Source code for pyface.viewer.viewer_sorter
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""" Abstract base class for all viewer sorters. """
from traits.api import HasTraits
[docs]class ViewerSorter(HasTraits):
""" Abstract base class for all viewer sorters. """
# ------------------------------------------------------------------------
# 'ViewerSorter' interface.
# ------------------------------------------------------------------------
[docs] def sort(self, viewer, parent, elements):
""" Sorts a list of elements IN PLACE.
'viewer' is the viewer that we are sorting elements for.
'parent' is the parent element.
'elements' is the list of elements to sort.
Returns the list that was sorted IN PLACE (for convenience).
"""
# This creates a comparison function with the names 'viewer' and
# 'parent' bound to the corresponding arguments to this method.
def key(element):
""" Key function. """
return self.key(viewer, parent, element)
elements.sort(key=key)
return elements
[docs] def key(self, viewer, parent, element):
""" Returns the result of comparing two elements.
'viewer' is the viewer that we are sorting elements for.
'parent' is the parent element.
'element' is the the first element being sorted.
"""
# Get the category
category = self.category(viewer, parent, element)
# Get the label
if hasattr(viewer, "label_provider"):
label = viewer.label_provider.get_text(viewer, element)
else:
label = viewer.node_model.get_text(viewer, element)
return (category, label)
[docs] def category(self, viewer, parent, element):
""" Returns the category (an integer) for an element.
'parent' is the parent element.
'elements' is the element to return the category for.
Categories are used to sort elements into bins. The bins are
arranged in ascending numeric order. The elements within a bin
are arranged as dictated by the sorter's 'compare' method.
By default all elements are given the same category (0).
"""
return 0
[docs] def is_sorter_trait(self, element, trait_name):
""" Is the sorter affected by changes to an element's trait?
'element' is the element.
'trait_name' is the name of the trait.
Returns True if the sorter would be affected by changes to the trait
named 'trait_name' on the specified element.
By default we return False.
"""
return False
