[DataGrid] Add fluid columns width support

docs/src/pages/components/data-grid/columns/ColumnFluidWidthGrid.js

@@ -0,0 +1,34 @@
+import * as React from 'react';
+import { DataGrid } from '@material-ui/data-grid';
+
+const rows = [
+  {
+    id: 1,
+    username: 'defunkt',
+    age: 38,
+  },
+];
+
+export default function ColumnFluidWidthGrid() {
+  return (
+    <div style={{ height: 250, width: '100%' }}>
+      <DataGrid
+        columns={[
+          {
+            field: 'id',
+            flex: 1,
+          },
+          {
+            field: 'username',
+            width: 200,
+          },
+          {
+            field: 'age',
+            flex: 0.3,
+          },
+        ]}
+        rows={rows}
+      />
+    </div>
+  );
+}

docs/src/pages/components/data-grid/columns/ColumnFluidWidthGrid.tsx

@@ -0,0 +1,34 @@
+import * as React from 'react';
+import { DataGrid } from '@material-ui/data-grid';
+
+const rows = [
+  {
+    id: 1,
+    username: 'defunkt',
+    age: 38,
+  },
+];
+
+export default function ColumnFluidWidthGrid() {
+  return (
+    <div style={{ height: 250, width: '100%' }}>
+      <DataGrid
+        columns={[
+          {
+            field: 'id',
+            flex: 1,
+          },
+          {
+            field: 'username',
+            width: 200,
+          },
+          {
+            field: 'age',
+            flex: 0.3,
+          },
+        ]}
+        rows={rows}
+      />
+    </div>
+  );
+}

docs/src/pages/components/data-grid/columns/columns.md

@@ -49,6 +49,22 @@ To change the width of a column, use the `width` property available in `ColDef`.
 
 {{"demo": "pages/components/data-grid/columns/ColumnWidthGrid.js", "bg": "inline"}}
 
+### Fluid width
+
+Each column has a fixed width of 100 pixels by default, but column fluidity (responsiveness) can be by achieved by setting the `flex` property in `ColDef`.
+
+The `flex` property accepts a value between 0 and ∞.
+
+The `flex` property works by dividing the remaining space in the grid among all flex columns in proportion to their `flex` value.
+For example, consider a grid with a total width of 500px that has three columns: the first with `width: 200`; the second with `flex: 1`; and third with `flex: 0.5`.
+The first column will be 200px wide, leaving 300px remaining. The column with `flex: 1` is twice the size of `flex: 0.5`, which means that final sizes will be: 200px, 200px, 100px.
+
+Note that `flex` doesn't work together with `width`. If you set both `flex` and `width` in `ColDef`, `flex` will override `width`.
+
+In addition, `flex` does not work if the combined width of the columns that have `width` is more than the width of the grid itself. If that is the case a scroll bar will be visible, and the columns that have `flex` will default back to their base value of 100px.
+
+{{"demo": "pages/components/data-grid/columns/ColumnFluidWidthGrid.js", "bg": "inline"}}
+
 ## Column resizing [<span role="img" title="Enterprise">⚡️</span>](https://material-ui.com/store/items/material-ui-x/)
 
 By default, `XGrid` allows all columns to be resized by dragging the right portion of the column separator.

packages/grid/_modules_/grid/components/styled-wrappers/GridRootStyles.ts

@@ -126,6 +126,10 @@ export const useStyles = makeStyles(
           cursor: 'col-resize',
           '&:hover, &.Mui-resizing': {
             color: theme.palette.text.primary,
+            // Reset on touch devices, it doesn't add specificity
+            '@media (hover: none)': {
+              color: borderColor,
+            },
           },
         },
         '& .MuiDataGrid-iconSeparator': {

packages/grid/_modules_/grid/hooks/features/columns/useColumns.ts

@@ -16,14 +16,47 @@ import { useApiMethod } from '../../root/useApiMethod';
 import { Logger, useLogger } from '../../utils/useLogger';
 import { useGridState } from '../core/useGridState';
 
