Improve the selection tab algorithm after removing the selected tab

(#6876)

New protected method TabSheet.selectedTabIndexAfterTabRemove
where anyone can implement his/hers own algorithm for selecting
a new tab.

Change-Id: I6a3dd62e7fc84e4dacb08d30d567f357678dd7e4

3 files changed, 237 insertions, 0 deletions

diff --git a/server/src/com/vaadin/ui/TabSheet.java b/server/src/com/vaadin/ui/TabSheet.java
index 8b13ecf1a4..0e4ea0d034 100644
--- a/server/src/com/vaadin/ui/TabSheet.java
+++ b/server/src/com/vaadin/ui/TabSheet.java
@@ -193,6 +193,9 @@ public class TabSheet extends AbstractComponentContainer implements Focusable,
     @Override
     public void removeComponent(Component component) {
         if (component != null && components.contains(component)) {
+
+            int componentIndex = components.indexOf(component);
+
             super.removeComponent(component);
             keyMapper.remove(component);
             components.remove(component);
@@ -206,6 +209,24 @@ public class TabSheet extends AbstractComponentContainer implements Focusable,
                 if (components.isEmpty()) {
                     setSelected(null);
                 } else {
+
+                    int newSelectedIndex = selectedTabIndexAfterTabRemove(componentIndex);
+
+                    // Make sure the component actually exists, in case someone
+                    // override it and provide a non existing component.
+                    if (0 <= newSelectedIndex
+                            && newSelectedIndex < components.size()) {
+
+                        Component newSelectedComponent = components
+                                .get(newSelectedIndex);
+
+                        // Select only if the tab is enabled.
+                        Tab newSelectedTab = tabs.get(newSelectedComponent);
+                        if (newSelectedTab.isEnabled()) {
+                            setSelected(newSelectedComponent);
+                        }
+                    }
+
                     // select the first enabled and visible tab, if any
                     updateSelection();
                     fireSelectedTabChange();
@@ -216,6 +237,40 @@ public class TabSheet extends AbstractComponentContainer implements Focusable,
     }
 
     /**
+     * Called when a selected tab is removed to specify the new tab to select.
+     * Can be overridden to provide another algorithm that calculates the new
+     * selection.
+     * 
+     * Current implementation will choose the first enabled tab to the right of
+     * the removed tab if it's not the last one, otherwise will choose the
+     * closer enabled tab to the left.
+     * 
+     * @since
+     * @param removedTabIndex
+     *            the index of the selected tab which was just remove.
+     * @return the index of the tab to be selected or -1 if there are no more
+     *         enabled tabs to select.
+     */
+    protected int selectedTabIndexAfterTabRemove(int removedTabIndex) {
+
+        for (int i = removedTabIndex; i < components.size(); i++) {
+            Tab tab = getTab(i);
+            if (tab.isEnabled()) {
+                return i;
+            }
+        }
+
+        for (int i = removedTabIndex - 1; i >= 0; i--) {
+            Tab tab = getTab(i);
+            if (tab.isEnabled()) {
+                return i;
+            }
+        }
+
+        return -1;
+    }
+
+    /**
      * Removes a {@link Tab} and the component associated with it, as previously
      * added with {@link #addTab(Component)},
      * {@link #addTab(Component, String, Resource)} or
diff --git a/uitest/src/com/vaadin/tests/components/tabsheet/NewSelectionAfterTabRemove.java b/uitest/src/com/vaadin/tests/components/tabsheet/NewSelectionAfterTabRemove.java
new file mode 100644
index 0000000000..939bd645ea
--- /dev/null
+++ b/uitest/src/com/vaadin/tests/components/tabsheet/NewSelectionAfterTabRemove.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2000-2014 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.tests.components.tabsheet;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.TabSheet;
+import com.vaadin.ui.TabSheet.Tab;
+
+/**
+ * In case a selected tab is removed the new selected one should be a neighbor.
+ * 
+ * In case an unselected tab is removed and the selected one is not visible, the
+ * scroll should not jump to the selected one.
+ * 
+ * @since
+ * @author Vaadin Ltd
+ */
+public class NewSelectionAfterTabRemove extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        TabSheet tabSheet = new TabSheet();
+
+        for (int i = 0; i < 20; i++) {
+
+            String caption = "Tab " + i;
+            Label label = new Label(caption);
+
+            Tab tab = tabSheet.addTab(label, caption);
+            tab.setClosable(true);
+        }
+
+        addComponent(tabSheet);
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "When a selected tab is removed, its neighbor should become selected.";
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 6876;
+    }
+
+}
diff --git a/uitest/src/com/vaadin/tests/components/tabsheet/NewSelectionAfterTabRemoveTest.java b/uitest/src/com/vaadin/tests/components/tabsheet/NewSelectionAfterTabRemoveTest.java
new file mode 100644
index 0000000000..bffbc3ecdf
--- /dev/null
+++ b/uitest/src/com/vaadin/tests/components/tabsheet/NewSelectionAfterTabRemoveTest.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright 2000-2014 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.tests.components.tabsheet;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.WebElement;
+
+import com.vaadin.testbench.TestBenchElement;
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+/**
+ * Automatic test of the default TabSheet selection algorithm when removing a
+ * selected tab.
+ * 
+ * @since
+ * @author Vaadin Ltd
+ */
+public class NewSelectionAfterTabRemoveTest extends MultiBrowserTest {
+
+    @Test
+    public void testSelection() throws IOException, InterruptedException {
+        openTestURL();
+
+        while (scrollRight()) {
+        }
+
+        selectAndClose(tab(19));
+
+        Assert.assertTrue("Tab 18 selected", isTabSelected(tab(18)));
+
+        selectAndClose(tab(16));
+
+        Assert.assertTrue("Tab 17 selected", isTabSelected(tab(17)));
+    }
+
+    /*
+     * Select the specified tab and close it.
+     */
+    private void selectAndClose(TestBenchElement tab)
+            throws InterruptedException {
+        tab.click(5, 5);
+
+        sleep(10);
+
+        tabClose(tab).click(2, 2);
+
+        sleep(10);
+    }
+
+    /*
+     * Gets the selected state of the specified tab.
+     */
+    private boolean isTabSelected(TestBenchElement tab) {
+        return tab.getAttribute("class").contains(
+                "v-tabsheet-tabitemcell-selected")
+                && tab.getAttribute("class").contains(
+                        "v-tabsheet-tabitemcell-focus");
+    }
+
+    /*
+     * Scroll the tabsheet bar to the right.
+     */
+    private boolean scrollRight() {
+        List<WebElement> scrollElements = getDriver().findElements(
+                By.className("v-tabsheet-scrollerNext"));
+        if (!scrollElements.isEmpty()) {
+            TestBenchElement rightScrollElement = (TestBenchElement) scrollElements
+                    .get(0);
+            rightScrollElement.click(5, 5);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /*
+     * Provide the tab close button for the specified tab.
+     */
+    private TestBenchElement tabClose(TestBenchElement tab) {
+        return (TestBenchElement) tab.findElement(By
+                .className("v-tabsheet-caption-close"));
+    }
+
+    /*
+     * Provide the tab at specified index.
+     */
+    private TestBenchElement tab(int index) {
+        By by = By.className("v-tabsheet-tabitemcell");
+
+        List<WebElement> tabs = getDriver().findElements(by);
+
+        String expected = "Tab " + index;
+
+        for (WebElement tab : tabs) {
+            if (tab.getText().startsWith(expected)) {
+                return (TestBenchElement) tab;
+            }
+        }
+
+        return null;
+    }
+
+}