Hi Shi,
You seem to have created a circular construction situation. Login
creates a new MenuHome which, when you select LOGIN from the menu the
command creates a new Login, which then creates a new MenuHome
etc ............ Since you haven't posted the code that kicks all this
off in the first place, it's a bit difficult to know which is the
chicken and which is the egg. Whatever, this does not look like it's
going to work.
Why not simply take the references to MenuHome out of Login, i.e.:
/// MenuHome mhome = new MenuHome();
private VerticalPanel panelVert;
private Button loginButton;
public Login(){
panelVert = new VerticalPanel();
panelVert.setHorizontalAlignment(HasHorizontalAlignment.ALIGN_CENTER);
panelVert.setVerticalAlignment(HasVerticalAlignment.ALIGN_MIDDLE);
loginButton = new Button("Login");
panelVert.add(loginButton);
initWidget(panelVert);
/// mhome.vPanel2.add(panelVert); //
<-----------------the error add the
panel to the //main container of class MenuHome
Will that not do what you want? If not what exactly are you trying to
do?
regards
gregor
On Sep 20, 2:33 am, Shi <[EMAIL PROTECTED]> wrote:
> Hi!
> I'm trying to make my class MenuHome as a container through the
> abstract class com.google.gwt.user.client.ui.Composite.java but I
> have always the same problem:
> This widget's parent does not implement HasWidgets.
> In the main class I want a panel that could contain all the widget
> children (instances of other classes) and then be able to remove any
> time a widget you do not have to see, perhaps with a command
> vPanel2.clean()
>
> When run my application, when I click on LOGIN shows this exception.
> How could solve?
>
> My code simplified:
>
> -----MenuHome.java-------container
>
> import com.google.gwt.user.client.Command;
> import com.google.gwt.user.client.ui.Composite;
> import com.google.gwt.user.client.ui.MenuBar;
> import com.google.gwt.user.client.ui.VerticalPanel;
>
> public class MenuHome extends Composite {
>
> private VerticalPanel vPanel;
> private Login login;
> public VerticalPanel vPanel2;
>
> public MenuHome() {
> super();
> Command cmd = new Command(){
> public void execute(){
> vPanel2.clear();
> }
> };
> Command cmdOpen = new Command(){
> public void execute(){
> if(vPanel2.getWidgetCount() == 0){
> login = new Login();
> vPanel2.add(login);
> }
>
> }
> };
>
> vPanel = new VerticalPanel();
> MenuBar menu = new MenuBar();
> vPanel2 = new VerticalPanel();
>
> menu.addItem("HOME", cmd);
> menu.addItem("LOGIN", cmdOpen);
> vPanel.add(menu);
>
> vPanel.add(vPanel2);
> initWidget(vPanel);
> }
> protected void onAttach() {
> super.onAttach();
> }
>
> }
>
> ------------------Login.java--------class child
>
> import com.google.gwt.user.client.ui.Composite;
> import com.google.gwt.user.client.ui.HasHorizontalAlignment;
> import com.google.gwt.user.client.ui.HasVerticalAlignment;
> import com.google.gwt.user.client.ui.HasWidgets;
> import com.google.gwt.user.client.ui.VerticalPanel;
> import com.google.gwt.user.client.ui.Widget;
> import com.gwtext.client.widgets.Button;
> public class Login extends Composite{
>
> MenuHome mhome = new MenuHome();
> private VerticalPanel panelVert;
> private Button loginButton;
>
> public Login(){
> panelVert = new VerticalPanel();
>
> panelVert.setHorizontalAlignment(HasHorizontalAlignment.ALIGN_CENTER);
>
> panelVert.setVerticalAlignment(HasVerticalAlignment.ALIGN_MIDDLE);
> loginButton = new Button("Login");
> panelVert.add(loginButton);
> initWidget(panelVert);
> mhome.vPanel2.add(panelVert); //<-----------------the error
> add the
> panel to the //main container of class MenuHome
>
> }
>
> }
>
> -------------------------
> Error
> [ERROR] Uncaught exception escaped
> java.lang.IllegalStateException: This widget's parent does not
> implement HasWidgets
> at com.google.gwt.user.client.ui.Widget.removeFromParent(Widget.java:
> 67)
> at com.google.gwt.user.client.ui.ComplexPanel.add(ComplexPanel.java:
> 77)
> at com.google.gwt.user.client.ui.VerticalPanel.add(VerticalPanel.java:
> 53)
> at com.gwt.client.Login.<init>(Login.java:55)
> at com.gwt.client.MenuHome$2.execute(MenuHome.java:29)
> at
> com.google.gwt.user.client.CommandExecutor.doExecuteCommands(CommandExecutor.java:
> 311)
> at com.google.gwt.user.client.CommandExecutor
> $2.run(CommandExecutor.java:206)
> at com.google.gwt.user.client.Timer.fireImpl(Timer.java:164)
> at com.google.gwt.user.client.Timer.fireAndCatch(Timer.java:150)
> at com.google.gwt.user.client.Timer.fire(Timer.java:142)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:
> 39)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:
> 25)
> at java.lang.reflect.Method.invoke(Method.java:597)
> at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:
> 103)
> at
> com.google.gwt.dev.shell.moz.MethodDispatch.invoke(MethodDispatch.java:
> 80)
> at org.eclipse.swt.internal.gtk.OS._g_main_context_iteration(Native
> Method)
> at org.eclipse.swt.internal.gtk.OS.g_main_context_iteration(OS.java:
> 1428)
> at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2840)
> at com.google.gwt.dev.GWTShell.pumpEventLoop(GWTShell.java:720)
> at com.google.gwt.dev.GWTShell.run(GWTShell.java:593)
> at com.google.gwt.dev.GWTShell.main(GWTShell.java:357)
>
> I hope someone can help me kindly.
> Thanks
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