/*
* Geotoolkit - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2010, Geomatys
*
* 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.geotoolkit.display2d.style;
import java.util.ArrayList;
import java.util.Collection;
import org.geotoolkit.display2d.GO2Utilities;
import org.geotoolkit.style.StyleConstants;
import org.opengis.filter.expression.Expression;
import org.opengis.style.Displacement;
/**
*
* @author Johann Sorel (Geomatys)
* @module
*/
public abstract class CachedDisplacement{
protected final Displacement styleElement;
private final Collection<String> attributs;
private CachedDisplacement(final Displacement anchor, final Collection<String> attributs) {
this.styleElement = anchor;
this.attributs = attributs;
}
/**
* @return the original object
*/
public Displacement getSource(){
return styleElement;
}
public boolean isStatic(){
return attributs.isEmpty();
}
/**
* Returns the list of attributs requiered by this style.
* This can be used to help caching a light version of the feature.
*
* @return Collection<String> : all requiered feature attributs name
*/
public Collection<String> getRequieredAttributsName(final Collection<String> buffer){
if(buffer == null){
return attributs;
}else{
buffer.addAll(attributs);
return buffer;
}
}
public abstract float[] getValues(Object candidate, float[] buffer);
public static CachedDisplacement cache(final Displacement anchor){
float cachedX = Float.NaN;
float cachedY = Float.NaN;
final Collection<String> attributs;
if(anchor != null){
attributs = new ArrayList<String>();
final Expression expX = anchor.getDisplacementX();
final Expression expY = anchor.getDisplacementY();
if(GO2Utilities.isStatic(expX)){
cachedX = GO2Utilities.evaluate(expX, null, Float.class, 0.5f);
}else{
GO2Utilities.getRequieredAttributsName(expX,attributs);
}
if(GO2Utilities.isStatic(expY)){
cachedY = GO2Utilities.evaluate(expY, null, Float.class, 0.5f);
}else{
GO2Utilities.getRequieredAttributsName(expY,attributs);
}
}else{
attributs = Cache.EMPTY_ATTRIBUTS;
//we can cache X and Y with default values
cachedX = StyleConstants.DEFAULT_DISPLACEMENT_Xf;
cachedY = StyleConstants.DEFAULT_DISPLACEMENT_Yf;
}
if(attributs.isEmpty()){
return new StaticDisplacement(anchor, cachedX, cachedY);
}else{
return new DynamicDisplacement(anchor, cachedX, cachedY,attributs);
}
}
/**
*
* @param candidate
* @param coeff
* @return maximum displacement value along x and y.
*/
public abstract float getMargin(Object candidate, float coeff);
private static final class StaticDisplacement extends CachedDisplacement{
private final float cachedX;
private final float cachedY;
public StaticDisplacement(final Displacement anchor, final float cachedX, final float cachedY) {
super(anchor,Cache.EMPTY_ATTRIBUTS);
this.cachedX = cachedX;
this.cachedY = cachedY;
}
@Override
public float[] getValues(final Object candidate, final float[] buffer){
if(buffer == null){
return new float[]{cachedX,cachedY};
}else{
buffer[0] = cachedX;
buffer[1] = cachedY;
return buffer;
}
}
@Override
public float getMargin(Object candidate, float coeff) {
return Math.max(cachedX, cachedY);
}
}
private static final class DynamicDisplacement extends CachedDisplacement{
private final float cachedX;
private final float cachedY;
public DynamicDisplacement(final Displacement anchor, final float cachedX, final float cachedY, final Collection<String> attributs) {
super(anchor,attributs);
this.cachedX = cachedX;
this.cachedY = cachedY;
}
@Override
public float[] getValues(final Object candidate, float[] buffer){
if(buffer == null){
buffer = new float[2];
}
buffer[0] = evalX(candidate);
buffer[1] = evalY(candidate);
return buffer;
}
private float evalX(Object candidate){
if(Float.isNaN(cachedX)){
//if value is NaN it means it is dynamic
final Expression anchorX = styleElement.getDisplacementX();
return GO2Utilities.evaluate(anchorX, candidate, Float.class, StyleConstants.DEFAULT_DISPLACEMENT_Xf);
} else {
return cachedX;
}
}
private float evalY(Object candidate){
if(Float.isNaN(cachedY)){
//if Y is null it means it is dynamic
final Expression anchorY = styleElement.getDisplacementY();
return GO2Utilities.evaluate(anchorY, candidate, Float.class, StyleConstants.DEFAULT_DISPLACEMENT_Yf);
} else {
return cachedY;
}
}
@Override
public float getMargin(Object candidate, float coeff) {
if(candidate==null) return Float.NaN;
return Math.max(evalX(candidate), evalY(candidate));
}
}
}