Table of Contents

Class PositionStyle

Namespace
ThinkGeo.Core
Assembly
ThinkGeo.Core.dll

This abstract class encapsulates the labeling position logic. It is inherited by other styles, such as the TextSytle.

public abstract class PositionStyle : Style
Inheritance
PositionStyle
Derived
Inherited Members

Remarks

This abstract class is meant to be inherited by other classes and specialized to meet the needs of various labelers.

Constructors

PositionStyle()

This is the default constructor for the class.

protected PositionStyle()

Remarks

None

Properties

AbbreviationDictionary 

public Dictionary<string, string> AbbreviationDictionary { get; set; }

Property Value

Dictionary<string, string>

Alignment

Controls the horizontal alignment of multi-line text content. This property has no effect on single-line text.

protected DrawingTextAlignment Alignment { get; set; }

Property Value

DrawingTextAlignment

AllowLabelNudging 

public bool AllowLabelNudging { get; set; }

Property Value

bool

AllowLineCarriage

This property gets and sets whether the labeler will allow carriage returns to be inserted.

public bool AllowLineCarriage { get; set; }

Property Value

bool

This property gets whether the labeler will allow carriage returns to be inserted.

Remarks

This property enables the labeler to split long labels into multiple lines if need be. For instance, if you have a lake whose name is "Southern Homestead Lake," then the labeler may try and break the name onto multiple lines in order to better label the feature.

AllowSpline

This property gets and sets whether line labels are allowed to spline around curved lines.

protected bool AllowSpline { get; set; }

Property Value

bool

This property gets whether line labels are allowed to spline around curved lines.

Remarks

This property will allow the labeler to spline the label around curved lines. This is useful for curved streets that need to be labeled. This can have a considerable performance impact, so we suggest you experiment with it to ensure it can meet your needs.

BasePoint 

protected PointStyle BasePoint { get; set; }

Property Value

PointStyle

BestPlacementSymbolHeight 

public float BestPlacementSymbolHeight { get; set; }

Property Value

float

BestPlacementSymbolWidth 

public float BestPlacementSymbolWidth { get; set; }

Property Value

float

CustomTextStyles

This property returns a collection of area styles, allowing you to stack multiple area styles on top of each other.

protected Collection<TextStyle> CustomTextStyles { get; }

Property Value

Collection<TextStyle>

This property returns a collection of area styles.

Remarks

Using this collection you can stack multiple area styles on top of each other. When we draw the feature we will draw them in order in the collection. You can use these stacks to create drop shadow effects along with multiple colored outlines etc.

DateFormat

This property gets and sets the format that will be applied to the text which can be parsed to DateTime type.

protected string DateFormat { get; set; }

Property Value

string

This property gets the format that will be applied to the text which can be parsed to DateTime type..

Remarks

With this property, you can apply formats to the text that is retrieved from the feature.

DrawingLevel

Gets or sets the DrawingLavel for this style.

protected DrawingLevel DrawingLevel { get; set; }

Property Value

DrawingLevel

DuplicateRule

This property gets and sets the rule that determines how duplicate labels are handled.

public LabelDuplicateRule DuplicateRule { get; set; }

Property Value

LabelDuplicateRule

This property gets the rule that determines how duplicate labels are handled.

Remarks

There are three ways to handle duplicate label names. The first is to suppress all duplicates, which means if there are two street segments with the same name then only one will be drawn. The second way is to suppress duplicate labels only if they are in one quarter of the screen. In this way, the screen will be divided into four quadrants, and if the two duplicate labels are in different quadrants, then they will both draw. The last way is to draw all duplicates.

FittingLineInScreen

This property gets and sets whether the labeler will try to fit the label as best as it can on the visible part of a line on the screen.

protected bool FittingLineInScreen { get; set; }

Property Value

bool

This property gets whether the labeler will try to fit the label as best as it can on the visible part of a line on the screen.

Remarks

A label will normally be displayed in the center of a line. If only a small piece of the line is visible on the screen, we cannot see it's label by default. If we set this property to ture though, the label will be displayed in the center of that piece in screen.

