TileOverlay¶

Namespace: ThinkGeo.Core

Represents an overlay that maintains tiles.

public abstract class TileOverlay : Overlay, System.IDisposable

Inheritance Object → Overlay → TileOverlay
Implements IDisposable

Properties¶

ImageFormat¶

Gets and sets drawing format for the tiles.

public GeoImageFormat ImageFormat { get; set; }

Property Value¶

GeoImageFormat

JpegQuality¶

Gets or sets the image quality when the TileImageFormat is Jpeg; otherwise this property has no effects. Its default value is 80.

public int JpegQuality { get; set; }

Property Value¶

Int32

IsCacheOnly¶

Gets or sets a value indicating whether this instance is cache only.

public bool IsCacheOnly { get; set; }

Property Value¶

Boolean
true if this instance is cache only; otherwise, false.

Opacity¶

public double Opacity { get; set; }

Property Value¶

Double

IsVisible¶

Gets or sets if this overlay is visible.

public bool IsVisible { get; set; }

Property Value¶

Boolean

DrawingQuality¶

public DrawingQuality DrawingQuality { get; set; }

Property Value¶

DrawingQuality

TileSizeMode¶

Gets or sets the tile size mode.

public TileSizeMode TileSizeMode { get; set; }

Property Value¶

TileSizeMode

        The tile size mode.

TileType¶

Gets and sets the overlay is formed by multiple tiles or single tile.

public TileType TileType { get; set; }

Property Value¶

TileType

TileWidth¶

Gets and sets the width of the tile.

public int TileWidth { get; set; }

Property Value¶

Int32

TileHeight¶

Gets and sets the height of the tile.

public int TileHeight { get; set; }

Property Value¶

Int32

TileCache¶

Gets and sets a tile cache object for saving the tiles.

public RasterTileCache TileCache { get; set; }

Property Value¶

RasterTileCache

TileSnappingMode¶

Gets or sets the tileView snapping mode.

public TileSnappingMode TileSnappingMode { get; set; }

Property Value¶

TileSnappingMode

TileBuffer¶

This property gets and sets the number of extra rows and colums of tiles on each side which will surround the minimum grid tiles to cover the map.

public int TileBuffer { get; set; }

Property Value¶

Int32

MaxExtent¶

This property gets or sets the max extent of matrix to calculate the tiles.

public RectangleShape MaxExtent { get; set; }

Property Value¶

RectangleShape

Remarks:

By default, MaxExtent is null; the matrix is created depending on the GeographyUnit of current map. When it's DecimalDegree, the matrix' is calculated as (-180, 90, 180, -90) as MaxExtent. While it's not DecimalDegree, the matrix is (-20037508.2314698, 20037508.2314698, 20037508.2314698, -20037508.2314698); It's allowed to modify it to customize the matrix.

WrappingMode¶

Thie property gets or sets whether allow wrap date line.

public WrappingMode WrappingMode { get; set; }

Property Value¶

WrappingMode

WrappingExtent¶

public RectangleShape WrappingExtent { get; set; }

Property Value¶

RectangleShape

CanRefreshRegion¶

public bool CanRefreshRegion { get; protected set; }

Property Value¶

Boolean

IsBase¶

public bool IsBase { get; set; }

Property Value¶

Boolean

Name¶

Gets or sets the name of this overaly.

public string Name { get; set; }

Property Value¶

String

MapArguments¶

Gets or sets current map information which will be used for calculating mechanism.

public MapArguments MapArguments { get; set; }

Property Value¶

MapArguments

OverlayCanvas¶

Gets or sets the actual canvas which maintains all the visual elements on the overlay.

public Canvas OverlayCanvas { get; set; }

Property Value¶

Canvas

DrawingExceptionMode¶

This property gets and sets the DrawingExceptionMode used when an exception occurs during drawing.

public DrawingExceptionMode DrawingExceptionMode { get; set; }

Property Value¶

DrawingExceptionMode

Attribution¶

public string Attribution { get; set; }

Property Value¶

String

IsEmpty¶

This property gets if this overlay is empty or not.

public bool IsEmpty { get; }

Property Value¶

Boolean

Remarks:

This property enhances the performance of the overlay while drawing. If is true, we will skip drawing this overlay and continue drawing the next overlay.

