Add scrollTo methods to Grid (#8203) (#8410)

* Add scroll methods to serverside grid (#8203)

Added scrollToTop(), scrollToEnd() and scrollTo(int row)

* Fix scrolling to view of opened details (#8203)

Removed dependency for DetailsManagerConnector from GridConnector.
GridConnector now handles one off listeners.

* Rename detailsRefresh to better show that it's one-off.
Add missing copyright header.

5 files changed, 763 insertions, 0 deletions

diff --git a/uitest/src/main/java/com/vaadin/tests/components/grid/GridDetailsLocation.java b/uitest/src/main/java/com/vaadin/tests/components/grid/GridDetailsLocation.java
new file mode 100644
index 0000000000..74e8f44b1f
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/grid/GridDetailsLocation.java
@@ -0,0 +1,73 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.tests.util.Person;
+import com.vaadin.tests.util.PersonContainer;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.CheckBox;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.TextField;
+
+public class GridDetailsLocation extends AbstractTestUI {
+
+    private TextField numberTextField;
+    private Grid<Person> grid;
+    private List<Person> testData;
+
+    @Override
+    protected void setup(VaadinRequest request) {
+
+        grid = new Grid<>();
+        testData = new ArrayList<>(PersonContainer.createTestData(1000));
+        grid.setItems(testData);
+        grid.addColumn(item -> item.getFirstName()).setCaption("First Name");
+        grid.addColumn(item -> item.getLastName()).setCaption("Last Name");
+
+        grid.setSelectionMode(Grid.SelectionMode.NONE);
+        addComponent(grid);
+
+        final CheckBox checkbox = new CheckBox("Details generator");
+        checkbox.addValueChangeListener(event -> {
+            if (checkbox.getValue()) {
+                grid.setDetailsGenerator(person -> {
+                    Label label = new Label(
+                            person.getFirstName() + " " + person.getLastName());
+                    // currently the decorator row doesn't change its height
+                    // when the content height is different.
+                    label.setHeight("30px");
+                    return label;
+                });
+            } else {
+                grid.setDetailsGenerator(null);
+            }
+        });
+        addComponent(checkbox);
+
+        numberTextField = new TextField("Row");
+        addComponent(numberTextField);
+
+        addComponent(new Button("Toggle and scroll", clickEvent -> {
+            toggle();
+            scrollTo();
+        }));
+        addComponent(new Button("Scroll and toggle", clickEvent -> {
+            scrollTo();
+            toggle();
+        }));
+    }
+
+    private void toggle() {
+        Person itemId = testData.get(Integer.parseInt(numberTextField.getValue()));
+        boolean isVisible = grid.isDetailsVisible(itemId);
+        grid.setDetailsVisible(itemId, !isVisible);
+    }
+
+    private void scrollTo() {
+        grid.scrollTo(Integer.parseInt(numberTextField.getValue()));
+    }
+}
diff --git a/uitest/src/main/java/com/vaadin/tests/components/grid/GridFastAsyncUpdate.java b/uitest/src/main/java/com/vaadin/tests/components/grid/GridFastAsyncUpdate.java
new file mode 100644
index 0000000000..3f4391d504
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/grid/GridFastAsyncUpdate.java
@@ -0,0 +1,169 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.Calendar;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.logging.Level;
+
+import com.vaadin.annotations.Push;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.HorizontalLayout;
+import com.vaadin.ui.VerticalLayout;
+
+@Push
+public class GridFastAsyncUpdate extends AbstractTestUI {
+
+    private final Runnable addRowsTask = new Runnable() {
+        @Override
+        public void run() {
+            System.out.println("Logging...");
+            try {
+                Random random = new Random();
+                while (!Thread.currentThread().isInterrupted()) {
+                    Thread.sleep(random.nextInt(100));
+
+                    GridFastAsyncUpdate.this.access(() -> {
+                        ++counter;
+                        Item item = new Item(counter,
+                                (Calendar.getInstance().getTimeInMillis()
+                                        - loggingStart),
+                                Level.INFO.toString(), "Message");
+                        items.add(item);