FittingPolygon

This property gets and sets whether the labeler will try to fit the label as best as it can within the boundary of a polygon.

public bool FittingPolygon { get; set; }

Property Value

bool

This property gets whether the labeler will try to fit the label as best as it can within the boundary of a polygon.

Remarks

None

FittingPolygonFactor

This property gets and sets the factor to which it will keep the label inside of the polygon.

public double FittingPolygonFactor { get; set; }

Property Value

double

This property gets the factor to which it will keep the label inside of the polygon.

Remarks

None

FittingPolygonInScreen

This property gets and sets whether the labeler will try to fit the label as best as it can on the visible part of a polygon on the screen.

protected bool FittingPolygonInScreen { get; set; }

Property Value

bool

This property gets whether the labeler will try to fit the label as best as it can on the visible part of a polygon on the screen.

Remarks

A label will normally be displayed in the center of a polygon. If only a small piece of the polygon is visible on the screen, we cannot see it's label by default. If we set this property to ture though, the label will be displayed in the center of that piece in screen.

Font

This property gets and sets the font that will be used to draw the text.

protected GeoFont Font { get; set; }

Property Value

GeoFont

This property gets the font that will be used to draw the text.

Remarks

None

ForceHorizontalLabelForLine

This property gets and sets whether we should force horizontal labeling for lines.

protected bool ForceHorizontalLabelForLine { get; set; }

Property Value

bool

This property gets whether we should force horizontal labeling for lines.

Remarks

Normally, lines are labeled in the direction of the line. There may be some cases, however, when you want to have the line labeled horizontally regardless of the line's direction. In such a case, you can set this property to force the lines to be labeled horizontally.

ForceLineCarriage

This property gets and sets whether the labeler will force carriage returns to be inserted.

public bool ForceLineCarriage { get; set; }

Property Value

bool

This property gets whether the labeler will force carriage returns to be inserted.

Remarks

This property forces the labeler to split long labels into multiple lines. For instance, if you have a lake whose name is "Southern Homestead Lake," then the labeler will break the name onto multiple lines in order to better label the feature.

GridSize

This property gets and sets the grid size used for deterministic labeling.

public int GridSize { get; set; }

Property Value

int

This property gets the grid sized used for deterministic labeling.

Remarks

The grid size determines how many labels will be considered as candidates for drawing. The smaller the grid size, the higher the density of candidates. Making the grid size too small may have a performance impact.

HaloPen

This property gets and sets the halo pen you may use to draw a halo around the text.

protected GeoPen HaloPen { get; set; }

Property Value

GeoPen

This property gets the halo pen you may use to draw a halo around the text.

Remarks

The halo pen allows you to draw a halo effect around the text, making it stand out more on a busy background.

LabelAllLineParts

This property gets and sets whether the labeler will label every part of a multi-part line.

public bool LabelAllLineParts { get; set; }

Property Value

bool

This property gets whether the labeler will label every part of a multi-part line.

Remarks

In some cases, you may want to label all of the parts of a multi-part line, while in other cases you may not.

LabelAllPolygonParts

This property gets and sets whether the labeler will label every part of a multi-part polygon.

public bool LabelAllPolygonParts { get; set; }

Property Value

bool

This property gets whether the labeler will label every part of a multi-part polygon.

Remarks

In some cases, you may want to label all of the parts of a multi-part polygon, while in other cases you may not. For example, you may have a series of lakes where you do want to label each polygon. In another case, you may have a country with many small islands and in this case you only want to label the largest polygon.

