Maintenance release picks

src/main/java/com/vaadin/flow/component/grid/Grid.java

@@ -244,6 +244,8 @@ public static class Column<T> extends AbstractColumn<Column<T>> {
 
         private Registration columnDataGeneratorRegistration;
 
+        private Renderer<T> renderer;
+
         /**
          * Constructs a new Column for use inside a Grid.
          *
@@ -252,11 +254,13 @@ public static class Column<T> extends AbstractColumn<Column<T>> {
          * @param columnId
          *            unique identifier of this column
          * @param renderer
-         *            the renderer to use in this column
+         *            the renderer to use in this column, must not be {@code null}
          */
         public Column(Grid<T> grid, String columnId, Renderer<T> renderer) {
             super(grid);
+            Objects.requireNonNull(renderer);
             this.columnInternalId = columnId;
+            this.renderer = renderer;
 
             comparator = (a, b) -> 0;
 
@@ -285,6 +289,19 @@ protected String getInternalId() {
             return columnInternalId;
         }
 
+        /**
+         * Get the renderer used for this column.
+         *
+         * Note: Mutating the renderer after the Grid has been rendered
+         * on the client will not change the column, and can lead to
+         * undefined behavior.
+         *
+         * @return the renderer used for this column, should never be {@code null}
+         */
+        public Renderer<T> getRenderer() {
+            return renderer;
+        }
+
         /**
          * Sets the width of this column as a CSS-string.
          *

src/main/resources/META-INF/resources/frontend/gridConnector.js

@@ -133,15 +133,15 @@ window.Vaadin.Flow.gridConnector = {
       }
     }
 
-    const sorterChangeListener = function(event) {
+    const sorterChangeListener = function() {
       grid.$server.sortersChanged(grid._sorters.map(function(sorter) {
         return {
           path: sorter.path,
           direction: sorter.direction
         };
       }));
     }
-    grid.addEventListener('sorter-changed', sorterChangeListener);
+    grid._createPropertyObserver("_previousSorters", sorterChangeListener);
 
     const itemsUpdated = function(items) {
       if (!items || !Array.isArray(items)) {

src/test/java/com/vaadin/flow/component/grid/GridColumnTest.java

@@ -21,16 +21,23 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import com.vaadin.flow.component.Component;
 import com.vaadin.flow.component.grid.Grid.Column;
+import com.vaadin.flow.component.html.Label;
 import com.vaadin.flow.data.provider.SortDirection;
+import com.vaadin.flow.data.renderer.IconRenderer;
 import com.vaadin.flow.function.SerializableComparator;
+import com.vaadin.flow.function.SerializableFunction;
 
 public class GridColumnTest {
 
     Grid<String> grid;
     Column<String> firstColumn;
     Column<String> secondColumn;
     Column<String> thirdColumn;
+    Column<String> fourthColumn;
+
+    IconRenderer<String> renderer;
 
     @Rule
     public ExpectedException thrown = ExpectedException.none();
@@ -41,6 +48,8 @@ public void init() {
         firstColumn = grid.addColumn(str -> str);
         secondColumn = grid.addColumn(str -> str);
         thirdColumn = grid.addColumn(str -> str);
+        renderer = new IconRenderer<String>(generator -> new Label(":D"));
+        fourthColumn = grid.addColumn(renderer);
     }
 
     @Test
@@ -164,6 +173,11 @@ public void addColumn_defaultComparator() {
                 -1, result);
     }
 
+    @Test
+    public void testRenderer() {
+        assert renderer!= null;
+        Assert.assertEquals(renderer, fourthColumn.getRenderer());
+    }
     private void expectNullPointerException(String message) {
         thrown.expect(NullPointerException.class);
         thrown.expectMessage(message);

src/test/java/com/vaadin/flow/component/grid/it/ButtonInGridIT.java

@@ -16,7 +16,6 @@
 package com.vaadin.flow.component.grid.it;
 
 import org.junit.Assert;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.openqa.selenium.By;
 import org.openqa.selenium.Keys;
@@ -30,15 +29,6 @@
 public class ButtonInGridIT extends AbstractComponentIT {
 
     @Test
-    @Ignore
-    /**
-     * The test is disabled due #4268. The test is for grid#122 (which is
-     * actually an issue in the flow-component-renderer inside flow-data
-     * module).
-     *
-     * At the moment the bug is not fixed. So the test fails. Should be enabled
-     * back once the gird#122 is fixed.
-     */
     public void pressButtonUsingKeyboard() {
         open();