C# Class SharpMap.Rendering.Thematics.GradientTheme

Inheritance: SharpMap.Rendering.Thematics.GradientThemeBase
Show file Open project: jumpinjackie/fdotoolbox Class Usage Examples

Public Methods

Method Description
GetStyle ( SharpMap row ) : SharpMap.Styles.IStyle

Returns the style based on a numeric DataColumn, where style properties are linearly interpolated between max and min values.
GradientTheme ( string columnName, double minValue, double maxValue, SharpMap minStyle, SharpMap maxStyle ) : System

Initializes a new instance of the GradientTheme class

The gradient theme interpolates linearly between two styles based on a numerical attribute in the datasource. This is useful for scaling symbols, line widths, line and fill colors from numerical attributes.

Colors are interpolated between two colors, but if you want to interpolate through more colors (fx. a rainbow), set the TextColorBlend, LineColorBlend and FillColorBlend properties to a custom ColorBlend.

The following properties are scaled (properties not mentioned here are not interpolated): PropertyRemarks System.Drawing.ColorRed, Green, Blue and Alpha values are linearly interpolated. System.Drawing.PenThe color, width, color of pens are interpolated. MiterLimit,StartCap,EndCap,LineJoin,DashStyle,DashPattern,DashOffset,DashCap,CompoundArray, and Alignment are switched in the middle of the min/max values. System.Drawing.SolidBrushSolidBrush color are interpolated. Other brushes are not supported. SharpMap.Styles.VectorStyleMaxVisible, MinVisible, Line, Outline, Fill and SymbolScale are scaled linearly. Symbol, EnableOutline and Enabled switch in the middle of the min/max values. SharpMap.Styles.LabelStyleFontSize, BackColor, ForeColor, MaxVisible, MinVisible, Offset are scaled linearly. All other properties use min-style.

Creating a rainbow colorblend showing colors from red, through yellow, green and blue depicting the population density of a country. //Create two vector styles to interpolate between SharpMap.Styles.VectorStyle min = new SharpMap.Styles.VectorStyle(); SharpMap.Styles.VectorStyle max = new SharpMap.Styles.VectorStyle(); min.Outline.Width = 1f; //Outline width of the minimum value max.Outline.Width = 3f; //Outline width of the maximum value //Create a theme interpolating population density between 0 and 400 SharpMap.Rendering.Thematics.GradientTheme popdens = new SharpMap.Rendering.Thematics.GradientTheme("PopDens", 0, 400, min, max); //Set the fill-style colors to be a rainbow blend from red to blue. popdens.FillColorBlend = SharpMap.Rendering.Thematics.ColorBlend.Rainbow5; myVectorLayer.Theme = popdens;

Private Methods

Method Description
CalculateLabelStyle ( SharpMap min, SharpMap max, double value ) : LabelStyle
CalculateVectorStyle ( SharpMap min, SharpMap max, double value ) : VectorStyle
Fraction ( double attr ) : double
InterpolateBool ( bool min, bool max, double attr ) : bool
InterpolateBrush ( System min, System max, double attr ) : System.Drawing.SolidBrush
InterpolateColor ( System minCol, System maxCol, double attr ) : System.Drawing.Color
InterpolateDouble ( double min, double max, double attr ) : double
InterpolateFloat ( float min, float max, double attr ) : float
InterpolatePen ( System min, System max, double attr ) : System.Drawing.Pen

Method Details

GetStyle() public method

Returns the style based on a numeric DataColumn, where style properties are linearly interpolated between max and min values.
public GetStyle ( SharpMap row ) : SharpMap.Styles.IStyle
row SharpMap Feature
return SharpMap.Styles.IStyle

GradientTheme() public method

Initializes a new instance of the GradientTheme class

The gradient theme interpolates linearly between two styles based on a numerical attribute in the datasource. This is useful for scaling symbols, line widths, line and fill colors from numerical attributes.

Colors are interpolated between two colors, but if you want to interpolate through more colors (fx. a rainbow), set the TextColorBlend, LineColorBlend and FillColorBlend properties to a custom ColorBlend.

The following properties are scaled (properties not mentioned here are not interpolated): PropertyRemarks System.Drawing.ColorRed, Green, Blue and Alpha values are linearly interpolated. System.Drawing.PenThe color, width, color of pens are interpolated. MiterLimit,StartCap,EndCap,LineJoin,DashStyle,DashPattern,DashOffset,DashCap,CompoundArray, and Alignment are switched in the middle of the min/max values. System.Drawing.SolidBrushSolidBrush color are interpolated. Other brushes are not supported. SharpMap.Styles.VectorStyleMaxVisible, MinVisible, Line, Outline, Fill and SymbolScale are scaled linearly. Symbol, EnableOutline and Enabled switch in the middle of the min/max values. SharpMap.Styles.LabelStyleFontSize, BackColor, ForeColor, MaxVisible, MinVisible, Offset are scaled linearly. All other properties use min-style.

Creating a rainbow colorblend showing colors from red, through yellow, green and blue depicting the population density of a country. //Create two vector styles to interpolate between SharpMap.Styles.VectorStyle min = new SharpMap.Styles.VectorStyle(); SharpMap.Styles.VectorStyle max = new SharpMap.Styles.VectorStyle(); min.Outline.Width = 1f; //Outline width of the minimum value max.Outline.Width = 3f; //Outline width of the maximum value //Create a theme interpolating population density between 0 and 400 SharpMap.Rendering.Thematics.GradientTheme popdens = new SharpMap.Rendering.Thematics.GradientTheme("PopDens", 0, 400, min, max); //Set the fill-style colors to be a rainbow blend from red to blue. popdens.FillColorBlend = SharpMap.Rendering.Thematics.ColorBlend.Rainbow5; myVectorLayer.Theme = popdens;
public GradientTheme ( string columnName, double minValue, double maxValue, SharpMap minStyle, SharpMap maxStyle ) : System
columnName string Name of column to extract the attribute
minValue double Minimum value
maxValue double Maximum value
minStyle SharpMap Color for minimum value
maxStyle SharpMap Color for maximum value
return System