From c0b87a84c6220cfa7b9c411609bf140b9c5928d5 Mon Sep 17 00:00:00 2001
From: Teng-Hui Zhu <ztenghui@google.com>
Date: Wed, 16 Mar 2016 14:54:51 -0700
Subject: [PATCH] Document the cache bitmap behavior for VD

b/26454083

Change-Id: I22aeef9760aaf6bb79dca85740281cf94e19e601
---
 .../android/graphics/drawable/VectorDrawable.java     | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/graphics/java/android/graphics/drawable/VectorDrawable.java b/graphics/java/android/graphics/drawable/VectorDrawable.java
index ae98c22dd4b00..150ecbbee1235 100644
--- a/graphics/java/android/graphics/drawable/VectorDrawable.java
+++ b/graphics/java/android/graphics/drawable/VectorDrawable.java
@@ -53,8 +53,15 @@ import java.util.HashMap;
 import java.util.Stack;
 
 /**
- * This lets you create a drawable based on an XML vector graphic. It can be
- * defined in an XML file with the <code>&lt;vector></code> element.
+ * This lets you create a drawable based on an XML vector graphic.
+ * <p/>
+ * <strong>Note:</strong> To optimize for the re-drawing performance, one bitmap cache is created
+ * for each VectorDrawable. Therefore, referring to the same VectorDrawable means sharing the same
+ * bitmap cache. If these references don't agree upon on the same size, the bitmap will be recreated
+ * and redrawn every time size is changed. In other words, if a VectorDrawable is used for
+ * different sizes, it is more efficient to create multiple VectorDrawables, one for each size.
+ * <p/>
+ * VectorDrawable can be defined in an XML file with the <code>&lt;vector></code> element.
  * <p/>
  * The vector drawable has the following elements:
  * <p/>