feat: conditional selection of grid items (#6740)

* implement items selectable provider for single selection

* allow selectable provider to be null

* hide select all checkbox when using conditional selection

* add select all test cases

* make item selectable check handle undefined values

* update selected items when selecting null from server

* update tests

* handle null items

vaadin-grid-flow-parent/vaadin-grid-flow-integration-tests/src/main/java/com/vaadin/flow/component/grid/it/ConditionalSelectionPage.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2000-2024 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.component.grid.it;
+
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import com.vaadin.flow.component.grid.Grid;
+import com.vaadin.flow.component.html.Div;
+import com.vaadin.flow.component.html.NativeButton;
+import com.vaadin.flow.component.html.Span;
+import com.vaadin.flow.data.selection.SelectionEvent;
+import com.vaadin.flow.router.Route;
+
+@Route("vaadin-grid/conditional-selection")
+public class ConditionalSelectionPage extends Div {
+    private final Span selectedItems;
+
+    public ConditionalSelectionPage() {
+        Grid<Integer> grid = new Grid<>();
+        grid.setItems(IntStream.range(0, 10).boxed().toList());
+        grid.addColumn(i -> i).setHeader("Item");
+
+        selectedItems = new Span();
+        selectedItems.setId("selected-items");
+
+        NativeButton enableSingleSelect = new NativeButton(
+                "Enable single selection", e -> {
+                    grid.setSelectionMode(Grid.SelectionMode.SINGLE);
+                    grid.addSelectionListener(this::updateSelection);
+                });
+        enableSingleSelect.setId("enable-single-selection");
+
+        NativeButton enableMultiSelect = new NativeButton(
+                "Enable multi selection", e -> {
+                    grid.setSelectionMode(Grid.SelectionMode.MULTI);
+                    grid.addSelectionListener(this::updateSelection);
+                });
+        enableMultiSelect.setId("enable-multi-selection");
+
+        NativeButton disableSelectionFirstFive = new NativeButton(
+                "Disable selection for first five items", e -> {
+                    grid.setItemSelectableProvider(item -> item >= 5);
+                });
+        disableSelectionFirstFive.setId("disable-selection-first-five");
+
+        NativeButton allowSelectionFirstFive = new NativeButton(
+                "Allow selection for first five items", e -> {
+                    grid.setItemSelectableProvider(item -> item < 5);
+                });
+        allowSelectionFirstFive.setId("allow-selection-first-five");
+
+        add(grid);
+        add(new Div(enableSingleSelect, enableMultiSelect));
+        add(new Div(disableSelectionFirstFive, allowSelectionFirstFive));
+        add(new Div(new Span("Selected items: "), selectedItems));
+    }
+
+    private void updateSelection(
+            SelectionEvent<Grid<Integer>, Integer> selectionEvent) {
+        String items = selectionEvent.getAllSelectedItems().stream()
+                .map(Object::toString).collect(Collectors.joining(","));
+        selectedItems.setText(items);
+    }
+}

vaadin-grid-flow-parent/vaadin-grid-flow-integration-tests/src/test/java/com/vaadin/flow/component/grid/it/ConditionalSelectionIT.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright 2000-2024 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.component.grid.it;
+
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.vaadin.flow.component.grid.testbench.GridElement;
+import com.vaadin.flow.testutil.TestPath;
+import com.vaadin.testbench.TestBenchElement;
+import com.vaadin.tests.AbstractComponentIT;
+
+@TestPath("vaadin-grid/conditional-selection")
+public class ConditionalSelectionIT extends AbstractComponentIT {
+    private GridElement grid;
+
+    @Before
+    public void init() {
+        open();
+        grid = $(GridElement.class).waitForFirst();
+    }
+
+    @Test
+    public void singleSelect_clickRow_preventsSelection() {
+        $("button").id("enable-single-selection").click();
+        $("button").id("disable-selection-first-five").click();
+
+        // Prevents selection of non-selectable item
+        grid.select(0);
+        assertSelectedItems(Set.of());
+
+        // Allows selection of selectable item
+        grid.select(5);
+        assertSelectedItems(Set.of(5));
+    }
+
+    @Test
+    public void singleSelect_clickRow_preventsDeselection() {
+        $("button").id("enable-single-selection").click();
+        grid.select(0);
+
+        $("button").id("disable-selection-first-five").click();
+
+        // Prevents deselection of non-selectable item
+        grid.deselect(0);
+        assertSelectedItems(Set.of(0));
+
+        // Allows deselection of selectable item
+        grid.select(5);
+        grid.deselect(5);
+        assertSelectedItems(Set.of());
+    }
+
+    @Test
+    public void multiSelect_hidesCheckboxes() {
+        $("button").id("enable-multi-selection").click();
+        $("button").id("disable-selection-first-five").click();
+
+        Assert.assertFalse(getItemCheckbox(0).isDisplayed());
+        Assert.assertTrue(getItemCheckbox(5).isDisplayed());
+    }
+
+    @Test
+    public void multiSelect_updateProvider_updatesCheckboxes() {
+        $("button").id("enable-multi-selection").click();
+        $("button").id("disable-selection-first-five").click();
+
+        Assert.assertFalse(getItemCheckbox(0).isDisplayed());
+        Assert.assertTrue(getItemCheckbox(5).isDisplayed());
+
+        $("button").id("allow-selection-first-five").click();
+
+        Assert.assertTrue(getItemCheckbox(0).isDisplayed());
+        Assert.assertFalse(getItemCheckbox(5).isDisplayed());
+    }
+
+    private TestBenchElement getItemCheckbox(int index) {
+        return grid.getCell(index, 0).$("vaadin-checkbox").first();
+    }
+
+    private Set<Integer> getServerSelectedItems() {
+        var items = $("span").id("selected-items").getText();
+        return items.isEmpty() ? Set.of()
+                : Stream.of(items.split(",")).map(Integer::parseInt)
+                        .collect(Collectors.toSet());
+    }
+
+    @SuppressWarnings("unchecked")
+    private Set<Integer> getClientSelectedItems() {
+        var itemNames = (List<String>) getCommandExecutor().executeScript(
+                "return arguments[0].selectedItems.map(item => item.col0)",
+                grid);
+        return itemNames.stream().map(Integer::parseInt)
+                .collect(Collectors.toSet());
+    }
+
+    private void assertSelectedItems(Set<Integer> items) {
+        Assert.assertEquals(items, getServerSelectedItems());
+        Assert.assertEquals(items, getClientSelectedItems());
+    }
+}

