All,
Currently, Pivot allows a caller to disable individual items in list,
table, and tree views via index (or path, in the tree case). This
works, but does require some effort on the part of the caller, since
the caller needs to know which indexes map to the items they want
disabled.
I'd like to propose what I think is a better solution: what if we
instead allow the caller to set a "disabled item filter"? This would
basically amount to an implementation of some interface such as:
package org.apache.pivot.util;
public interface Filter {
public boolean accept(Object object);
}
or possibly:
package org.apache.pivot.util;
public interface Filter<T> {
public boolean accept(T t);
}
It would certainly simplify the code in TreeView, TableView, and
ListView, since we'd no longer need to maintain the list of disabled
indexes. It is also more efficient, for the same reason. Finally, it
is more flexible, since any items matching the filter would be
automatically disabled - the caller would not need to manually update
the disabled index list as new items were added.
The downside is that, if the caller does actually want to disable
items by index, it would be difficult (or impossible) do. We could add
an index or path to the accept() method, but that seems like overkill.
I guess the question is - what use case are we addressing with
disabled items? Is a caller more likely to want to disable items by
nature or by index? I'd guess the former, but I'm not 100% sure.
Please let me know what you think.
Thanks,
Greg
