SvgSymbol Class
Represents a symbol rendered with an SVG (Scalable Vector Graphics) document.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CECore assembly)
Syntax
public class SvgSymbol : SymbolRemarks
SvgSymbol is a symbol defined by an SVG document. SVG stands for Scalable Vector Graphics, and is a standard defined by World Wide Web Consortium for describing vector graphics. SvgSymbol implements a subset of the SVG Tiny 1.2 version of the standard, plus a few additional features from the full SVG 1.1 standard.
The SVG document may be stored in an external disk file, or may be supplied directly to the SvgSymbol by the application or inlined in the Carmenta Engine configuration file.
Supported SVG features
Most static features of the SVG Tiny 1.2 specification are supported, such as lines, polygons, paths, text objects etc. Multimedia contents such as images, audio or video streams are not supported. Scripting and animations are also not supported. Most of the styling attributes for controlling colors, line styles etc, are supported, with the exception of various types of color gradients.
Specifically, the following SVG elements are supported:
<svg>, <g>, <rect>, <circle>, <ellipse>, <line> <polyline>, <path>, <text>.
The <path> element supports all path commands from SVG Tiny 1.2 standard, plus the "elliptic arc" command specified by SVG 1.1.
The following styling attributes are supported, both as separate XML attributes or as part of a style attribute:
fill, fill-opacity, fill-rule, stroke, stroke-opacity, stroke-width, stroke-linecap, stroke-linejoin , stroke-dasharray, vector-effect, font-family, font-size, font-weight, font-style, text-anchor, visibility.
Controlling SVG rendering with feature attributes
The SVG Tiny 1.2 specification allows specifying a color as the special value currentColor. It is up to the SVG renderer to decide what this color is. In Carmenta Engine, the current color is taken from the color property of the SymbolVisualizer. This makes it possible to control one color of an SvgSymbol from feature attributes.
In addition to this, SvgSymbol also implements another, more powerful way of using feature attributes to control how a symbol is rendered. By adding certain XML attributes to the SVG elements, most of the SVG styling attributes and a few others can be "overridden" by values calculated from the attributes of the feature being rendered. The following shows an example of an SVG symbol where the fill color of a <rect> element is taken from an attribute of the current feature:
<svg
xmlns="http://www.w3.org/2000/svg"
xmlns:carmenta="http://www.carmenta.com/Engine5/svg"
width="50"
height="10">
<g>
<rect
carmenta:fill='fillcolor, "yellow"'
style="opacity:1;fill:#000000;stroke:#000000;stroke-opacity:1"
width="30"
height="10"
x="10"
y="30"/>
</g>
</svg>
Note the namespace declaration at the top, all override attributes must be defined in this namespace. Then look at the <rect> element, where a carmenta:fill attribute is specified. This will override the SVG fill color, specified in a separate fill attribute or, as in this case, the style attribute.
The value of the carmenta:fill attribute is an expression that is evaluated in the context of the attributes from the current feature. This is similar to how a condition on a visualizer is evaluated. For a full description of the expression format, please see Expression Syntax. The value of the expression should be a string, which should be an SVG color specification. In this example, it will look for a 'fillcolor' attribute of the current feature, and default to "yellow" if the attribute is missing. The resulting string is then parsed as an SVG color specification.
The following SVG attributes can be overridden this way:
fill, fill-opacity, fill-rule, stroke, stroke-opacity, stroke-width, stroke-linecap , stroke-linejoin, vector-effect, font-family, font-size, font-weight, font-style , text-anchor, visibility, transform.
In addition, the text contents of a <text> element can be overridden by a carmenta:text attribute.
Even though new attributes are added, the resulting XML documents are still valid SVG documents, and can be viewed or edited in any other SVG viewer/editor.
If the fill or stroke colors are specified with currentColor or a Carmenta override attribute, the alpha value of the color will be used. Any fill-opacity, stroke-opacity or their Carmenta override attributes will be ignored.
SVG editors
If you want to create a new SVG symbol, you can write the SVG yourself in any text editor, but it's much easier to use an SVG editor. Many different SVG editors exist, both commercial and open source. One widely used SVG editor is Inkscape.
Inheritance Hierarchy
System.Object (not available in C#)
EngineObject
ResourceObject
Symbol
SvgSymbol
Platforms
Windows, Linux, Android
SvgSymbol Members
The SvgSymbol type has the following members.
