1 files changed, 20 insertions, 0 deletions
diff --git a/src/com/android/launcher3/util/MultiHashMap.java b/src/com/android/launcher3/util/MultiHashMap.java
new file mode 100644
index 000000000..f54ab8840
--- /dev/null
+++ b/src/com/android/launcher3/util/MultiHashMap.java
@@ -0,0 +1,20 @@
+package com.android.launcher3.util;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+/**
+ * A utility map from keys to an ArrayList of values.
+ */
+public class MultiHashMap<K, V> extends HashMap<K, ArrayList<V>> {
+    public void addToList(K key, V value) {
+        ArrayList<V> list = get(key);
+        if (list == null) {
+            list = new ArrayList<>();
+            list.add(value);
+            put(key, list);
+        } else {
+            list.add(value);
+        }
+    }
+}