Added mapview module

sbapp/mapview/source.py

@@ -0,0 +1,212 @@
+# coding=utf-8
+
+__all__ = ["MapSource"]
+
+import hashlib
+from math import atan, ceil, cos, exp, log, pi, tan
+
+from kivy.metrics import dp
+
+from mapview.constants import (
+    CACHE_DIR,
+    MAX_LATITUDE,
+    MAX_LONGITUDE,
+    MIN_LATITUDE,
+    MIN_LONGITUDE,
+)
+from mapview.downloader import Downloader
+from mapview.utils import clamp
+
+
+class MapSource:
+    """Base class for implementing a map source / provider
+    """
+
+    attribution_osm = 'Maps & Data © [i][ref=http://www.osm.org/copyright]OpenStreetMap contributors[/ref][/i]'
+    attribution_thunderforest = 'Maps © [i][ref=http://www.thunderforest.com]Thunderforest[/ref][/i], Data © [i][ref=http://www.osm.org/copyright]OpenStreetMap contributors[/ref][/i]'
+
+    # list of available providers
+    # cache_key: (is_overlay, minzoom, maxzoom, url, attribution)
+    providers = {
+        "osm": (
+            0,
+            0,
+            19,
+            "http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
+            attribution_osm,
+        ),
+        "osm-hot": (
+            0,
+            0,
+            19,
+            "http://{s}.tile.openstreetmap.fr/hot/{z}/{x}/{y}.png",
+            "",
+        ),
+        "osm-de": (
+            0,
+            0,
+            18,
+            "http://{s}.tile.openstreetmap.de/tiles/osmde/{z}/{x}/{y}.png",
+            "Tiles @ OSM DE",
+        ),
+        "osm-fr": (
+            0,
+            0,
+            20,
+            "http://{s}.tile.openstreetmap.fr/osmfr/{z}/{x}/{y}.png",
+            "Tiles @ OSM France",
+        ),
+        "cyclemap": (
+            0,
+            0,
+            17,
+            "http://{s}.tile.opencyclemap.org/cycle/{z}/{x}/{y}.png",
+            "Tiles @ Andy Allan",
+        ),
+        "thunderforest-cycle": (
+            0,
+            0,
+            19,
+            "http://{s}.tile.thunderforest.com/cycle/{z}/{x}/{y}.png",
+            attribution_thunderforest,
+        ),
+        "thunderforest-transport": (
+            0,
+            0,
+            19,
+            "http://{s}.tile.thunderforest.com/transport/{z}/{x}/{y}.png",
+            attribution_thunderforest,
+        ),
+        "thunderforest-landscape": (
+            0,
+            0,
+            19,
+            "http://{s}.tile.thunderforest.com/landscape/{z}/{x}/{y}.png",
+            attribution_thunderforest,
+        ),
+        "thunderforest-outdoors": (
+            0,
+            0,
+            19,
+            "http://{s}.tile.thunderforest.com/outdoors/{z}/{x}/{y}.png",
+            attribution_thunderforest,
+        ),
+        # no longer available
+        # "mapquest-osm": (0, 0, 19, "http://otile{s}.mqcdn.com/tiles/1.0.0/map/{z}/{x}/{y}.jpeg", "Tiles Courtesy of Mapquest", {"subdomains": "1234", "image_ext": "jpeg"}),
+        # "mapquest-aerial": (0, 0, 19, "http://oatile{s}.mqcdn.com/tiles/1.0.0/sat/{z}/{x}/{y}.jpeg", "Tiles Courtesy of Mapquest", {"subdomains": "1234", "image_ext": "jpeg"}),
+        # more to add with
+        # https://github.com/leaflet-extras/leaflet-providers/blob/master/leaflet-providers.js
+        # not working ?