+function mapColumns(
+  columns: Columns,
+  columnTypes: ColumnTypesRecord,
+  containerWidth: number,
+): Columns {
+  let extendedColumns = columns.map((c) => ({ ...getColDef(columnTypes, c.type), ...c }));
+  const numberOfFluidColumns = columns.filter((column) => !!column.flex).length;
+  let flexDivider = 0;
+
+  if (numberOfFluidColumns && containerWidth) {
+    extendedColumns.forEach((column) => {
+      if (!column.flex) {
+        containerWidth -= column.width!;
+      } else {
+        flexDivider += column.flex;
+      }
+    });
+  }
+
+  if (containerWidth > 0 && numberOfFluidColumns) {
+    const flexMultiplier = containerWidth / flexDivider;
+    extendedColumns = extendedColumns.map((column) => {
+      return {
+        ...column,
+        width: column.flex! ? Math.floor(flexMultiplier * column.flex!) : column.width,
+      };
+    });
+  }
+
+  return extendedColumns;
+}
+
 function hydrateColumns(
   columns: Columns,
   columnTypes: ColumnTypesRecord,
+  containerWidth: number,
   withCheckboxSelection: boolean,
   logger: Logger,
 ): Columns {
   logger.debug('Hydrating Columns with default definitions');
-  let mappedCols = columns.map((c) => ({ ...getColDef(columnTypes, c.type), ...c }));
+  let mappedCols = mapColumns(columns, columnTypes, containerWidth);
   if (withCheckboxSelection) {
     mappedCols = [checkboxSelectionColDef, ...mappedCols];
   }
@@ -58,14 +91,15 @@ function toMeta(logger: Logger, visibleColumns: Columns): ColumnsMeta {
 const resetState = (
   columns: Columns,
   columnTypes: ColumnTypesRecord,
+  containerWidth: number,
   withCheckboxSelection: boolean,
   logger: Logger,
 ): InternalColumns => {
   if (columns.length === 0) {
     return getInitialColumnsState();
   }
 
-  const all = hydrateColumns(columns, columnTypes, withCheckboxSelection, logger);
+  const all = hydrateColumns(columns, columnTypes, containerWidth, withCheckboxSelection, logger);
   const visible = filterVisible(logger, all);
   const meta = toMeta(logger, visible);
   const lookup = toLookup(logger, all);
@@ -115,7 +149,7 @@ const getUpdatedColumnState = (
 export function useColumns(columns: Columns, apiRef: ApiRef): InternalColumns {
   const logger = useLogger('useColumns');
   const [gridState, setGridState, forceUpdate] = useGridState(apiRef);
-
+  const viewportWidth = gridState.containerSizes ? gridState.containerSizes.viewportSize.width : 0;
   const updateState = React.useCallback(
     (newState: InternalColumns, emit = true) => {
       logger.debug('Updating columns state.');
@@ -134,6 +168,7 @@ export function useColumns(columns: Columns, apiRef: ApiRef): InternalColumns {
     const newState = resetState(
       columns,
       gridState.options.columnTypes,
+      viewportWidth,
       !!gridState.options.checkboxSelection,
       logger,
     );
@@ -142,6 +177,7 @@ export function useColumns(columns: Columns, apiRef: ApiRef): InternalColumns {
     columns,
     gridState.options.columnTypes,
     gridState.options.checkboxSelection,
+    viewportWidth,
     logger,
     updateState,
   ]);

packages/grid/_modules_/grid/models/colDef/colDef.ts

@@ -32,6 +32,10 @@ export interface ColDef {
    * @default 100
    */
   width?: number;
+  /**
+   * If set, it indicates that a column has fluid width. Range [0, ∞].
+   */
+  flex?: number;
   /**
    * If `true`, hide the column.
    * @default false;