Properties
| Name | Description |
|---|---|
 Brick | Gets the predefined brick fill pattern. Inherited from Symbol |
| Bullseye | Gets the predefined bullseye symbol. Inherited from Symbol |
| Burst | Gets the predefined burst symbol. Inherited from Symbol |
| CacheAsBitmap | Gets or sets a value that determines whether the symbol is cached as a bitmap. |
| Circle | Gets the predefined circle symbol. Inherited from Symbol |
| CircleCross | Gets the predefined circleCross symbol. Inherited from Symbol |
| CircleX | Gets the predefined circleX symbol. Inherited from Symbol |
| Cross | Gets the predefined cross symbol. Inherited from Symbol |
| DeciduousTree | Gets the predefined deciduousTree fill pattern. Inherited from Symbol |
| Diamond | Gets the predefined diamond symbol. Inherited from Symbol |
| Dots1 | Gets the predefined dots1 fill pattern. Inherited from Symbol |
| Dots2 | Gets the predefined dots2 fill pattern. Inherited from Symbol |
| Empty | Gets an empty symbol or fill pattern. Inherited from Symbol |
| EvergreenTree | Gets the predefined evergreenTree fill pattern. Inherited from Symbol |
| FileName | Gets the name of the file that contains the SVG document used to create the symbol. |
| Floodable | Gets the predefined floodable fill pattern. Inherited from Symbol |
| Glacier | Gets the predefined glacier fill pattern. Inherited from Symbol |
| Grassland | Gets the predefined grassland fill pattern. Inherited from Symbol |
| Grid1 | Gets the predefined grid1 fill pattern. Inherited from Symbol |
| Grid2 | Gets the predefined grid2 fill pattern. Inherited from Symbol |
| HollowCircle | Gets the predefined hollow circle symbol. Inherited from Symbol |
| HollowDiamond | Gets the predefined hollow diamond symbol. Inherited from Symbol |
| HollowRoundedSquare | Gets the predefined hollow rounded square symbol. Inherited from Symbol |
| HollowSquare | Gets the predefined hollow square symbol. Inherited from Symbol |
| HollowTriangle | Gets the predefined hollow triangle symbol. Inherited from Symbol |
| IsDisposed | Gets a value that tells whether the current SvgSymbol has been disposed. Inherited from EngineObject |
| Mangrove | Gets the predefined mangrove fill pattern. Inherited from Symbol |
| MixedTree | Gets the predefined mixedTree fill pattern. Inherited from Symbol |
| Name | Gets or sets the name of the SvgSymbol. Inherited from ResourceObject |
| NativeHandle | Gets the native Carmenta Engine kernel object the current SvgSymbol represents. Inherited from EngineObject |
| NorthArrow | Gets a predefined north arrow symbol: an arrowhead without an N label. Inherited from Symbol |
| NorthArrowN | Gets a predefined north arrow symbol: an arrowhead with an N label. Inherited from Symbol |
| OrchardPlantation | Gets the predefined orchard/plantation fill pattern. Inherited from Symbol |
| Path | Gets the path to the directory where the file containing the SVG document used to create the symbol is located. |
| Rice | Gets the predefined rice fill pattern. Inherited from Symbol |
| RoundedSquare | Gets the predefined rounded square symbol. Inherited from Symbol |
| Sand | Gets the predefined sand fill pattern. Inherited from Symbol |
| SandAndGravel | Gets the predefined sandAndGravel fill pattern. Inherited from Symbol |
| ScrubThicket | Gets the predefined scrub/thicket fill pattern. Inherited from Symbol |
| SmallDot | Gets the predefined small dot symbol. Inherited from Symbol |
| SmallPlus | Gets the predefined small plus symbol. Inherited from Symbol |
| Solid | Gets the predefined solid fill pattern. Inherited from Symbol |
| Square | Gets the predefined square symbol. Inherited from Symbol |
| Star | Gets the predefined star symbol. Inherited from Symbol |
| Stripes1 | Gets the predefined stripes1 fill pattern. Inherited from Symbol |
| Stripes10 | Gets the predefined stripes10 fill pattern. Inherited from Symbol |
| Stripes11 | Gets the predefined stripes11 fill pattern. Inherited from Symbol |
| Stripes12 | Gets the predefined stripes12 fill pattern. Inherited from Symbol |
| Stripes2 | Gets the predefined stripes2 fill pattern. Inherited from Symbol |
| Stripes3 | Gets the predefined stripes3 fill pattern. Inherited from Symbol |
| Stripes4 | Gets the predefined stripes4 fill pattern. Inherited from Symbol |
| Stripes5 | Gets the predefined stripes5 fill pattern. Inherited from Symbol |
| Stripes6 | Gets the predefined stripes6 fill pattern. Inherited from Symbol |
| Stripes7 | Gets the predefined stripes7 fill pattern. Inherited from Symbol |
| Stripes8 | Gets the predefined stripes8 fill pattern. Inherited from Symbol |
| Stripes9 | Gets the predefined stripes9 fill pattern. Inherited from Symbol |
| Svg | Gets the SVG that this symbol was created from (unless it was created from a file). |
| Swamp | Gets the predefined swamp fill pattern. Inherited from Symbol |
| Triangle | Gets the predefined triangle symbol. Inherited from Symbol |
| IUserProperties.UserProperties | Gets the AttributeSet that contains the user properties. Inherited from IUserProperties |
| VineyardHops | Gets the predefined vineyard/hops fill pattern. Inherited from Symbol |
| X | Gets the predefined x symbol. Inherited from Symbol |
Methods
| Name | Description |
|---|---|
| Clone | Creates a copy of an object. Inherited from EngineObject |
| Dispose | Releases the reference to the native Carmenta Engine kernel instance the EngineObject represents. Inherited from EngineObject |
| Equals | Determines whether this instance is equal to another. Inherited from EngineObject |
| FromFile | Creates a new instance of the SvgSymbol class from an external SVG file. |
| FromSvg | Creates a new instance of the SvgSymbol class from the supplied SVG code. |