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Diffstat (limited to 'src/mbgl/style/tile_source_impl.cpp')
| -rw-r--r-- | src/mbgl/style/tile_source_impl.cpp | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/src/mbgl/style/tile_source_impl.cpp b/src/mbgl/style/tile_source_impl.cpp new file mode 100644 index 0000000000..634ef39808 --- /dev/null +++ b/src/mbgl/style/tile_source_impl.cpp @@ -0,0 +1,196 @@ +#include <mbgl/style/tile_source_impl.hpp> +#include <mbgl/style/source_observer.hpp> +#include <mbgl/style/parser.hpp> +#include <mbgl/util/tileset.hpp> +#include <mbgl/util/mapbox.hpp> +#include <mbgl/storage/file_source.hpp> +#include <mbgl/platform/log.hpp> + +#include <rapidjson/document.h> +#include <rapidjson/error/en.h> + +#include <sstream> + +namespace mbgl { +namespace style { + +namespace { + +void parseTileJSONMember(const JSValue& value, std::vector<std::string>& target, const char* name) { + if (!value.HasMember(name)) { + return; + } + + const JSValue& property = value[name]; + if (!property.IsArray()) { + return; + } + + for (rapidjson::SizeType i = 0; i < property.Size(); i++) { + if (!property[i].IsString()) { + return; + } + } + + for (rapidjson::SizeType i = 0; i < property.Size(); i++) { + target.emplace_back(std::string(property[i].GetString(), property[i].GetStringLength())); + } +} + +void parseTileJSONMember(const JSValue& value, std::string& target, const char* name) { + if (!value.HasMember(name)) { + return; + } + + const JSValue& property = value[name]; + if (!property.IsString()) { + return; + } + + target = { property.GetString(), property.GetStringLength() }; +} + +void parseTileJSONMember(const JSValue& value, uint8_t& target, const char* name) { + if (!value.HasMember(name)) { + return; + } + + const JSValue& property = value[name]; + if (!property.IsUint()) { + return; + } + + unsigned int uint = property.GetUint(); + if (uint > std::numeric_limits<uint8_t>::max()) { + return; + } + + target = uint; +} + +Tileset parseTileJSON(const JSValue& value) { + Tileset result; + + parseTileJSONMember(value, result.tiles, "tiles"); + parseTileJSONMember(value, result.zoomRange.min, "minzoom"); + parseTileJSONMember(value, result.zoomRange.max, "maxzoom"); + parseTileJSONMember(value, result.attribution, "attribution"); + + return result; +} + +} // end namespace + +Tileset TileSourceImpl::parseTileJSON(const std::string& json, const std::string& sourceURL, SourceType type, uint16_t tileSize) { + rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> document; + document.Parse<0>(json.c_str()); + + if (document.HasParseError()) { + std::stringstream message; + message << document.GetErrorOffset() << " - " << rapidjson::GetParseError_En(document.GetParseError()); + throw std::runtime_error(message.str()); + } + + Tileset result = mbgl::style::parseTileJSON(document); + + // TODO: Remove this hack by delivering proper URLs in the TileJSON to begin with. + if (util::mapbox::isMapboxURL(sourceURL)) { + for (auto& url : result.tiles) { + url = util::mapbox::canonicalizeTileURL(url, type, tileSize); + } + } + + return result; +} + +optional<variant<std::string, Tileset>> TileSourceImpl::parseURLOrTileset(const JSValue& value) { + if (!value.HasMember("url")) { + return { mbgl::style::parseTileJSON(value) }; + } + + const JSValue& urlVal = value["url"]; + if (!urlVal.IsString()) { + Log::Error(Event::ParseStyle, "source url must be a string"); + return {}; + } + + return { std::string(urlVal.GetString(), urlVal.GetStringLength()) }; +} + +TileSourceImpl::TileSourceImpl(SourceType type_, std::string id_, Source& base_, + variant<std::string, Tileset> urlOrTileset_, + uint16_t tileSize_) + : Impl(type_, std::move(id_), base_), + urlOrTileset(std::move(urlOrTileset_)), + tileSize(tileSize_) { +} + +TileSourceImpl::~TileSourceImpl() = default; + +void TileSourceImpl::load(FileSource& fileSource) { + if (urlOrTileset.is<Tileset>()) { + tileset = urlOrTileset.get<Tileset>(); + loaded = true; + return; + } + + if (req) { + return; + } + + const std::string& url = urlOrTileset.get<std::string>(); + req = fileSource.request(Resource::source(url), [this, url](Response res) { + if (res.error) { + observer->onSourceError(base, std::make_exception_ptr(std::runtime_error(res.error->message))); + } else if (res.notModified) { + return; + } else if (res.noContent) { + observer->onSourceError(base, std::make_exception_ptr(std::runtime_error("unexpectedly empty TileJSON"))); + } else { + Tileset newTileset; + + // Create a new copy of the Tileset object that holds the base values we've parsed + // from the stylesheet. Then merge in the values parsed from the TileJSON we retrieved + // via the URL. + try { + newTileset = parseTileJSON(*res.data, url, type, tileSize); + } catch (...) { + observer->onSourceError(base, std::current_exception()); + return; + } + + // Check whether previous information specifies different tile + if (tileset.tiles != newTileset.tiles) { + // Tile URLs changed: force tiles to be reloaded. + invalidateTiles(); + + // Tile size changed: We need to recalculate the tiles we need to load because we + // might have to load tiles for a different zoom level + // This is done automatically when we trigger the onSourceLoaded observer below. + + // Min/Max zoom changed: We need to recalculate what tiles to load, if we have tiles + // loaded that are outside the new zoom range + // This is done automatically when we trigger the onSourceLoaded observer below. + + // Attribution changed: We need to notify the embedding application that this + // changed. See https://github.com/mapbox/mapbox-gl-native/issues/2723 + // This is not yet implemented. + + // Center/bounds changed: We're not using these values currently + } + + tileset = newTileset; + loaded = true; + + observer->onSourceLoaded(base); + } + }); +} + +Range<uint8_t> TileSourceImpl::getZoomRange() { + assert(loaded); + return tileset.zoomRange; +} + +} // namespace style +} // namespace mbgl |