+        # "openseamap": (0, 0, 19, "http://tiles.openseamap.org/seamark/{z}/{x}/{y}.png",
+        #    "Map data @ OpenSeaMap contributors"),
+    }
+
+    def __init__(
+        self,
+        url="http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
+        cache_key=None,
+        min_zoom=0,
+        max_zoom=19,
+        tile_size=256,
+        image_ext="png",
+        attribution="© OpenStreetMap contributors",
+        subdomains="abc",
+        **kwargs
+    ):
+        if cache_key is None:
+            # possible cache hit, but very unlikely
+            cache_key = hashlib.sha224(url.encode("utf8")).hexdigest()[:10]
+        self.url = url
+        self.cache_key = cache_key
+        self.min_zoom = min_zoom
+        self.max_zoom = max_zoom
+        self.tile_size = tile_size
+        self.image_ext = image_ext
+        self.attribution = attribution
+        self.subdomains = subdomains
+        self.cache_fmt = "{cache_key}_{zoom}_{tile_x}_{tile_y}.{image_ext}"
+        self.dp_tile_size = min(dp(self.tile_size), self.tile_size * 2)
+        self.default_lat = self.default_lon = self.default_zoom = None
+        self.bounds = None
+        self.cache_dir = kwargs.get('cache_dir', CACHE_DIR)
+
+    @staticmethod
+    def from_provider(key, **kwargs):
+        provider = MapSource.providers[key]
+        cache_dir = kwargs.get('cache_dir', CACHE_DIR)
+        options = {}
+        is_overlay, min_zoom, max_zoom, url, attribution = provider[:5]
+        if len(provider) > 5:
+            options = provider[5]
+        return MapSource(
+            cache_key=key,
+            min_zoom=min_zoom,
+            max_zoom=max_zoom,
+            url=url,
+            cache_dir=cache_dir,
+            attribution=attribution,
+            **options
+        )
+
+    def get_x(self, zoom, lon):
+        """Get the x position on the map using this map source's projection
+        (0, 0) is located at the top left.
+        """
+        lon = clamp(lon, MIN_LONGITUDE, MAX_LONGITUDE)
+        return ((lon + 180.0) / 360.0 * pow(2.0, zoom)) * self.dp_tile_size
+
+    def get_y(self, zoom, lat):
+        """Get the y position on the map using this map source's projection
+        (0, 0) is located at the top left.
+        """
+        lat = clamp(-lat, MIN_LATITUDE, MAX_LATITUDE)
+        lat = lat * pi / 180.0
+        return (
+            (1.0 - log(tan(lat) + 1.0 / cos(lat)) / pi) / 2.0 * pow(2.0, zoom)
+        ) * self.dp_tile_size
+
+    def get_lon(self, zoom, x):
+        """Get the longitude to the x position in the map source's projection
+        """
+        dx = x / float(self.dp_tile_size)
+        lon = dx / pow(2.0, zoom) * 360.0 - 180.0
+        return clamp(lon, MIN_LONGITUDE, MAX_LONGITUDE)
+
+    def get_lat(self, zoom, y):
+        """Get the latitude to the y position in the map source's projection
+        """
+        dy = y / float(self.dp_tile_size)
+        n = pi - 2 * pi * dy / pow(2.0, zoom)
+        lat = -180.0 / pi * atan(0.5 * (exp(n) - exp(-n)))
+        return clamp(lat, MIN_LATITUDE, MAX_LATITUDE)
+
+    def get_row_count(self, zoom):
+        """Get the number of tiles in a row at this zoom level
+        """
+        if zoom == 0:
+            return 1
+        return 2 << (zoom - 1)
+
+    def get_col_count(self, zoom):
+        """Get the number of tiles in a col at this zoom level
+        """
+        if zoom == 0:
+            return 1
+        return 2 << (zoom - 1)
+
+    def get_min_zoom(self):
+        """Return the minimum zoom of this source
+        """
+        return self.min_zoom
+
+    def get_max_zoom(self):
+        """Return the maximum zoom of this source
+        """
+        return self.max_zoom
+
+    def fill_tile(self, tile):
+        """Add this tile to load within the downloader
+        """
+        if tile.state == "done":
+            return
+        Downloader.instance(cache_dir=self.cache_dir).download_tile(tile)