AutoRefreshInterval¶

public TimeSpan AutoRefreshInterval { get; set; }

Property Value¶

TimeSpan

Methods¶

AdjustExtentForWrapDateline(RectangleShape)¶

protected RectangleShape AdjustExtentForWrapDateline(RectangleShape targetDrawingExtent)

Parameters¶

targetDrawingExtent RectangleShape

Returns¶

RectangleShape

ClearTiles()¶

Clears the tiles.

public void ClearTiles()

DrawAsyncCore(RectangleShape, OverlayRefreshType, CancellationToken)¶

Draws current overlay with provided world extent.

protected Task DrawAsyncCore(RectangleShape targetExtent, OverlayRefreshType overlayRefreshType, CancellationToken cancellationToken)

Parameters¶

targetExtent RectangleShape
A world extent for drawing.

overlayRefreshType OverlayRefreshType

cancellationToken CancellationToken

Returns¶

Task

PositionExistingTilesCore(RectangleShape)¶

protected void PositionExistingTilesCore(RectangleShape targetExtent)

Parameters¶

targetExtent RectangleShape

PrefillDataToTiles(IEnumerable<TileView>)¶

protected void PrefillDataToTiles(IEnumerable<TileView> tiles)

Parameters¶

tiles IEnumerable<TileView>

PrefillDataToTilesCore(IEnumerable<TileView>)¶

protected void PrefillDataToTilesCore(IEnumerable<TileView> tiles)

Parameters¶

tiles IEnumerable<TileView>

OnDrawTilesProgressChanged(DrawTilesProgressChangedTileOverlayEventArgs)¶

Occurs when Tiles' download progress is changed.

protected void OnDrawTilesProgressChanged(DrawTilesProgressChangedTileOverlayEventArgs args)

Parameters¶

args DrawTilesProgressChangedTileOverlayEventArgs
Event arguments for DownloadProgress event.

OnDrawingTile(DrawingTileTileOverlayEventArgs)¶

This method raises before a tile is drawing.

protected void OnDrawingTile(DrawingTileTileOverlayEventArgs args)

Parameters¶

args DrawingTileTileOverlayEventArgs
This is an event argument for DrawingTile event.

OnDrawnTile(DrawnTileTileOverlayEventArgs)¶

This method raises after a tile is drawn.

protected void OnDrawnTile(DrawnTileTileOverlayEventArgs args)

Parameters¶

args DrawnTileTileOverlayEventArgs
This is an event argument for DrawnTile event.

GetTileCore()¶

Chooses a tile object to form the TileOverlay.

When overriding this method, consider the initialize parameters setting on the tile.

protected TileView GetTileCore()

Returns¶

TileView
A tile object to form the TileOverlay.

SaveStateCore()¶

This method saves overlay state to a byte array.

protected Byte[] SaveStateCore()

Returns¶

Byte[]
A byte array indicates current overlay state.

LoadStateCore(Byte[])¶

This method restore the overlay state back from the specified state.

protected void LoadStateCore(Byte[] state)

Parameters¶

state Byte[]
This parameter indicates the state for restore the overlay.

DrawTileAsync(TileView, MapArguments, CancellationToken)¶

protected Task DrawTileAsync(TileView tileView, MapArguments mapArguments, CancellationToken cancellationToken)

Parameters¶

tileView TileView

mapArguments MapArguments

cancellationToken CancellationToken

Returns¶

Task

DrawTileAsyncCore(GeoCanvas, TileView)¶

Redraws a specified tile with the provided world extent.

protected Task DrawTileAsyncCore(GeoCanvas geoCanvas, TileView tile)

Parameters¶

geoCanvas GeoCanvas
A geoCanvas for drawing the passed tile.

tile TileView
A TileView object that is created by the GetTile() method to draw.

Returns¶

Task

GetDrawingCells(RectangleShape, Int32)¶

This method gets the cells for drawing in the passed world extent.

protected Dictionary<string, MatrixCell> GetDrawingCells(RectangleShape targetExtent, int tileBuffer)

Parameters¶

targetExtent RectangleShape
A world extent for getting the drawing cells.

tileBuffer Int32

Returns¶

Dictionary<String, MatrixCell>
A dictionary of cells for drawing in the passed world extent.

GetDrawingCellsCore(RectangleShape, Int32)¶

This method gets the cells for drawing in the passed world extent.

protected Dictionary<string, MatrixCell> GetDrawingCellsCore(RectangleShape targetExtent, int tileBuffer)

Parameters¶

targetExtent RectangleShape
A world extent for getting the drawing cells.

tileBuffer Int32

Returns¶

Dictionary<String, MatrixCell>
A dictionary of cells for drawing in the passed world extent.

Remarks:

When overriding this method, consider that the TileBuffer affects the passed world extent.

GetTileMatrix(Double)¶

public TileMatrix GetTileMatrix(double scale)

Parameters¶

scale Double

Returns¶

TileMatrix

GetTileMatrixCore(Double)¶

protected TileMatrix GetTileMatrixCore(double scale)

Parameters¶

scale Double

Returns¶

TileMatrix

DrawException(GeoCanvas, Exception)¶

This method will draw on the canvas when the layer.Draw throw exception and the DrawExceptionMode is set to DrawException instead of ThrowException.

protected void DrawException(GeoCanvas canvas, Exception e)

Parameters¶

canvas GeoCanvas
The target canvas to draw the layer.

e Exception
The exception thrown when layer.Draw().

