NoSelectionModel for Grid

Fixes vaadin/framework8-issues#518

Change-Id: Ice6bdef03c3b62dd2c74376f98cfb8004dfa0bbf

2 files changed, 140 insertions, 0 deletions

diff --git a/server/src/main/java/com/vaadin/ui/components/grid/NoSelectionModel.java b/server/src/main/java/com/vaadin/ui/components/grid/NoSelectionModel.java
new file mode 100644
index 0000000000..047ee54491
--- /dev/null
+++ b/server/src/main/java/com/vaadin/ui/components/grid/NoSelectionModel.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2000-2016 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.ui.components.grid;
+
+import java.util.Collections;
+import java.util.Optional;
+import java.util.Set;
+
+import com.vaadin.server.AbstractExtension;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.Grid.GridSelectionModel;
+
+/**
+ * Selection model that doesn't allow selecting anything from the grid.
+ *
+ * @author Vaadin Ltd
+ *
+ * @since 8.0
+ *
+ * @param <T>
+ *            the type of items in the grid
+ */
+public class NoSelectionModel<T> extends AbstractExtension
+        implements GridSelectionModel<T> {
+
+    /**
+     * Creates a new no selection model and attaches it for the given grid.
+     *
+     * @param grid
+     *            the grid to bind the selection model into
+     */
+    public NoSelectionModel(Grid<T> grid) {
+        extend(grid);
+    }
+
+    @Override
+    public Set<T> getSelectedItems() {
+        return Collections.emptySet();
+    }
+
+    @Override
+    public Optional<T> getFirstSelectedItem() {
+        return Optional.empty();
+    }
+
+    @Override
+    public void select(T item) {
+    }
+
+    @Override
+    public void deselect(T item) {
+    }
+
+    @Override
+    public void deselectAll() {
+    }
+
+}
\ No newline at end of file
diff --git a/server/src/test/java/com/vaadin/tests/components/grid/GridNoSelectionModelTest.java b/server/src/test/java/com/vaadin/tests/components/grid/GridNoSelectionModelTest.java
new file mode 100644
index 0000000000..15456bd950
--- /dev/null
+++ b/server/src/test/java/com/vaadin/tests/components/grid/GridNoSelectionModelTest.java
@@ -0,0 +1,69 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.Arrays;
+import java.util.LinkedHashSet;
+import java.util.Optional;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.vaadin.server.data.provider.bov.Person;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.Grid.GridSelectionModel;
+import com.vaadin.ui.components.grid.MultiSelectionModelImpl;
+import com.vaadin.ui.components.grid.NoSelectionModel;
+import com.vaadin.ui.components.grid.SingleSelectionModelImpl;
+
+public class GridNoSelectionModelTest {
+
+    public static final Person PERSON_C = new Person("c", 3);
+    public static final Person PERSON_B = new Person("b", 2);
+    public static final Person PERSON_A = new Person("a", 1);
+
+    private Grid<Person> grid;
+    private GridSelectionModel<Person> model;
+
+    @Before
+    public void setUp() {
+        grid = new Grid<>();
+        grid.setItems(PERSON_A, PERSON_B, PERSON_C);
+
+        model = new NoSelectionModel<>(grid);
+        grid.setSelectionModel(model);
+    }
+
+    @Test
+    public void select() {
+        model.select(PERSON_A);
+
+        Assert.assertFalse(model.isSelected(PERSON_A));
+        Assert.assertEquals(0, model.getSelectedItems().size());
+        Assert.assertEquals(Optional.empty(), model.getFirstSelectedItem());
+
+        model.select(PERSON_B);
+
+        Assert.assertFalse(model.isSelected(PERSON_B));
+        Assert.assertEquals(0, model.getSelectedItems().size());
+        Assert.assertEquals(Optional.empty(), model.getFirstSelectedItem());
+    }
+
+    @Test
+    public void changingToSingleSelectionModel() {
+        grid.setSelectionModel(new SingleSelectionModelImpl<>(grid));
+
+        grid.getSelectionModel().select(PERSON_B);
+        Assert.assertEquals(PERSON_B,
+                grid.getSelectionModel().getFirstSelectedItem().get());
+    }
+
+    @Test
+    public void changingToMultiSelectionModel() {
+        grid.setSelectionModel(new MultiSelectionModelImpl<>(grid));
+
+        grid.getSelectionModel().select(PERSON_B);
+        Assert.assertEquals(new LinkedHashSet<>(Arrays.asList(PERSON_B)),
+                grid.getSelectionModel().getSelectedItems());
+    }
+
+}