Replaced Grid's internal size calculation fix with an indexing fix. (#11154)

- More lightweight, and fixes things for any custom implementations of
Escalator as well.

Fixes #11044

client/src/main/java/com/vaadin/client/widgets/Escalator.java

@@ -67,7 +67,6 @@ import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.BrowserInfo;
 import com.vaadin.client.ComputedStyle;
 import com.vaadin.client.DeferredWorker;
-import com.vaadin.client.LayoutManager;
 import com.vaadin.client.Profiler;
 import com.vaadin.client.WidgetUtil;
 import com.vaadin.client.ui.SubPartAware;
@@ -3896,6 +3895,7 @@ public class Escalator extends Widget
                                 visualRowOrder.getLast()) + 1;
                         moveAndUpdateEscalatorRows(Range.withOnly(0),
                                 visualRowOrder.size(), newLogicalIndex);
+                        updateTopRowLogicalIndex(1);
                     }
                 }
             }

client/src/main/java/com/vaadin/client/widgets/Grid.java

@@ -76,7 +76,10 @@ import com.google.gwt.user.client.ui.MenuItem;
 import com.google.gwt.user.client.ui.PopupPanel;
 import com.google.gwt.user.client.ui.ResizeComposite;
 import com.google.gwt.user.client.ui.Widget;
-import com.vaadin.client.*;
+import com.vaadin.client.BrowserInfo;
+import com.vaadin.client.DeferredWorker;
+import com.vaadin.client.Focusable;
+import com.vaadin.client.WidgetUtil;
 import com.vaadin.client.WidgetUtil.Reference;
 import com.vaadin.client.data.DataChangeHandler;
 import com.vaadin.client.data.DataSource;
@@ -3339,7 +3342,6 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     private class AutoColumnWidthsRecalculator {
         private double lastCalculatedInnerWidth = -1;
-        private double lastCalculatedInnerHeight = -1;
 
         private final ScheduledCommand calculateCommand = new ScheduledCommand() {
 
@@ -3434,7 +3436,6 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
 
             // Update latest width to prevent recalculate on height change.
             lastCalculatedInnerWidth = escalator.getInnerWidth();
-            lastCalculatedInnerHeight = getEscalatorInnerHeight();
         }
 
         private boolean columnsAreGuaranteedToBeWiderThanGrid() {
@@ -9147,15 +9148,6 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
                 recalculateColumnWidths();
             }
 
-            if (getEscalatorInnerHeight() != autoColumnWidthsRecalculator.lastCalculatedInnerHeight) {
-                Scheduler.get().scheduleFinally(() -> {
-                    // Trigger re-calculation of all row positions.
-                    RowContainer.BodyRowContainer body = getEscalator()
-                            .getBody();
-                    body.setDefaultRowHeight(body.getDefaultRowHeight());
-                });
-            }
-
             // Vertical resizing could make editor positioning invalid so it
             // needs to be recalculated on resize
             if (isEditorActive()) {
@@ -9169,11 +9161,6 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
         });
     }
 
-    private double getEscalatorInnerHeight() {
-        return new ComputedStyle(getEscalator().getTableWrapper())
-                .getHeightIncludingBorderPadding();
-    }
-
     /**
      * Grid does not support adding Widgets this way.
      * <p>

uitest/src/main/java/com/vaadin/tests/components/grid/GridScrolledToBottom.java

@@ -0,0 +1,47 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.data.bean.Person;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.VerticalSplitPanel;
+
+public class GridScrolledToBottom extends SimpleGridUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        Grid<Person> grid = createGrid();
+        grid.setSizeFull();
+
+        VerticalSplitPanel splitPanel = new VerticalSplitPanel(grid,
+                new Label("Foo"));
+        splitPanel.setHeight("200px");
+        splitPanel.setSplitPosition(100);
+        getLayout().addComponent(splitPanel);
+    }
+
+    @Override
+    protected List<Person> createPersons() {
+        List<Person> persons = new ArrayList<>();
+        for (int i = 0; i < 100; ++i) {
+            Person person = new Person();
+            person.setFirstName("Person " + i);
+            person.setAge(i);
+            persons.add(person);
+        }
+        return persons;
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "Resizing a Grid when it's scrolled to bottom shouldn't cause indexing to jump.";
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 11044;
+    }
+}

uitest/src/test/java/com/vaadin/tests/components/grid/GridScrolledToBottomTest.java