vaadin-grid-flow-parent/vaadin-grid-flow-integration-tests/test/grid-connector-selection.test.ts

@@ -141,6 +141,95 @@ describe('grid connector - selection', () => {
         expect(grid.$server.deselect).not.to.be.called;
       });
     });
+
+    describe('conditional selection', () => {
+      let items;
+
+      beforeEach(async () => {
+        items = Array.from({ length: 4 }, (_, i) => ({
+          key: i.toString(),
+          name: i.toString(),
+          selectable: i >= 2
+        }));
+        setRootItems(grid.$connector, items);
+        await nextFrame();
+        grid.requestContentUpdate();
+      });
+
+      it('should prevent selection of non-selectable items on click', () => {
+        getBodyCellContent(grid, 0, 0)!.click();
+        expect(grid.selectedItems).to.be.empty;
+        expect(grid.$server.select).to.not.be.called;
+      });
+
+      it('should allow selection of selectable items on click', async () => {
+        getBodyCellContent(grid, 2, 0)!.click();
+        expect(grid.selectedItems).to.deep.equal([items[2]]);
+        expect(grid.$server.select).to.be.calledWith(items[2].key);
+      });
+
+      it('should prevent deselection of non-selectable items on click', () => {
+        grid.$connector.doSelection([items[0]], false);
+        getBodyCellContent(grid, 0, 0)!.click();
+        expect(grid.selectedItems).to.deep.equal([items[0]]);
+        expect(grid.$server.deselect).to.not.be.called;
+      });
+
+      it('should prevent deselection of non-selectable items when clicking another non-selectable item', () => {
+        grid.$connector.doSelection([items[0]], false);
+        getBodyCellContent(grid, 1, 0)!.click();
+        expect(grid.selectedItems).to.deep.equal([items[0]]);
+        expect(grid.$server.deselect).to.not.be.called;
+      });
+
+      it('should prevent deselection of non-selectable items on row click when active item data is stale', () => {
+        // item is selectable initially and is selected
+        grid.$connector.doSelection([items[2]], false);
+
+        // update grid items to make the item non-selectable
+        const updatedItems = items.map((item) => ({ ...item, selectable: false }));
+        setRootItems(grid.$connector, updatedItems);
+
+        // active item still references the original item with selectable: true
+        expect(grid.activeItem.selectable).to.be.true;
+
+        // however clicking the row should not deselect the item
+        getBodyCellContent(grid, 2, 0)!.click();
+        expect(grid.selectedItems).to.deep.equal([updatedItems[2]]);
+        expect(grid.$server.deselect).to.not.be.called;
+      });
+
+      it('should allow deselection of selectable items on row click', () => {
+        grid.$connector.doSelection([items[2]], false);
+        getBodyCellContent(grid, 2, 0)!.click();
+        expect(grid.selectedItems).to.be.empty;
+        expect(grid.$server.deselect).to.be.calledWith(items[2].key);
+      });
+
+      it('should always allow selection from server', () => {
+        // non-selectable item
+        grid.$connector.doSelection([items[0]], false);
+        expect(grid.selectedItems).to.deep.equal([items[0]]);
+        expect(grid.activeItem).to.deep.equal(items[0]);
+
+        // selectable item
+        grid.$connector.doSelection([items[2]], false);
+        expect(grid.selectedItems).to.deep.equal([items[2]]);
+        expect(grid.activeItem).to.deep.equal(items[2]);
+      })
+
+      it('should always allow deselection from server', () => {
+        // non-selectable item
+        grid.$connector.doSelection([items[0]], false);
+        grid.$connector.doDeselection([items[0]], false);
+        expect(grid.selectedItems).to.deep.equal([]);
+
+        // selectable item
+        grid.$connector.doSelection([items[2]], false);
+        grid.$connector.doDeselection([items[2]], false);
+        expect(grid.selectedItems).to.deep.equal([]);
+      })
+    });
   });
 
