[TreeView] New API method: setItemExpansion

docs/data/tree-view/rich-tree-view/expansion/ChangeItemExpansion.js

@@ -0,0 +1,51 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import Stack from '@mui/material/Stack';
+import Button from '@mui/material/Button';
+import { RichTreeView } from '@mui/x-tree-view/RichTreeView';
+
+import { useTreeViewApiRef } from '@mui/x-tree-view/hooks';
+
+const MUI_X_PRODUCTS = [
+  {
+    id: 'grid',
+    label: 'Data Grid',
+    children: [
+      { id: 'grid-community', label: '@mui/x-data-grid' },
+      { id: 'grid-pro', label: '@mui/x-data-grid-pro' },
+      { id: 'grid-premium', label: '@mui/x-data-grid-premium' },
+    ],
+  },
+  {
+    id: 'pickers',
+    label: 'Date and Time Pickers',
+    children: [
+      { id: 'pickers-community', label: '@mui/x-date-pickers' },
+      { id: 'pickers-pro', label: '@mui/x-date-pickers-pro' },
+    ],
+  },
+];
+
+export default function ChangeItemExpansion() {
+  const apiRef = useTreeViewApiRef();
+
+  const handleExpandClick = (event) => {
+    apiRef.current.setItemExpansion(event, 'grid', true);
+  };
+
+  const handleCollapseClick = (event) => {
+    apiRef.current.setItemExpansion(event, 'grid', false);
+  };
+
+  return (
+    <Box sx={{ flexGrow: 1, maxWidth: 400 }}>
+      <Stack sx={{ mb: 1 }} spacing={2} direction="row">
+        <Button onClick={handleExpandClick}>Expand Data Grid</Button>
+        <Button onClick={handleCollapseClick}>Collapse Data Grid</Button>
+      </Stack>
+      <Box sx={{ minHeight: 220, flexGrow: 1 }}>
+        <RichTreeView items={MUI_X_PRODUCTS} apiRef={apiRef} />
+      </Box>
+    </Box>
+  );
+}

docs/data/tree-view/rich-tree-view/expansion/ChangeItemExpansion.tsx

@@ -0,0 +1,51 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import Stack from '@mui/material/Stack';
+import Button from '@mui/material/Button';
+import { RichTreeView } from '@mui/x-tree-view/RichTreeView';
+import { TreeViewBaseItem } from '@mui/x-tree-view/models';
+import { useTreeViewApiRef } from '@mui/x-tree-view/hooks';
+
+const MUI_X_PRODUCTS: TreeViewBaseItem[] = [
+  {
+    id: 'grid',
+    label: 'Data Grid',
+    children: [
+      { id: 'grid-community', label: '@mui/x-data-grid' },
+      { id: 'grid-pro', label: '@mui/x-data-grid-pro' },
+      { id: 'grid-premium', label: '@mui/x-data-grid-premium' },
+    ],
+  },
+  {
+    id: 'pickers',
+    label: 'Date and Time Pickers',
+    children: [
+      { id: 'pickers-community', label: '@mui/x-date-pickers' },
+      { id: 'pickers-pro', label: '@mui/x-date-pickers-pro' },
+    ],
+  },
+];
+
+export default function ChangeItemExpansion() {
+  const apiRef = useTreeViewApiRef();
+
+  const handleExpandClick = (event: React.MouseEvent) => {
+    apiRef.current!.setItemExpansion(event, 'grid', true);
+  };
+
+  const handleCollapseClick = (event: React.MouseEvent) => {
+    apiRef.current!.setItemExpansion(event, 'grid', false);
+  };
+
+  return (
+    <Box sx={{ flexGrow: 1, maxWidth: 400 }}>
+      <Stack sx={{ mb: 1 }} spacing={2} direction="row">
+        <Button onClick={handleExpandClick}>Expand Data Grid</Button>
+        <Button onClick={handleCollapseClick}>Collapse Data Grid</Button>
+      </Stack>
+      <Box sx={{ minHeight: 220, flexGrow: 1 }}>
+        <RichTreeView items={MUI_X_PRODUCTS} apiRef={apiRef} />
+      </Box>
+    </Box>
+  );
+}

