cola/models/selection.py

   1 """Provides a selection model to handle selection."""
   2 from __future__ import absolute_import, division, print_function, unicode_literals
   3 import collections
   4
   5 from qtpy import QtCore
   6 from qtpy.QtCore import Signal
   7
   8 State = collections.namedtuple('State', 'staged unmerged modified untracked')
   9
  10
  11 def create():
  12     """Create a SelectionModel"""
  13     return SelectionModel()
  14
  15
  16 def pick(selection):
  17     """Choose the first list from stage, unmerged, modified, untracked"""
  18     if selection.staged:
  19         files = selection.staged
  20     elif selection.unmerged:
  21         files = selection.unmerged
  22     elif selection.modified:
  23         files = selection.modified
  24     elif selection.untracked:
  25         files = selection.untracked
  26     else:
  27         files = []
  28     return files
  29
  30
  31 def union(selection):
  32     """Return the union of all selected items in a sorted list"""
  33     values = set(
  34         selection.staged + selection.unmerged + selection.modified + selection.untracked
  35     )
  36     return list(sorted(values))
  37
  38
  39 def _filter(values, remove):
  40     """Filter a list in-place by removing items"""
  41     remove_set = set(remove)
  42     values_copy = list(values)
  43     last = len(values_copy) - 1
  44     for idx, value in enumerate(reversed(values)):
  45         if value not in remove_set:
  46             values.pop(last - idx)
  47
  48
  49 class SelectionModel(QtCore.QObject):
  50     """Provides information about selected file paths."""
  51
  52     selection_changed = Signal()
  53
  54     # These properties wrap the individual selection items
  55     # to provide higher-level pseudo-selections.
  56     unstaged = property(lambda self: self.unmerged + self.modified + self.untracked)
  57
  58     def __init__(self):
  59         super(SelectionModel, self).__init__()
  60         self.staged = []
  61         self.unmerged = []
  62         self.modified = []
  63         self.untracked = []
  64         self.line_number = None
  65
  66     def reset(self):
  67         self.staged = []
  68         self.unmerged = []
  69         self.modified = []
  70         self.untracked = []
  71         self.line_number = None
  72
  73     def is_empty(self):
  74         return not (
  75             bool(self.staged or self.unmerged or self.modified or self.untracked)
  76         )
  77
  78     def set_selection(self, s):
  79         """Set the new selection."""
  80         self.staged = s.staged
  81         self.unmerged = s.unmerged
  82         self.modified = s.modified
  83         self.untracked = s.untracked
  84         self.selection_changed.emit()
  85
  86     def update(self, other):
  87         _filter(self.staged, other.staged)
  88         _filter(self.unmerged, other.unmerged)
  89         _filter(self.modified, other.modified)
  90         _filter(self.untracked, other.untracked)
  91         self.selection_changed.emit()
  92
  93     def selection(self):
  94         return State(self.staged, self.unmerged, self.modified, self.untracked)
  95
  96     def single_selection(self):
  97         """Scan across staged, modified, etc. and return a single item."""
  98         staged = None
  99         modified = None
 100         unmerged = None
 101         untracked = None
 102         if self.staged:
 103             staged = self.staged[0]
 104         elif self.modified:
 105             modified = self.modified[0]
 106         elif self.unmerged:
 107             unmerged = self.unmerged[0]
 108         elif self.untracked:
 109             untracked = self.untracked[0]
 110         return State(staged, unmerged, modified, untracked)
 111
 112     def filename(self):
 113         paths = [path for path in self.single_selection() if path is not None]
 114         if paths:
 115             filename = paths[0]
 116         else:
 117             filename = None
 118         return filename
 119
 120     def group(self):
 121         """A list of selected files in various states of being"""
 122         return pick(self.selection())
 123
 124     def union(self):
 125         """Return the union of all selected items in a sorted list"""
 126         return union(self)