2009/10/30 Jody Garnett
<jody.garnett@xxxxxxxxx>
> - i created an operation, used the net.refractions.udig.ui.operation
> extension point to get an Action for the targetClass
> net.refractions.udig.project.ILayer
Okay- so your operation should work on a Layer; or anything that can
adapt to a Layer - so probably a Map as well (assuming the current
layer).
Right.
> - subclassed AbstractPropertyValue and created my own PropertyValue class
> (checks preferences for layer using a preferences store)
> - the user select a layer, changed the preference for the selected layer and
> as a result an operation should be available within the context menu of the
> still selected layer
> BUT the action (OpAction) is not visible (PropertyValue would return true)
> because the selection didn't changed.
> If the customer deselects the layer and selects it again it works.
Oh I see; so you somehow want to ask it to check again. I am pretty
sure it only wants to check once for speed (rather then making the
right click operation slow). I wonder if the property value could
listen to the Layer? Or would that also be slow.
I guess the property value could listen to the layer but the changes occurs not on the layer or layer related objects. It's in the PreferencesStore, updated from a StyleEditorPage. Or is it even possible to set some properties for a layer? So maybe the PropertyValue implementation could listen to the layer(-properties).
> What I'm doing wrong? In my opinion the OpAction.updateEnablement method
> should not check whether the internal selection changed (see attached file
> OpAction.patch). But it is possible to run into performance issues if
> PropertyValue implementations are very heavy.
Agreed.
> Could somebody comment my thoughts? If required I can create an issue for this.
I would like to create an issue for this so that:
a) we can talk to Jesse about it (who write the PropertyValue code)
b) work on a patch for his review
Jody
OK, i create an issue and upload a patch. Jody, have you looked into
the appended? Do you thing it solves the problem? I've seen there are
some implementations but not to many and all of them are not so
expensive at runtime, are they? Thanks for comments so far.
Frank
