Problem while copying WidgetCollection in GWT?

I have quite a strange problem ,

While copying one WidgetCollection from one FlowPanel into another one. Widgets in WidgetCollection are moving instead of copying.Because of this couple of widgets remain in previous Panel.

Here is my code:

    final FlowPanel toDelete = getWidgetByID(from);
    final FlowPanel toPaste = getWidgetByID(to);
    final Iterator<Widget> iterator = toDelete.iterator();
    while (iterator.hasNext()) {
        toPaste.add(iterator.next());
    }

and next version:

    final FlowPanel toDelete = getWidgetByID(from);
    final FlowPanel toPaste = getWidgetByID(to);
    final int count = toDelete.getWidgetCount();
    for (int i = 0; i < count; i++) {
        toPaste.add(toDelete.getWidget(i));// here, i'm getting IndexOutOfTheBounds exception
    }

Wh开发者_如何学JAVAat's wrong here? Thanks in advance!!!

When you add a widget to a new panel, it is automatically removed from its previous panel. There's no super-easy way to get around this. You need to make a new instance of each widget and then add that copy.

If it's just your goal to move widgets from one panel to another, just change toDelete.getWidget(i) to toDelete.getWidget(0). You might also consider just moving the toDelete panel itself instead of moving all of its widgets.