Remarks:

This method can be overriden its logic by rewrite the DrawExceptionCore.

DrawExceptionCore(GeoCanvas, Exception)¶

This method will draw on the canvas when the layer.Draw throw exception and the DrawExceptionMode is set to DrawException instead of ThrowException.

protected void DrawExceptionCore(GeoCanvas canvas, Exception e)

Parameters¶

canvas GeoCanvas
The target canvas to draw the layer.

e Exception
The exception thrown when layer.Draw().

OnDrawingException(DrawingExceptionTileOverlayEventArgs)¶

protected void OnDrawingException(DrawingExceptionTileOverlayEventArgs e)

Parameters¶

e DrawingExceptionTileOverlayEventArgs

OnDrawnException(DrawnExceptionTileOverlayEventArgs)¶

protected void OnDrawnException(DrawnExceptionTileOverlayEventArgs e)

Parameters¶

e DrawnExceptionTileOverlayEventArgs

OnTileTypeChanged(TileTypeChangedTileOverlayEventArgs)¶

protected void OnTileTypeChanged(TileTypeChangedTileOverlayEventArgs e)

Parameters¶

e TileTypeChangedTileOverlayEventArgs

OnTileTypeChanging(TileTypeChangingTileOverlayEventArgs)¶

protected void OnTileTypeChanging(TileTypeChangingTileOverlayEventArgs e)

Parameters¶

e TileTypeChangingTileOverlayEventArgs

GetBufferedExtent(RectangleShape, Double, Int32)¶

internal RectangleShape GetBufferedExtent(RectangleShape targetExtent, double resolution, int tileBuffer)

Parameters¶

targetExtent RectangleShape

resolution Double

tileBuffer Int32

Returns¶

RectangleShape

GetTile(RectangleShape, Int32, Int32, Int64, Int64, Int32, Double)¶

internal TileView GetTile(RectangleShape targetExtent, int tileScreenWidth, int tileScreenHeight, long tileColumnIndex, long tileRowIndex, int zoomLevelIndex, double scale)

Parameters¶

targetExtent RectangleShape

tileScreenWidth Int32

tileScreenHeight Int32

tileColumnIndex Int64

tileRowIndex Int64

zoomLevelIndex Int32

scale Double

Returns¶

TileView

GetSortedCells(Dictionary<String, MatrixCell>, RectangleShape)¶

protected Dictionary<string, MatrixCell> GetSortedCells(Dictionary<string, MatrixCell> cells, RectangleShape targetExtent)

Parameters¶

cells Dictionary<String, MatrixCell>

targetExtent RectangleShape

Returns¶

Dictionary<String, MatrixCell>

GetSortedCellsCore(Dictionary<String, MatrixCell>, RectangleShape)¶

protected Dictionary<string, MatrixCell> GetSortedCellsCore(Dictionary<string, MatrixCell> cells, RectangleShape targetExtent)

Parameters¶

cells Dictionary<String, MatrixCell>

targetExtent RectangleShape

Returns¶

Dictionary<String, MatrixCell>

Events¶

DrawTilesProgressChanged¶

This event raises when download progress is changed.

public event EventHandler<DrawTilesProgressChangedTileOverlayEventArgs> DrawTilesProgressChanged;

DrawingTile¶

This event raises before the tile is drawing.

public event EventHandler<DrawingTileTileOverlayEventArgs> DrawingTile;

DrawnTile¶

This event raises after the tile is drawn.

public event EventHandler<DrawnTileTileOverlayEventArgs> DrawnTile;

DrawingException¶

public event EventHandler<DrawingExceptionTileOverlayEventArgs> DrawingException;

DrawnException¶

public event EventHandler<DrawnExceptionTileOverlayEventArgs> DrawnException;

TileTypeChanged¶

public event EventHandler<TileTypeChangedTileOverlayEventArgs> TileTypeChanged;

TileTypeChanging¶

public event EventHandler<TileTypeChangingTileOverlayEventArgs> TileTypeChanging;

Drawing¶

This event raises before the overlay is drawing.

public event EventHandler<DrawingOverlayEventArgs> Drawing;

Drawn¶

This event raises after the overlay is drawn.

public event EventHandler<DrawnOverlayEventArgs> Drawn;

DrawingAttribution¶

public event EventHandler<DrawingAttributionOverlayEventArgs> DrawingAttribution;

DrawnAttribution¶

public event EventHandler<DrawnAttributionOverlayEventArgs> DrawnAttribution;

ThrowingException¶

public event EventHandler<ThrowingExceptionOverlayEventArgs> ThrowingException;