docs/data/tree-view/rich-tree-view/expansion/ChangeItemExpansion.tsx.preview

@@ -0,0 +1,7 @@
+<Stack sx={{ mb: 1 }} spacing={2} direction="row">
+  <Button onClick={handleExpandClick}>Expand Data Grid</Button>
+  <Button onClick={handleCollapseClick}>Collapse Data Grid</Button>
+</Stack>
+<Box sx={{ minHeight: 220, flexGrow: 1 }}>
+  <RichTreeView items={MUI_X_PRODUCTS} apiRef={apiRef} />
+</Box>

docs/data/tree-view/rich-tree-view/expansion/expansion.md

@@ -32,3 +32,9 @@ Learn more about the _Controlled and uncontrolled_ pattern in the [React documen
 Use the `onItemExpansionToggle` prop if you want to react to an item expansion change:
 
 {{"demo": "TrackItemExpansionToggle.js"}}
+
+## Change item expansion
+
+You can use the `setItemExpansion` API method to imperatively change the expansion of an item:
+
+{{"demo": "ChangeItemExpansion.js"}}

docs/data/tree-view/simple-tree-view/expansion/ChangeItemExpansion.js

@@ -0,0 +1,41 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import Stack from '@mui/material/Stack';
+import Button from '@mui/material/Button';
+import { SimpleTreeView } from '@mui/x-tree-view/SimpleTreeView';
+import { TreeItem } from '@mui/x-tree-view/TreeItem';
+import { useTreeViewApiRef } from '@mui/x-tree-view/hooks';
+
+export default function ChangeItemExpansion() {
+  const apiRef = useTreeViewApiRef();
+
+  const handleExpandClick = (event) => {
+    apiRef.current.setItemExpansion(event, 'grid', true);
+  };
+
+  const handleCollapseClick = (event) => {
+    apiRef.current.setItemExpansion(event, 'grid', false);
+  };
+
+  return (
+    <Box sx={{ flexGrow: 1, maxWidth: 400 }}>
+      <Stack sx={{ mb: 1 }} spacing={2} direction="row">
+        <Button onClick={handleExpandClick}>Expand Data Grid</Button>
+        <Button onClick={handleCollapseClick}>Collapse Data Grid</Button>
+      </Stack>
+      <Box sx={{ minHeight: 220, flexGrow: 1 }}>
+        <SimpleTreeView apiRef={apiRef}>
+          <TreeItem itemId="grid" label="Data Grid">
+            <TreeItem itemId="grid-community" label="@mui/x-data-grid" />
+            <TreeItem itemId="grid-pro" label="@mui/x-data-grid-pro" />
+            <TreeItem itemId="grid-premium" label="@mui/x-data-grid-premium" />
+          </TreeItem>
+          <TreeItem itemId="pickers" label="Date and Time Pickers">
+            <TreeItem itemId="pickers-community" label="@mui/x-date-pickers" />
+            <TreeItem itemId="pickers-pro" label="@mui/x-date-pickers-pro" />
+          </TreeItem>
+        </SimpleTreeView>
+      </Box>
+    </Box>
+  );
+}

