TextureView: add setSurfaceTexture method

This change adds support for transferring control of a TextureView's
SurfaceTexture between the UI framework and the application.  It makes the
TextureView detach the SurfaceTexture from the UI framework's GLES context
before calling the surfaceTextureDestroyed callback, allowing the app to use
the SurfaceTexture in its own GLES context if it so chooses.  This change also
adds the TextureView#setSurfaceTexture method, allowing an app have the
TextureView use a SurfaceTexture that already exists rather than creating a new
one.

Change-Id: Iac9cc917687e4239dd1c24eae553709aa37512da

1 files changed, 45 insertions, 3 deletions

diff --git a/core/java/android/view/TextureView.java b/core/java/android/view/TextureView.java
index 83999a1c3a79..3cd8b715b669 100644
--- a/core/java/android/view/TextureView.java
+++ b/core/java/android/view/TextureView.java
@@ -115,6 +115,7 @@ public class TextureView extends View {
 
     private final Object[] mLock = new Object[0];
     private boolean mUpdateLayer;
+    private boolean mUpdateSurface;
 
     private SurfaceTexture.OnFrameAvailableListener mUpdateListener;
 
@@ -208,6 +209,8 @@ public class TextureView extends View {
 
     private void destroySurface() {
         if (mLayer != null) {
+            mSurface.detachFromGLContext();
+
             boolean shouldRelease = true;
             if (mListener != null) {
                 shouldRelease = mListener.onSurfaceTextureDestroyed(mSurface);
@@ -322,9 +325,13 @@ public class TextureView extends View {
             }
 
             mLayer = mAttachInfo.mHardwareRenderer.createHardwareLayer(mOpaque);
-            mSurface = mAttachInfo.mHardwareRenderer.createSurfaceTexture(mLayer);
+            if (!mUpdateSurface) {
+                // We already have a SurfaceTexture to use, and we will pass it
+                // to mLayer below.
+                mSurface = mAttachInfo.mHardwareRenderer.createSurfaceTexture(mLayer);
+            }
             nSetDefaultBufferSize(mSurface, getWidth(), getHeight());
-            nCreateNativeWindow(mSurface);            
+            nCreateNativeWindow(mSurface);
 
             mUpdateListener = new SurfaceTexture.OnFrameAvailableListener() {
                 @Override
@@ -344,6 +351,15 @@ public class TextureView extends View {
             }
         }
 
+        if (mUpdateSurface) {
+            // Someone has requested that we use a specific SurfaceTexture, so
+            // tell mLayer about it and set the SurfaceTexture to use the
+            // current view size.
+            mUpdateSurface = false;
+            mAttachInfo.mHardwareRenderer.setSurfaceTexture(mLayer, mSurface);
+            nSetDefaultBufferSize(mSurface, getWidth(), getHeight());
+        }
+
         applyUpdate();
         applyTransformMatrix();
 
@@ -371,7 +387,7 @@ public class TextureView extends View {
         mUpdateLayer = true;
         invalidate();
     }
-    
+
     private void applyUpdate() {
         if (mLayer == null) {
             return;
@@ -636,6 +652,32 @@ public class TextureView extends View {
     }
 
     /**
+     * Set the {@link SurfaceTexture} for this view to use. If a {@link
+     * SurfaceTexture} is already being used by this view, it is immediately
+     * released and not be usable any more.  The {@link
+     * SurfaceTextureListener#onSurfaceTextureDestroyed} callback is <b>not</b>
+     * called.
+     *
+     * The {@link SurfaceTexture} object must be detached from all OpenGL ES
+     * contexts prior to calling this method.
+     *
+     * @param surfaceTexture The {@link SurfaceTexture} that the view should use.
+     * @see SurfaceTexture#detachFromGLContext()
+     * @hide
+     */
+    public void setSurfaceTexture(SurfaceTexture surfaceTexture) {
+        if (surfaceTexture == null) {
+            throw new NullPointerException("surfaceTexture must not be null");
+        }
+        if (mSurface != null) {
+            mSurface.release();
+        }
+        mSurface = surfaceTexture;
+        mUpdateSurface = true;
+        invalidateParentIfNeeded();
+    }
+
+    /**
      * Returns the {@link SurfaceTextureListener} currently associated with this
      * texture view.
      *