Develop Reference

Wicket quick double click submit button

I have a problem with a Wicket Form. In my form if a User click twice quickly on a SubmitLink the onSubmit method called twice and there where 2 instances of an object. How can I prevent this? I have tried using a boolean variable
#Override
public void onSubmit(){
if(!submitted){
submitted = true;
dao.save(object);
setResponsePage(differentPage.class);
}
}
This method doesn't work for me. Can anyone help me please?

There are some work around To prevent double submit.
I guess you may not added renderStrategy.So first add setRenderStrategy in Your application class .
Direct, IRequestCycleSettings.RenderStrategy.ONE_PASS_RENDER. Everything is handled in one physical request. This is efficient, and is the best option if you want to do sophisticated clustering. It does not however, shield you from what is commonly known as the Double submit problem.
getRequestCycleSettings().setRenderStrategy(RequestCycleSettings.RenderStrategy.ONE_PASS_RENDER);
Probably above solution will work with your case. On top of that
You can disable the button on click submit or You can use some indicatorbutton link .

I resolve with this lines of code
save_btn = new AjaxSubmitLink("submit_btn", this) {
protected void onSubmit(AjaxRequestTarget art){
art.appendJavaScript("e.preventDefault();");
}
};
And the
getRequestCycleSettings().setRenderStrategy(RequestCycleSettings.RenderStrategy.ONE_PASS_RENDER);
of course

How to listen on save button or assign an event after it was clicked in Vaadin 7

When I am editing grid inline I can save or cancel my grid row changes. I want to update my database entries after button 'save' will be pushed(Data base mechanism has already done) How can I implement it?
My container:
BeanItemContainer<CategoryOfService> beansContainer;
Editing view:
All what I need it know which listeners I have to use. I found some CommitHandler which I can add by EditorFieldGroup class but I can't implement it properly maybe there is have to be another way to resolve problem.

There's kind of a way to capture inline Save click on the grid.
grid.getEditorFieldGroup().addCommitHandler(new FieldGroup.CommitHandler() {
#Override
public void preCommit(FieldGroup.CommitEvent commitEvent) throws FieldGroup.CommitException {
//...
}
#Override
public void postCommit(FieldGroup.CommitEvent commitEvent) throws FieldGroup.CommitException {
//...
}
});
After clicking Save both methods preCommit and postCommit get called.
Hope it helps :)

Grid does not currently give you any direct way of adding listeners to the save and cancel buttons for the inline editor, although that is something that might change in Vaadin 7.6.
As a workaround before that happens, the CommitHandler approach that you already mentioned is still supposed to work. You can find a basic example here. The contents of your BeanItemContainer should be fully updated in the postCommit phase.

grid.getEditor().addSaveListener((EditorSaveListener<Product>) event -> {
//your stuf
HibernateDataSource.updateProduct(event.getBean());
});

Validate CTabFolder before switching tabs

In a CTabFolder, I'd like to check the content for unsaved data before the user can switch from one tab to another. SWT does not provide a PreSelection event, as stated here.
I found a workaround, suggesting to switch back to the old tab when a selection is triggered, validate the data and then perform the desired switch again, if data is valid.
I do understand the general idea of this workaround, however, it is not working for me. oldPageIndex and newPageIndex do always have the same value, though I did not click on the same tab.
this.tabContainer.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent event) {
int oldPageIndex = tabContainer.getSelectionIndex();
int newPageIndex = tabContainer.indexOf((CTabItem)event.item);
// Here: oldPageIndex == newPageIndex
...
}
});
Is this workaround still working or is there anything I could possibly be doing wrong? Or maybe, has there been any fix for a real PreSelection event in the meantime? I tried using event.doit, but the SelectionEvent is fired, when the tabs have been switched already.

You can use the selection listener but as you have found the getSelectionIndex() does not give you the old tab. So you will have to maintain the old tab index yourself.
This is the technique used by the Eclipse FormEditor.

