Grid editor: TAB now skips non-editable columns (#11573)

* Grid editor: TAB now skips non-editable columns

Pressing TAB would shift the focus to non-editable cells when the Grid was in edit mode.
This patch makes DefaultEditorEventHandler to skip such columns.

Closes #10970

* Add tests

3 files changed, 302 insertions, 8 deletions

diff --git a/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java b/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java
index ad99719aa8..426d7c3016 100644
--- a/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java
+++ b/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java
@@ -23,9 +23,12 @@ import com.google.gwt.user.client.Event;
 import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.WidgetUtil;
 import com.vaadin.client.ui.FocusUtil;
+import com.vaadin.client.widgets.Grid;
 import com.vaadin.client.widgets.Grid.Editor;
 import com.vaadin.client.widgets.Grid.EditorDomEvent;
 
+import java.util.List;
+
 /**
  * The default handler for Grid editor events. Offers several overridable
  * protected methods for easier customization.
@@ -164,20 +167,26 @@ public class DefaultEditorEventHandler<T> implements Editor.EventHandler<T> {
 
                 int columnCount = event.getGrid().getVisibleColumns().size();
 
-                int colIndex = event.getFocusedColumnIndex() + colDelta;
+                int colIndex = colDelta > 0
+                        ? findNextEditableColumnIndex(event.getGrid(),
+                                event.getFocusedColumnIndex() + colDelta)
+                        : findPrevEditableColumnIndex(event.getGrid(),
+                                event.getFocusedColumnIndex() + colDelta);
                 int rowIndex = event.getRowIndex();
 
                 // Handle row change with horizontal move when column goes out
                 // of range.
-                if (rowDelta == 0) {
-                    if (colIndex >= columnCount
+                if (rowDelta == 0 && colIndex < 0) {
+                    if (colDelta > 0
                             && rowIndex < event.getGrid().getDataSource().size()
                                     - 1) {
                         rowDelta = 1;
-                        colIndex = 0;
-                    } else if (colIndex < 0 && rowIndex > 0) {
+                        colIndex = findNextEditableColumnIndex(event.getGrid(),
+                                0);
+                    } else if (colDelta < 0 && rowIndex > 0) {
                         rowDelta = -1;
-                        colIndex = columnCount - 1;
+                        colIndex = findPrevEditableColumnIndex(event.getGrid(),
+                                columnCount - 1);
                     }
                 }
 
@@ -191,6 +200,52 @@ public class DefaultEditorEventHandler<T> implements Editor.EventHandler<T> {
     }
 
     /**
+     * Finds index of the first editable column, starting at the specified
+     * index.
+     *
+     * @param grid
+     *            the current grid, not null.
+     * @param startingWith
+     *            start with this column. Index into the
+     *            {@link Grid#getVisibleColumns()}.
+     * @return the index of the nearest visible column; may return the
+     *         <code>startingWith</code> itself. Returns -1 if there is no such
+     *         column.
+     */
+    private int findNextEditableColumnIndex(Grid<T> grid, int startingWith) {
+        final List<Grid.Column<?, T>> columns = grid.getVisibleColumns();
+        for (int i = startingWith; i < columns.size(); i++) {
+            if (columns.get(i).isEditable()) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    /**
+     * Finds index of the last editable column, searching backwards starting at
+     * the specified index.
+     *
+     * @param grid
+     *            the current grid, not null.
+     * @param startingWith
+     *            start with this column. Index into the
+     *            {@link Grid#getVisibleColumns()}.
+     * @return the index of the nearest visible column; may return the
+     *         <code>startingWith</code> itself. Returns -1 if there is no such
+     *         column.
+     */
+    private int findPrevEditableColumnIndex(Grid<T> grid, int startingWith) {
+        final List<Grid.Column<?, T>> columns = grid.getVisibleColumns();
+        for (int i = startingWith; i >= 0; i--) {
+            if (columns.get(i).isEditable()) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    /**
      * Moves the editor to another column if the received event is a move event.
      * By default the editor is moved on a keydown event with keycode
      * {@link #KEYCODE_MOVE_HORIZONTAL}. This moves the editor left or right if
@@ -218,8 +273,15 @@ public class DefaultEditorEventHandler<T> implements Editor.EventHandler<T> {
             // Prevent tab out of Grid Editor
             event.getDomEvent().preventDefault();
 