LabelPositions

Gets a value represents a keyValuepair which is a feature id and label position of the feature

protected Dictionary<string, WorldLabelingCandidate> LabelPositions { get; }

Property Value

Dictionary<string, WorldLabelingCandidate>

LeaderLineMinimumLengthInPixels 

public float LeaderLineMinimumLengthInPixels { get; set; }

Property Value

float

LeaderLineRule 

public LabelLeaderLinesRule LeaderLineRule { get; set; }

Property Value

LabelLeaderLinesRule

LeaderLineStyle 

public LineStyle LeaderLineStyle { get; set; }

Property Value

LineStyle

LetterCase 

protected DrawingTextLetterCase LetterCase { get; set; }

Property Value

DrawingTextLetterCase

Mask

This property gets and sets the AreaStyle used to draw a mask behind the text.

protected AreaStyle Mask { get; set; }

Property Value

AreaStyle

This property gets the AreaStyle used to draw a mask behind the text.

Remarks

A mask is a plate behind the text that is rectangular and slightly larger than the width and height of the text. It allows the label to stand out well on a busy background. You can also try the HaloPen property instead of the mask, if the mask effect is too pronounced.

MaskMargin

This property gets and sets the margin around the text that will be used for the mask.

protected DrawingMargin MaskMargin { get; set; }

Property Value

DrawingMargin

This property gets the margin around the text that will be used for the mask.

Remarks

This determines how much larger the mask is than the text, in pixels.

MaskType 

public MaskType MaskType { get; set; }

Property Value

MaskType

MaxAdjacentCharDeltaAngle 

public double MaxAdjacentCharDeltaAngle { get; set; }

Property Value

double

MaxCharAngleDelta 

protected double MaxCharAngleDelta { get; set; }

Property Value

double

MaxNudgingInPixel 

public int MaxNudgingInPixel { get; set; }

Property Value

int

MinDistance 

protected double MinDistance { get; set; }

Property Value

double

NudgingIntervalInPixel 

public float NudgingIntervalInPixel { get; set; }

Property Value

float

NumericFormat

This property gets and sets the format that will be applied to the text which can be parsed to double type.

protected string NumericFormat { get; set; }

Property Value

string

This property gets the format that will be applied to the text which can be parsed to double type..

Remarks

With this property, you can apply formats to the text that is retrieved from the feature.

OverlappingRule

This property gets and sets the rule that determines how overlapping labels are handled.

public LabelOverlappingRule OverlappingRule { get; set; }

Property Value

LabelOverlappingRule

This property gets the rule that determines overlapping labels are handled.

Remarks

This defines the rules for label overlapping. Currently, either we allow overlapping or we do not. In the future, we may extend this to allow some percentage of partial overlapping.

PolygonLabelingLocationMode

This property gets and sets the mode that determines how to locate polygon's labeling

public PolygonLabelingLocationMode PolygonLabelingLocationMode { get; set; }

Property Value

PolygonLabelingLocationMode

This property gets the mode that determines how to locate polygon's labeling

Remarks

There are two ways to handle polygon's labeling location. The first is to use polygon's centroid as the labeling location, the second way is to use polygon's boungdingbox center as the labeling location.

RotationAngle

This property gets and sets the rotation angle of the item being positioned.

protected double RotationAngle { get; set; }

Property Value

double

This property gets the rotation angle of the item being positioned.

Remarks

None

Spacing 

protected double Spacing { get; set; }

Property Value

double

SplineType

Gets or sets the SplineType for labeling.

protected SplineType SplineType { get; set; }

Property Value

SplineType

SuppressPartialLabels

This property gets and sets whether a partial label in the current extent will be drawn or not.

public bool SuppressPartialLabels { get; set; }

Property Value

bool

Remarks

This property provides a solution to the "cut off" label issue in Map Suite Web Edition and Desktop Edition, which occurs when multiple tiles exist. When you set this property to true, any labels outside of the current extent will not be drawn.

TextBrush

This property gets and sets the SolidBrush that will be used to draw the text.

protected GeoBrush TextBrush { get; set; }

Property Value

GeoBrush

This property gets the SolidBrush that will be used to draw the text.

Remarks

You can use this property to draw a solid color; however, if you need to use other brushes, you can access them through the Advanced property of this class.

TextColumnName

This property gets and sets the column name in the data that you want to get the text from.

protected string TextColumnName { get; set; }

Property Value

string

This property gets the column name in the data that you want to get the text from.

