I want to disable my toolbar handle directly after the execution. I saved in the past in e3, the IAction object via the "selectionChanged" method and so I set after the run logic the action.setEnabled(false).
public void selectionChanged(IAction action, ISelection selection) {
this.delegate = action;
}
Exist in e4 any possibility to do the same behavior?
You use the #CanExecute method of a handler to control the enablement.
#CanExecute
public boolean canExecute()
{
// TODO return enablement
}
This method is called when most things that could change the enablement run, or you can force it to be run by calling
#Inject
IEventBroker eventBroker;
eventBroker.send(UIEvents.REQUEST_ENABLEMENT_UPDATE_TOPIC, UIEvents.ALL_ELEMENT_ID);
Related
I need to solve a simple problem, but yet I have not been able to found out any solution yet.
I have a simple DropDownChoice with AJAX onChange() JS event. I need to add a confirm box before the onUpdate() action is done - this is not difficult, BUT I need to display the confirm box only if the new selected value of the DropDownChoice is X (one certain value), and do not display the confirm box in any other case. Is it doable?
Short example snippet:
DropDownChoice<Integer> choice = new DropDownChoice<Integer>("id", new Model<Integer>(0));
choice.add(new AjaxFormComponentUpdatingBehavior("onchange") {
#Override
protected void onUpdate(AjaxRequestTarget target) {
// do some stuff
}
#Override
protected void updateAjaxAttributes(AjaxRequestAttributes attributes) {
super.updateAjaxAttributes(attributes);
attributes.getAjaxCallListeners().add(new AjaxCallListener() {
#Override
public CharSequence getPrecondition(Component component) {
return "return confirm('Really?')"; // I NEED THIS DISPLAYED CONDITIONALLY
}
}
}
}
I don't know how to access the "choice" model object (converted input...) with the proposed value to add it to a condition in updateAjaxAttributes() method.
Thank you.
I think you should go for a JavaScript-based solution. The code of AJAX call listener is executed in a scope where you can use variable attrs. This variable contains the parameters used to perform AJAX call, including the id of the component. In this way you could check for selected value.
See more at http://wicket.apache.org/guide/guide/ajax.html#ajax_5
I have a list of items that goes to another page, That page is hooked up to a view model. In the constructor of this view model I have code that grabs data from the server for that particular item.
What I found is that when I hit the back button and choose another item fromt hat list and it goes to the other page the constructor does not get hit.
I think it is because the VM is now created and thinks it does not need a new one. I am wondering how do I force a cleanup so that a fresh one is always grabbed when I select from my list?
I faced the same issue, that's how i solved it.
Have a BaseView class, override OnNavigatedTo
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
if (NavigatedToCommand != null && NavigatedToCommand.CanExecute(null))
NavigatedToCommand.Execute(null);
}
add DependencyProperty.
public static readonly DependencyProperty NavigatedToCommandProperty =
DependencyProperty.Register("NavigatedToCommand", typeof(ICommand), typeof(BaseView), null);
public ICommand NavigatedToCommand
{
get { return (ICommand)GetValue(NavigatedToCommandProperty); }
set { SetValue(NavigatedToCommandProperty, value); }
}
On the necessary pages, add to xaml (and, of course, inherit BaseView )
NavigatedToCommand="{Binding OnNavigatedToCommand}"
In the ViewModel, make command itself
public RelayCommand OnNavigatedToCommand
{ get { return new RelayCommand(OnNavigatedTo); } }
and implement method you want to call to update list
public async void OnNavigatedTo()
{
var result = await myDataService.UpdateMyList();
if (result.Status == OK)
MyList = result.List;
}
So, now, every time you navigate to page with list, inside of overriden OnNavigatedTo(), a NavigatedToCommand would be executed, which would execute OnNavigatedToCommand (which you set in xaml), which would call OnNavigatedTo, which would update your list.
A bit messy, but MVVM :)
EDIT: What about cleanings, they can be done in OnNavigatedFrom(), which works the same. Or OnNavigatingFrom(), which also can be useful in some cases.