+                        grid.setItems(items);
+
+                        if (grid != null && !scrollLock) {
+                            grid.scrollToEnd();
+                        }
+                    });
+                }
+            } catch (InterruptedException e) {
+                System.out.println("logging thread interrupted");
+            }
+        }
+    };
+
+    private int counter;
+    private List<Item> items = new LinkedList<>();
+
+    private Grid<Item> grid;
+    private long loggingStart;
+    private volatile boolean scrollLock = false;
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        final VerticalLayout layout = new VerticalLayout();
+        layout.setSizeFull();
+        layout.setMargin(true);
+        addComponent(layout);
+
+        HorizontalLayout buttons = new HorizontalLayout();
+        layout.addComponent(buttons);
+
+        final ExecutorService logExecutor = Executors.newSingleThreadExecutor();
+
+        final Button logButton = new Button("Start logging");
+        logButton.addClickListener(clickEvent -> {
+            if ("Start logging".equals(logButton.getCaption())) {
+                loggingStart = Calendar.getInstance().getTimeInMillis();
+                logExecutor.submit(addRowsTask);
+                logButton.setCaption("Stop logging");
+            } else {
+                System.out.println("Stop logging...");
+                try {
+                    logExecutor.shutdownNow();
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+                logButton.setCaption("Start logging");
+            }
+        });
+        buttons.addComponent(logButton);
+
+        final Button scrollButton = new Button("Stop scrolling");
+        scrollButton.addClickListener(clickEvent -> {
+            if (!scrollLock) {
+                System.out.println("Stop scrolling");
+                scrollButton.setCaption("Start scrolling");
+                scrollLock = true;
+            } else {
+                System.out.println("Start scrolling");
+                scrollButton.setCaption("Stop scrolling");
+                scrollLock = false;
+            }
+        });
+        buttons.addComponent(scrollButton);
+
+        grid = new Grid<>();
+        grid.addColumn(Item::getSequenceNumber).setCaption("");
+        grid.addColumn(Item::getMillis).setCaption("");
+        grid.addColumn(Item::getLevel).setCaption("");
+        grid.addColumn(Item::getMessage).setCaption("");
+
+        grid.setWidth("100%");
+        grid.setSelectionMode(Grid.SelectionMode.SINGLE);
+        grid.addSelectionListener(selectionEvent -> {
+            if (!selectionEvent.getAllSelectedItems().isEmpty()) {
+                disableScroll();
+            }
+        });
+
+        layout.addComponent(grid);
+        layout.setExpandRatio(grid, 1.0f);
+    }
+
+    protected void disableScroll() {
+        scrollLock = true;
+    }
+
+    protected class Item {
+        Integer sequenceNumber;
+        Long millis;
+        String level, message;
+
+        public Item(Integer sequanceNumber, Long millis, String level,
+                String message) {
+            this.sequenceNumber = sequanceNumber;
+            this.millis = millis;
+            this.level = level;
+            this.message = message;
+        }
+
+        public Integer getSequenceNumber() {
+            return sequenceNumber;
+        }
+
+        public void setSequenceNumber(Integer sequenceNumber) {
+            this.sequenceNumber = sequenceNumber;
+        }
+
+        public Long getMillis() {
+            return millis;
+        }
+
+        public void setMillis(Long millis) {
+            this.millis = millis;
+        }
+
+        public String getLevel() {
+            return level;
+        }
+
+        public void setLevel(String level) {
+            this.level = level;
+        }
+
+        public String getMessage() {
+            return message;
+        }
+
+        public void setMessage(String message) {
+            this.message = message;
+        }
+    }
+}
diff --git a/uitest/src/main/java/com/vaadin/tests/components/grid/GridScrollTo.java b/uitest/src/main/java/com/vaadin/tests/components/grid/GridScrollTo.java
new file mode 100644
index 0000000000..9f83436a11
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/grid/GridScrollTo.java
@@ -0,0 +1,67 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.vaadin.data.ValueProvider;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.HorizontalLayout;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.TextField;
