def center_on(self, *args):
"""Center the map on the coordinate :class:`Coordinate`, or a (lat, lon)
"""
map_source = self.map_source
zoom = self._zoom
if len(args) == 1 and isinstance(args[0], Coordinate):
coord = args[0]
lat = coord.lat
lon = coord.lon
elif len(args) == 2:
lat, lon = args
else:
raise Exception("Invalid argument for center_on")
lon = clamp(lon, MIN_LONGITUDE, MAX_LONGITUDE)
lat = clamp(lat, MIN_LATITUDE, MAX_LATITUDE)
scale = self._scatter.scale
x = map_source.get_x(zoom, lon) - self.center_x / scale
y = map_source.get_y(zoom, lat) - self.center_y / scale
self.delta_x = -x
self.delta_y = -y
self.lon = lon
self.lat = lat
self._scatter.pos = 0, 0
self.trigger_update(True)
def on_transform(self, *args):
self._invalid_scale = True
if self._transform_lock:
return
self._transform_lock = True
# recalculate viewport
map_source = self.map_source
zoom = self._zoom
scatter = self._scatter
scale = scatter.scale
if scale >= 2.:
zoom += 1
scale /= 2.
elif scale < 1:
zoom -= 1
scale *= 2.
zoom = clamp(zoom, map_source.min_zoom, map_source.max_zoom)
if zoom != self._zoom:
self.set_zoom_at(zoom, scatter.x, scatter.y, scale=scale)
self.trigger_update(True)
else:
if zoom == map_source.min_zoom and scatter.scale < 1.:
scatter.scale = 1.
self.trigger_update(True)
else:
self.trigger_update(False)
if map_source.bounds:
self._apply_bounds()
self._transform_lock = False
self._scale = self._scatter.scale
def scale_at(self, scale, x, y):
scatter = self._scatter
scale = clamp(scale, scatter.scale_min, scatter.scale_max)
rescale = scale * 1.0 / scatter.scale
scatter.apply_transform(Matrix().scale(rescale, rescale, rescale),
post_multiply=True,
anchor=scatter.to_local(x, y))
def bbox_for_zoom(self, vx, vy, w, h, zoom):
# return a tile-bbox for the zoom
map_source = self.map_source
size = map_source.dp_tile_size
scale = self._scale
max_x_end = map_source.get_col_count(zoom)
max_y_end = map_source.get_row_count(zoom)
x_count = int(ceil(w / scale / float(size))) + 1
y_count = int(ceil(h / scale / float(size))) + 1
tile_x_first = int(clamp(vx / float(size), 0, max_x_end))
tile_y_first = int(clamp(vy / float(size), 0, max_y_end))
tile_x_last = tile_x_first + x_count
tile_y_last = tile_y_first + y_count
tile_x_last = int(clamp(tile_x_last, tile_x_first, max_x_end))
tile_y_last = int(clamp(tile_y_last, tile_y_first, max_y_end))
x_count = tile_x_last - tile_x_first
y_count = tile_y_last - tile_y_first
return (tile_x_first, tile_y_first, tile_x_last, tile_y_last,
x_count, y_count)
def set_zoom_at(self, zoom, x, y, scale=None):
"""Sets the zoom level, leaving the (x, y) at the exact same point
in the view.
"""
zoom = clamp(zoom,
self.map_source.get_min_zoom(),
self.map_source.get_max_zoom())
if int(zoom) == int(self._zoom):
if scale is None:
return
elif scale == self.scale:
return
scale = scale or 1.
# first, rescale the scatter
scatter = self._scatter
scale = clamp(scale, scatter.scale_min, scatter.scale_max)
rescale = scale * 1.0 / scatter.scale
scatter.apply_transform(Matrix().scale(rescale, rescale, rescale),
post_multiply=True,
anchor=scatter.to_local(x, y))
# adjust position if the zoom changed
c1 = self.map_source.get_col_count(self._zoom)
c2 = self.map_source.get_col_count(zoom)
if c1 != c2:
f = float(c2) / float(c1)
self.delta_x = scatter.x + self.delta_x * f
self.delta_y = scatter.y + self.delta_y * f
# back to 0 every time
scatter.apply_transform(Matrix().translate(
-scatter.x, -scatter.y, 0
), post_multiply=True)
# avoid triggering zoom changes.
self._zoom = zoom
self.zoom = self._zoom
def on_map_source(self, instance, source):
if isinstance(source, string_types):
self.map_source = MapSource.from_provider(source)
elif isinstance(source, (tuple, list)):
cache_key, min_zoom, max_zoom, url, attribution, options = source
self.map_source = MapSource(url=url, cache_key=cache_key,
min_zoom=min_zoom, max_zoom=max_zoom,
attribution=attribution,
cache_dir=self.cache_dir, **options)
elif isinstance(source, MapSource):
self.map_source = source
else:
raise Exception("Invalid map source provider")
self.zoom = clamp(self.zoom,
self.map_source.min_zoom, self.map_source.max_zoom)
self.remove_all_tiles()
self.trigger_update(True)