@@ -0,0 +1,97 @@
+package com.vaadin.tests.components.grid;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.number.IsCloseTo.closeTo;
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.interactions.Actions;
+
+import com.vaadin.testbench.TestBenchElement;
+import com.vaadin.testbench.elements.GridElement;
+import com.vaadin.testbench.elements.GridElement.GridRowElement;
+import com.vaadin.testbench.elements.VerticalSplitPanelElement;
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+public class GridScrolledToBottomTest extends MultiBrowserTest {
+
+    @Test
+    public void testResizingAndBack() {
+        openTestURL();
+        GridElement grid = $(GridElement.class).first();
+        grid.scrollToRow(99);
+
+        GridRowElement row99 = grid.getRow(99);
+        int rowHeight = row99.getSize().getHeight();
+        assertThat(grid.getLocation().getY() + grid.getSize().getHeight(),
+                greaterThan(row99.getLocation().getY() + rowHeight - 2));
+
+        VerticalSplitPanelElement splitPanel = $(
+                VerticalSplitPanelElement.class).first();
+        TestBenchElement splitter = splitPanel.getSplitter();
+        // resize by three rows
+        Actions actions = new Actions(driver);
+        actions.clickAndHold(splitter).moveByOffset(0, -rowHeight * 3).release()
+                .perform();
+        // resize back by two rows
+        actions.clickAndHold(splitter).moveByOffset(0, rowHeight * 2).release()
+                .perform();
+
+        GridRowElement row95 = grid.getRow(95);
+        GridRowElement row97 = grid.getRow(97);
+        assertThat((double) row97.getLocation().getY(),
+                greaterThan(row95.getLocation().getY() + rowHeight * 1.5));
+    }
+
+    @Test
+    public void testResizingHalfRow() {
+        openTestURL();
+        GridElement grid = $(GridElement.class).first();
+        grid.scrollToRow(99);
+
+        GridRowElement row99 = grid.getRow(99);
+        int rowHeight = row99.getSize().getHeight();
+        int gridBottomY = grid.getLocation().getY()
+                + grid.getSize().getHeight();
+
+        // ensure that grid really is scrolled to bottom
+        assertThat((double) gridBottomY,
+                closeTo((double) row99.getLocation().getY() + rowHeight, 1d));
+
+        VerticalSplitPanelElement splitPanel = $(
+                VerticalSplitPanelElement.class).first();
+        TestBenchElement splitter = splitPanel.getSplitter();
+        // resize by half a row
+        Actions actions = new Actions(driver);
+        actions.clickAndHold(splitter).moveByOffset(0, -rowHeight / 2).release()
+                .perform();
+        // the last row is now only half visible, and in DOM tree it's actually
+        // the first row now but positioned to the bottom
+
+        // can't query grid.getRow(99) now or it moves the row position,
+        // have to use element query instead
+        List<WebElement> rows = grid.findElement(By.className("v-grid-body"))
+                .findElements(By.className("v-grid-row"));
+        WebElement firstRow = rows.get(0);
+        WebElement lastRow = rows.get(rows.size() - 1);
+
+        // ensure the scrolling didn't jump extra
+        assertEquals("Person 99",
+                firstRow.findElement(By.className("v-grid-cell")).getText());
+        assertEquals("Person 98",
+                lastRow.findElement(By.className("v-grid-cell")).getText());
+
+        // re-calculate current end position
+        gridBottomY = grid.getLocation().getY() + grid.getSize().getHeight();
+        // ensure the correct final row really is only half visible at the
+        // bottom
+        assertThat(gridBottomY, greaterThan(firstRow.getLocation().getY()));
+        assertThat(firstRow.getLocation().getY() + rowHeight,
+                greaterThan(gridBottomY));
+    }
+}