Description David Cummings 2007-05-24 13:46:45 EDT

Marker views (such as the Tasks and Problems view) allow filtering based on a MarkerFilter.  A marker filter allows filtering based on:
 * On any element
 * On any element in same project
 * On selected element only
 * On selected element and its children
 * On working set

For the "selected element only" and "selected element and its children" options, the element that the user has selected is adapted to a Resource.  For cases where the selected element is a resource, such as a Java file, this is sufficient).  Unfortunately in cases where the selection is not a resource (such as an object in a GEF/GMF diagram), this can confuse the user.  Every element in their diagram will adapt to the same resource, thus no matter the selection in their diagram, all markers for that resource will be shown.

Marker filtering for the "selected element only" and "selected element and its children" should be more robust, allowing clients to contribute selection filter helpers.  Clients could contribute, through an extension point, a class that maps a given selection to a given marker, and determines whether the marker is applicable for the selection.  In the extension clients could define:
a) Which types of selections the class is applicable for
b) Which types of markers the class is applicable for
c) The class itself, which accepts an object (or collection of objects) and a marker and determines whether or not the marker is applicable for the given selection

If none of these contributions were present, the default resource adapter functionality would remain.