ADT/Layoutlib: New API to let the caller instantiate the bitmap.

This allows us to use a bitmap more compatible with SWT.

In ADT's case, because the bitmap needs to be converted to SWT
before being displayed, we create a BufferedImage using a byte[]
instead of a int[] so that we can simply do an array copy.

Also, we reuse the generated BufferedImage unless the size changed,
which lets us see less GC during animation playback.

Change-Id: I0062a4f4442ff6469cf0ad4f501c1fbe8c719400

2 files changed, 52 insertions, 0 deletions

diff --git a/layoutlib_api/src/com/android/layoutlib/api/IImageFactory.java b/layoutlib_api/src/com/android/layoutlib/api/IImageFactory.java
new file mode 100644
index 0000000..626423e
--- /dev/null
+++ b/layoutlib_api/src/com/android/layoutlib/api/IImageFactory.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.layoutlib.api;
+
+import java.awt.image.BufferedImage;
+
+/**
+ * Image Factory Interface.
+ *
+ * An Image factory's task is to create the {@link BufferedImage} into which the scene will be
+ * rendered. The goal is to let the layoutlib caller create an image that's optimized for its use
+ * case.
+ *
+ * If no factory is passed in {@link SceneParams#setImageFactory(IImageFactory)}, then a default
+ * {@link BufferedImage} of type {@link BufferedImage#TYPE_INT_ARGB} is created.
+ *
+ */
+public interface IImageFactory {
+
+    /**
+     * Creates a buffered image with the given size
+     * @param width the width of the image
+     * @param height the height of the image
+     * @return a new (or reused) BufferedImage of the given size.
+     */
+    BufferedImage getImage(int width, int height);
+}
diff --git a/layoutlib_api/src/com/android/layoutlib/api/SceneParams.java b/layoutlib_api/src/com/android/layoutlib/api/SceneParams.java
index 0eb9768..1bbd96a 100644
--- a/layoutlib_api/src/com/android/layoutlib/api/SceneParams.java
+++ b/layoutlib_api/src/com/android/layoutlib/api/SceneParams.java
@@ -64,6 +64,8 @@ public class SceneParams {
     private int mCustomBackgroundColor;
     private long mTimeout;
 
+    private IImageFactory mImageFactory = null;
+
     /**
      *
      * @param layoutDescription the {@link IXmlPullParser} letting the LayoutLib Bridge visit the
@@ -136,6 +138,7 @@ public class SceneParams {
         mCustomBackgroundEnabled = params.mCustomBackgroundEnabled;
         mCustomBackgroundColor = params.mCustomBackgroundColor;
         mTimeout = params.mTimeout;
+        mImageFactory = params.mImageFactory;
     }
 
     public void setCustomBackgroundColor(int color) {
@@ -147,6 +150,10 @@ public class SceneParams {
         mTimeout = timeout;
     }
 
+    public void setImageFactory(IImageFactory imageFactory) {
+        mImageFactory = imageFactory;
+    }
+
     public IXmlPullParser getLayoutDescription() {
         return mLayoutDescription;
     }
@@ -214,4 +221,8 @@ public class SceneParams {
     public long getTimeout() {
         return mTimeout;
     }
+
+    public IImageFactory getImageFactory() {
+        return mImageFactory;
+    }
 }