In my application i have a Custom AlertView, which works quite good so far. I can open it the first time, do, what i want to do, and then close it. If i want to open it again, i'll get
java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first
so, here some code:
public Class ReadingTab
{
...
private AlertDialog AD;
...
protected override void OnCreate(Bundle bundle)
{
btnAdd.Click += delegate
{
if (IsNewTask)
{
...
AlertDialog.Builer adb = new AlertDialog.Builer(this);
...
View view = LayoutInflater.Inflate(Resource.Layout.AlertDView15ET15TVvert, null);
adb.setView(view)
}
AD = adb.show();
}
}
}
that would be the rough look of my code.
Inside of btnAdd are two more buttons, and within one of them (btnSafe) i do AD.Dismiss() to close the Alert dialoge, adb.dispose() hasn't done anything.
the first time works fine, but when i call it the secon time, the debugger holds at AD = adb.show(); with the Exception mentioned above.
So what do i have to do, to remove the Dialoge from the parent? i can't find removeView() anywhere.
If you are setting up an AlertView once and then using it in multiple places (especially if you are using the same AlertView across different Activities) then you should consider creating a static AlertDialog class that you can then call from all over the place, passing in the current context as a parameter each time you want to show it. Then when a button is clicked you can simply dismiss the dialog and set the instance to null. Here is a basic example:
internal static class CustomAlertDialog
{
private static AlertDialog _instance;
private const string CANCEL = #"Cancel";
private const string OK = #"OK";
private static EventHandler _handler;
// Static method that creates your dialog instance with the given title, message, and context
public static void Show(string title,
string message,
Context context)
{
if (_instance != null)
{
throw new Exception(#"Cannot have more than one confirmation dialog at once.");
}
var builder = new AlertDialog.Builder(context);
builder.SetTitle(title);
builder.SetMessage(message);
// Set buttons and handle clicks
builder.SetPositiveButton(OK, delegate { /* some action here */ });
builder.SetNegativeButton(CANCEL, delegate { /* some action here */});
// Create a dialog from the builder and show it
_instance = builder.Create();
_instance.SetCancelable(false);
_instance.Show();
}
}
And from your Activity you would call your CustomAlertDialog like this:
CustomAlertDialog.Show(#"This is my title", #"This is my message", this);
i have a little problem with javafx. i added a change listener like this:
private final ChangeListener<String> pageItemSelected = new ChangeListener<String>()
{
#Override
public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue){
pageGotSelected(newValue);
}
};
now to the problem: if i change an page item like this:
guiPageList.setValue(model.getCurrentTargetPage());
the event gets also(as it get by selecting something with the mouse or key) fired. is there a way to disable the event firing or another way?
i need the event only, if the element got selected by the user and not if i change it with the setValue() function...
perhaps consuming the event, but i don´t know what kind of event this would be.
thanks in advance!!!
You can temporarily remove the listener and add it again:
guiPageList.getSelectionModel().selectedItemProperty().removeListener(pageItemSelected);
guiPageList.setValue(model.getCurrentTargetPage());
guiPageList.getSelectionModel().selectedItemProperty().addListener(pageItemSelected);
Alternatively you could decorate the listener with another listener implementation, the code would be something like:
class InvalidationListenerEventBlocker implements InvalidationListener {
InvalidationListener decoratedListener;
boolean block;
public void invalidated(Observable observable) {
if(!block) {
decoratedListener.invalidated(observable);
}
}
}
Add a setter for the block boolean and send the listener in through the constructor. Set block to true to stop events.
This is very old question, but I came to some solution I personally use, that's reusable and does not require storing a reference to the listener (but it needs a reference to the exposing/muffling property thou).