+
+public class GridScrollTo extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        List<String> data = new ArrayList<>();
+        for (int i = 0; i < 200; i++) {
+            data.add("Name " + i);
+        }
+
+        Grid<String> grid = new Grid<>();
+        grid.setItems(data);
+
+        grid.setSelectionMode(Grid.SelectionMode.NONE);
+
+        grid.addColumn(ValueProvider.identity()).setId("Name")
+                .setCaption("Name");
+
+        grid.setDetailsGenerator(item -> {
+            final HorizontalLayout detailsLayout = new HorizontalLayout();
+            detailsLayout.setWidth(100, Unit.PERCENTAGE);
+            detailsLayout.setHeightUndefined();
+
+            final Label lbl1 = new Label(item + " details");
+            detailsLayout.addComponent(lbl1);
+            return detailsLayout;
+        });
+
+        grid.addItemClickListener(event -> {
+            final String itemId = event.getItem();
+            grid.setDetailsVisible(itemId, !grid.isDetailsVisible(itemId));
+        });
+
+        Button scrollToTop = new Button("Scroll to top",
+                clickEvent -> grid.scrollToStart());
+        scrollToTop.setId("top");
+
+        Button scrollToEnd = new Button("Scroll to end",
+                clickEvent -> grid.scrollToEnd());
+        scrollToEnd.setId("end");
+
+        TextField rowField = new TextField("Target row");
+        rowField.setId("row-field");
+
+        Button scrollToRow = new Button("Scroll to row", clickEvent -> grid
+                .scrollTo(Integer.parseInt(rowField.getValue())));
+        scrollToRow.setId("row");
+
+        addComponent(grid);
+
+        addComponent(new HorizontalLayout(scrollToTop, scrollToEnd, rowField,
+                scrollToRow));
+    }
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/GridDetailsLocationTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/GridDetailsLocationTest.java
new file mode 100644
index 0000000000..e54fe8b0d3
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/GridDetailsLocationTest.java
@@ -0,0 +1,303 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.Keys;
+import org.openqa.selenium.StaleElementReferenceException;
+import org.openqa.selenium.WebDriver;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.support.ui.ExpectedCondition;
+
+import com.vaadin.testbench.TestBenchElement;
+import com.vaadin.testbench.elements.ButtonElement;
+import com.vaadin.testbench.elements.CheckBoxElement;
+import com.vaadin.testbench.elements.GridElement;
+import com.vaadin.testbench.elements.TextFieldElement;
+import com.vaadin.testbench.parallel.TestCategory;
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+@TestCategory("grid")
+public class GridDetailsLocationTest extends MultiBrowserTest {
+
+    private static final int detailsDefaultHeight = 51;
+    private static final int detailsDefinedHeight = 33;
+
+    private static class Param {
+        private final int rowIndex;
+        private final boolean useGenerator;
+        private final boolean scrollFirstToBottom;
+
+        public Param(int rowIndex, boolean useGenerator,
+                boolean scrollFirstToBottom) {
+            this.rowIndex = rowIndex;
+            this.useGenerator = useGenerator;
+            this.scrollFirstToBottom = scrollFirstToBottom;
+        }
+
+        public int getRowIndex() {
+            return rowIndex;
+        }
+
+        public boolean useGenerator() {
+            return useGenerator;
+        }
+
+        public boolean scrollFirstToBottom() {
+            return scrollFirstToBottom;
+        }
+
+        @Override
+        public String toString() {
+            return "Param [rowIndex=" + getRowIndex() + ", useGenerator="
+                    + useGenerator() + ", scrollFirstToBottom="
+                    + scrollFirstToBottom() + "]";
+        }
+
+    }
+
+    public static Collection<Param> parameters() {
+        List<Param> data = new ArrayList<>();
+
+        int[] params = new int[] { 0, 500, 999 };
+
+        for (int rowIndex : params) {
+
+            data.add(new Param(rowIndex, true, false));
+            data.add(new Param(rowIndex, true, true));
+        }
+
+        return data;
+    }
+
+    @Before
+    public void setUp() {
+        setDebug(true);
+    }
+
+    @Test
+    public void toggleAndScroll() throws Throwable {
+        for (Param param : parameters()) {
+            try {
