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XyzTileAsyncLayer

Namespace: ThinkGeo.Core

Legacy base class for XYZ tile layers; superseded by WebRasterXyzTileAsyncLayer.

public abstract class XyzTileAsyncLayer : WebBasedAsyncLayer, IHttpRequestService

Inheritance objectLayerBaseAsyncLayerWebBasedAsyncLayerXyzTileAsyncLayer
Implements IHttpRequestService

Properties

TileWidth

Gets or sets the width of each tile in pixels.

public int TileWidth { get; set; }

Property Value

int

TileHeight

Gets or sets the height of each tile in pixels.

public int TileHeight { get; set; }

Property Value

int

MapUnit

Gets or sets the map unit that the XYZ dataset is stored in.

public GeographyUnit MapUnit { get; set; }

Property Value

GeographyUnit

HasBoundingBox

Gets or sets the HasBoundingBox.

public bool HasBoundingBox { get; }

Property Value

bool

TileCache

Gets or sets the cache used to store downloaded tiles.

public RasterTileCache TileCache { get; set; }

Property Value

RasterTileCache

ProjectedTileCache

Gets or sets the cache that holds reprojected tiles when needed.

public RasterTileCache ProjectedTileCache { get; set; }

Property Value

RasterTileCache

ProjectionConverter

Gets or sets the projection converter used when the source tiles are in a different projection.

public ProjectionConverter ProjectionConverter { get; set; }

Property Value

ProjectionConverter

MaxExtent

This is the full extent of the matrix griding the xyz tiles.

public RectangleShape MaxExtent { get; set; }

Property Value

RectangleShape

ProjectionConverterFromServerProjection

Gets or sets the ProjectionConverterFromServerProjection.

public ProjectionConverter ProjectionConverterFromServerProjection { get; set; }

Property Value

ProjectionConverter

HttpClient

Gets or sets the HTTP client reused for outbound requests.

public HttpClient HttpClient { get; set; }

Property Value

HttpClient

WebProxy

Gets or sets the proxy through which all HTTP requests should be routed.

public IWebProxy WebProxy { get; set; }

Property Value

IWebProxy

TimeoutInSeconds

Gets or sets the request timeout, in seconds.

public int TimeoutInSeconds { get; set; }

Property Value

int

Credentials

Gets or sets the credential provider used when authenticating HTTP requests.

public ICredentials Credentials { get; set; }

Property Value

ICredentials

UserAgent

This property allows you to specify a custom user-agent request header when making requests to a Web server. This header provides information about the client application or device and can be useful for server-side logging and analytics.

public string UserAgent { get; set; }

Property Value

string

UpperThreshold

This property gets and sets the upper threshold in the scale at which to display the image.

public double UpperThreshold { get; set; }

Property Value

double
This property gets the upper threshold in the scale at which to display the image.

Remarks:

Above the upper threshold in scale, the image will not be displayed. This, in conjunction with the LowerThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.max and lower threshold is 0. This means the image should always display.

LowerThreshold

This property gets and sets the lower threshold in the scale at which to display the image.

public double LowerThreshold { get; set; }

Property Value

double
This property gets the lower threshold in the scale at which to display the image.

Remarks:

Below the lower threshold in scale, the image will not be displayed. This, in conjunction with the UpperThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.max and lower threshold is 0. This means the image should always display.

UpperScale

This property gets and sets the upper threshold in the scale at which to display the image.

public double UpperScale { get; set; }

Property Value

double
This property gets the upper threshold in the scale at which to display the image.

Remarks:

Above the upper threshold in scale, the image will not be displayed. This, in conjunction with the LowerThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.max and lower threshold is 0. This means the image should always display.

LowerScale

This property gets and sets the lower threshold in the scale at which to display the image.

public double LowerScale { get; set; }

Property Value

double
This property gets the lower threshold in the scale at which to display the image.

Remarks:

Below the lower threshold in scale, the image will not be displayed. This, in conjunction with the UpperThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.max and lower threshold is 0. This means the image should always display.

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

bool
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

bool
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

Projection

DrawingExceptionMode

Gets or sets how drawing exceptions are handled when the layer renders.

public DrawingExceptionMode DrawingExceptionMode { get; set; }

Property Value

DrawingExceptionMode

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

float
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

float
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

float
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

float
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

Collection<GeoColor>

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

bool
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

bool
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

WrappingMode

WrappingExtent

Gets or sets the geographic extent to use when wrapping is enabled.

public RectangleShape WrappingExtent { get; set; }

Property Value

RectangleShape

Methods

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.

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.

GetTileScale()

Returns tile scale.

protected int GetTileScale()

Returns

int
The result of the operation.

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.

GetBoundingBoxCore()

Provides the overridable implementation that returns the bounding box that encloses the relevant geometry.

protected RectangleShape GetBoundingBoxCore()

Returns

RectangleShape
The result of the operation.

DownloadImageAsync(int, long, long, float, CancellationToken)

Performs download image async.

public Task<Byte[]> DownloadImageAsync(int zoomLevelIndex, long x, long y, float scaleFactor, CancellationToken cancellationToken)

Parameters

zoomLevelIndex int
The zoom level index.

x long
The x-coordinate, in pixels.

y long
The y-coordinate, in pixels.

scaleFactor float
The scale factor to apply.

cancellationToken CancellationToken
A cancellation or authentication token, depending on context.

Returns

Task<Byte[]>
A task that represents the asynchronous operation and provides the result.

GetImageUriAsync(int, long, long, float)

Returns image URI async for the specified parameters.

public Task<string> GetImageUriAsync(int zoomLevel, long x, long y, float resolutionFactor)

Parameters

zoomLevel int
The zoom level.

x long
The x-coordinate, in pixels.

y long
The y-coordinate, in pixels.

resolutionFactor float
The resolution factor.

Returns

Task<string>
A task that represents the asynchronous operation and provides the result.

GetImageUriAsyncCore(int, long, long, float)

Provides the overridable implementation that returns image URI async for the specified parameters.

protected abstract Task<string> GetImageUriAsyncCore(int zoomLevel, long x, long y, float resolutionFactor)

Parameters

zoomLevel int
The zoom level.

x long
The x-coordinate, in pixels.

y long
The y-coordinate, in pixels.

resolutionFactor float
The resolution factor.

Returns

Task<string>
A task that represents the asynchronous operation and provides the result.

Events

SendingHttpRequest

Occurs before an HTTP request is dispatched so callers can inspect or cancel it.

public event EventHandler<SendingHttpRequestMessageEventArgs> SendingHttpRequest;

ReceivedHttpResponse

Occurs after an HTTP response is received.

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;