So first the concept: we're going to create lambda (InvalidationListener), that is going to be called only if above mentioned exposing/muffling property is set to true/false. For that we are going to define another functional interface that provides described behavior:
#FunctionalInterface
private interface ManageableInvalidationListener
extends InvalidationListener {
public static InvalidationListener exposing(
BooleanProperty expose,
ManageableInvalidationListener listener) {
return ob -> {
if (expose.get()) {
listener.invalidate(ob);
}
};
}
public static InvalidationListener muffling(
BooleanProperty muffle,
ManageableInvalidationListener listener) {
return ob -> {
if (!muffle.get()) {
listener.invalidated(ob);
}
}
}
public abstract void invalidated(Observable ob);
}
This interface defines two static methods we're going to use in our code. We pass a steering property as first argument (it will tell if listener should be called) and actual implementation to be performed, when it will be called. Please note, that there is no need to extend InvalidationListener, but I'd like to keep ManageableInvalidationListener in sync with InvalidationListener.
So we would call exposing if we need to create a (manageabale) listener that would notify the (invalidation) listener if expose property has value of true. In other case we would create the listener with muffling, if true of the steering property would mean, well, to muffle the notification.
How to use it?
//- Let's make life easier and import expose method statically
import static ManageableInvalidationListener.exposing;
// ...
//- This is the steering property.
BooleanProperty notify = new SimpleBooleanProperty(true);
//- This is our main property with the listener.
ObjectProperty<Foobar> foobar = new SimpleObjectProperty<>();
//- Let's say we are going to notify the listener, if the
// notify property is set to true.
foobar.addListener(exposing(notify, ob -> {
//- Here comes the InvalidListener code.
}));
And then somewhere in the code:
//- Listener will be notified as usual.
foobar.set(new Foobar());
//- Now temporarily disable notifications.
notify.set(false);
//- The listener will not get the notification this time.
foobar.set(new Foobar());
//- Re-enable notifications.
notify.set(true);
Hope this somehow helps. You're free to use the code in this post as pleases you.
I have searched the web for the correct answer, but I've been failing to achieve this :
In EntryPoint class, I need to manage widgets according to events that occur in nested widgets. I've cleaned of the code to focus only on what is important here.
I have built a few UiBinder widgets, for example, a Login pane where the user can enter his credentials. In my EntryPoint class, I add the widgets in the correct position.
// This is from EntryPoint class
public void onModuleLoad() {
LoginPane lp = new LoginPane();
RootPanel.get("headerRightPane").add(lp);
lp.setFocus();
// Other widgets added in same manner after this point...
}
I would like a successful login to remove the LoginPane and replace it by another widget (AccountPane) that would show the account information for the user that is logged in. I have an onClick event, in LoginPane, that sends a request to a fully functional Servlet that checks the credentials. At this exact point, if the Servlet determines that the login is indeed successful, I would like to fire a "successfulLogin" event (from LoginPane) that could notify the EntryPoint class that the LoginPane can now be replaced by the AccountPane.
// This is from LoginPane class
#UiHandler("loginButton")
void onClick(ClickEvent e) {
checkCredentials(usernameField.getText(), passwordField.getText());
}
public void checkCredentials(String username, String password) {
String usernameToServer = username;
String passwordToServer = password;
credentialsService.credentialsServer(usernameToServer, passwordToServer,
new AsyncCallback<CredentialsPaneContent>() {
public void onFailure(Throwable caught) {
answerLabel.setText(Utilities.SERVER_ERROR);
}
public void onSuccess(CredentialsPaneContent result) {
if ( result == null ) {
answerLabel.setText("Login Failed.");
} else {
// Fire event here (to be caught by EntryPoint class)
answerLabel.setText("Login Successful.");
}
}
});
}
So, the question : How should I proceed to create, fire and listen to the event from my nested widget?
Use an EventBus. Additionally, consider adopting the Model-View-Presenter pattern to keep your application maintainable as it grows:
Large scale application development and MVP, Part I
Large scale application development and MVP, Part II
GWT MVP Development with Activities and Places
Lets have an interface which is implemented by EntryPoint class,
now have a referrence of interface type which actually an object of interface.
Using this interface referrence invoke the listner(interface) mothod, which serves your purpose.