ScaleBarAdornmentLayer¶
Namespace: ThinkGeo.Core
The ScaleBarAdornmentLayer class allows you show a bar graphic on the map that displays the distance scale for the current map extent.
public class ScaleBarAdornmentLayer : AdornmentLayer
Inheritance Object → LayerBase → Layer → AdornmentLayer → ScaleBarAdornmentLayer
Remarks:
Use the ScaleBarAdornmentLayer class as a quick way to implement a ScaleBar. When using the ScaleBarAdornmentLayer, you also need to add a ScaleLineAdornmentLayer to the map control. One thing we should pay attention to is that the ScaleBar will not be drawn when the CurrentExtent is outside of Range(-90,180,90,-180).
Properties¶
DisplayUnitString¶
Gets the dictionary that defines the label text for each unit displayed in the ScaleBar.
public Dictionary<string, string> DisplayUnitString { get; }
Property Value¶
Remarks:
Each entry represents the abbreviated label for a unit of measure; for example: "m" for meters or "ft" for feet.
DisplayUnitLabel¶
Gets or sets the DisplayUnitLabel.
public Dictionary<DistanceUnit, string> DisplayUnitLabel { get; }
Property Value¶
Dictionary<DistanceUnit, String>
UnitFamily¶
Gets or sets the UnitSystem (Imperial/Metric) to be used for the ScaleBar.
public UnitSystem UnitFamily { get; set; }
Property Value¶
Remarks:
By setting this property, you can control whether to use a metric or imperial measurement system for the ScaleBar.
Thickness¶
Gets or sets the thickness of the ScaleBar. It is an integer value representing the height of the ScaleBar in screen units.
public int Thickness { get; set; }
Property Value¶
MaxWidth¶
Gets or Sets the MaxWidth of the ScaleBar.
public int MaxWidth { get; set; }
Property Value¶
Remarks:
You can use this property to set the maximum width that you want the ScaleBar to occupy on the map. The ScaleBarAdornmentLayer will automatically adjust its size based upon the current extent of the map. By setting this property, you can control the maximum width the ScaleBar will occupy on the map.
Margin¶
Gets or sets the pixel margin applied when the adornment is anchored to the map edges.
public float Margin { get; set; }
Property Value¶
BarBrush¶
Gets or sets the GeoBrush that is used to draw the primary ScaleBar segments.
public GeoBrush BarBrush { get; set; }
Property Value¶
Remarks:
This BarBrush property will give you full control over the appearance of the ScaleBarAdornmentLayer.
TextStyle¶
Gets or sets the text style applied to ScaleBar labels.
public TextStyle TextStyle { get; set; }
Property Value¶
LabelFont¶
Gets or sets the LabelFont.
public GeoFont LabelFont { get; set; }
Property Value¶
LabelBrush¶
Gets or sets the LabelBrush.
public GeoBrush LabelBrush { get; set; }
Property Value¶
AlternateBarBrush¶
Gets or sets the GeoBrush used to draw alternating ScaleBar segments.
public GeoBrush AlternateBarBrush { get; set; }
Property Value¶
Remarks:
This AlternateBarBrush property will give you full control over the appearance of the ScaleBarAdornmentLayer.
MaskBrush¶
Gets or sets the brush used for the ScaleBarAdornmentLayer's mask when ScaleBarAdornmentLayer.HasMask is true.
public GeoBrush MaskBrush { get; set; }
Property Value¶
HasMask¶
Gets or sets a value indicating whether the ScaleBar renders a mask behind the bar graphic.
public bool HasMask { get; set; }
Property Value¶
Remarks:
Depending upon the look of your map and your requirements, you may or may not want a mask on the ScaleBar. You can control whether or not the ScaleBar has a mask by setting this property. If you set the HasMask property to true, be sure to specify a mask color (or texture) by using the MaskBrush property.
MaskContour¶
Gets or sets the pen for the outline of the ScaleBar mask.
public GeoPen MaskContour { get; set; }
Property Value¶
Remarks:
By using this property you can control the border of the mask, if the HasMask property is set to true. If you do not want a contour or border to show, you should set the pen to transparent.
BarPen¶
Gets or sets the pen used to outline each segment of the ScaleBar.
public GeoPen BarPen { get; set; }
Property Value¶
UpdateWhilePanning¶
public bool UpdateWhilePanning { get; }
Property Value¶
Width¶
Gets or sets the adornment width in pixels. Deprecated; use .
public float Width { get; set; }
Property Value¶
ResizeScale¶
Gets or sets the resize scale applied to the adornment layer.
public float ResizeScale { get; set; }
Property Value¶
Remarks:
A value of 1 preserves the original size; values greater than 1 enlarge; values less than 1 shrink.
