[news.eclipse.modeling.gmt.amw] Re: extending defaultWeavingPanel

[Marcos Didonet Del Fabro <marcos.didonet-del-fabro@xxxxxxxxxxxxxx>]

Hello,

see the answers below.

> I´m extending DefaultWeavingPanel. I trigger a validation when i add a right
> link (I modified "createWLinkEndActions" method). If validation method 
> return
> false i want to delete right link, but this is difficult. 

In the weaver we use the "Editing Domain" notion of EMF editor to modify 
the models in a easier way. Take a look at the 
"org.eclipse.weaver.plugin.util.WeaverUtil" class, "setPropertyValue" 
method.
We use these commands only to add or modify the elements. You can try to 
do the same to delete elements.

Then i had thought
> in
> other option:
>
> I want to trigger the validation in the moment i click over a element on 
> right
> Panel. If validation method return false i want to disabled drop action.. is 
> it
> possible? how?
>
> I had seen some similar in weaver plugin, i attached a screenshot.
>
> Sincerely thanks for your help,
>
> Kelly. 

The drag and drop actions are implemented in the 
"org.eclipse.weaver.extension.panel.WeavingPanelDndManager". You have to 
modify two methods, "helper", that is responsible for enabling or 
disabling the drop action (here you call your validation method), and 
"drop", that is the action that is executed in the moment you drop an 
element.

- helper method:

After you execute you validation method, there are two main attributes 
that must be set.

1) event.detail: used to enable/disable the drop action. This is 
internally used by the component.

event.detail = DND.DROP_NONE means the drop is disabled. This is the 
default action.

event.detail = DND.DROP_LINK means the drop is enabled. You can set this 
attribute depending on the result of you validation. In the weaver 
extension, it depends on the type of the element.

There are other types of DNDs, but we used only these two types.

2) selectionType: this attribute defines the type of the selection, and 
it is used by the "drop" method.

You can create the selection types you want, since it is an Integer 
attribute. We have selection types based on the type of the current element.

- drop method:

This method is called if you set the event.detail to a different value 
than DND.DROP_NONE (DROP_LINK in our case).

Then you can check the value of the selectionType attribute, and execute 
the appropriate action.


Regards,

Marcos.