Remarks

This property is used when retrieving text from a feature. You will want to specify the name of the column that contains the text you want to draw.

TextContent

This property gives you the option to customize the labeling by using one or more columns. For example supposing I have 2 columns "ColumnA" and "ColumnB" with the values of "ValueA" and "ValueB", by setting this property to "{ColumnA} - {ColumnB}", it will draw "ValueA - ValueB" for the corresponding feature.
Do remember to add the columns you want to draw (ColumnA and ColumnB in the case above) to RequiredColumnNames collection;

public string TextContent { get; set; }

Property Value

string

TextFormat

This property gets and sets the format that will be applied to the text.

protected string TextFormat { get; set; }

Property Value

string

This property gets the format that will be applied to the text.

Remarks

With this property, you can apply formats to the text that is retrieved from the feature.

TextLineSegmentRatio

This property gets and sets the ratio required for the label length to match the line length.

public double TextLineSegmentRatio { get; set; }

Property Value

double

This property gets the ratio required for the label length to match the line length.

Remarks

This allows you to suppress labels where the label length would greatly exceed the line length. For example, if you set the ratio to 1, then the label will be suppressed if it is longer than the line. If the ratio is lower, then the label would need to be shorter than the line. If higher, then the label is allowed to run past the length of the line. This allows you to control the look of things like road labeling.

TextPlacement

This property gets and sets the location of the label for point features relative to the point.

public TextPlacement TextPlacement { get; set; }

Property Value

TextPlacement

This property gets the location of the label for point features relative to the point.

Remarks

This property allows you to choose where the labels are created relative to the point. For example, you can set the property to RightCenter, which would ensure that all labels are placed to the right of and vertically centered with the point. Different kinds of point layers can be positioned differently. If the point layer is dense and position is not a main concern, then you can try the BestPlacement property. That property overrides this property and tries to fit the label in the best location so that the minimum number of labels are suppressed due to overlapping issues.

WrapWidth 

protected double WrapWidth { get; set; }

Property Value

double

XOffsetInPixel

This property gets and sets the X pixel offset used for drawing each feature.

protected float XOffsetInPixel { get; set; }

Property Value

float

This property gets the X pixel offset used for drawing each feature.

Remarks

This property allows you to specify an X offset. When combined with a Y offset, it is useful to allow you to achieve effects such as drop shadows, etc. There also may be times when you need to modify the location of feature data so as to better align it with raster satellite data.

YOffsetInPixel

This property gets and sets the Y pixel offset used for drawing each feature.

protected float YOffsetInPixel { get; set; }

Property Value

float

This property gets the Y pixel offset used for drawing each feature.

Remarks

This property allows you to specify a Y offset. When combined with an X offset, it is useful to allow you to achieve effects such as drop shadows, etc. There also may be times when you need to modify the location of feature data so as to better align it with raster satellite data.

Methods

AbbreviateText(Feature, GeoCanvas) 

protected void AbbreviateText(Feature feature, GeoCanvas canvas)

Parameters

feature Feature
canvas GeoCanvas

AbbreviateTextCore(Feature, GeoCanvas) 

protected virtual void AbbreviateTextCore(Feature feature, GeoCanvas canvas)

Parameters

feature Feature
canvas GeoCanvas

CheckDuplicate(LabelingCandidate, GeoCanvas, Collection<SimpleCandidate>, Collection<SimpleCandidate>)

This method will determine whether the label will be suppressed because it is a duplicate.

protected bool CheckDuplicate(LabelingCandidate labelingCandidate, GeoCanvas canvas, Collection<SimpleCandidate> labelsInThisLayer, Collection<SimpleCandidate> labelsInAllLayers)

Parameters

labelingCandidate LabelingCandidate

This parameter is the labeling candidate that will be checked to determine if it is a duplicate.

canvas GeoCanvas

This parameter is the view used for calculations.

labelsInThisLayer Collection<SimpleCandidate>

The labels will be drawn in the current layer only.

labelsInAllLayers Collection<SimpleCandidate>

The labels will be drawn in all layers.

