I'm trying to handle the event when the close button of a Window is clicked:
// View Code
#Override
public void attachWindowListener(WindowListener listener) {
window.addWindowListener(listener);
}
// Presenter code
view.attachWindowListener(new WindowListener(){
public void windowHide(WindowEvent we) {
GWT.log("Window Event - Processing fields");
processFields();
}
});
However, the windowHide function seems to be not executed since I can't see the log I placed there.
How to properly handle that event?
How about
Window.addCloseHandler(
new CloseHandler<Window>()
{
public void onClose( CloseEvent<Window> windowCloseEvent )
{
// Do your worst here
}
} );
I usually put this in onModuleLoad() in my EntryPoint class.
Cheers,
Based on the information provided I would guess that either a.) the events you think are firing do not fire for the Window component (even if it seems like they should) or b.) the events are firing but in a different order than you expect.
For example, it's possible that a BrowserEvent or some other event is firing first as the window is being closed and the Window object's WindowEvent never fires. According to the API docs for GXT 2.x, the WindowEvent will fire on hide and deactivate but it does not specify that it fires on close. The GXT 3.0.x API doc is less clear on this point but I would assume the same behavior. Unfortunately Sencha does not provide good documentation on what events fire for a given component and in what order.
With that said, I have had some luck working through similar issues to this by using a debug class which outputs all the events on a component to which it is attached. This may shed some light on which events are firing and their order of execution, and you may find an optimal event to which you can attach your processFields() method.
For a good example of a debugger class, see this answer from a related post: https://stackoverflow.com/a/2891746/460638. It also includes an example of how to attach the debugger to your component.
API Doc for Window, GXT 2.x: http://dev.sencha.com/deploy/gxt-2.2.5/docs/api/com/extjs/gxt/ui/client/widget/Window.html
API Doc for Window, GXT 3.0.x: http://dev.sencha.com/deploy/gxt-3.0.0/javadoc/gxt/com/sencha/gxt/widget/core/client/Window.html
This worked:
window.addListener(Events.Hide, new Listener<ComponentEvent>() {
#Override
public void handleEvent(ComponentEvent be) {
// Do stuff
}
});
Related
I've got a GWT 2.4 app where I'm "swapping views" by switching out one Composite widget on the RootPanel for another, using the usual RootPanel.get().clear() and RootPanel.get().add(newWidget) to remove and add, respectively.
The first composite widget contains a PasswordTextBox. It listens for the Enter keypress, which triggers the swap. Nothing too fancy:
getDisplay().getPasswordBoxForKeyPresses().addKeyPressHandler(new KeyPressHandler() {
public void onKeyPress(KeyPressEvent event) {
if (event.getNativeEvent().getKeyCode() == KeyCodes.KEY_ENTER) {
swapWidgets(); // clear RootPanel and add new widget
}
}
});
The problem is that there is a DOM memory leak: after RootPanel.get().clear() is called, the old composite widget is stuck in the detached DOM tree because the HTMLInputElement for the PasswordTextBox has some strange reference to it which I cannot identify.
Update:
I took the helpful advice below, compiled at style=detailed and started trying to drive down the tree to look a reference to the element in JS. I'm pretty new with GWT, so it still isn't obvious to me what's going on. So starting with the second line in the retaining tree, I can see that lastEvent in _2 contains the nativeKeyTarget listed at the top of tree. But where do I go from there?
I tracked the reference down to SmartGWT. It tracks the last click event within ISC_Core.js. Further questions are
How will this behavior further affect memory usage in my app?
Can this behavior be bypassed if need be?
But those questions are for another post!
Looks like you may not be tracking the handler registrations which will cause memory leaks, prevent objects from being recovered, and cause phantom event captures.
In pure GWT, it looks like this
// class member
HandlerRegistration reg;
// save for recovery
reg = getDisplay().getPasswordBoxForKeyPresses().addKeyPressHandler(...);
public void onDetatch() {
// recover memory
reg.removeHandler();
reg = null;
}
GXT has a nice grouping feature to prevent registration sprawl, it looks like this
// class member
GroupingHandlerRegistration regs = new GroupingHandlerRegistration();
// save for later recovery
regs.add( getDisplay().getPasswordBoxForKeyPresses().addKeyPressHandler(...) );
// recover memory
regs.removeHandler();
Source code for GroupingHandlerRegistration
Given the following code:
TextBox tb = new TextBox();
tb.addValueChangeHandler(new ValueChangeHandler<String>() {
#Override
public void onValueChange(ValueChangeEvent<String> event) {
Window.alert(event.getValue());
}
});
onValueChange will be called if the TextBox loses focus. I am trying to have it called whenever the input value changes. The solutions I have read all involve handling the keyup and paste events such as in this answer. How to build a Facebook-style input box in GWT Hasn't this been addresses in GWT 2.5.1? Is there a way to bind to the native input change method? Another widget or using the UI framework would be acceptable if they have this functionality
The only way in GWT is to bind to the key down/key up and paste events.
