9757: [Geography] update map tiles on demand

gramps/plugins/lib/maps/geography.py

@@ -412,6 +412,16 @@ class GeoGraphyView(OsmGps, NavigationView):
             changemapitem.connect("activate", self.change_map, my_map)
             changemap.append(changemapitem)
 
+        reload_text = _("Reload all visible tiles for '%(map)s'.") % {
+                   'map' : map_name
+                  }
+        self.reloadtiles = Gtk.MenuItem(label=reload_text)
+        reloadtiles = self.reloadtiles
+        reloadtiles.connect("activate", self.reload_visible_tiles)
+
+        reloadtiles.show()
+        menu.append(reloadtiles)
+
         clear_text = _("Clear the '%(map)s' tiles cache.") % {
                    'map' : map_name
                   }
@@ -428,6 +438,11 @@ class GeoGraphyView(OsmGps, NavigationView):
                    None, event.button, event.time)
         return 1
 
+    def reload_visible_tiles(self, menu):
+        """
+        We need to reload all visible tiles for the current map
+        """
+        self.reload_tiles()
 
     def clear_map(self, menu, the_map):
         """

gramps/plugins/lib/maps/osmgps.py

@@ -26,6 +26,7 @@
 #
 #-------------------------------------------------------------------------
 import os
+from math import pi, sin, atanh, floor
 
 #------------------------------------------------------------------------
 #
@@ -81,6 +82,23 @@ except:
 # pylint: disable=no-member
 # pylint: disable=maybe-no-member
 
+def lon2pixel(zoom, longitude, size):
+    """
+    pixel_x = (2^zoom * size * longitude) / 2PI + (2^zoom * size) / 2
+    """
+    value = ((longitude * size * (2**zoom)) / (2*pi)) + ((2**zoom) * size / 2)
+    return int(value)
+
+def lat2pixel(zoom, latitude, size):
+    """
+    http://manialabs.wordpress.com/2013/01/26/converting-latitude-and-longitude-to-map-tile-in-mercator-projection/
+
+    pixel_y = -(2^zoom * size * lat_m) / 2PI + (2^zoom * size) / 2
+    """
+    lat_m = atanh(sin(latitude))
+    value = -((lat_m * size * (2**zoom)) / (2*pi)) + ((2**zoom) * (size/2))
+    return int(value)
+
 class OsmGps:
     """
     This class is used to create a map
@@ -246,6 +264,40 @@ class OsmGps:
         self.vbox.pack_start(self.osm, True, True, 0)
         self.goto_handle(handle=None)
 
+    def reload_tiles(self):
+        """
+        We need to reload all visible tiles for the current map
+        """
+        map_idx = config.get("geography.map_service")
+        map_name = constants.TILES_PATH[map_idx]
+        map_path = os.path.join(config.get('geography.path'), map_name)
+        # get the top left corner and bottom right corner
+        bbox = self.osm.get_bbox()
+        pt1 = bbox[0]
+        pt2 = bbox[1]
+        self.zoom = config.get("geography.zoom")
+        tile_size = float(256)
+        # get the file extension depending on the map provider
+        img_format = self.osm.source_get_image_format(map_idx)
+        # calculate the number of images to download in rows and columns
+        pt1_x = floor(lon2pixel(self.zoom, pt1.rlon, tile_size) / tile_size)
+        pt1_y = floor(lat2pixel(self.zoom, pt1.rlat, tile_size) / tile_size)
+        pt2_x = floor(lon2pixel(self.zoom, pt2.rlon, tile_size) / tile_size)
+        pt2_y = floor(lat2pixel(self.zoom, pt2.rlat, tile_size) / tile_size)
+        for ptx_i in range(pt1_x, pt2_x):
+            for pty_j in range(pt1_y, pt2_y):
+                tile_path = "%s%c%d%c%d%c%d.%s" % (map_path, os.sep, self.zoom,
+                                                   os.sep, ptx_i, os.sep, pty_j,
+                                                   img_format)
+                _LOG.debug("file removed : %s", tile_path)
+                try:
+                    os.unlink(tile_path)
+                except:
+                    # The tile doesn't exist because it is in the load queue.
+                    # That occurs when zooming.
+                    pass
+        self.osm.download_maps(pt1, pt2, self.zoom, self.zoom)
+
     def update_shortcuts(self, arg):
         """
         connect the keyboard or the keypad for shortcuts