+                openTestURL();
+                useGenerator(param.useGenerator());
+                scrollToBottom(param.scrollFirstToBottom());
+
+                // the tested method
+                toggleAndScroll(param.getRowIndex());
+
+                verifyLocation(param);
+            } catch (Throwable t) {
+                throw new Throwable("" + param, t);
+            }
+        }
+    }
+
+    @Test
+    public void scrollAndToggle() throws Throwable {
+        for (Param param : parameters()) {
+            try {
+                openTestURL();
+                useGenerator(param.useGenerator());
+                scrollToBottom(param.scrollFirstToBottom());
+
+                // the tested method
+                scrollAndToggle(param.getRowIndex());
+
+                verifyLocation(param);
+
+            } catch (Throwable t) {
+                throw new Throwable("" + param, t);
+            }
+        }
+    }
+
+    @Test
+    public void testDetailsHeightWithGenerator() {
+        openTestURL();
+        useGenerator(true);
+        toggleAndScroll(5);
+
+        verifyDetailsRowHeight(5, detailsDefinedHeight, 0);
+        verifyDetailsDecoratorLocation(5, 0, 0);
+
+        toggleAndScroll(0);
+
+        verifyDetailsRowHeight(0, detailsDefinedHeight, 0);
+        // decorator elements are in DOM in the order they have been added
+        verifyDetailsDecoratorLocation(0, 0, 1);
+
+        verifyDetailsRowHeight(5, detailsDefinedHeight, 1);
+        verifyDetailsDecoratorLocation(5, 1, 0);
+    }
+
+    private void verifyDetailsRowHeight(int rowIndex, int expectedHeight,
+            int visibleIndexOfSpacer) {
+        waitForDetailsVisible();
+        WebElement details = getDetailsElement(visibleIndexOfSpacer);
+        Assert.assertEquals("Wrong details row height", expectedHeight,
+                details.getSize().getHeight());
+    }
+
+    private void verifyDetailsDecoratorLocation(int row,
+            int visibleIndexOfSpacer, int visibleIndexOfDeco) {
+        WebElement detailsElement = getDetailsElement(visibleIndexOfSpacer);
+        WebElement detailsDecoElement = getDetailsDecoElement(
+                visibleIndexOfDeco);
+        GridElement.GridRowElement rowElement = getGrid().getRow(row);
+
+        Assert.assertEquals(
+                "Details deco top position does not match row top pos",
+                rowElement.getLocation().getY(),
+                detailsDecoElement.getLocation().getY());
+        Assert.assertEquals(
+                "Details deco bottom position does not match details bottom pos",
+                detailsElement.getLocation().getY()
+                        + detailsElement.getSize().getHeight(),
+                detailsDecoElement.getLocation().getY()
+                        + detailsDecoElement.getSize().getHeight());
+    }
+
+    private void verifyLocation(Param param) {
+        Assert.assertFalse("Notification was present",
+                isElementPresent(By.className("v-Notification")));
+
+        TestBenchElement headerRow = getGrid().getHeaderRow(0);
+        final int topBoundary = headerRow.getLocation().getX()
+                + headerRow.getSize().height;
+        final int bottomBoundary = getGrid().getLocation().getX()
+                + getGrid().getSize().getHeight()
+                - getHorizontalScrollbar().getSize().height;
+
+        GridElement.GridRowElement row = getGrid().getRow(param.getRowIndex());
+        final int rowTop = row.getLocation().getX();
+
+        waitForDetailsVisible();
+        WebElement details = getDetailsElement();
+        final int detailsBottom = details.getLocation().getX()
+                + details.getSize().getHeight();
+
+        assertGreaterOrEqual("Row top should be inside grid, gridTop:"
+                + topBoundary + " rowTop" + rowTop, topBoundary, rowTop);
+        assertLessThanOrEqual(
+                "Decorator bottom should be inside grid, gridBottom:"
+                        + bottomBoundary + " decoratorBotton:" + detailsBottom,
+                detailsBottom, bottomBoundary);
+
+        verifyDetailsRowHeight(param.getRowIndex(), param.useGenerator()
+                ? detailsDefinedHeight : detailsDefaultHeight, 0);
+        verifyDetailsDecoratorLocation(param.getRowIndex(), 0, 0);
+
+        Assert.assertFalse("Notification was present",
+                isElementPresent(By.className("v-Notification")));
+    }
+
+    private final By locator = By.className("v-grid-spacer");
