Add the SurfaceTexture java class.

This class exposes to Java the application-side interface to the
SurfaceTexture C++ class.

Change-Id: I0dba42aad90257c7adbde6fa362658c0717b70d0

1 files changed, 90 insertions, 0 deletions

diff --git a/graphics/java/android/graphics/SurfaceTexture.java b/graphics/java/android/graphics/SurfaceTexture.java
new file mode 100644
index 0000000..883c4eb
--- /dev/null
+++ b/graphics/java/android/graphics/SurfaceTexture.java
@@ -0,0 +1,90 @@
+/*
+ * 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 android.graphics;
+
+/**
+ * Captures frames from an image stream as an OpenGL ES texture.
+ *
+ * <p>The image stream may come from either video playback or camera preview.  A SurfaceTexture may
+ * be used in place of a SurfaceHolder when specifying the output destination of a MediaPlayer or
+ * Camera object.  This will cause all the frames from that image stream to be sent to the
+ * SurfaceTexture object rather than to the device's display.  When {@link #updateTexImage} is
+ * called, the contents of the texture object specified when the SurfaceTexture was created is
+ * updated to contain the most recent image from the image stream.  This may cause some frames of
+ * the stream to be skipped.
+ *
+ * <p>The texture object uses the GL_TEXTURE_EXTERNAL_OES texture target, which is defined by the
+ * OES_EGL_image_external OpenGL ES extension.  This limits how the texture may be used.
+ */
+public class SurfaceTexture {
+
+    @SuppressWarnings("unused")
+    private int mSurfaceTexture;
+
+    /**
+     * Callback interface for being notified that a new stream frame is available.
+     */
+    public interface OnFrameAvailableListener {
+        void onFrameAvailable(SurfaceTexture surfaceTexture);
+    }
+
+    /**
+     * Exception thrown when a surface couldn't be created or resized
+     */
+    public static class OutOfResourcesException extends Exception {
+        public OutOfResourcesException() {
+        }
+        public OutOfResourcesException(String name) {
+            super(name);
+        }
+    }
+
+    /**
+     * Construct a new SurfaceTexture to stream images to a given OpenGL texture.
+     *
+     * @param texName the OpenGL texture object name (e.g. generated via glGenTextures)
+     */
+    public SurfaceTexture(int texName) {
+        init(texName);
+    }
+
+    /**
+     * Register a callback to be invoked when a new image frame becomes available to the
+     * SurfaceTexture.  Note that this callback may be called on an arbitrary thread, so it is not
+     * safe to call {@link #updateTexImage} without first binding the OpenGL ES context to the
+     * thread invoking the callback.
+     */
+    public void setOnFrameAvailableListener(OnFrameAvailableListener l) {
+        // TODO: Implement this!
+    }
+
+    /**
+     * Update the texture image to the most recent frame from the image stream.  This may only be
+     * called while the OpenGL ES context that owns the texture is bound to the thread.  It will
+     * implicitly bind its texture to the GL_TEXTURE_EXTERNAL_OES texture target.
+     */
+    public native void updateTexImage();
+
+    private native void init(int texName);
+
+    /*
+     * We use a class initializer to allow the native code to cache some
+     * field offsets.
+     */
+    private static native void nativeClassInit();
+    static { nativeClassInit(); }
+}