Add DefaultList

A DefaultList is a list that returns a given default value for OOB
indexes, instead of an exception

1 files changed, 80 insertions, 0 deletions

diff --git a/base/src/main/java/bjc/utils/esodata/DefaultList.java b/base/src/main/java/bjc/utils/esodata/DefaultList.java
new file mode 100644
index 0000000..235a1a8
--- /dev/null
+++ b/base/src/main/java/bjc/utils/esodata/DefaultList.java
@@ -0,0 +1,80 @@
+package bjc.utils.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
+ */
+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;
+
+	public DefaultList() {
+		this(new ArrayList<>(), null);
+	}
+
+	public DefaultList(ValueType defVal) {
+		this(new ArrayList<>(), defVal);
+	}
+
+	public DefaultList(List<ValueType> backer) {
+		this(backer, null);
+	}
+
+	public DefaultList(List<ValueType> backer, ValueType defVal) {
+		this.defVal = defVal;
+
+		this.backing = backer;
+	}
+
+	public ValueType getDefault() {
+		return defVal;
+	}
+
+	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);
+	}
+}