add support for grid and display grid cell for custom locations already

src/c3nav/mapdata/grid.py

@@ -0,0 +1,61 @@
+import bisect
+import string
+from abc import ABC, abstractmethod
+from typing import Optional
+
+from django.conf import settings
+
+
+class AbstractGrid(ABC):
+    @abstractmethod
+    def get_cell_for_point(self, x, y) -> Optional[str]:
+        pass
+
+
+class Grid(AbstractGrid):
+    def __init__(self, rows, cols):
+        rows = tuple(float(y) for y in rows)
+        cols = tuple(float(x) for x in cols)
+        self.rows = tuple(sorted(rows))
+        self.cols = tuple(sorted(cols))
+
+        if self.rows == rows:
+            self.invert_y = False
+        elif self.rows == tuple(reversed(rows)):
+            self.invert_y = True
+        else:
+            raise ValueError('row coordinates are not ordered')
+
+        if self.cols == cols:
+            self.invert_x = False
+        elif self.cols == tuple(reversed(cols)):
+            self.invert_x = True
+        else:
+            raise ValueError('column coordinates are not ordered')
+
+    def get_cell_for_point(self, x, y):
+        x = bisect.bisect(self.cols, x)
+        if x <= 0 or x >= len(self.cols):
+            return None
+
+        y = bisect.bisect(self.rows, y)
+        if y <= 0 or y >= len(self.rows):
+            return None
+
+        if self.invert_x:
+            x = len(self.cols) - x
+        if self.invert_y:
+            y = len(self.rows) - y
+
+        return '%s%d' % (string.ascii_uppercase[x-1], y)
+
+
+class DummyGrid(AbstractGrid):
+    def get_cell_for_point(self, x, y):
+        return None
+
+
+if settings.GRID_COLS and settings.GRID_ROWS:
+    grid = Grid(settings.GRID_ROWS.split(','), settings.GRID_COLS.split(','))
+else:
+    grid = DummyGrid()

src/c3nav/mapdata/utils/locations.py

@@ -13,6 +13,7 @@ from django.utils.functional import cached_property
 from django.utils.translation import ugettext_lazy as _
 from shapely.ops import cascaded_union
 
+from c3nav.mapdata.grid import grid
 from c3nav.mapdata.models import Level, Location, LocationGroup, MapUpdate
 from c3nav.mapdata.models.access import AccessPermission
 from c3nav.mapdata.models.geometry.base import GeometryMixin
@@ -367,9 +368,12 @@ class CustomLocation:
 
     @cached_property
     def title_subtitle(self):
+        grid_cell = grid.get_cell_for_point(self.x, self.y)
+        level_subtitle = self.level.title if grid_cell is None else ','.join((grid_cell, str(self.level.title)))
+
         title = _('In %(level)s') % {'level': self.level.title}
         if not self.space:
-            return title, self.level.title,
+            return title, level_subtitle
 
         subtitle = ()
         if self.near_poi:
@@ -385,9 +389,10 @@ class CustomLocation:
         elif self.near_area:
             title = _('Near %(area)s') % {'area': self.near_area.title}
         else:
-            return _('In %(space)s') % {'space': self.space.title}, self.level.title
+            return _('In %(space)s') % {'space': self.space.title}, level_subtitle
 
-        subtitle = ', '.join(str(title) for title in chain(subtitle, (self.space.title, self.level.title)))
+        subtitle_segments = chain((grid_cell, ), subtitle, (self.space.title, self.level.title))
+        subtitle = ', '.join(str(title) for title in subtitle_segments if title is not None)
         return title, subtitle
 
     @cached_property

src/c3nav/settings.py

@@ -90,6 +90,9 @@ CACHE_RESOLUTION = config.get('c3nav', 'cache_resolution', fallback=4)
 INITIAL_LEVEL = config.get('c3nav', 'initial_level', fallback=None)
 INITIAL_BOUNDS = config.get('c3nav', 'initial_bounds', fallback='').split(' ')
 
+GRID_ROWS = config.get('c3nav', 'grid_rows', fallback=None)
+GRID_COLS = config.get('c3nav', 'grid_cols', fallback=None)
+
 if len(INITIAL_BOUNDS) == 4:
     try:
         INITIAL_BOUNDS = tuple(float(i) for i in INITIAL_BOUNDS)