Returns

bool

This method returns whether the label will be suppressed as a duplicate.

Remarks

This method is the concrete wrapper for the abstract method CheckDuplicateCore. This method will determine if the label will be suppressed because it is a duplicate. It also takes into consideration the duplicate rules for the class. So, for example, if we set to allow duplicates, then the method will always return false. If the class is set to not allow duplicates and this label is a duplicate, then it will return true and be suppressed.

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.

CheckDuplicateCore(LabelingCandidate, GeoCanvas, Collection<SimpleCandidate>, Collection<SimpleCandidate>)

This method will determine if the label will be suppressed because it is a duplicate.

protected virtual bool CheckDuplicateCore(LabelingCandidate labelingCandidate, GeoCanvas canvas, Collection<SimpleCandidate> labelsInThisLayer, Collection<SimpleCandidate> labelsInAllLayers)

Parameters

labelingCandidate LabelingCandidate

This parameter is the labeling candidate that will be checked to determine if it is a duplicate.

canvas GeoCanvas

This parameter is the view that will be used for calculations.

labelsInThisLayer Collection<SimpleCandidate>

The labels will be drawn in the current layer only.

labelsInAllLayers Collection<SimpleCandidate>

The labels will be drawn in all layers.

Returns

bool

This method returns whether the label will be suppressed as a duplicate.

Remarks

This overridden method is called from the concrete public method CheckDuplicate. This method will determine if the label will be suppressed because it is a duplicate. It also takes into consideration the duplicate rules for the class. So, for example, if we set to allow duplicates, then the method will always return false. If the class is set to not allow duplicates and this label is a duplicate, then it will return true and be suppressed.

CheckOverlapping(LabelingCandidate, GeoCanvas, GeoFont, float, float, double, Collection<SimpleCandidate>, Collection<SimpleCandidate>)

This method will determine if the label will be suppressed because of overlapping.

protected bool CheckOverlapping(LabelingCandidate labelingCandidate, GeoCanvas canvas, GeoFont font, float xOffsetInPixel, float yOffsetInPixel, double rotationAngle, Collection<SimpleCandidate> labelsInThisLayer, Collection<SimpleCandidate> labelsInAllLayers)

Parameters

labelingCandidate LabelingCandidate

This parameter is the labeling candidate that will be checked to determine if it is overlapping.

canvas GeoCanvas

This parameter is the view that will be used for calculations.

font GeoFont
xOffsetInPixel float
yOffsetInPixel float
rotationAngle double
labelsInThisLayer Collection<SimpleCandidate>

The labels will be drawn in the current layer only.

labelsInAllLayers Collection<SimpleCandidate>

The labels will be drawn in all layers.

Returns

bool

This method returns whether the label will be suppressed because of overlapping.

Remarks

This method is the concrete wrapper for the abstract method CheckOverlappingCore. This method will determine if the label will be suppressed because it is overlapping another label. It also takes into consideration the overlapping rules for the class. So, for example, if we set to allow overlap, then the method will always return false. If the class is set to not allow overlap and this label is overlapping, then it will return true and be suppressed.

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.

CheckOverlappingCore(LabelingCandidate, GeoCanvas, Collection<SimpleCandidate>, Collection<SimpleCandidate>)

This method will determine whether the label will be suppressed because of overlapping.

protected virtual bool CheckOverlappingCore(LabelingCandidate labelingCandidate, GeoCanvas canvas, Collection<SimpleCandidate> labelsInThisLayer, Collection<SimpleCandidate> labelsInAllLayers)

Parameters

labelingCandidate LabelingCandidate

This parameter is the labeling candidate that will be checked to determine if it is overlapping.

canvas GeoCanvas

This parameter is the view that will be used for calculations.

labelsInThisLayer Collection<SimpleCandidate>

The labels will be drawn in the current layer only.

labelsInAllLayers Collection<SimpleCandidate>

The labels will be drawn in all layers.