+
+    private WebElement getDetailsElement() {
+        return getDetailsElement(0);
+    }
+
+    private WebElement getDetailsElement(int index) {
+        return findElements(locator).get(index);
+    }
+
+    private WebElement getDetailsDecoElement(int index) {
+        return findElements(By.className("v-grid-spacer-deco")).get(index);
+    }
+
+    private void waitForDetailsVisible() {
+        waitUntil(new ExpectedCondition<WebElement>() {
+
+            @Override
+            public WebElement apply(WebDriver driver) {
+                try {
+                    WebElement detailsElement = getDetailsElement();
+                    return detailsElement.isDisplayed()
+                            && detailsElement.getSize().getHeight() > 3
+                                    ? detailsElement : null;
+                } catch (StaleElementReferenceException e) {
+                    return null;
+                }
+            }
+
+            @Override
+            public String toString() {
+                return "visibility of element located by " + locator;
+            }
+
+        }, 5);
+        waitForElementVisible(By.className("v-grid-spacer"));
+    }
+
+    private void scrollToBottom(boolean scrollFirstToBottom) {
+        if (scrollFirstToBottom) {
+            executeScript("arguments[0].scrollTop = 9999999",
+                    getVerticalScrollbar());
+        }
+    }
+
+    private void useGenerator(boolean use) {
+        CheckBoxElement checkBox = $(CheckBoxElement.class).first();
+        boolean isChecked = isCheckedValo(checkBox);
+        if (use != isChecked) {
+            clickValo(checkBox);
+        }
+    }
+
+    @SuppressWarnings("boxing")
+    private boolean isCheckedValo(CheckBoxElement checkBoxElement) {
+        WebElement checkbox = checkBoxElement.findElement(By.tagName("input"));
+        Object value = executeScript("return arguments[0].checked;", checkbox);
+        return (Boolean) value;
+    }
+
+    private void clickValo(CheckBoxElement checkBoxElement) {
+        checkBoxElement.click(5, 5);
+    }
+
+    private void scrollAndToggle(int row) {
+        setRow(row);
+        getScrollAndToggle().click();
+    }
+
+    private void toggleAndScroll(int row) {
+        setRow(row);
+        getToggleAndScroll().click();
+    }
+
+    private ButtonElement getScrollAndToggle() {
+        return $(ButtonElement.class).caption("Scroll and toggle").first();
+    }
+
+    private ButtonElement getToggleAndScroll() {
+        return $(ButtonElement.class).caption("Toggle and scroll").first();
+    }
+
+    private void setRow(int row) {
+        $(TextFieldElement.class).first().clear();
+        $(TextFieldElement.class).first().sendKeys(String.valueOf(row),
+                Keys.ENTER, Keys.TAB);
+    }
+
+    private GridElement getGrid() {
+        return $(GridElement.class).first();
+    }
+
+    private WebElement getVerticalScrollbar() {
+        WebElement scrollBar = getGrid()
+                .findElement(By.className("v-grid-scroller-vertical"));
+        return scrollBar;
+    }
+
+    private WebElement getHorizontalScrollbar() {
+        WebElement scrollBar = getGrid()
+                .findElement(By.className("v-grid-scroller-horizontal"));
+        return scrollBar;
+    }
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/GridScrollToTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/GridScrollToTest.java
new file mode 100644
index 0000000000..8bdb246d81
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/GridScrollToTest.java
@@ -0,0 +1,151 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.Optional;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.WebElement;
+
+import com.vaadin.testbench.By;
+import com.vaadin.testbench.elements.ButtonElement;
+import com.vaadin.testbench.elements.GridElement;
+import com.vaadin.testbench.elements.TextFieldElement;
+import com.vaadin.testbench.parallel.TestCategory;
+import com.vaadin.tests.tb3.SingleBrowserTest;
+import com.vaadin.ui.Button;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+@TestCategory("grid")
+public class GridScrollToTest extends SingleBrowserTest {
+
+    @Test
+    public void testScrollToEnd() {
+        openTestURL();
+        String finalCellText = "199";
+
+        assertEquals("Found final element even though should be at top of list",
+                0, cellsContaining(finalCellText));
+
+        $(ButtonElement.class).id("end").click();
+