-            editRow(event, event.getRowIndex(), event.getFocusedColumnIndex()
-                    + (e.getShiftKey() ? -1 : +1));
+            final int newColIndex = e.getShiftKey()
+                    ? findPrevEditableColumnIndex(event.getGrid(),
+                            event.getFocusedColumnIndex() - 1)
+                    : findNextEditableColumnIndex(event.getGrid(),
+                            event.getFocusedColumnIndex() + 1);
+
+            if (newColIndex >= 0) {
+                editRow(event, event.getRowIndex(), newColIndex);
+            }
 
             return true;
         } else if (e.getType().equals(BrowserEvents.KEYDOWN)
diff --git a/uitest/src/main/java/com/vaadin/tests/components/grid/GridEditorTabSkipsNonEditableCells.java b/uitest/src/main/java/com/vaadin/tests/components/grid/GridEditorTabSkipsNonEditableCells.java
new file mode 100644
index 0000000000..cf8c673c09
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/grid/GridEditorTabSkipsNonEditableCells.java
@@ -0,0 +1,102 @@
+package com.vaadin.tests.components.grid;
+
+import com.vaadin.annotations.Widgetset;
+import com.vaadin.data.provider.ListDataProvider;
+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.TextField;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Shows a Grid with the only editable columns being the column 1 and 3. That
+ * will allow us to test that Tab/Shift+Tab skips cells that are not editable.
+ */
+@Widgetset("com.vaadin.DefaultWidgetSet")
+public class GridEditorTabSkipsNonEditableCells extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        final List<TestBean> items = new ArrayList<>();
+        Grid<TestBean> grid = new Grid<TestBean>(TestBean.class);
+        for (int i = 0; i < 10; i++) {
+            items.add(new TestBean(i));
+        }
+        grid.setDataProvider(new ListDataProvider<>(items));
+        grid.setWidth("100%");
+        grid.setHeight("400px");
+        grid.getEditor().setEnabled(true);
+        grid.getColumn("col1").setEditorComponent(new TextField());
+        grid.getColumn("col3").setEditorComponent(new TextField());
+        grid.setColumnOrder("col0", "col1", "col2", "col3", "col4");
+
+        getLayout().addComponent(
+                new Button("Set Editor Buffered Mode On", event -> {
+                    grid.getEditor().cancel();
+                    grid.getEditor().setBuffered(true);
+                }));
+        getLayout().addComponent(
+                new Button("Set Editor Buffered Mode Off", event -> {
+                    grid.getEditor().cancel();
+                    grid.getEditor().setBuffered(false);
+                }));
+
+        getLayout().addComponent(grid);
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 11573;
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "Pressing TAB doesn't shift the focus to non-editable cells when the Grid is in edit mode.";
+    }
+
+    public class TestBean {
+        private final int row;
+
+        public TestBean(int row) {
+            this.row = row;
+        }
+
+        public String getCol0() {
+            return "col0_" + row;
+        }
+
+        public String getCol1() {
+            return "col1_" + row;
+        }
+
+        public String getCol2() {
+            return "col2_" + row;
+        }
+
+        public String getCol3() {
+            return "col3_" + row;
+        }
+
+        public String getCol4() {
+            return "col4_" + row;
+        }
+
+        public void setCol0(String value) {
+        }
+
+        public void setCol1(String value) {
+        }
+
+        public void setCol2(String value) {
+        }
+
+        public void setCol3(String value) {
+        }
+
+        public void setCol4(String value) {
+        }
+    }
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/GridEditorTabSkipsNonEditableCellsTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/GridEditorTabSkipsNonEditableCellsTest.java
new file mode 100644
index 0000000000..9092f0a22f
