New Event Handling and Composites
I am just not getting the new Event handling. I have went over every
example I can find, but it is not clicking. How do you let composite
widgets subscribe to events from other composite widgets? From reading
it sounds like there is a HandlerManager that you register with by
implementing the HasxxHandlers interface, but I cannot piece together
how the Class that creates the event fires it off to the subscribers.
For example I have the following SimpleWidget that extends Composite
that contains a single button. I have another Composite widget that
wishes to be notified when that button is clicked. Can someone fill in
the blanks for me?
(Note I did not attempt to add the event handlers because I do not
want to confuse others who may have the same issue.)
public class SimpleWidget extends Composite{
private Button button;
public SimpleWidget() {
FlowPanel fp = new FlowPanel();
button = new Button("Click me");
//With listeners I would create an anonymous inner class
//that fires the click events to registered listeners.
//I don't know how to fire events for handlers
//button.addClickHandler(handler);???
fp.add(button);
initWidget(fp);
}
}
public class DoSomething extends Composite{
public DoSomething() {
FlowPanel fp = new FlowPanel();
SimpleWidget simple = new SimpleWidget();
fp.add(simple);
initWidget(fp);
}
}
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
"Google Web Toolkit" group.
To post to this group, send email to Google-Web-Toolkit@googlegroups.com
To unsubscribe from this group, send email to
google-web-toolkit+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/Google-Web-Toolkit?hl=en
-~--~~~~--~~--~--~---
Re: New Event Handling and Composites
Thx Thomas I really appreciate this.
That worked, but when I handle the event in DoSomething, I need to
know what button was clicked.
e.g.
public class DoSomething extends Composite implements ClickHandler{
private SimpleWidget simpleWidget;
public DoSomething() {
FlowPanel fp = new FlowPanel();
simple = new SimpleWidget();
simple.addClickHandler(this);
fp.add(simpleWidget);
initWidget(fp);
}
public void onClick(ClickEvent event) {
if (event.getSource() == simple.getButton()) {
//do something
}else if(event.getSource() == smiple.getSomeOtherButton(){
//do something else.
}
}
}
So in the onClick handler event.getSource() sources SimpleWidget, but
I really need to know what button was clicked.
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
"Google Web Toolkit" group.
To post to this group, send email to Google-Web-Toolkit@googlegroups.com
To unsubscribe from this group, send email to
google-web-toolkit+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/Google-Web-Toolkit?hl=en
-~--~~~~--~~--~--~---
Re: New Event Handling and Composites
So tracing the fireEvent method, I found that the source does indeed
reference the button, but in HandlerManager, the source gets changed
to SimpleWidget.
Object oldSource = event.getSource(); //event.getSouce is button
event.setSource(source); //here source is SimpleWidget
Not sure why.
the full method.
/**
* Fires the given event to the handlers listening to the event's
type.
*
* Note, any subclass should be very careful about overriding this
method, as
* adds/removes of handlers will not be safe except within this
* implementation.
*
* @param event the event
*/
public void fireEvent(GwtEvent event) {
// If it not live we should revive it.
if (!event.isLive()) {
event.revive();
}
Object oldSource = event.getSource();
event.setSource(source);
try {
firingDepth++;
registry.fireEvent(event, isReverseOrder);
} finally {
firingDepth--;
if (firingDepth == 0) {
handleQueuedAddsAndRemoves();
}
}
if (oldSource == null) {
// This was my event, so I should kill it now that I'm done.
event.kill();
} else {
// Restoring the source for the next handler to use.
event.setSource(oldSource);
}
}
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
"Google Web Toolkit" group.
To post to this group, send email to Google-Web-Toolkit@googlegroups.com
To unsubscribe from this group, send email to
google-web-toolkit+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/Google-Web-Toolkit?hl=en
-~--~~~~--~~--~--~---