Please send a patch to add support for the input event (using addBitlessDomHandler): http://www.gwtproject.org/makinggwtbetter.html, it should be rather easy (add a acase in DOMImpl) and has good chances to make it in (and if sent early enough, would have good chances to ship in GWT 2.6)
The solution is use the right event and that is the input event, so look how to hook on it, there are many ways to do it. Because I work with elements and not with Widgets this the code that I use it:
Element input = Document.get().getElementById("my-input");
DOM.sinkBitlessEvent(input, "input");
DOM.setEventListener(input, event -> GWT.log("Event!"));
You can just use addChangeHandler() and onChange, tb.getValue().
I used the following to detect when the value of a textbox changes. Just bare in mind this only detects if the text box goes from empty to full or full to empty. This was done to try reduce async calls to the server to validate the input
#UiHandler("notes")
#SuppressWarnings("unused")
public void notes(KeyUpEvent event) {
if (!areNotesCaptured && !notes.getText().isEmpty()){
fireLeaveSelectionUpdatedEvent();
areNotesCaptured = true;
} else if (areNotesCaptured && notes.getText().isEmpty()){
fireLeaveSelectionUpdatedEvent();
areNotesCaptured = false;
}
}
in the silverstripe backend I´m managing certain PageTypes via a ModelAdmin. That works fine so far, the only thing i can´t figure out is how to make a Page being "Published" when saving it.
Thats my code:
class ProjectPage extends Page {
public function onAfterWrite() {
$this->doPublish();
parent::onAfterWrite();
}
}
At the moment I can still see the ModelAdmin-created Pages in the Sitetree and I can see they are in Draft Mode. If I use the code above I get this error:
Maximum execution time of 30 seconds exceeded in
.../framework/model/DataList.php
Many thx,
Florian
the reason why you get "Maximum execution time exceeded" is because $this->doPublish(); calls $this->write(); which then calls $this->onAfterWrite();. And there you have your endless loop.
So doing this in onAfterWrite() or write() doesn't really work
you should just display the save & publish button instead of the save button
But I guess its easier said than done.
Well adding a button is actually just a few lines, but we also need a provide the functions that do what the button says it does.
This sounds like the perfect call for creating a new Module that allows proper handling of Pages in model admin. I have done this in SS2.4, and I have a pretty good idea of how to do it in SS3, but no time this week, poke me on the silverstripe irc channel on the weekend, maybe I have time on the weekend.
I found the same need/lack and I built a workaround that seems to work for me, maybe it can be useful.
public function onAfterWrite()
{
if(!$this->isPublished() || $this->getIsModifiedOnStage())
{
$this->publish('Stage', 'Live');
Controller::curr()->redirectBack();
}
parent::onAfterWrite();
}
Create a class that extends ModelAdmin and define an updateEditForm function to add a publish button to the actions in the GridFieldDetailForm component of the GridField.
public function updateEditForm($form) {
if ( ! singleton($this->owner->modelClass)->hasExtension('Versioned') ) return;
$gridField = $form->Fields()->fieldByName($this->owner->modelClass);
$gridField->getConfig()->getComponentByType('GridFieldDetailForm')->setItemEditFormCallback(function ($form) {
$form->Actions()->push(FormAction::create('doPublish', 'Save & Publish'));
});
}
Then create a class that extends GridFieldDetailForm_ItemRequest to provide an action handler for your publish button.
public function doPublish($data, $form) {
$return = $this->owner->doSave($data, $form);
$this->owner->record->publish('Stage', 'Live');
return $return;
}
Make sure the extensions are applied and you're done.
Or, you could just grab all the code you need from GitHub.
