view flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/ZoomScale.java @ 5449:504a62887217

Datacage: Compile XPath expressions and reuse them. With the introduction of filters in dc:elements XPath expressions are evalutated very often so compiling them should reduce the overhead significantly.
author Sascha L. Teichmann <teichmann@intevation.de>
date Wed, 27 Mar 2013 10:59:55 +0100
parents e8c6fbed889b
children
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package de.intevation.flys.artifacts.model;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

import org.apache.log4j.Logger;

import de.intevation.flys.artifacts.math.Linear;


public class ZoomScale
{
    private static Logger logger = Logger.getLogger(ZoomScale.class);

    private HashMap<String, TreeMap<Double, Double>> rivers;

    public ZoomScale() {
        this.rivers = new HashMap<String, TreeMap<Double, Double>>();
    }

    public ZoomScale(String river) {
        this();
        rivers.put(river, new TreeMap<Double, Double>());
    }

    public double getRadius(String river, double lower, double upper) {
        double range = Math.abs(upper) - Math.abs(lower);
        TreeMap<Double, Double> ranges = rivers.get(river);
        if (ranges == null) {
            return 0.001;
        }
        Map.Entry<Double, Double> next = ranges.higherEntry(range);
        Map.Entry<Double, Double> prev = ranges.lowerEntry(range);
        double x0 = 0d;
        double x1 = 0d;
        double y0 = 0d;
        double y1 = 0d;
        if (prev == null && next != null) {
            x1 = next.getKey();
            y1 = next.getValue();
        }
        else if (prev != null && next == null) {
            return prev.getValue();
        }
        else {
            x0 = prev.getKey();
            x1 = next.getKey();
            y0 = prev.getValue();
            y1 = next.getValue();
        }
        return Linear.linear(range, x0, x1, y0, y1);
    }

    public void addRiver(String river) {
        if (!this.rivers.containsKey(river)) {
            this.rivers.put(river, new TreeMap<Double, Double>());
        }
    }

    public Set<String> getRivers() {
        return this.rivers.keySet();
    }

    public void addRange(String river, double range, double radius) {
        if (this.rivers.containsKey(river)) {
            this.rivers.get(river).put(range, radius);
        }
        else {
            this.rivers.put(river, new TreeMap<Double, Double>());
            this.rivers.get(river).put(range, radius);
        }
    }
}

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