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/GridEditorTabSkipsNonEditableCellsTest.java
@@ -0,0 +1,130 @@
+package com.vaadin.tests.components.grid;
+
+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.MultiBrowserTest;
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.Keys;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.interactions.Actions;
+
+import static org.junit.Assert.fail;
+
+/**
+ * Makes sure that pressing Tab when the Grid is in edit mode will make focus
+ * skip cells that are not editable.
+ */
+@TestCategory("grid")
+public class GridEditorTabSkipsNonEditableCellsTest extends MultiBrowserTest {
+    /**
+     * The grid with 5 columns. First, third and fifth columns are not editable.
+     */
+    private GridElement grid;
+
+    @Override
+    public void setup() throws Exception {
+        super.setup();
+        openTestURL();
+        grid = $(GridElement.class).first();
+    }
+
+    @Test
+    public void tabSkipsOverNotEditableFieldBuffered() {
+        setBuffered(true);
+        openEditor(0, 1);
+        pressTab();
+        Assert.assertEquals("col3_0", getFocusedEditorCellContents());
+    }
+
+    @Test
+    public void tabDoesNothingIfAlreadyOnLastEditableFieldBuffered() {
+        setBuffered(true);
+        openEditor(0, 3);
+        pressTab();
+        Assert.assertEquals("col3_0", getFocusedEditorCellContents());
+    }
+
+    @Test
+    public void tabSkipsOverNotEditableFieldUnbuffered() {
+        setBuffered(false);
+        openEditor(0, 1);
+        pressTab();
+        Assert.assertEquals("col3_0", getFocusedEditorCellContents());
+    }
+
+    @Test
+    public void tabMovesToNextRowFirstEditableFieldUnbuffered() {
+        setBuffered(false);
+        openEditor(0, 3);
+        pressTab();
+        Assert.assertEquals("col1_1", getFocusedEditorCellContents());
+    }
+
+    @Test
+    public void shiftTabSkipsOverNotEditableFieldBuffered() {
+        setBuffered(true);
+        openEditor(0, 3);
+        pressShiftTab();
+        Assert.assertEquals("col1_0", getFocusedEditorCellContents());
+    }
+
+    @Test
+    public void shiftTabDoesNothingIfAlreadyOnLastEditableFieldBuffered() {
+        setBuffered(true);
+        openEditor(0, 1);
+        pressShiftTab();
+        Assert.assertEquals("col1_0", getFocusedEditorCellContents());
+    }
+
+    @Test
+    public void shiftTabSkipsOverNotEditableFieldUnbuffered() {
+        setBuffered(false);
+        openEditor(0, 3);
+        pressShiftTab();
+        Assert.assertEquals("col1_0", getFocusedEditorCellContents());
+    }
+
+    @Test
+    public void shiftTabMovesToNextRowFirstEditableFieldUnbuffered() {
+        setBuffered(false);
+        openEditor(1, 1);
+        pressShiftTab();
+        Assert.assertEquals("col3_0", getFocusedEditorCellContents());
+    }
+
+    private void openEditor(int rowIndex, int colIndex) {
+        grid.getCell(rowIndex, colIndex).doubleClick();
+    }
+
+    private void pressTab() {
+        new Actions(getDriver()).sendKeys(Keys.TAB).perform();
+    }
+
+    private void pressShiftTab() {
+        new Actions(getDriver()).keyDown(Keys.SHIFT).sendKeys(Keys.TAB)
+                .keyUp(Keys.SHIFT).perform();
+    }
+
+    private void setBuffered(boolean buffered) {
+        $(ButtonElement.class).caption(buffered ? "Set Editor Buffered Mode On"
+                : "Set Editor Buffered Mode Off").first().click();
+    }
+
+    private String getFocusedEditorCellContents() {
+        final GridElement.GridEditorElement editor = grid.getEditor();
+        final WebElement focusedElement = getFocusedElement();
+        for (int i = 0; i < 5; i++) {
+            if (editor.isEditable(i)
+                    && editor.getField(i).equals(focusedElement)) {
+                return (editor.getField(i).wrap(TextFieldElement.class))
+                        .getValue();
+            }
+        }
+        fail("Currently focused element is not a cell editor: "
+                + focusedElement);
+        return null;
+    }
+}