I am using a SuggestBox and trying to capture the SuggestionEvent that is fired when the user selects a Suggestion. I can do this with normal event handlers easily enough:
itemInputBox.addEventHandler(new SuggestionHandler() {
#Override
public void onSuggestionSelect(SuggestionEvent event) {
Window.alert(event.getSelectedSuggestion().getReplacementString());
}
});
That works fine, event fires with the correct replacement string. However, I like to use UiHandler whenever possible due to how much cleaner the code is. So I've tried the following:
#UiHandler("itemInputBox")
void onSuggestionSelect(SuggestionEvent event) {
Window.alert(event.getSelectedSuggestion().getReplacementString());
}
But this results in the following errors:
[WARN] [jsonp] - Method 'getAssociatedType()' could not be found in the event 'SuggestionEvent'.
[ERROR] [jsonp] - Parameter 'SuggestionEvent' is not an event (subclass of GwtEvent).
I have a different UiHandler working correctly on the same SuggestBox so I am kind of confused where I'm going wrong:
#UiHandler("itemInputBox")
void onKeyUp(KeyUpEvent event) {
Window.alert("Key up event firing.");
}
I don't understand why one UiHandler fires correctly, while the other results in a error.
SuggestionEvent does not extend GwtEvent instead it extends java.util.EventObject.
This is why it will not work with UiBinder. I will bring this up on the GWT contributer list to see if there is a specific reason for this. Right now I am just guessing that it was forgotten when moving to the new event system.
I've been looking at a view examples of the typical "raise dialog from viewmodel" problem, noting 3 main solutions:
use attached behaviors
use a mediator pattern
use a service
I'm getting a bit bogged down though and struggling to find a solution that easily fits into my problem space - which is a very simple file copy problem:
My viewmodel is processing a loop (copying a list of files)
When a file already exists at the destination I need to raise a modal dialog to get confirmation to replace
The vm needs to wait for and receive confirmation before continuing
The "modal dialog" is actually not a new window but a hidden overlay in my MainWindow, as per http://www.codeproject.com/KB/WPF/wpfmodaldialog.aspx (thanks Ronald!)
I'm mostly there but the biggest struggles I have are:
- how to pause the loop in the viewmodel while it waits for input
- how to get input back to the viewmodel within the loop so it can carry on
So far I'm leaning towards the service solution because it seems a direct method call with a return that the vm must wait for. However, it does mean the service needs to tie directly to the view in order to make an element visible?
If anyone can post some simple code that deals directly with this problem I (and the net) would be very happy! Thanks!
For example, you have a service called IDialogService with the following interface:
public interface IDialogService
{
bool ConfirmAction(string title, string confirmationText);
}
As you mentioned, in order for the service to be able to show the actual dialog it needs to have a reference to the view that will show the actual overlay element. But instead of directly referencing the view I prefer to reference it via an interface. Lets call it ICanShowDialog and it will have the following members:
public interface ICanShowDialog
{
void ShowDialog(object dialogContent);
void HideDialog();
}
This interface will be implemented by your view that owns the dialog overlay (e.g. your main window).
Now the interesting part: suspending the code execution while the dialog is shown. First of all, I would recommend you not to use overlay elements but use usual windows if possible. Then you will not have that problem. You can style the dialog window so it will look just like the overlay element.
Anyway, if you still want to use overlay elements then you can do the following trick to suspend the code execution:
Here is pseudo code of the ConfirmAction method of the IDialogService inteface:
public bool ConfirmAction(string title, string confirmationText)
{
ConfirmationDialogView dialogView = new ConfirmationDialogView(title, confirmationText);
DialogShower.ShowDialog(dialogView); // DialogShower is of type ICanShowDialog
while (!dialogView.ResultAvailable)
{
DispatcherUtils.DoEvents();
}
DialogShower.HideDialog();
return dialogView.Result;
}
Here is the code of DispatcherUtils.DoEvents() (that was taken from here: http://dedjo.blogspot.com/2007/08/how-to-doevents-in-wpf.html):
public static class DispatcherUtils
{
public static void DoEvents()
{
DispatcherFrame f = new DispatcherFrame();
Dispatcher.CurrentDispatcher.BeginInvoke(
DispatcherPriority.Background,
(SendOrPostCallback)delegate(object arg) {
DispatcherFrame fr = arg as DispatcherFrame;
fr.Continue=True;
}, f);
Dispatcher.PushFrame(frame);
}
}
But I must warn you. Using DoEvents can result in some subtle bugs caused by inner dispatcher loops.
As an alternative to suspending the code execution while a dialog is shown you can use callbacks:
public interface IDialogService
{
void ConfirmAction(string title, string confirmationText, Action<bool> dialogResultCallback);
}
But it will not be so convenient to use.