gt-dxf
DXF feature reader implementation for modern releases of GeoTools.
This library is forked from the old, unsupported gt-dxf module, and since then the libary has seen multiple features added. What is most important, the library is kept up-to-date with GeoTools developments. Currently, the library provides quite feature complete DXF read-only support in GeoTools.
Building and installing
The library uses Maven as the build system. It can simply be built and installed in the local Maven repository by issuing command:
$ mvn install
There are no tests in the code, unfortunately.
Usage
Basically the software provides a feature store factory, that can be used for reading the DXF data, along with CRS information and possible additional affine transform for the data (example in Kotlin):
import org.geotools.data.dxf.DXFDataStoreFactory
val factory = DXFDataStoreFactory()
val map = HashMap<String, Any?>()
// Source CRS
map.put(DXFDataStoreFactory.PARAM_SRS.key, "EPSG:)
// Target CRS
map.put(DXFDataStoreFactory.PARAM_TARGET_SRS.key, "EPSG:4326")
map.put(DXFDataStoreFactory.PARAM_AFFINE_TRANSFORM.key, AffineTransform())
// URL to the DXF file
map.put(DXFDataStoreFactory.PARAM_URL.key, url)
val store = factory.createDataStore(map)
val featureSource = store.getFeatureSource("")Afterwards, the layer can be added to MapContent:
content.addLayer(FeatureLayer(featureSource, createStyle(), name))All the DXF information for styling is exposed. The following code can be used for creating Style for FeatureLayer that properly displays the DXF with all the right colors and so on:
import org.geotools.data.FeatureSource
import org.geotools.data.FileDataStore
import org.geotools.data.dxf.DXFDataStoreFactory
import org.geotools.data.simple.SimpleFeatureCollection
import org.geotools.factory.CommonFactoryFinder
import org.geotools.filter.AttributeExpressionImpl
import org.geotools.map.FeatureLayer
import org.geotools.map.MapContent
import org.geotools.styling.Displacement
import org.geotools.styling.FeatureTypeStyle
import org.geotools.styling.PointPlacementImpl
import org.geotools.styling.Style
import org.geotools.styling.StyleBuilder
import org.geotools.styling.TextSymbolizer
import org.opengis.feature.simple.SimpleFeature
import org.opengis.feature.simple.SimpleFeatureType
import org.opengis.filter.expression.Expression
import org.opengis.referencing.crs.CoordinateReferenceSystem
import org.opengis.style.GraphicalSymbol
// Class definition etc.
val FILTER_FACTORY = CommonFactoryFinder.getFilterFactory(null)
val STYLE_FACTORY = CommonFactoryFinder.getStyleFactory(null)
/** Create a style and rule for point elements. */
fun createPointStyle(): FeatureTypeStyle {
val color = AttributeExpressionImpl("color")
// Create stroke with the specific color and with of 1 px
val stroke = STYLE_FACTORY.createStroke(color, FILTER_FACTORY.literal(1))
// Symbolize points with
val symbols = ArrayList<GraphicalSymbol>()
symbols.add(STYLE_FACTORY.mark(FILTER_FACTORY.literal("circle"), null, stroke))
val circle = STYLE_FACTORY.graphic(symbols, null, FILTER_FACTORY.literal(8), null, null, null)
val sym = STYLE_FACTORY.createPointSymbolizer(circle, null)
sym.unitOfMeasure = SI.METRE // Make sure the diameter is in meters
// Create rule that renders visible DXFPoint elements using the style
val rule = STYLE_FACTORY.createRule()
rule.filter = FILTER_FACTORY.and(FILTER_FACTORY.notEqual(AttributeExpressionImpl("visible"),
FILTER_FACTORY.literal(0)), FILTER_FACTORY.equals(AttributeExpressionImpl("class"),
FILTER_FACTORY.literal("DXFPoint")))
rule.symbolizers().add(sym)
return STYLE_FACTORY.createFeatureTypeStyle(arrayOf(rule))
}
/** Create a style and rule for line elements. */
protected fun createLineStyle(): FeatureTypeStyle {
val color = AttributeExpressionImpl("color")
// Create stroke with the defined color and thickness from so named attribute
