a weird IndexOutOfBoundsException after removing a tab from the DecoratedTabPanel

[Denis]

Hello,

I got a weird exception after removing a tab. Details of the exception
is at the end of this message. Even though I got the exception, the
application still functions normally and the tab can be removed
successfully. I don't know where the exception comes from and what I
should do to avoid it.

The following code is my extension to DecoratedTabPanel to make it
dynamically closable. Any input will be appreciated.

public class ClosableTabPanel extends DecoratedTabPanel {
private boolean isReadyToRemove = false;

public ClosableTabPanel() {
addBeforeSelectionHandler(new BeforeSelectionHandler<Integer>() {
public void onBeforeSelection(BeforeSelectionEvent<Integer> event)
{
if (isReadyToRemove) {
remove(event.getItem());
isReadyToRemove = false;

}
}
});
}

@Override
public void add(Widget w, String tabText) {
HorizontalPanel tab = new HorizontalPanel();
Button button = new Button("x", new ClickHandler() {

@Override
public void onClick(ClickEvent event) {
Widget widget = (Widget) event.getSource();
...
final ClosableTabPanel tab = (ClosableTabPanel) widget;
tab.isReadyToRemove = true;
}
});

.....
}
}




java.lang.IndexOutOfBoundsException: null
at
com.google.gwt.user.client.ui.ComplexPanel.checkIndexBoundsForAccess(ComplexPanel.java:
128)
at
com.google.gwt.user.client.ui.DeckPanel.showWidget(DeckPanel.java:313)
at
com.google.gwt.user.client.ui.TabPanel.onTabSelected(TabPanel.java:
382)
at com.google.gwt.user.client.ui.ListenerWrapper
$WrappedTabListener.onSelection(ListenerWrapper.java:754)
at
com.google.gwt.event.logical.shared.SelectionEvent.dispatch(SelectionEvent.java:
89)
at
com.google.gwt.event.logical.shared.SelectionEvent.dispatch(SelectionEvent.java:
1)
at com.google.gwt.event.shared.HandlerManager
$HandlerRegistry.fireEvent(HandlerManager.java:65)
at com.google.gwt.event.shared.HandlerManager
$HandlerRegistry.access$1(HandlerManager.java:53)
at
com.google.gwt.event.shared.HandlerManager.fireEvent(HandlerManager.java:
178)
at com.google.gwt.user.client.ui.Widget.fireEvent(Widget.java:52)
at
com.google.gwt.event.logical.shared.SelectionEvent.fire(SelectionEvent.java:
43)
at com.google.gwt.user.client.ui.TabBar.selectTab(TabBar.java:462)
at
com.google.gwt.user.client.ui.TabBar.selectTabByTabWidget(TabBar.java:
601)
at com.google.gwt.user.client.ui.TabBar.access$0(TabBar.java:596)
at com.google.gwt.user.client.ui.TabBar
$ClickDelegatePanel.onBrowserEvent(TabBar.java:151)
at com.google.gwt.user.client.DOM.dispatchEventImpl(DOM.java:1307)
at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1263)
at sun.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at
com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
157)
at
com.google.gwt.dev.shell.BrowserChannel.reactToMessagesWhileWaitingForReturn(BrowserChannel.java:
1713)
at
com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:
165)
at
com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:
120)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:
507)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:
264)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:
91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:188)
at sun.reflect.GeneratedMethodAccessor18.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at
com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
157)
at
com.google.gwt.dev.shell.BrowserChannel.reactToMessages(BrowserChannel.java:
1668)
at
com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:
401)
at
com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:
222)
at java.lang.Thread.run(Unknown Source)