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import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.io.File;
import java.util.HashSet;
import java.util.Set;
import javax.swing.JButton;
import javax.swing.JToolBar;
import org.geotools.data.FileDataStore;
import org.geotools.data.FileDataStoreFinder;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.map.DefaultMapContext;
import org.geotools.map.MapContext;
import org.geotools.styling.FeatureTypeStyle;
import org.geotools.styling.Fill;
import org.geotools.styling.Graphic;
import org.geotools.styling.Mark;
import org.geotools.styling.Rule;
import org.geotools.styling.Stroke;
import org.geotools.styling.Style;
import org.geotools.styling.StyleFactory;
import org.geotools.styling.Symbolizer;
import org.geotools.swing.JMapFrame;
import org.geotools.swing.data.JFileDataStoreChooser;
import org.geotools.swing.event.MapMouseEvent;
import org.geotools.swing.tool.CursorTool;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.type.GeometryDescriptor;
import org.opengis.filter.Filter;
import org.opengis.filter.FilterFactory2;
import org.opengis.filter.identity.FeatureId;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.MultiLineString;
import com.vividsolutions.jts.geom.MultiPolygon;
import com.vividsolutions.jts.geom.Polygon;
/**
* In this example we create a map tool to select a feature clicked
* with the mouse. The selected feature will be painted yellow.
*
* @source $URL$
*/
public class SelectionLab {
/*
* Factories that we will use to create style and filter objects
*/
private StyleFactory sf = CommonFactoryFinder.getStyleFactory(null);
private FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2(null);
/*
* Convenient constants for the type of feature geometry in the shapefile
*/
private enum GeomType { POINT, LINE, POLYGON };
/*
* Some default style variables
*/
private static final Color LINE_COLOUR = Color.BLUE;
private static final Color FILL_COLOUR = Color.CYAN;
private static final Color SELECTED_COLOUR = Color.YELLOW;
private static final float OPACITY = 1.0f;
private static final float LINE_WIDTH = 1.0f;
private static final float POINT_SIZE = 10.0f;
private JMapFrame mapFrame;
private SimpleFeatureSource featureSource;
private String geometryAttributeName;
private GeomType geometryType;
/*
* The application method
*/
public static void main(String[] args) throws Exception {
SelectionLab me = new SelectionLab();
File file = JFileDataStoreChooser.showOpenFile("shp", null);
if (file == null) {
return;
}
me.displayShapefile(file);
}
// docs end main
// docs start display shapefile
/**
* This method connects to the shapefile; retrieves information about
* its features; creates a map frame to display the shapefile and adds
* a custom feature selection tool to the toolbar of the map frame.
*/
public void displayShapefile(File file) throws Exception {
FileDataStore store = FileDataStoreFinder.getDataStore(file);
featureSource = store.getFeatureSource();
setGeometry();
/*
* Create the JMapFrame and set it to display the shapefile's features
* with a default line and colour style
*/
MapContext map = new DefaultMapContext();
map.setTitle("Feature selection tool example");
Style style = createDefaultStyle();
map.addLayer(featureSource, style);
mapFrame = new JMapFrame(map);
mapFrame.enableToolBar(true);
mapFrame.enableStatusBar(true);
/*
* Before making the map frame visible we add a new button to its
* toolbar for our custom feature selection tool
*/
JToolBar toolBar = mapFrame.getToolBar();
JButton btn = new JButton("Select");
toolBar.addSeparator();
toolBar.add(btn);
/*
* When the user clicks the button we want to enable
* our custom feature selection tool. Since the only
* mouse action we are intersted in is 'clicked', and
* we are not creating control icons or cursors here,
* we can just create our tool as an anonymous sub-class
* of CursorTool.
*/
btn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
mapFrame.getMapPane().setCursorTool(
new CursorTool() {
@Override
public void onMouseClicked(MapMouseEvent ev) {
selectFeatures(ev);
}
});
}
});
/**
* Finally, we display the map frame. When it is closed
* this application will exit.
*/
mapFrame.setSize(600, 600);
mapFrame.setVisible(true);
}
// docs end display shapefile
// docs start select features
/**
* This method is called by our feature selection tool when
* the user has clicked on the map.
*
* @param pos map (world) coordinates of the mouse cursor
*/
void selectFeatures(MapMouseEvent ev) {
System.out.println("Mouse click at: " + ev.getMapPosition());
/*
* Construct a 5x5 pixel rectangle centred on the mouse click position
*/
Point screenPos = ev.getPoint();
Rectangle screenRect = new Rectangle(screenPos.x-2, screenPos.y-2, 5, 5);
/*
* Transform the screen rectangle into bounding box in the coordinate
* reference system of our map context. Note: we are using a naive method
* here but GeoTools also offers other, more accurate methods.
