/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2011, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.swing.tool;
import java.awt.Rectangle;
import java.lang.ref.WeakReference;
import org.geotools.coverage.grid.GridCoverage2D;
import org.geotools.coverage.grid.GridEnvelope2D;
import org.geotools.coverage.grid.GridGeometry2D;
import org.geotools.coverage.grid.io.AbstractGridFormat;
import org.geotools.coverage.grid.io.GridCoverage2DReader;
import org.geotools.geometry.DirectPosition2D;
import org.geotools.map.GridReaderLayer;
import org.geotools.map.Layer;
import org.geotools.parameter.Parameter;
import org.geotools.resources.geometry.XRectangle2D;
import org.opengis.coverage.PointOutsideCoverageException;
import org.opengis.coverage.grid.GridEnvelope;
import org.opengis.geometry.DirectPosition;
import org.opengis.parameter.GeneralParameterValue;
import org.opengis.referencing.datum.PixelInCell;
import org.opengis.referencing.operation.MathTransform;
/**
* Helper class used by {@linkplain InfoTool} to query values in a
* {@linkplain org.geotools.map.GridReaderLayer}.
*
* @author Michael Bedward
* @since 8.0
*
* @source $URL$
* @version $URL$
*/
public class GridReaderLayerHelper extends InfoToolHelper {
private static final int CACHED_RASTER_WIDTH = 20;
private WeakReference<GridCoverage2DReader> sourceRef;
private GridCoverage2D cachedCoverage;
public GridReaderLayerHelper() {
}
@Override
public boolean isSupportedLayer(Layer layer) {
return (layer instanceof GridReaderLayer);
}
@Override
public void setLayer(Layer layer) {
if (!(layer instanceof GridReaderLayer)) {
throw new IllegalArgumentException("layer must be an instance of GridReaderLayer");
}
super.setLayer(layer);
sourceRef = new WeakReference<GridCoverage2DReader>(
((GridReaderLayer) layer).getReader());
}
@Override
public boolean isValid() {
return super.isValid() && sourceRef != null && sourceRef.get() != null;
}
@Override
public InfoToolResult getInfo(DirectPosition2D pos) throws Exception {
InfoToolResult result = new InfoToolResult();
if (isValid()) {
DirectPosition trPos =
InfoToolHelperUtils.getTransformed(pos, getContentToLayerTransform());
if (cachedCoverage == null || !cachedCoverage.getEnvelope2D().contains(trPos)) {
if (!renewCachedCoverage(trPos)) {
return result;
}
}
try {
Object objArray = cachedCoverage.evaluate(trPos);
Number[] bandValues = InfoToolHelperUtils.asNumberArray(objArray);
if (bandValues != null) {
result.newFeature("Raw values");
for (int i = 0; i < bandValues.length; i++) {
result.setFeatureValue("Band " + i, bandValues[i]);
}
}
} catch (PointOutsideCoverageException e) {
// The empty result will be returned
}
}
return result;
}
private boolean renewCachedCoverage(DirectPosition centrePos) {
final Rectangle queryRect = createQueryGridEnvelope(centrePos);
if (queryRect.isEmpty()) {
return false;
}
final GridCoverage2DReader reader = sourceRef.get();
GeneralParameterValue parameter = new Parameter(
AbstractGridFormat.READ_GRIDGEOMETRY2D,
new GridGeometry2D(new GridEnvelope2D(queryRect),
reader.getOriginalGridToWorld(PixelInCell.CELL_CENTER),
reader.getCoordinateReferenceSystem()));
try {
cachedCoverage = (GridCoverage2D) reader.read(new GeneralParameterValue[]{parameter});
return cachedCoverage != null;
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
private Rectangle createQueryGridEnvelope(DirectPosition pos) {
final GridCoverage2DReader reader = sourceRef.get();
try {
MathTransform worldToGridTransform =
reader.getOriginalGridToWorld(PixelInCell.CELL_CORNER).inverse();
DirectPosition midPos = worldToGridTransform.transform(pos, null);
int x = (int) midPos.getOrdinate(0);
int y = (int) midPos.getOrdinate(1);
int halfWidth = CACHED_RASTER_WIDTH / 2;
final Rectangle queryRect = new Rectangle(
x - halfWidth, y - halfWidth,
CACHED_RASTER_WIDTH, CACHED_RASTER_WIDTH);
GridEnvelope gridEnv = reader.getOriginalGridRange();
Rectangle rect = new Rectangle(
gridEnv.getLow(0), gridEnv.getLow(1),
gridEnv.getSpan(0), gridEnv.getSpan(1));
XRectangle2D.intersect(queryRect, rect, queryRect);
return queryRect;
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
}