MvtTilesAsyncLayer¶
Namespace: ThinkGeo.Core
Renders Mapbox Vector Tiles that are described by a style JSON document or MBTiles source.
public class MvtTilesAsyncLayer : XyzTilesAsyncLayer, IHttpRequestService, IFeatureLayer
Inheritance Object → LayerBase → AsyncLayer → XyzTilesAsyncLayer → MvtTilesAsyncLayer
Implements IHttpRequestService, IFeatureLayer
Fields¶
NoLayerName¶
Represents the default layer name used when a source layer name is not available.
public static string NoLayerName;
Properties¶
HttpClient¶
Gets or sets the MvtTilesAsyncLayer.HttpClient instance that will be used to download remote tiles.
public HttpClient HttpClient { get; set; }
Property Value¶
HttpClient
WebProxy¶
Gets or sets the web proxy that should be applied when issuing HTTP requests.
public IWebProxy WebProxy { get; set; }
Property Value¶
IWebProxy
TimeoutInSeconds¶
Gets or sets the request timeout, in seconds, used for outbound HTTP calls.
public int TimeoutInSeconds { get; set; }
Property Value¶
Credentials¶
Gets or sets the credentials that are supplied when authenticating against secured tile services.
public ICredentials Credentials { get; set; }
Property Value¶
ICredentials
UserAgent¶
Gets or sets the custom user-agent string that is attached to outbound HTTP requests.
public string UserAgent { get; set; }
Property Value¶
LabelDisplayMode¶
Gets or sets how labels should be drawn for the styles in this layer.
public LabelDisplayMode LabelDisplayMode { get; set; }
Property Value¶
StyleJsonUri¶
Gets or sets the URI of the Mapbox style JSON that describes the visual appearance of the tiles.
public string StyleJsonUri { get; set; }
Property Value¶
VectorTileCache¶
Gets or sets the cache that stores vector tiles retrieved from remote sources.
public FileTileCache VectorTileCache { get; set; }
Property Value¶
ScaleFactor¶
Gets or sets the factor that scales sprite icons defined in the style JSON.
public float ScaleFactor { get; set; }
Property Value¶
ProjectionConverter¶
Gets or sets the projection converter used to transform coordinates during rendering.
public ProjectionConverter ProjectionConverter { get; set; }
Property Value¶
TileMatrixSet¶
Gets or sets the tile matrix set describing the XYZ grid.
public TileMatrixSet TileMatrixSet { get; set; }
Property Value¶
TileWidth¶
Gets or sets the TileWidth.
public int TileWidth { get; set; }
Property Value¶
TileHeight¶
Gets or sets the TileHeight.
public int TileHeight { get; set; }
Property Value¶
MaxExtent¶
This is the full extent of the matrix griding the xyz tiles. It's NOT the bounding box of the data itself.
public RectangleShape MaxExtent { get; set; }
Property Value¶
MapUnit¶
Gets or sets the MapUnit.
public GeographyUnit MapUnit { get; set; }
Property Value¶
HasBoundingBox¶
Gets or sets the HasBoundingBox.
public bool HasBoundingBox { get; }
Property Value¶
Name¶
Gets or sets the display name for the layer.
public string Name { get; set; }
Property Value¶
String
The name used to identify the layer within UI components such as legends.
Remarks:
The name is user defined. Assign a descriptive value so tooling such as legends and layer lists can surface a meaningful label to end users.
IsOpen¶
Gets a value indicating whether the layer is currently open.
public bool IsOpen { get; }
Property Value¶
Boolean
true if the layer has completed its open routine; otherwise, false.
Remarks:
This method is the concrete wrapper for the abstract method IsOpenCore. Various methods on the Layer require that it be in an open state. If one of those methods is called when the state is not open, then the method will throw an exception. To enter the open state, you must call the Layer Open method. The method will raise an exception if the current Layer is already open.
As this is a concrete public method that wraps a Core method, we reserve the right to add events and other logic to pre- or post-process data returned by the Core version of the method. In this way, we leave our framework open on our end, but also allow you the developer to extend our logic to suit your needs. If you have questions about this, please contact our support team as we would be happy to work with you on extending our framework.
IsVisible¶
Gets or sets a value indicating whether the layer is visible.
public bool IsVisible { get; set; }
Property Value¶
Boolean
true to draw the layer; otherwise, false.
Remarks:
If this property is set to false, the layer will not draw. We ensure this in the Draw method. This is useful for legends and other controls that control the visibility of layers.