Returns

bool

This method returns whether the label will be suppressed because of overlapping.

Remarks

This overridden method is called from the concrete public method CheckOverlapping. This method will determine if the label will be suppressed because it is overlapping another label. It also takes into consideration the overlapping rules for the class. So, for example, if we set to allow overlap, then the method will always return false. If the class is set to not allow overlap and this label is overlapping, then it will return true and be suppressed.

ConvertToScreenShape(Feature, GeoCanvas)

This method converts a feature in world coordinates to screen coordinates.

protected static BaseShape ConvertToScreenShape(Feature feature, GeoCanvas canvas)

Parameters

feature Feature

This parameter is the feature to be converted from world coordinates.

canvas GeoCanvas

This parameter is the view that will be used to convert the world coordinate feature to a screen coorindate feature.

Returns

BaseShape

A screen coordinate shape.

Remarks

This overridden method can be called by this class and its sub concrete classes. In this method, we take the view and the feature in world coordinates and convert it to screen coordinates.

DrawCore(IEnumerable<Feature>, GeoCanvas, Collection<SimpleCandidate>, Collection<SimpleCandidate>)

This method draws the features on the view you provided.

protected override void DrawCore(IEnumerable<Feature> features, GeoCanvas canvas, Collection<SimpleCandidate> labelsInThisLayer, Collection<SimpleCandidate> labelsInAllLayers)

Parameters

features IEnumerable<Feature>

This parameter represents the features you want to draw on the view.

canvas GeoCanvas

This parameter represents the view you want to draw the features on.

labelsInThisLayer Collection<SimpleCandidate>

The labels will be drawn in the current layer only.

labelsInAllLayers Collection<SimpleCandidate>

The labels will be drawn in all layers.

Remarks

This overridden method is called from the concrete public method Draw. In this method, we take the features you passed in and draw them on the view you provided. Each style (based on its properties) may draw each feature differently.


When overriding this 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.

Exceptions

InvalidOperationException

In the event you attempt to call this method when the GeoCanvas's IsDrawing mode is false, it will throw an InvalidOperationException.

ArgumentNullException

If you pass a null as the view, we will throw an ArgumentNullException.

ArgumentNullException

If you pass a null as the features, we will throw an ArgumentNullException.

DrawMask(LabelingCandidate, GeoCanvas, Collection<SimpleCandidate>, Collection<SimpleCandidate>) 

protected void DrawMask(LabelingCandidate labelingCandidate, GeoCanvas canvas, Collection<SimpleCandidate> labelsInThisLayer, Collection<SimpleCandidate> labelsInAllLayers)

Parameters

labelingCandidate LabelingCandidate
canvas GeoCanvas
labelsInThisLayer Collection<SimpleCandidate>
labelsInAllLayers Collection<SimpleCandidate>

FilterFeatures(IEnumerable<Feature>, GeoCanvas)

This method filters the features based on the grid size to facilitate deterministic labeling.

protected Collection<Feature> FilterFeatures(IEnumerable<Feature> features, GeoCanvas canvas)

Parameters

features IEnumerable<Feature>

This parameter represents the features that will be filtered.

canvas GeoCanvas

This parameter is the view that will be used for calculating font sizes.

Returns

Collection<Feature>

This method returns the features that will be considered for labeling.

Remarks

This method is the concrete wrapper for the abstract method FilterFeaturesCore. In this method, we filter the features based on the grid size to facilitate deterministic labeling.

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.

FilterFeaturesCore(IEnumerable<Feature>, GeoCanvas)

This method filters the features based on the grid size to facilitate deterministic labeling.

protected virtual Collection<Feature> FilterFeaturesCore(IEnumerable<Feature> features, GeoCanvas canvas)

Parameters

features IEnumerable<Feature>

This parameter represents the features that will be filtered.

canvas GeoCanvas

This parameter is the view that will be used for calculating font sizes.

Returns

Collection<Feature>

This method returns the features that will be considered for labeling.