packages/grid/data-grid/src/DataGrid.test.tsx

@@ -177,4 +177,122 @@ describe('<DataGrid />', () => {
       );
     });
   });
+
+  describe('column width', () => {
+    before(function beforeHook() {
+      if (/jsdom/.test(window.navigator.userAgent)) {
+        // Need layouting
+        this.skip();
+      }
+    });
+
+    it('should set the columns width to 100px by default', () => {
+      const rows = [
+        {
+          id: 1,
+          username: 'John Doe',
+          age: 30,
+        },
+      ];
+
+      const columns = [
+        {
+          field: 'id',
+        },
+        {
+          field: 'name',
+        },
+        {
+          field: 'age',
+        },
+      ];
+
+      const { getAllByRole } = render(
+        <div style={{ width: 300, height: 300 }}>
+          <DataGrid columns={columns} rows={rows} />
+        </div>,
+      );
+
+      const DOMColumns = getAllByRole('columnheader');
+      DOMColumns.forEach((col) => {
+        // @ts-expect-error need to migrate helpers to TypeScript
+        expect(col).toHaveInlineStyle({ width: '100px' });
+      });
+    });
+
+    it('should set the columns width value to what is provided', () => {
+      const rows = [
+        {
+          id: 1,
+          username: 'John Doe',
+          age: 30,
+        },
+      ];
+
+      const colWidthValues = [50, 50, 200];
+      const columns = [
+        {
+          field: 'id',
+          width: colWidthValues[0],
+        },
+        {
+          field: 'name',
+          width: colWidthValues[1],
+        },
+        {
+          field: 'age',
+          width: colWidthValues[2],
+        },
+      ];
+
+      const { getAllByRole } = render(
+        <div style={{ width: 300, height: 300 }}>
+          <DataGrid columns={columns} rows={rows} />
+        </div>,
+      );
+
+      const DOMColumns = getAllByRole('columnheader');
+      DOMColumns.forEach((col, index) => {
+        // @ts-expect-error need to migrate helpers to TypeScript
+        expect(col).toHaveInlineStyle({ width: `${colWidthValues[index]}px` });
+      });
+    });
+
+    it('should set the first column to be twice as wide as the second one', () => {
+      const rows = [
+        {
+          id: 1,
+          username: 'John Doe',
+          age: 30,
+        },
+      ];
+
+      const columns = [
+        {
+          field: 'id',
+          flex: 1,
+        },
+        {
+          field: 'name',
+          flex: 0.5,
+        },
+      ];
+
+      render(
+        <div style={{ width: 200, height: 300 }}>
+          <DataGrid columns={columns} rows={rows} />
+        </div>,
+      );
+
+      const firstColumn = document.querySelector('[role="columnheader"][aria-colindex="1"]');
+      const secondColumn: HTMLElement | null = document.querySelector(
+        '[role="columnheader"][aria-colindex="2"]',
+      );
+      const secondColumnWidthVal = secondColumn!.style.width.split('px')[0];
+      // @ts-expect-error need to migrate helpers to TypeScript
+      expect(firstColumn).toHaveInlineStyle({
+        width: `${2 * parseInt(secondColumnWidthVal, 10)}px`,
+      });
+    });
+  });
 });

packages/storybook/src/stories/grid-columns.stories.tsx

@@ -221,3 +221,54 @@ export function NewColumnTypes() {
     </div>
   );
 }
+
+export const FewFlexColumns = () => {
+  const data = useData(20, 3);
+  const transformColSizes = React.useCallback(
+    (columns: ColDef[]) =>
+      columns.map((col, index) =>
+        index % 2 === 0 ? { ...col, flex: index + 1 } : { ...col, width: 200 },
+      ),
+    [],
+  );
+
+  return (
+    <div className="grid-container">
+      <XGrid rows={data.rows} columns={transformColSizes(data.columns)} />
+    </div>
+  );
+};
+
+export const SeveralFlexColumn = () => {
+  const data = useData(20, 7);
+  const transformColSizes = React.useCallback(
+    (columns: ColDef[]) =>
+      columns.map((col, index) =>
+        index % 3 !== 0 ? { ...col, flex: index } : { ...col, flex: 1 },
+      ),
+    [],
+  );
+
+  return (
+    <div className="grid-container">
+      <XGrid rows={data.rows} columns={transformColSizes(data.columns)} />
+    </div>
+  );
+};
+
+export const FlexColumnWidth2000 = () => {
+  const data = useData(20, 3);
+  const transformColSizes = React.useCallback(
+    (columns: ColDef[]) =>
+      columns.map((col, index) =>
+        index % 2 !== 0 ? { ...col, width: 2000 } : { ...col, flex: index + 1 },
+      ),
+    [],
+  );
+
+  return (
+    <div className="grid-container">
+      <XGrid rows={data.rows} columns={transformColSizes(data.columns)} />
+    </div>
+  );
+};