An adapter which performs action filtering.
Within the workbench a plugin may extend the actions which appear in the context menu for any object. The visibility of each action extension is controlled by action filtering. By default, the workbench will filter each action extension using the objectClass
and optional nameFilter
attributes defined in xml. If the action extension passes this test the action will be added to the context menu for the object.
In some situations the object class and name are not enough to describe the intended target action. In those situations an action extension may define one or more filter
sub-elements. Each one of these elements describes one attribute of the action target using a name value
pair. The attributes for an object are type specific and beyond the domain of the workbench itself, so the workbench will delegate filtering at this level to an IActionFilter
. This is a filtering strategy which is provided by the selection itself and may perform type specific filtering.
The workbench will retrieve the filter from the selected object by testing to see if it implements IActionFilter
. If that fails, the workbench will ask for a filter through through the IAdaptable
mechanism. If a filter is found the workbench will pass each name value pair to the filter to determine if it matches the state of the selected object. If so, or there is no filter, the action will be added to the context menu for the object.
Clients that implement this filter mechanism are strongly encouraged to extend this interface to provide a list of attribute names and possible values that are considered public for other clients to reference.
@see org.eclipse.core.runtime.IAdaptable