+        assertEquals("Could not find final element", 1,
+                cellsContaining(finalCellText));
+    }
+
+    @Test
+    public void testScrollToRow() {
+        openTestURL();
+        String row = "50";
+
+        assertEquals("Found row element even though should be at top of list",
+                0, cellsContaining(row));
+
+        $(TextFieldElement.class).id("row-field").setValue(row);
+
+        $(ButtonElement.class).id("row").click();
+
+        assertEquals("Could not find row element", 1, cellsContaining(row));
+    }
+
+    @Test
+    public void testScrollTop() {
+        openTestURL();
+        String row = "Name 0";
+
+        assertEquals("Couldn't find first element", 1, cellsContaining(row));
+
+        getGrid().getVerticalScroller().scroll(800);
+
+        assertEquals(
+                "Found first element even though we should have scrolled down",
+                0, cellsContaining(row));
+
+        $(ButtonElement.class).id("top").click();
+
+        assertEquals("Couldn't find first element", 1, cellsContaining(row));
+    }
+
+    @Test
+    public void scrollToLastWithDetailsShowDetails() {
+        openTestURL();
+
+        // Scroll to end
+        $(ButtonElement.class).id("end").click();
+
+        // Open details
+        clickCellContaining("199");
+
+        waitForElementPresent(By.className("v-grid-spacer"));
+        waitForElementPresent(By.className("v-label"));
+        assertTrue("Details not visible", getGrid().findElements(By.className("v-label")).stream()
+                .filter(element -> element.getText().contains("Name 199 details")).findFirst().get().isDisplayed());
+        // scroll away
+        $(ButtonElement.class).id("top").click();
+
+        assertEquals("Found final element even though should be at top of list",
+                0, cellsContaining("199"));
+
+        assertFalse("Found final element  details even though should be at top of list", getGrid().findElements(By.className("v-label")).stream()
+                .filter(element -> element.getText().contains("Name 199 details")).findFirst().isPresent());
+
+        // Scroll to end
+        $(ButtonElement.class).id("end").click();
+
+        assertTrue("Details not visible", getGrid().findElements(By.className("v-label")).stream()
+                .filter(element -> element.getText().contains("Name 199 details")).findFirst().get().isDisplayed());
+    }
+
+    @Test
+    public void scrollToRowShowsDetails() {
+        openTestURL();
+
+        // Scroll to 50
+        $(TextFieldElement.class).id("row-field").setValue("50");
+
+        $(ButtonElement.class).id("row").click();
+
+        clickCellContaining("50");
+
+        waitForElementPresent(By.className("v-grid-spacer"));
+        waitForElementPresent(By.className("v-label"));
+        assertTrue("Details not visible", getGrid().findElements(By.className("v-label")).stream()
+                .filter(element -> element.getText().contains("Name 50 details")).findFirst().get().isDisplayed());
+        // scroll away
+        $(ButtonElement.class).id("top").click();
+
+        assertEquals("Found final element even though should be at top of list",
+                0, cellsContaining("50"));
+
+        assertFalse("Found final element  details even though should be at top of list", getGrid().findElements(By.className("v-label")).stream()
+                .filter(element -> element.getText().contains("Name 50 details")).findFirst().isPresent());
+
+        // Scroll to end
+        $(ButtonElement.class).id("row").click();
+
+        assertTrue("Details not visible", getGrid().findElements(By.className("v-label")).stream()
+                .filter(element -> element.getText().contains("Name 50 details")).findFirst().get().isDisplayed());
+    }
+
+    private GridElement getGrid() {
+        return $(GridElement.class).first();
+    }
+
+    private long cellsContaining(String text) {
+        return getGrid().findElements(By.className("v-grid-cell")).stream()
+                .filter(element -> element.getText().contains(text)).count();
+    }
+
+    private void clickCellContaining(String text) {
+        Optional<WebElement> first = getGrid()
+                .findElements(By.className("v-grid-cell")).stream()
+                .filter(element -> element.getText().contains(text))
+                .findFirst();
+        if (first.isPresent())
+            first.get().click();
+        else
+            Assert.fail("Cell not present");
+    }
+}