*/
AffineTransform screenToWorld = mapFrame.getMapPane().getScreenToWorldTransform();
Rectangle2D worldRect = screenToWorld.createTransformedShape(screenRect).getBounds2D();
ReferencedEnvelope bbox = new ReferencedEnvelope(
worldRect,
mapFrame.getMapContext().getCoordinateReferenceSystem());
/*
* Create a Filter to select features that intersect with
* the bounding box
*/
Filter filter = ff.intersects(ff.property(geometryAttributeName), ff.literal(bbox));
/*
* Use the filter to identify the selected features
*/
try {
SimpleFeatureCollection selectedFeatures =
featureSource.getFeatures(filter);
SimpleFeatureIterator iter = selectedFeatures.features();
Set<FeatureId> IDs = new HashSet<FeatureId>();
try {
while (iter.hasNext()) {
SimpleFeature feature = iter.next();
IDs.add(feature.getIdentifier());
System.out.println(" " + feature.getIdentifier());
}
} finally {
iter.close();
}
if (IDs.isEmpty()) {
System.out.println(" no feature selected");
}
displaySelectedFeatures(IDs);
} catch (Exception ex) {
ex.printStackTrace();
return;
}
}
// docs end select features
// docs start display selected
/**
* Sets the display to paint selected features yellow and
* unselected features in the default style.
*
* @param IDs identifiers of currently selected features
*/
public void displaySelectedFeatures(Set<FeatureId> IDs) {
Style style;
if (IDs.isEmpty()) {
style = createDefaultStyle();
} else {
style = createSelectedStyle(IDs);
}
mapFrame.getMapContext().getLayer(0).setStyle(style);
mapFrame.getMapPane().repaint();
}
// docs end display selected
// docs start default style
/**
* Create a default Style for feature display
*/
private Style createDefaultStyle() {
Rule rule = createRule(LINE_COLOUR, FILL_COLOUR);
FeatureTypeStyle fts = sf.createFeatureTypeStyle();
fts.rules().add(rule);
Style style = sf.createStyle();
style.featureTypeStyles().add(fts);
return style;
}
// docs end default style
// docs start selected style
/**
* Create a Style where features with given IDs are painted
* yellow, while others are painted with the default colors.
*/
private Style createSelectedStyle(Set<FeatureId> IDs) {
Rule selectedRule = createRule(SELECTED_COLOUR, SELECTED_COLOUR);
selectedRule.setFilter(ff.id(IDs));
Rule otherRule = createRule(LINE_COLOUR, FILL_COLOUR);
otherRule.setElseFilter(true);
FeatureTypeStyle fts = sf.createFeatureTypeStyle();
fts.rules().add(selectedRule);
fts.rules().add(otherRule);
Style style = sf.createStyle();
style.featureTypeStyles().add(fts);
return style;
}
// docs end selected style
// docs start create rule
/**
* Helper for createXXXStyle methods. Creates a new Rule containing
* a Symbolizer tailored to the geometry type of the features that
* we are displaying.
*/
private Rule createRule(Color outlineColor, Color fillColor) {
Symbolizer symbolizer = null;
Fill fill = null;
Stroke stroke = sf.createStroke(ff.literal(outlineColor), ff.literal(LINE_WIDTH));
switch (geometryType) {
case POLYGON:
fill = sf.createFill(ff.literal(fillColor), ff.literal(OPACITY));
symbolizer = sf.createPolygonSymbolizer(stroke, fill, geometryAttributeName);
break;
case LINE:
symbolizer = sf.createLineSymbolizer(stroke, geometryAttributeName);
break;
case POINT:
fill = sf.createFill(ff.literal(fillColor), ff.literal(OPACITY));
Mark mark = sf.getCircleMark();
mark.setFill(fill);
mark.setStroke(stroke);
Graphic graphic = sf.createDefaultGraphic();
graphic.graphicalSymbols().clear();
graphic.graphicalSymbols().add(mark);
graphic.setSize(ff.literal(POINT_SIZE));
symbolizer = sf.createPointSymbolizer(graphic, geometryAttributeName);
}
Rule rule = sf.createRule();
rule.symbolizers().add(symbolizer);
return rule;
}
// docs end create rule
// docs start set geometry
/**
* Retrieve information about the feature geometry
*/
private void setGeometry() {
GeometryDescriptor geomDesc = featureSource.getSchema().getGeometryDescriptor();
geometryAttributeName = geomDesc.getLocalName();
Class<?> clazz = geomDesc.getType().getBinding();
if (Polygon.class.isAssignableFrom(clazz) ||
MultiPolygon.class.isAssignableFrom(clazz)) {
geometryType = GeomType.POLYGON;
} else if (LineString.class.isAssignableFrom(clazz) ||
MultiLineString.class.isAssignableFrom(clazz)) {
geometryType = GeomType.LINE;
} else {
geometryType = GeomType.POINT;
}
}
// docs end set geometry
} |
