cola/models/selection.py

   1 """Provides a selection model to handle selection."""
   2
   3 from cola.models.observable import ObservableModel
   4 from cola.decorators import memoize
   5
   6
   7 @memoize
   8 def selection_model():
   9     """Provides access to a static SelectionModel instance."""
  10     return SelectionModel()
  11
  12
  13 def selection():
  14     """Return the current selection."""
  15     model = selection_model()
  16     return (model.staged, model.modified, model.unmerged, model.untracked)
  17
  18
  19 def single_selection():
  20     """Scan across staged, modified, etc. and return a single item."""
  21     staged, modified, unmerged, untracked = selection()
  22     s = None
  23     m = None
  24     um = None
  25     ut = None
  26     if staged:
  27         s = staged[0]
  28     elif modified:
  29         m = modified[0]
  30     elif unmerged:
  31         um = unmerged[0]
  32     elif untracked:
  33         ut = untracked[0]
  34     return s, m, um, ut
  35
  36
  37 def filename():
  38     s, m, um, ut = single_selection()
  39     if s:
  40         return s
  41     if m:
  42         return m
  43     if um:
  44         return um
  45     if ut:
  46         return ut
  47     return None
  48
  49
  50 class SelectionModel(ObservableModel):
  51     """Provides information about selected file paths."""
  52     # Notification message sent out when selection changes
  53     message_selection_changed = 'selection_changed'
  54
  55     # These properties wrap the individual selection items
  56     # to provide higher-level pseudo-selections.
  57     unstaged = property(lambda self: self.modified +
  58                                      self.unmerged +
  59                                      self.untracked)
  60
  61     all = property(lambda self: self.staged +
  62                                 self.modified +
  63                                 self.unmerged +
  64                                 self.untracked)
  65
  66     def __init__(self):
  67         ObservableModel.__init__(self)
  68         self.staged = []
  69         self.modified = []
  70         self.unmerged = []
  71         self.untracked = []
  72
  73     def set_selection(self, staged, modified, unmerged, untracked):
  74         """Set the new selection."""
  75         self.set_staged(staged)
  76         self.set_modified(modified)
  77         self.set_unmerged(unmerged)
  78         self.set_untracked(untracked)
  79         self.notify_message_observers(self.message_selection_changed)