val stroke = STYLE_FACTORY.createStroke(
color, AttributeExpressionImpl("thickness"))
val sym = STYLE_FACTORY.createLineSymbolizer(stroke, null)
// Render all visible line type features
val rule = STYLE_FACTORY.createRule()
rule.filter = FILTER_FACTORY.notEqual(AttributeExpressionImpl("visible"),
FILTER_FACTORY.literal(0))
rule.symbolizers().add(sym)
return STYLE_FACTORY.createFeatureTypeStyle(arrayOf(rule))
}
/** Create a style and rule for polygon elements. */
fun createPolygonStyle(): FeatureTypeStyle {
val color = AttributeExpressionImpl("color")
// Create stroke with the defined color and thickness from so named attribute
val stroke = STYLE_FACTORY.createStroke(color,
AttributeExpressionImpl("thickness"))
val sym = STYLE_FACTORY.createPolygonSymbolizer(stroke, null, null)
// Render all visible polygon type features
val rule = STYLE_FACTORY.createRule()
rule.filter = FILTER_FACTORY.notEqual(AttributeExpressionImpl("visible"),
FILTER_FACTORY.literal(0))
rule.symbolizers().add(sym)
return STYLE_FACTORY.createFeatureTypeStyle(arrayOf(rule))
}
/** Create a style and rule for text elements. */
fun createTextStyle(): FeatureTypeStyle {
val color = AttributeExpressionImpl("color")
val styleBuilder = StyleBuilder()
// Create an anchor that honors the horizontal and vertical text alignment of the element
val anchor = AnchorPoint()
anchor.anchorPointX = AttributeExpressionImpl("align1")
anchor.anchorPointY = AttributeExpressionImpl("align2")
// Construct the label placement object with right rotation
val labelPlacement = PointPlacementImpl(FILTER_FACTORY)
labelPlacement.rotation = FILTER_FACTORY.multiply(FILTER_FACTORY.literal(-1), AttributeExpressionImpl("rotation"))
labelPlacement.setAnchorPoint(anchor)
labelPlacement.setDisplacement(Displacement.DEFAULT)
// Use sans serif font and get text height (as meters) from the height attribute
val font = styleBuilder.createFont(FILTER_FACTORY.literal("SansSerif"),
FILTER_FACTORY.literal(1), FILTER_FACTORY.literal(1),
AttributeExpressionImpl("height"))
// Create fill and the actual symbolizer
val fill = STYLE_FACTORY.createFill(color)
val sym = STYLE_FACTORY.createTextSymbolizer(fill,
arrayOf(font), null, AttributeExpressionImpl("text"), labelPlacement, null)
// Finally set options so that labels can overlap and they are not moved
// from their specified locations and set units to meters
val options = sym.options
options.put(TextSymbolizer.CONFLICT_RESOLUTION_KEY, "false")
options.put(TextSymbolizer.GROUP_KEY, "false")
options.put(TextSymbolizer.AUTO_WRAP_KEY, "-1")
options.put(TextSymbolizer.GOODNESS_OF_FIT_KEY, "-1")
options.put(TextSymbolizer.MAX_DISPLACEMENT_KEY, "0")
options.put(TextSymbolizer.ALLOW_OVERRUNS_KEY, "true")
options.put(TextSymbolizer.MIN_GROUP_DISTANCE_KEY, "-1")
options.put(TextSymbolizer.SPACE_AROUND_KEY, "-1")
options.put(TextSymbolizer.LABEL_ALL_GROUP_KEY, "true")
options.put(TextSymbolizer.PARTIALS_KEY, "true")
options.put(TextSymbolizer.REMOVE_OVERLAPS_KEY, "false")
sym.unitOfMeasure = SI.METRE
// Create the rule to render visible DXFText and DXFMtext elements
val rule = STYLE_FACTORY.createRule()
rule.filter = FILTER_FACTORY.and(
FILTER_FACTORY.notEqual(AttributeExpressionImpl("visible"), FILTER_FACTORY.literal(0)),
FILTER_FACTORY.or(
FILTER_FACTORY.equals(AttributeExpressionImpl("class"), FILTER_FACTORY.literal("DXFText")),
FILTER_FACTORY.equals(AttributeExpressionImpl("class"), FILTER_FACTORY.literal("DXFMText"))
)
)
rule.symbolizers().add(sym)
return STYLE_FACTORY.createFeatureTypeStyle(arrayOf(rule))
}
/** Constructs the whole style for the layer. */
fun createStyle(): Style {
val s = STYLE_FACTORY.createStyle()
// Add other style definitions
s.featureTypeStyles().add(createPointStyle())
s.featureTypeStyles().add(createLineStyle())
s.featureTypeStyles().add(createPolygonStyle())
s.featureTypeStyles().add(createTextStyle())
return s
}