Remarks

This overridden method is called from the concrete public method FilterFeatures. In this method, we filter the features based on the grid size to facilitate deterministic labeling.

Format(string, BaseShape) 

protected string Format(string text, BaseShape labeledShape)

Parameters

text string
labeledShape BaseShape

Returns

string

FormatCore(string, BaseShape) 

protected virtual string FormatCore(string text, BaseShape labeledShape)

Parameters

text string
labeledShape BaseShape

Returns

string

GetLabelingCandidateCore(Feature, GeoCanvas, GeoFont, float, float, double)

This method determines whether the specified feature is a good candidate to be labeled, based on the labeling properties set.

protected virtual Collection<LabelingCandidate> GetLabelingCandidateCore(Feature feature, GeoCanvas canvas, GeoFont font, float xOffsetInPixel, float yOffsetInPixel, double rotationAngle)

Parameters

feature Feature

This parameter is the feature that will be considered as a labeling candidate.

canvas GeoCanvas

This parameter is the view that will be used to draw the feature. This method will not draw on this view, but rather will use it to determine font size, etc.

font GeoFont
xOffsetInPixel float
yOffsetInPixel float
rotationAngle double

Returns

Collection<LabelingCandidate>

A collection of labeling candidates.

Remarks

This overridden method is called from the concrete public method GetLabelingCanidate. In this method, we take the feature you passed in and determine if it is a candidate for labeling. If it is, then we will add it to the return collection. The algorithm to determine whether the label will draw is complex and determined by a number of properties and factors.

GetLabelingCandidates(Feature, GeoCanvas, GeoFont, float, float, double)

This method determines whether the specified feature is a good candidate to be labeled, based on the labeling properties set.

protected Collection<LabelingCandidate> GetLabelingCandidates(Feature feature, GeoCanvas canvas, GeoFont font, float xOffsetInPixel, float yOffsetInPixel, double rotationAngle)

Parameters

feature Feature

This parameter is the feature that will be considered as a labeling candidate.

canvas GeoCanvas

This parameter is the view that will be used to draw the feature. This method will not draw on this view, but rather will use it to determine font size, etc.

font GeoFont
xOffsetInPixel float
yOffsetInPixel float
rotationAngle double

Returns

Collection<LabelingCandidate>

A collection of labeling candidates.

Remarks

This method is the concrete wrapper for the abstract method GetLabelingCanidatesCore. This method determines if the feature passed in is a good candidate to be labeled based on the labeling properties set.

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.

GetRequiredColumnNamesCore()

This method returns the column data for each feature that is required for the style to properly draw.

protected override Collection<string> GetRequiredColumnNamesCore()

Returns

Collection<string>

This method returns a collection of the column names that it needs.

Remarks

This abstract method is called from the concrete public method GetRequiredFieldNames. In this method, we return the column names that are required for the style to draw the feature properly. For example, if you have a style that colors areas blue when a certain column value is over 100, then you need to be sure you include that column name. This will ensure that the column data is returned to you in the feature when it is ready to draw.

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.

Exceptions

ArgumentNullException

If columnName is null, we will throw an ArgumentNullException.

OnFormatted(FormattedPositionStyleEventArgs) 

protected virtual void OnFormatted(FormattedPositionStyleEventArgs e)

Parameters

e FormattedPositionStyleEventArgs

OnFormatting(FormattingPositionStyleEventArgs) 

protected virtual void OnFormatting(FormattingPositionStyleEventArgs e)

Parameters

e FormattingPositionStyleEventArgs

WrapText(string, GeoFont, GeoCanvas) 

public string WrapText(string text, GeoFont font, GeoCanvas canvas)

Parameters

text string
font GeoFont
canvas GeoCanvas

Returns

string

Events

Formatted 

public event EventHandler<FormattedPositionStyleEventArgs> Formatted

Event Type

EventHandler<FormattedPositionStyleEventArgs>

Formatting 

public event EventHandler<FormattingPositionStyleEventArgs> Formatting

Event Type

EventHandler<FormattingPositionStyleEventArgs>