impl.org.controlsfx.table.DupeCounter Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of controlsfx Show documentation

High quality UI controls and other tools to complement the core JavaFX distribution

There is a newer version: 11.2.1

package impl.org.controlsfx.table;

import java.util.HashMap;
import java.util.Optional;

final class DupeCounter {

    private final HashMap counts = new HashMap<>();
    private final boolean enforceFloor;

    public DupeCounter(boolean enforceFloor) {
        this.enforceFloor = enforceFloor;
    }
    public int add(T value) {
        Integer prev = counts.get(value);
        int newVal;
        if (prev == null) {
            newVal = 1;
            counts.put(value, newVal);
        }  else {
            newVal = prev + 1;
            counts.put(value, newVal);
        }
        return newVal;
    }
    public int get(T value) {
        return Optional.ofNullable(counts.get(value)).orElse(0);
    }
    public int remove(T value) {
        Integer prev = counts.get(value);
        if (prev != null && prev > 0) {
            int newVal = prev - 1;
            if (newVal == 0) {
                counts.remove(value);
            } else {
                counts.put(value, newVal);
            }
            return newVal;
        }
        else if (enforceFloor) {
            throw new IllegalStateException();
        }
        else {
            return 0;
        }
    }

    @Override
    public String toString() {
        return counts.toString();
    }
}