GWT event prevent default not working in Java

I'm new to GWT and I need to get a right click working. The doco I've read suggests that I need to override the onBrowserEvent() method. I'm just experimenting at this stage. the event is processed and my pop-up appears. However, as soon as I close the pop-up, the usual browser drop down menu appears (with options like "Bookmark this page" and such).
I'm using IceWeasel 24.5.0 (FireFox clone for Debian) and, obviously, Debian (wheezy).
Here's the relevant code:
public ActivityTextCell() {
super(BrowserEvents.MOUSEDOWN, BrowserEvents.MOUSEUP);
}
#Override
public void onBrowserEvent(
com.google.gwt.cell.client.Cell.Context context,
Element parent,
ActivityDTO value,
NativeEvent event,
ValueUpdater<ActivityDTO> valueUpdater) {
super.onBrowserEvent(context, parent, value, event, valueUpdater);
event.preventDefault();
event.stopPropagation();
if (event.getType().equals(BrowserEvents.MOUSEUP)) {
Window.alert("mouse up event");
}
else {
switch ( event.getButton()){
case NativeEvent.BUTTON_RIGHT:
Window.alert("right mouseclick");
break;
case NativeEvent.BUTTON_LEFT:
Window.alert("left mouseclick");
break;
case NativeEvent.BUTTON_MIDDLE:
default:
break; // Do nothing
}
}
The class ActivityTextCell extends AbstractCell.
So what am I missing? How do I stop the browser from reaticng to the mouse click?

Well it certainly wasn't a matter of a few minutes (as can be seen by the fact that it has taken me a week to get back to this), but I have a solution. I tried reversing the order of the the event.preventDefault() and super.onBrowserEvent() but it didn't really help.
I tried a little experiment on a normal web page. It turns out, that the MOUSEDOWN event doesn't do anything in that context and the usual browser selection menu appears on the MOUSEUP. So the if/else logic sort of fell by the wayside.
What did the trick is to include the following in the top level GUI class immediately after adding the main page:
RootLayoutPanel.get().addDomHandler(new ContextMenuHandler() {
#Override
public void onContextMenu(ContextMenuEvent event) {
event.preventDefault();
event.stopPropagation();
}
}, ContextMenuEvent.getType());
This has the additional benefit (for my purposes, at least) of preventing the Browser from reacting to a right click anywhere in the application view.
As an aside: The purpose of preventing the default action is to stop the Browser doing its own thing Stopping propagation is possibly not required, but I left it in anyway (propagation goes fro the node up to the root, not the other way around). The purpose of overridinging onBrowserEvent() is to enable your own application to handel that event. The use of super.onBrowserEvent() is to allow the event to be handled by your code in the first place. I've given the relevant reference in my previous comment. The book "GWT in Action" is well worth a read if you're likely to be doing a lot of GWT coding.

You call super.onBrowserEvent() which triggers the standard browser response.
You should move event.preventDefault() to the if part of your code, and super.onBrowserEvent() to the else part. You want one of them executed depending on a browser event, but not both.

CodeName One, Action event not working- need explanation

I'm trying to get and action event to fire on my HelloWorld. im using the GUI and when it auto creates the:
protected void onMain_Button1Action(Component c, ActionEvent event) {
// If the resource file changes the names of components this call will break notifying you that you should fix the code
super.onMain_Button1Action(c,event);
}
I know its not going to work because there is no void of the same type in the superclass.
protected void onMain_Button1Action(Component c, ActionEvent event) {
// If the resource file changes the names of components this call will break notifying you that you should fix the code
Dialog.show("Test", "it works", "OK",null);
}
And I'm still getting nothing. I've looked for other tutorials on how to use codenames as one but i cant find any. And I dont get the one made by the author. if any one can toss me a line i would be most appreciative.

You need to save the resource file in the designer and NOT delete the call to super. If you are using Eclipse you should refresh the project after saving in the designer using F5.