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/*
* esodata - data structures and other things, of varying utility
* Copyright 2022, Ben Culkin
*
* This program 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.
*
* This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
*/
package bjc.esodata;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.List;
/**
* A list that has a default value that out-of-bounds accesses return.
*
* @author Ben Culkin
* @param <ValueType>
* The type of the values contained in the list.
*/
public class DefaultList<ValueType> extends AbstractList<ValueType> {
/*
* @NOTE 9/17/18
*
* A possible feature to add would be the ability to set a 'default index', so
* that the default value is 'whatever is at that list index'
*
* Of course, this would cause an exception if that index was out of bounds, but
* what are you going to do?
*/
private ValueType defVal;
private List<ValueType> backing;
/**
* Create a new DefaultList.
*/
public DefaultList() {
this(new ArrayList<>(), null);
}
/**
* Create a new DefaultList, with a set default value.
*
* @param defVal
* The default value for the list.
*/
public DefaultList(ValueType defVal) {
this(new ArrayList<>(), defVal);
}
/**
* Create a new DefaultList, with a specific backing list.
*
* @param backer
* The backing list to use.
*
*/
public DefaultList(List<ValueType> backer) {
this(backer, null);
}
/**
* Create a new DefaultList, with a set default value.
*
* @param backer
* The backing list to use.
*
* @param defVal
* The default value for the list.
*/
public DefaultList(List<ValueType> backer, ValueType defVal) {
this.defVal = defVal;
this.backing = backer;
}
/**
* Get the default value.
*
* @return The default value.
*/
public ValueType getDefault() {
return defVal;
}
/**
* Set the default value.
*
* @param defVal
* The default value.
*/
public void setDefault(ValueType defVal) {
this.defVal = defVal;
}
@Override
public ValueType get(int idx) {
if (idx < 0 || idx >= backing.size()) return defVal;
return backing.get(idx);
}
@Override
public int size() {
return backing.size();
}
@Override
public ValueType set(int idx, ValueType val) {
return backing.set(idx, val);
}
@Override
public void add(int idx, ValueType val) {
backing.add(idx, val);
}
@Override
public ValueType remove(int idx) {
return backing.remove(idx);
}
}
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