I am currently trying to mimic the enyo.Popup behavior. I looked at the source at github but having a hard time to understand it.
Especially that is the code I have trouble with:
handlers: {
//...
onRequestShow: "requestShow",
onRequestHide: "requestHide"
},
//* #public
events: {
//* Fires after the popup is shown.
onShow: "",
//* Fires after the popup is hidden.
onHide: ""
},
And some where else in the code, there are calls to this.show().
Firstly, I did not found a declaration for this.show(). Secondly, though I assume that it must be inside this.show() and this.hide() respectively, where are the onShow and onHide events called?
And lastly, I defined a kind of myself, containing also the above code. But despite the show() and hide() methods are working, my own requestShow() and requestHide() methods were not called.
What am I missing?
Firstly, show is a function declared on enyo.Control: http://enyojs.com/api/#enyo.Control::show
onShow and onHide are events that can be subscribed to by the popup's owner (hence, their declaration in the events block). They are called in the showingChanged function. The method for calling events is do{EventNameWithoutOn}. In this case: doShow.
Check this documentation on events: https://github.com/enyojs/enyo/wiki/Event-Handling
(Or, you could buy my nice Enyo book! http://roysutton.com/2013/01/31/print-book-now-available/ )
The handlers block is a way for a control to subscribe to messages it (or its children) generate. Having said that, I don't see any place in the code that generates onRequestHide events.
I hope that helps!
Related
I have a SAPUI5 application and when I press on items to visit the detail or object page it shows the following error message in the following part of the code
It is not supported to change the behavior at runtime.
showObject: function(oItem) {
var sObjectId = oItem.getBindingContext().getProperty("Partner");
this.getRouter().navTo("object", {
objectId: encodeURIComponent(sObjectId)
}, false);
},
Are you sure that's where you're getting it? I've only seen that error when working with certain controls the UploadCollection and trying to fire a method like oUploadCollection.setUploadUrl("/url") which is not supported at runtime.
Without setting a property and given the code above, the error doesn't make sense.
*A side note: without seeing where your showObject method is called, it's hard to say... but if showObject is called directly off the press event of the ListItem you need to call getSource() on the event object. Might be throwing an error there about getBindingContext() not being a function.
In my application I need to wait until external program (using QProcess) is finished. I want to keep the application responsible so blocking methods are unacceptable.
Also I need to disallow user input. I've tried to make QEventLoop and exec it with QEventLoop::ExcludeUserInputEvents flag, but as documentation says it only delays an event handling:
the events are not discarded; they will be delivered the next time processEvents() is called without the ExcludeUserInputEvents flag.
So I implemented simple event filter and install it on qApp (the idea is took from Qt Application: Simulating modal behaviour (enable/disable user input)). It works well, but sometimes QApplication::processEvents function never returns even if I specify the maximum timeout. Could anyone help me to understand for what reasons it periodically happens?
class UserInputEater : public QObject
{
public:
bool eventFilter(QObject *object, QEvent *event)
{
switch(event->type())
{
case QEvent::UpdateRequest:
case QEvent::UpdateLater:
case QEvent::Paint:
return QObject::eventFilter(object, event);
default:
return true;
}
}
};
-
UserInputEater eventEater;
qApp->installEventFilter(&eventEater);
QProcess prc;
prc.start("...");
while(!prc.waitForFinished(10))
{
if(qApp->hasPendingEvents())
{
// Sometimes it never returns from processEvents
qApp->processEvents(QEventLoop::AllEvents, 100);
}
}
qApp->removeEventFilter(&eventEater);
UPD: Seems like it depends of the timeout value for QProcess::waitForFinished.
I guess you are filtering some useful events (for example, QEvent::SockAct could be involved). Try to add some debug output and find out which event types you're actually filtering. Or it might be better to specify the black list of events you want to block instead of white list of events you want to allow. See this answer.
Also you shouldn't use return QObject::eventFilter(object, event);. You should use return false. All other event filters will be called automatically.
This solution however seems weird and unreasonable to me because you can just call setEnabled(false) for your top level widget to block user input, and then you can use QApplication::processEvents without any flags.
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
}
});
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.
It's been a while since I used GTK+, and the last time I did was in C, not using gtkmm and C++ as I am now. Anyway, I have what I think should be an easy problem to solve:
I have a pop-up menu consisting of a list of radio buttons, and when I click one of them I want some action to occur. The code goes like this:
Gtk::RadioMenuItem::Group group;
for ( size_t i = 1; i < LH_MAX; ++i )
{
Gtk::RadioMenuItem* pItem = new Gtk::RadioMenuItem( group, names[i], names[i] );
pItem->set_name( names[i] );
pItem->signal_activate().connect( sigc::mem_fun(*this, &MyClass::on_item_activated) );
pItem->show();
m_Menu.append( *Gtk::manage(pItem) );
}
The only problem I see is that MyClass::on_item_activated gets called twice when a previously-unselected radio button is chosen from the menu. It's called only once when the already-selected radio button is clicked.
I'm guessing that the first firing is to say "something is no longer activate," and the second is for the new radio button activation. Whether I'm right or wrong, the question is the same: how best can I have my handler only take action once per click? Either I need the handler to get called only once, or I need something to check from inside it to know if the callback is a "duplicate" or not.
You could use sigc::bind to supply the item as a argument to the callback function.
pItem->signal_activate().sigc::bind(sigc::mem_fun(*this,&MyClass::on_item_activated),pItem));
Then you can use item->get_active() in the callback to respond to activations only.
void MyClass::on_item_activated(Gtk::RadioMenuItem* item) {
if (item->get_active()) {
// Do some stuff
}
}
That's what I do too, connect to signal_toggled() and check if get_active() is true.
I don't know exactly what you're trying to accomplish (or what MyClass is and what base classes it inherits from), but connecting to signal_toggled() might be more useful than signal_activate()
/Agree with Johannes. Check if the item is activated when receiving the signal.