How would I implement a handler here?

Question

Hey guys,

I've got 2 classes GLLayer and GLCamTest. I'm attempting to run a method located in GLCamTest...

        public Bitmap extractimage(int pos){
    LocationData tweets;
    tweets = new LocationData(this);
    SQLiteDatabase db = tweets.getWritableDatabase();
    //select the data
    String query = "SELECT * FROM tweets;";
    Cursor mcursor = db.rawQuery(query, null);
    //Move to Position specified.
    mcursor.moveToPosition(pos);

    //get it as a ByteArray
    byte[] imageByteArray=mcursor.getBlob(7);
    //the cursor is not needed anymore
    mcursor.close();

    //convert it back to an image
    ByteArrayInputStream imageStream = new ByteArrayInputStream(imageByteArray);
    Bitmap theImage = BitmapFactory.decodeStream(imageStream);
    return theImage;
    }

I'm looking to run in on a thread from GLLayer but from what I understand I need a Handler..

            public void run() {
    GLCamTest cam = new GLCamTest();
    image = cam.extractimage(q);

}

I'm starting the Thread from within public void onDrawFrame(GL10 gl) { my question is how would I implement said handler? I've read http://developer.android.com/reference/android/os/Handler.html but I still don't really understand how I'd implement it. could someone help me out?

Answer 1

Two things. One is that the GLThread never called Looper.prepare() therefore you can't add/create a handler inside that thread. (Should be inside the main UI thread).

Two, a handler isn't needed. If you just want to execute code inside the render thread...

GLSurfaceView mySurface = mMyCustomSurfaceIMadeEarlierWithTheRendererAlreadyAttached;
Runnable myRunnable = mMyRunnableThatIsSomewhere;
mySurface.queueEvent(myRunnable);

The runnable will be executed inside your render thread before the drawFrame method gets called on the next rendering pass.