Accordion causes SEVERE error in browser console (#15182)

Refactored to remove invisible widgets from DOM.

Change-Id: I94d0ba37f4a75d71df88fbb0b1767ae60f39432d

3 files changed, 37 insertions, 19 deletions

diff --git a/client/src/com/vaadin/client/ui/VAccordion.java b/client/src/com/vaadin/client/ui/VAccordion.java
index 3e89958a98..ff77a8cb91 100644
--- a/client/src/com/vaadin/client/ui/VAccordion.java
+++ b/client/src/com/vaadin/client/ui/VAccordion.java
@@ -159,6 +159,8 @@ public class VAccordion extends VTabsheetBase {
      */
     public class StackItem extends ComplexPanel implements ClickHandler {
 
+        private Widget widget;
+
         public void setHeight(int height) {
             if (height == -1) {
                 super.setHeight("");
@@ -171,10 +173,7 @@ public class VAccordion extends VTabsheetBase {
         }
 
         public Widget getComponent() {
-            if (getWidgetCount() < 2) {
-                return null;
-            }
-            return getWidget(1);
+            return widget;
         }
 
         @Override
@@ -268,24 +267,26 @@ public class VAccordion extends VTabsheetBase {
         }
 
         public Widget getChildWidget() {
-            if (getWidgetCount() > 1) {
-                return getWidget(1);
-            } else {
-                return null;
-            }
+            return widget;
         }
 
         public void replaceWidget(Widget newWidget) {
-            if (getWidgetCount() > 1) {
-                Widget oldWidget = getWidget(1);
-                remove(oldWidget);
-                widgets.remove(oldWidget);
+            if (widget != null) {
+                widgets.remove(widget);
+                if (open) {
+                    remove(widget);
+                }
             }
-            add(newWidget, content);
+            widget = newWidget;
             widgets.add(newWidget);
+            if (open) {
+                add(widget, content);
+            }
+
         }
 
         public void open() {
+            add(widget, content);
             open = true;
             content.getStyle().setTop(getCaptionHeight(), Unit.PX);
             content.getStyle().setLeft(0, Unit.PX);
@@ -298,6 +299,9 @@ public class VAccordion extends VTabsheetBase {
         }
 
         public void close() {
+            if (widget != null) {
+                remove(widget);
+            }
             content.getStyle().setVisibility(Visibility.HIDDEN);
             content.getStyle().setTop(-100000, Unit.PX);
             content.getStyle().setLeft(-100000, Unit.PX);
@@ -322,10 +326,10 @@ public class VAccordion extends VTabsheetBase {
          *            new content
          */
         public void setContent(Widget newWidget) {
-            if (getChildWidget() == null) {
-                add(newWidget, content);
+            if (widget == null) {
+                widget = newWidget;
                 widgets.add(newWidget);
-            } else if (getChildWidget() != newWidget) {
+            } else if (widget != newWidget) {
                 replaceWidget(newWidget);
             }
             if (isOpen() && isDynamicHeight()) {
diff --git a/client/src/com/vaadin/client/ui/accordion/AccordionConnector.java b/client/src/com/vaadin/client/ui/accordion/AccordionConnector.java
index c0caded759..72aa2dbdfd 100644
--- a/client/src/com/vaadin/client/ui/accordion/AccordionConnector.java
+++ b/client/src/com/vaadin/client/ui/accordion/AccordionConnector.java
@@ -50,12 +50,13 @@ public class AccordionConnector extends TabsheetBaseConnector implements
             StackItem selectedItem = getWidget().getStackItem(
                     getWidget().selectedItemIndex);
 
-            getWidget().open(getWidget().selectedItemIndex);
-
             ComponentConnector contentConnector = getChildComponents().get(0);
             if (contentConnector != null) {
                 selectedItem.setContent(contentConnector.getWidget());
             }
+
+            getWidget().open(getWidget().selectedItemIndex);
+
         } else if (getWidget().getOpenStackItem() != null) {
             getWidget().close(getWidget().getOpenStackItem());
         }
diff --git a/uitest/src/com/vaadin/tests/components/accordion/AccordionRemoveTabTest.java b/uitest/src/com/vaadin/tests/components/accordion/AccordionRemoveTabTest.java
index f5651e0ada..1047c070c8 100644
--- a/uitest/src/com/vaadin/tests/components/accordion/AccordionRemoveTabTest.java
+++ b/uitest/src/com/vaadin/tests/components/accordion/AccordionRemoveTabTest.java
@@ -44,6 +44,19 @@ public class AccordionRemoveTabTest extends MultiBrowserTest {
         checkFirstItemHeight("On third tab");
     }
 
+    @Test
+    public void testConsoleErrorOnSwitch() {
+        setDebug(true);
+        openTestURL();
+        WebElement firstItem = driver.findElement(By
+                .className("v-accordion-item-first"));
+        WebElement caption = firstItem.findElement(By
+                .className("v-accordion-item-caption"));
+        caption.click();
+        Assert.assertEquals("Errors present in console", 0,
+                findElements(By.className("SEVERE")).size());
+    }
+
     private void checkFirstItemHeight(String text) {
         WebElement firstItem = driver.findElement(By
                 .className("v-accordion-item-first"));