docs/data/tree-view/simple-tree-view/expansion/ChangeItemExpansion.tsx

@@ -0,0 +1,41 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import Stack from '@mui/material/Stack';
+import Button from '@mui/material/Button';
+import { SimpleTreeView } from '@mui/x-tree-view/SimpleTreeView';
+import { TreeItem } from '@mui/x-tree-view/TreeItem';
+import { useTreeViewApiRef } from '@mui/x-tree-view/hooks';
+
+export default function ChangeItemExpansion() {
+  const apiRef = useTreeViewApiRef();
+
+  const handleExpandClick = (event: React.MouseEvent) => {
+    apiRef.current!.setItemExpansion(event, 'grid', true);
+  };
+
+  const handleCollapseClick = (event: React.MouseEvent) => {
+    apiRef.current!.setItemExpansion(event, 'grid', false);
+  };
+
+  return (
+    <Box sx={{ flexGrow: 1, maxWidth: 400 }}>
+      <Stack sx={{ mb: 1 }} spacing={2} direction="row">
+        <Button onClick={handleExpandClick}>Expand Data Grid</Button>
+        <Button onClick={handleCollapseClick}>Collapse Data Grid</Button>
+      </Stack>
+      <Box sx={{ minHeight: 220, flexGrow: 1 }}>
+        <SimpleTreeView apiRef={apiRef}>
+          <TreeItem itemId="grid" label="Data Grid">
+            <TreeItem itemId="grid-community" label="@mui/x-data-grid" />
+            <TreeItem itemId="grid-pro" label="@mui/x-data-grid-pro" />
+            <TreeItem itemId="grid-premium" label="@mui/x-data-grid-premium" />
+          </TreeItem>
+          <TreeItem itemId="pickers" label="Date and Time Pickers">
+            <TreeItem itemId="pickers-community" label="@mui/x-date-pickers" />
+            <TreeItem itemId="pickers-pro" label="@mui/x-date-pickers-pro" />
+          </TreeItem>
+        </SimpleTreeView>
+      </Box>
+    </Box>
+  );
+}

docs/data/tree-view/simple-tree-view/expansion/expansion.md

@@ -31,3 +31,9 @@ Learn more about the _Controlled and uncontrolled_ pattern in the [React documen
 Use the `onItemExpansionToggle` prop to trigger an action upon an item being expanded.
 
 {{"demo": "TrackItemExpansionToggle.js"}}
+
+## Change item expansion
+
+You can use the `setItemExpansion` API method to imperatively change the expansion of an item:
+
+{{"demo": "ChangeItemExpansion.js"}}

docs/pages/x/api/tree-view/rich-tree-view.json

@@ -1,7 +1,10 @@
 {
   "props": {
     "apiRef": {
-      "type": { "name": "shape", "description": "{ current?: { focusItem: func, getItem: func } }" }
+      "type": {
+        "name": "shape",
+        "description": "{ current?: { focusItem: func, getItem: func, setItemExpansion: func } }"
+      }
     },
     "classes": { "type": { "name": "object" }, "additionalInfo": { "cssApi": true } },
     "defaultExpandedItems": {

docs/pages/x/api/tree-view/simple-tree-view.json

@@ -1,7 +1,10 @@
 {
   "props": {
     "apiRef": {
-      "type": { "name": "shape", "description": "{ current?: { focusItem: func, getItem: func } }" }
+      "type": {
+        "name": "shape",
+        "description": "{ current?: { focusItem: func, getItem: func, setItemExpansion: func } }"
+      }
     },
     "children": { "type": { "name": "node" } },
     "classes": { "type": { "name": "object" }, "additionalInfo": { "cssApi": true } },

docs/pages/x/api/tree-view/tree-view.json

@@ -1,7 +1,10 @@
 {
   "props": {
     "apiRef": {
-      "type": { "name": "shape", "description": "{ current?: { focusItem: func, getItem: func } }" }
+      "type": {
+        "name": "shape",
+        "description": "{ current?: { focusItem: func, getItem: func, setItemExpansion: func } }"
+      }
     },
     "children": { "type": { "name": "node" } },
     "classes": { "type": { "name": "object" }, "additionalInfo": { "cssApi": true } },

packages/x-tree-view/src/RichTreeView/RichTreeView.tsx

@@ -153,6 +153,7 @@ RichTreeView.propTypes = {
     current: PropTypes.shape({
       focusItem: PropTypes.func.isRequired,
       getItem: PropTypes.func.isRequired,
+      setItemExpansion: PropTypes.func.isRequired,
     }),
   }),
   /**

packages/x-tree-view/src/SimpleTreeView/SimpleTreeView.tsx

@@ -116,6 +116,7 @@ SimpleTreeView.propTypes = {
     current: PropTypes.shape({
       focusItem: PropTypes.func.isRequired,
       getItem: PropTypes.func.isRequired,
+      setItemExpansion: PropTypes.func.isRequired,
     }),
   }),
   /**