DrawingTime¶
Gets the last recorded drawing time for the layer.
public TimeSpan DrawingTime { get; protected set; }
Property Value¶
TimeSpan
The duration of the most recent draw operation.
Remarks:
We track the drawing time for the layer and report it back in this method. This is useful for determining the speed of various layers.
Projection¶
Gets the projection of the layer.
public Projection Projection { get; set; }
Property Value¶
DrawingExceptionMode¶
Gets or sets how drawing exceptions are handled when the layer renders.
public DrawingExceptionMode DrawingExceptionMode { get; set; }
Property Value¶
Background¶
Gets or sets the background color used when rendering the layer.
public GeoColor Background { get; set; }
Property Value¶
GeoColor
The fill applied to areas not covered by layer content.
Transparency¶
Gets or sets the amount of transparency applied to the rendered image.
public float Transparency { get; set; }
Property Value¶
Single
A value between 0 (fully transparent) and 255 (fully opaque).
BlueTranslation¶
Gets or sets the intensity adjustment applied to the blue channel.
public float BlueTranslation { get; set; }
Property Value¶
Single
A value between -255 and 255 representing the blue channel translation.
RedTranslation¶
Gets or sets the intensity adjustment applied to the red channel.
public float RedTranslation { get; set; }
Property Value¶
Single
A value between -255 and 255 representing the red channel translation.
GreenTranslation¶
Gets or sets the intensity adjustment applied to the green channel.
public float GreenTranslation { get; set; }
Property Value¶
Single
A value between -255 and 255 representing the green channel translation.
KeyColors¶
Gets the collection of key colors that should be rendered as transparent.
public Collection<GeoColor> KeyColors { get; }
Property Value¶
Remarks:
Attempting to access this collection when the associated GeoCanvas does not support key colors (see GeoCanvas.SupportKeyColor) results in an exception. Add colors to this collection to ensure they render as transparent.
IsNegative¶
Gets or sets a value indicating whether the image should be rendered with inverted colors.
public bool IsNegative { get; set; }
Property Value¶
Boolean
true to invert the color channels; otherwise, false.
IsGrayscale¶
Gets or sets a value indicating whether the image should be converted to grayscale prior to rendering.
public bool IsGrayscale { get; set; }
Property Value¶
Boolean
true to apply a grayscale filter; otherwise, false.
ThreadSafe¶
Gets or sets the threading guarantees provided by the layer implementation.
public ThreadSafetyLevel ThreadSafe { get; set; }
Property Value¶
ThreadSafetyLevel
The level of thread safety that callers can expect when interacting with the layer.
ColorMappings¶
Gets the color translation map that will be applied when rendering the layer.
public Dictionary<GeoColor, GeoColor> ColorMappings { get; }
Property Value¶
Dictionary<GeoColor, GeoColor>
WrappingMode¶
Gets or sets how the layer wraps when the map extent crosses world boundaries.
public WrappingMode WrappingMode { get; set; }
Property Value¶
WrappingExtent¶
Gets or sets the geographic extent to use when wrapping is enabled.
public RectangleShape WrappingExtent { get; set; }
Property Value¶
Constructors¶
MvtTilesAsyncLayer()¶
Initializes a new instance of the MvtTilesAsyncLayer class.
public MvtTilesAsyncLayer()
MvtTilesAsyncLayer(String)¶
Initializes a new instance of the MvtTilesAsyncLayer class using the specified style JSON.
public MvtTilesAsyncLayer(string styleJsonUri)
Parameters¶
styleJsonUri String
The URI that points to the style JSON document to load.
Methods¶
GetRasterContentTypeCore()¶
Vector tile sources render cartographic content.
protected RasterContentType GetRasterContentTypeCore()
Returns¶
OpenAsyncCore(CancellationToken)¶
Provides the overridable implementation that asynchronously opens the instance and initializes the resources it depends on.
protected Task OpenAsyncCore(CancellationToken cancellationToken)
Parameters¶
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task
A task that represents the asynchronous operation.
GetFeaturesInsideBoundingBoxAsync(RectangleShape, Double, CancellationToken)¶
Fetches, buckets, and returns all features intersecting the given extent, grouped by their source-layer name.
public Task<Dictionary<string, Collection<Feature>>> GetFeaturesInsideBoundingBoxAsync(RectangleShape extent, double scale, CancellationToken cancellationToken)
Parameters¶
extent RectangleShape
The world extent to query.
scale Double
The current map scale that will be used to evaluate zoom-dependent styles.
cancellationToken CancellationToken
The token that can be used to cancel the operation.
