cola/models/selection.py

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