packages/x-tree-view/src/TreeItem/TreeItem.test.tsx

@@ -24,6 +24,7 @@ const TEST_TREE_VIEW_CONTEXT_VALUE: TreeViewContextValue<SimpleTreeViewPlugins>
   publicAPI: {
     focusItem: () => {},
     getItem: () => ({}),
+    setItemExpansion: () => {},
   },
   runItemPlugins: () => ({ rootRef: null, contentRef: null }),
   wrapItem: ({ children }) => children,

packages/x-tree-view/src/TreeView/TreeView.tsx

@@ -93,6 +93,7 @@ TreeView.propTypes = {
     current: PropTypes.shape({
       focusItem: PropTypes.func.isRequired,
       getItem: PropTypes.func.isRequired,
+      setItemExpansion: PropTypes.func.isRequired,
     }),
   }),
   /**

packages/x-tree-view/src/internals/plugins/useTreeViewExpansion/useTreeViewExpansion.test.tsx

@@ -300,5 +300,77 @@ describeTreeView<UseTreeViewExpansionSignature>(
         expect(onItemExpansionToggle.lastCall.args[2]).to.equal(false);
       });
     });
+
+    describe('setItemExpansion api method', () => {
+      it('should expand a collapsed item when calling the setItemExpansion method with `isExpanded=true`', () => {
+        const onItemExpansionToggle = spy();
+
+        const response = render({
+          items: [{ id: '1', children: [{ id: '1.1' }] }],
+          onItemExpansionToggle,
+        });
+
+        act(() => {
+          response.apiRef.current.setItemExpansion({} as any, '1', true);
+        });
+
+        expect(response.isItemExpanded('1')).to.equal(true);
+        expect(onItemExpansionToggle.callCount).to.equal(1);
+        expect(onItemExpansionToggle.lastCall.args[1]).to.equal('1');
+        expect(onItemExpansionToggle.lastCall.args[2]).to.equal(true);
+      });
+
+      it('should collapse an expanded item when calling the setItemExpansion method with `isExpanded=false`', () => {
+        const onItemExpansionToggle = spy();
+
+        const response = render({
+          items: [{ id: '1', children: [{ id: '1.1' }] }],
+          defaultExpandedItems: ['1'],
+          onItemExpansionToggle,
+        });
+
+        act(() => {
+          response.apiRef.current.setItemExpansion({} as any, '1', false);
+        });
+
+        expect(response.isItemExpanded('1')).to.equal(false);
+        expect(onItemExpansionToggle.callCount).to.equal(1);
+        expect(onItemExpansionToggle.lastCall.args[1]).to.equal('1');
+        expect(onItemExpansionToggle.lastCall.args[2]).to.equal(false);
+      });
+
+      it('should do nothing when calling the setItemExpansion method with `isExpanded=true` on an already expanded item', () => {
+        const onItemExpansionToggle = spy();
+
+        const response = render({
+          items: [{ id: '1', children: [{ id: '1.1' }] }],
+          defaultExpandedItems: ['1'],
+          onItemExpansionToggle,
+        });
+
+        act(() => {
+          response.apiRef.current.setItemExpansion({} as any, '1', true);
+        });
+
+        expect(response.isItemExpanded('1')).to.equal(true);
+        expect(onItemExpansionToggle.callCount).to.equal(0);
+      });
+
+      it('should do nothing when calling the setItemExpansion method with `isExpanded=false` on an already collapsed item', () => {
+        const onItemExpansionToggle = spy();
+
+        const response = render({
+          items: [{ id: '1', children: [{ id: '1.1' }] }],
+          onItemExpansionToggle,
+        });
+
+        act(() => {
+          response.apiRef.current.setItemExpansion({} as any, '1', false);
+        });
+
+        expect(response.isItemExpanded('1')).to.equal(false);
+        expect(onItemExpansionToggle.callCount).to.equal(0);
+      });
+    });
   },
 );