Returns¶
Task<Dictionary<String, Collection<Feature>>>
A dictionary of features keyed by their source-layer names.
DrawAsyncCore(GeoCanvas, Collection<SimpleCandidate>)¶
Provides the overridable implementation that asynchronously draws onto and appends any label candidates to .
protected Task DrawAsyncCore(GeoCanvas canvas, Collection<SimpleCandidate> labelsInAllLayers)
Parameters¶
canvas GeoCanvas
The to draw to.
labelsInAllLayers Collection<SimpleCandidate>
A shared collection that receives label candidates generated during drawing.
Returns¶
Task
A task that represents the asynchronous operation.
Draw(GeoCanvas, Dictionary<String, Collection<Feature>>, Collection<SimpleCandidate>)¶
Draws the supplied features using the loaded styles.
public void Draw(GeoCanvas canvas, Dictionary<string, Collection<Feature>> featuresByLayerNames, Collection<SimpleCandidate> labelsInAllLayers)
Parameters¶
canvas GeoCanvas
The canvas to draw on.
featuresByLayerNames Dictionary<String, Collection<Feature>>
The features grouped by their source-layer names.
labelsInAllLayers Collection<SimpleCandidate>
The label candidates from previously drawn layers.
CloseAsyncCore(CancellationToken)¶
Provides the overridable implementation that asynchronously closes the instance and releases any resources it holds.
protected Task CloseAsyncCore(CancellationToken cancellationToken)
Parameters¶
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task
A task that represents the asynchronous operation.
GetTileAsyncCore(String, Int32, Int32, Int32, CancellationToken)¶
Provides the overridable implementation that returns tile async for the specified parameters.
protected Task<Tile> GetTileAsyncCore(string tileUriTemplate, int zoom, int x, int y, CancellationToken cancellationToken)
Parameters¶
tileUriTemplate String
The tile URI template.
zoom Int32
The zoom.
x Int32
The x-coordinate, in pixels.
y Int32
The y-coordinate, in pixels.
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task<Tile>
A task that represents the asynchronous operation and provides the result.
GetFeaturesInsideBoundingBoxAsync(String, RectangleShape, Double, Int32, CancellationToken)¶
Returns the features whose bounding boxes intersect the specified bounding box.
protected Task<Dictionary<string, Collection<Feature>>> GetFeaturesInsideBoundingBoxAsync(string requestTemplate, RectangleShape extent, double scale, int maxZoomOfData, CancellationToken cancellationToken)
Parameters¶
requestTemplate String
The request template.
extent RectangleShape
The world extent represented by the canvas during the drawing session.
scale Double
The scale factor to apply.
maxZoomOfData Int32
The max zoom of data.
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task<Dictionary<String, Collection<Feature>>>
A task that represents the asynchronous operation and provides the result.
OnSendingHttpRequestMessage(SendingHttpRequestMessageEventArgs)¶
Performs on sending HTTP request message.
protected void OnSendingHttpRequestMessage(SendingHttpRequestMessageEventArgs e)
Parameters¶
e SendingHttpRequestMessageEventArgs
The e.
OnReceivedHttpResponseMessage(ReceivedHttpResponseMessageEventArgs)¶
Performs on received HTTP response message.
protected void OnReceivedHttpResponseMessage(ReceivedHttpResponseMessageEventArgs e)
Parameters¶
e ReceivedHttpResponseMessageEventArgs
The e.
SendWebRequestAsync(HttpRequestMessage, CancellationToken)¶
Performs send web request async.
protected Task<HttpResponseMessage> SendWebRequestAsync(HttpRequestMessage httpRequest, CancellationToken cancellationToken)
Parameters¶
httpRequest HttpRequestMessage
The HTTP request.
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task<HttpResponseMessage>
A task that represents the asynchronous operation and provides the result.
Events¶
SendingHttpRequest¶
Occurs immediately before an HTTP request for a vector tile is sent.
public event EventHandler<SendingHttpRequestMessageEventArgs> SendingHttpRequest;
ReceivedHttpResponse¶
Occurs after an HTTP response is received for a previously issued tile request.
public event EventHandler<ReceivedHttpResponseMessageEventArgs> ReceivedHttpResponse;
DrawingException¶
Occurs when the DrawingException event is raised.
public event EventHandler<DrawingExceptionLayerEventArgs> DrawingException;
DrawnException¶
Occurs when the DrawnException event is raised.
public event EventHandler<DrawnExceptionLayerEventArgs> DrawnException;