureRef, suffixMeasureRef, shownItems };
+}