Height¶
Gets or sets the adornment height in pixels. Deprecated; use .
public float Height { get; set; }
Property Value¶
DragMode¶
Gets or sets how the adornment responds to drag operations.
public AdornmentDragMode DragMode { get; set; }
Property Value¶
ResizeMode¶
public AdornmentResizeMode ResizeMode { get; set; }
Property Value¶
BackgroundMask¶
Gets or sets the fill/outline style drawn behind the adornment content.
public AreaStyle BackgroundMask { get; set; }
Property Value¶
Location¶
This property gets and sets the drawing location of the AdornmentLayer.
public AdornmentLocation Location { get; set; }
Property Value¶
XOffsetInPixel¶
This property gets and sets the X pixel offset for the AdornmentLayer.
public float XOffsetInPixel { get; set; }
Property Value¶
Remarks:
This property allows you to specify an X offset. It is useful, when combined with a Y offset, to do things like modify the location of the adornment.
YOffsetInPixel¶
This property gets and sets the Y pixel offset for the AdornmentLayer.
public float YOffsetInPixel { get; set; }
Property Value¶
Remarks:
This property allows you to specify a Y offset. It is useful, when combined with an X offset, to do things like modify the location of the adornment.
RequestDrawingInterval¶
Gets or sets the interval between automatic draw requests. Obsolete.
public TimeSpan RequestDrawingInterval { get; set; }
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.
HasBoundingBox¶
Gets a value indicating whether the layer supports retrieving its bounding box.
public bool HasBoundingBox { get; }
Property Value¶
Remarks:
When this property is false, calls to or GetFullExtent throw an exception. The default implementation returns 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¶
ScaleBarAdornmentLayer()¶
Creates a new instance of the ScaleBarAdornmentLayer class.
public ScaleBarAdornmentLayer()
Remarks:
When displaying a ScaleBarAdornmentLayer, we need to instance a ScaleLineAdornmentLayer and add it to MapEngine. The ScaleBar will not be drawn when the CurrentExtent is outside of the world Extent(-90,180-,90,-180).
Methods¶
GetSelectionLocationCore(Single, Single, Single, Single)¶
Returns the selection origin for hit-testing.
protected ScreenPointF GetSelectionLocationCore(float mapWidth, float mapHeight, float adornmentWidth, float adornmentHeight)
Parameters¶
mapWidth Single
mapHeight Single
adornmentWidth Single
adornmentHeight Single
Returns¶
GetWidthCore()¶
Returns the last drawn width for selection and hit-testing.
protected float GetWidthCore()
Returns¶
GetHeightCore()¶
Returns the last drawn height for selection and hit-testing.
protected float GetHeightCore()
Returns¶
OpenCore()¶
Provides the overridable implementation that opens the instance and initializes the resources it depends on.
protected void OpenCore()
CloseCore()¶
Provides the overridable implementation that closes the instance and releases any resources it holds.
protected void CloseCore()
DrawCore(GeoCanvas, Collection<SimpleCandidate>)¶
This method draws the Layer.
protected void DrawCore(GeoCanvas canvas, Collection<SimpleCandidate> labelsInAllLayers)
Parameters¶
canvas GeoCanvas
This parameter is the view object or a NativeImage to draw on.
labelsInAllLayers Collection<SimpleCandidate>
This parameter represents the labels used for collision detection and duplication checking.
Remarks:
This abstract method is called from the concrete public method Draw. This method draws the representation of the layer based on the extent you provided.
When implementing this abstract method, consider each feature and its column data values. You can use the full power of the GeoCanvas to do the drawing. If you need column data for a feature, be sure to override the GetRequiredColumnNamesCore and add the columns you need to the collection. In many of the styles, we add properties to allow the user to specify which field they need; then, in the GetRequiredColumnNamesCore, we read that property and add it to the collection.
Events¶
DrawingProgressChanged¶
Occurs as the layer reports drawing progress (useful for async or tiled rendering scenarios).
public event EventHandler<DrawingProgressChangedEventArgs> DrawingProgressChanged;
RequestedDrawing¶
Raised after the drawing buffer elapses so consumers can handle a legacy drawing cycle. Obsolete.
public event EventHandler<RequestedDrawingLayerEventArgs> RequestedDrawing;
RequestingDrawing¶
Raised before the drawing buffer elapses so consumers can cancel a legacy drawing operation. Obsolete.
public event EventHandler<RequestingDrawingLayerEventArgs> RequestingDrawing;
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;