# vtkAbstractPicker::SetPropCollection

**URL:** https://discourse.vtk.org/t/vtkabstractpicker-setpropcollection/683
**Category:** Development
**Tags:** proposal
**Created:** [April 4, 2019, 8:00am UTC](https://discourse.vtk.org/t/vtkabstractpicker-setpropcollection/683 "2019-04-04T08:00:05Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![andreasbuykx](https://discourse.vtk.org/user_avatar/discourse.vtk.org/andreasbuykx/32/8137_2.png) [@andreasbuykx](https://discourse.vtk.org/u/andreasbuykx)
#### Post date: [April 4, 2019, 8:00am UTC](https://discourse.vtk.org/t/vtkabstractpicker-setpropcollection/683/1 "2019-04-04T08:00:06Z")

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There is no method to assign a new prop collection to a picker, but all methods are in place to modify the prop collection, and the prop collection itself is accessible for modification. This however requires iterating over a collection and making a ‘deep copy’.

Another issue is that I think the vtkAbstractPicker should have a GetMTime() that depends on the modification time of its prop-collection: at the moment it is possible to modify the prop collection without the picker being Modified(), while the picker’s own methods do call Modified().

My proposal is to add a SetPropCollection method and a GetMTime method, and adjust the current methods for adding/removing props (they no longer need to call Modified()).