   describe('none selection mode', () => {

vaadin-grid-flow-parent/vaadin-grid-flow-integration-tests/test/shared.ts

@@ -46,6 +46,7 @@ export type Item = {
   key: string;
   name?: string;
   price?: number,
+  selectable?: boolean;
   selected?: boolean;
   detailsOpened?: boolean;
   style?: Record<string, string>;

vaadin-grid-flow-parent/vaadin-grid-flow/src/main/java/com/vaadin/flow/component/grid/AbstractGridMultiSelectionModel.java

@@ -75,8 +75,7 @@ public AbstractGridMultiSelectionModel(Grid<T> grid) {
                 this::clientDeselectAll);
         selectAllCheckBoxVisibility = SelectAllCheckboxVisibility.DEFAULT;
 
-        selectionColumn
-                .setSelectAllCheckBoxVisibility(isSelectAllCheckboxVisible());
+        updateSelectAllCheckBoxVisibility();
 
         if (grid.getElement().getNode().isAttached()) {
             this.insertSelectionColumn(grid, selectionColumn);
@@ -89,6 +88,11 @@ public AbstractGridMultiSelectionModel(Grid<T> grid) {
         }
     }
 
+    void updateSelectAllCheckBoxVisibility() {
+        selectionColumn
+                .setSelectAllCheckBoxVisibility(isSelectAllCheckboxVisible());
+    }
+
     private void insertSelectionColumn(Grid<T> grid,
             GridSelectionColumn selectionColumn) {
         grid.getElement().insertChild(0, selectionColumn.getElement());
@@ -105,7 +109,8 @@ protected void remove() {
 
     @Override
     public void selectFromClient(T item) {
-        if (isSelected(item)) {
+        boolean selectable = getGrid().isItemSelectable(item);
+        if (isSelected(item) || !selectable) {
             return;
         }
 
@@ -131,7 +136,8 @@ public void selectFromClient(T item) {
 
     @Override
     public void deselectFromClient(T item) {
-        if (!isSelected(item)) {
+        boolean selectable = getGrid().isItemSelectable(item);
+        if (!isSelected(item) || !selectable) {
             return;
         }
 
@@ -320,6 +326,10 @@ public SelectAllCheckboxVisibility getSelectAllCheckboxVisibility() {
 
     @Override
     public boolean isSelectAllCheckboxVisible() {
+        if (getGrid().getItemSelectableProvider() != null) {
+            return false;
+        }
+
         switch (selectAllCheckBoxVisibility) {
         case DEFAULT:
             return getGrid().getDataCommunicator().getDataProvider()
@@ -376,8 +386,8 @@ protected abstract void fireSelectionEvent(
             SelectionEvent<Grid<T>, T> event);
 
     protected void clientSelectAll() {
+        // ignore call if the checkbox is hidden
         if (!isSelectAllCheckboxVisible()) {
-            // ignore event if the checkBox was meant to be hidden
             return;
         }
         Stream<T> allItemsStream;
@@ -439,8 +449,8 @@ private Stream<T> fetchAllDescendants(T parent,
     }
 
     protected void clientDeselectAll() {
+        // ignore call if the checkbox is hidden
         if (!isSelectAllCheckboxVisible()) {
-            // ignore event if the checkBox was meant to be hidden
             return;
         }
         doUpdateSelection(Collections.emptySet(), getSelectedItems(), true);

vaadin-grid-flow-parent/vaadin-grid-flow/src/main/java/com/vaadin/flow/component/grid/AbstractGridSingleSelectionModel.java

@@ -60,7 +60,8 @@ public AbstractGridSingleSelectionModel(Grid<T> grid) {
 
     @Override
     public void selectFromClient(T item) {
-        if (isSelected(item)) {
+        boolean selectable = getGrid().isItemSelectable(item);
+        if (isSelected(item) || !selectable) {
             return;
         }
         doSelect(item, true);
@@ -78,8 +79,9 @@ public void select(T item) {
 
     @Override
     public void deselectFromClient(T item) {
-        if (isSelected(item) && isDeselectAllowed()) {
-            selectFromClient(null);
+        boolean selectable = getGrid().isItemSelectable(item);
+        if (isSelected(item) && selectable && isDeselectAllowed()) {
+            doSelect(null, true);
         }
     }