Use ArrayMap instead of HashMap in transitions

The new ArrayMap class is more efficient for small collections.
Transitions use maps all over the place to collect/use property
values in setting up the transition animations. Changing to ArrayMap
should be more efficient, especially in terms of memory allocations
and GCs.

Issue #9276256 Transitions: Reduce memory allocations

Change-Id: I07b7d4ba68d5a207808eca11943aa3578fa90e3e

1 files changed, 10 insertions, 0 deletions

diff --git a/core/java/android/util/ArrayMap.java b/core/java/android/util/ArrayMap.java
index 6da7546..edda779 100644
--- a/core/java/android/util/ArrayMap.java
+++ b/core/java/android/util/ArrayMap.java
@@ -206,6 +206,16 @@ public final class ArrayMap<K, V> implements Map<K, V> {
         }
         mSize = 0;
     }
+    /**
+     * Create a new ArrayMap with the mappings from the given ArrayMap.
+     */
+    public ArrayMap(ArrayMap map) {
+        this();
+        if (map != null) {
+            putAll(map);
+        }
+    }
+
 
     /**
      * Make the array map empty.  All storage is released.