Fix moving a single component inside a split panel (#11920)

Change-Id: Ib9b3625e4104763143906eb1b7986ef7b3b80737

client/src/com/vaadin/client/ui/VAbstractSplitPanel.java

@@ -511,6 +511,10 @@ public class VAbstractSplitPanel extends ComplexPanel {
         firstChild = w;
     }
 
+    public Widget getFirstWidget() {
+        return firstChild;
+    }
+
     /** For internal use only. May be removed or replaced in the future. */
     public void setSecondWidget(Widget w) {
         if (secondChild == w) {
@@ -525,6 +529,10 @@ public class VAbstractSplitPanel extends ComplexPanel {
         secondChild = w;
     }
 
+    public Widget getSecondWidget() {
+        return secondChild;
+    }
+
     @Override
     public void onBrowserEvent(Event event) {
         switch (DOM.eventGetType(event)) {

client/src/com/vaadin/client/ui/splitpanel/AbstractSplitPanelConnector.java

@@ -161,6 +161,35 @@ public abstract class AbstractSplitPanelConnector extends
         getLayoutManager().setNeedsLayout(this);
 
         getWidget().makeScrollable();
+
+        handleSingleComponentMove();
+    }
+
+    /**
+     * Handles the case when there is only one child component and that
+     * component is moved between first <-> second. This does not trigger a
+     * hierarchy change event as the list of children contains the same
+     * component in both cases.
+     */
+    private void handleSingleComponentMove() {
+        if (getChildComponents().size() == 1) {
+            Widget stateFirstChild = null;
+            Widget stateSecondChild = null;
+            if (getState().firstChild != null) {
+                stateFirstChild = ((ComponentConnector) getState().firstChild)
+                        .getWidget();
+            }
+            if (getState().secondChild != null) {
+                stateSecondChild = ((ComponentConnector) getState().secondChild)
+                        .getWidget();
+            }
+
+            if (stateFirstChild == getWidget().getSecondWidget()
+                    || stateSecondChild == getWidget().getFirstWidget()) {
+                handleHierarchyChange();
+            }
+        }
+
     }
 
     @Override
@@ -212,6 +241,10 @@ public abstract class AbstractSplitPanelConnector extends
 
     @Override
     public void onConnectorHierarchyChange(ConnectorHierarchyChangeEvent event) {
+        handleHierarchyChange();
+    }
+
+    private void handleHierarchyChange() {
         /*
          * When the connector gets detached, the state isn't updated but there's
          * still a hierarchy change -> verify that the child from the state is

uitest/src/com/vaadin/tests/components/splitpanel/SplitPanelMoveComponent.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2000-2013 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.splitpanel;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.Button.ClickEvent;
+import com.vaadin.ui.Button.ClickListener;
+import com.vaadin.ui.HorizontalSplitPanel;
+
+public class SplitPanelMoveComponent extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        final HorizontalSplitPanel split = new HorizontalSplitPanel();
+        split.setHeight("200px");
+        final Button targetComponent = new Button(
+                "Button in splitpanel. Click to move to the other side");
+        split.setFirstComponent(targetComponent);
+
+        targetComponent.addClickListener(new ClickListener() {
+
+            @Override
+            public void buttonClick(ClickEvent event) {
+                if (split.getFirstComponent() != null) {
+                    split.setFirstComponent(null);
+                    split.setSecondComponent(targetComponent);
+                } else {
+                    split.setSecondComponent(null);
+                    split.setFirstComponent(targetComponent);
+
+                }
+            }
+
+        });
+
+        addComponent(split);
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "Fail to swap components in HorizontalSplitPanel";
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 11920;
+    }
+
+}

uitest/src/com/vaadin/tests/components/splitpanel/SplitPanelMoveComponentTest.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2000-2013 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.splitpanel;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.WebElement;
+
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+public class SplitPanelMoveComponentTest extends MultiBrowserTest {
+
+    private static final String BUTTON_TEXT = "Button in splitpanel. Click to move to the other side";
+
+    @Test
+    public void moveComponent() {
+        openTestURL();
+        Assert.assertEquals(BUTTON_TEXT, getFirstChild().getText());
+        getFirstChild().click();
+        Assert.assertEquals(BUTTON_TEXT, getSecondChild().getText());
+        getSecondChild().click();
+        Assert.assertEquals(BUTTON_TEXT, getFirstChild().getText());
+    }
+
+    private WebElement getFirstChild() {
+        WebElement container = getDriver()
+                .findElement(
+                        By.xpath("//div[contains(@class,'v-splitpanel-first-container')]"));
+        return container.findElement(By
+                .xpath("//div[contains(@class, 'v-button')]"));
+    }
+
+    private WebElement getSecondChild() {
+        WebElement container = getDriver()
+                .findElement(
+                        By.xpath("//div[contains(@class,'v-splitpanel-second-container')]"));
+        return container.findElement(By
+                .xpath("//div[contains(@class, 'v-button')]"));
+    }
+
+}