For a grid that contains a column with a checkbox (mapped to pySelected for example, or another true/false property), how could a "Select All" button be configured that will select all displayed rows accross all pages.

i.e. if a filter is applied all filtered rows should be selected, including those on pages that are not displayed on screen, and the filter should remain in place after the selection.

I can do this pretty easily for the data on the clipboard using a data transform but this selects all the filtered out stuff too.