feat(base.collection): methods for inserting an element at specified …

…position in list

[skip ci]

src/main/java/org/auioc/mcmod/arnicalib/base/collection/ListUtils.java

@@ -12,6 +12,7 @@ public static <T> T getLast(List<T> list) {
         return list.get(list.size() - 1);
     }
 
+
     public static <T> int indexOf(List<T> list, Predicate<T> predicate, int ordinal) {
         for (int i = 0, l = list.size(); i < l; ++i) {
             if (predicate.test(list.get(i))) {
@@ -47,4 +48,22 @@ public <T> int[] allIndexesOf(List<T> list, Predicate<T> predicate) {
             .toArray();
     }
 
+
+    public static <T> boolean add(List<T> list, int index, T element) {
+        try {
+            list.add(index, element);
+            return true;
+        } catch (IndexOutOfBoundsException e) {
+            return false;
+        }
+    }
+
+    public static <T> boolean addBefore(List<T> list, Predicate<T> refPredicate, T element) {
+        return add(list, indexOf(list, refPredicate), element);
+    }
+
+    public static <T> boolean addAfter(List<T> list, Predicate<T> refPredicate, T element) {
+        return add(list, indexOf(list, refPredicate) + 1, element);
+    }
+
 }