/*
* This file is part of Skript.
*
* Skript is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Skript 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Skript. If not, see <http://www.gnu.org/licenses/>.
*
*
* Copyright 2011-2014 Peter Güttinger
*
*/
package ch.njol.skript.classes;
import org.eclipse.jdt.annotation.NonNullByDefault;
import org.eclipse.jdt.annotation.Nullable;
import ch.njol.skript.registrations.Converters;
/**
* used to convert data from one type to another.
*
* @param <F> the accepted type of objects to convert <u>f</u>rom
* @param <T> the type to convert <u>t</u>o
* @author Peter Güttinger
* @see Converters#registerConverter(Class, Class, Converter)
*/
public interface Converter<F, T> {
public final static int NO_LEFT_CHAINING = 1;
public final static int NO_RIGHT_CHAINING = 2;
public final static int NO_CHAINING = NO_LEFT_CHAINING | NO_RIGHT_CHAINING;
public final static int NO_COMMAND_ARGUMENTS = 4;
/**
* holds information about a converter
*
* @author Peter Güttinger
* @param <F> same as in {@link Converter}
* @param <T> dito
*/
@SuppressWarnings("null")
@NonNullByDefault
public final static class ConverterInfo<F, T> {
public final Class<F> from;
public final Class<T> to;
public final Converter<F, T> converter;
public final int options;
public ConverterInfo(final Class<F> from, final Class<T> to, final Converter<F, T> converter, final int options) {
this.from = from;
this.to = to;
this.converter = converter;
this.options = options;
}
}
/**
* Converts an object from the given to the desired type.
*
* @param f The object to convert.
* @return the converted object
*/
@Nullable
public T convert(F f);
public final static class ConverterUtils {
public final static <F, T> Converter<?, T> createInstanceofConverter(final ConverterInfo<F, T> conv) {
return createInstanceofConverter(conv.from, conv.converter);
}
public final static <F, T> Converter<?, T> createInstanceofConverter(final Class<F> from, final Converter<F, T> conv) {
return new Converter<Object, T>() {
@SuppressWarnings("unchecked")
@Override
@Nullable
public T convert(final Object o) {
if (!from.isInstance(o))
return null;
return conv.convert((F) o);
}
};
}
public final static <F, T> Converter<F, T> createInstanceofConverter(final Converter<F, ?> conv, final Class<T> to) {
return new Converter<F, T>() {
@SuppressWarnings("unchecked")
@Override
@Nullable
public T convert(final F f) {
final Object o = conv.convert(f);
if (to.isInstance(o))
return (T) o;
return null;
}
};
}
public final static <F, T> Converter<?, T> createDoubleInstanceofConverter(final ConverterInfo<F, ?> conv, final Class<T> to) {
return createDoubleInstanceofConverter(conv.from, conv.converter, to);
}
public final static <F, T> Converter<?, T> createDoubleInstanceofConverter(final Class<F> from, final Converter<F, ?> conv, final Class<T> to) {
return new Converter<Object, T>() {
@SuppressWarnings("unchecked")
@Override
@Nullable
public T convert(final Object o) {
if (!from.isInstance(o))
return null;
final Object o2 = conv.convert((F) o);
if (to.isInstance(o2))
return (T) o2;
return null;
}
};
}
}
}