How to save drawing cache every 2 seconds?

Question

I'm developing an application that save the drawing cache as image.png. I want to save every every 2 seconds the image and then send it to my server.

public static void getImagen(){
    mView.setDrawingCacheEnabled(true);
    mView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
    mBitmap = mView.getDrawingCache();
    String path = Environment.getExternalStorageDirectory().getAbsolutePath();
    File file = new File(path+"/signature.png");
    FileOutputStream ostream;
    try {
        file.createNewFile();
        ostream = new FileOutputStream(file);
        mBitmap.compress(CompressFormat.PNG, 100, ostream);
        ostream.flush();
        ostream.close();
        Log.w("LOGCAT", "La imagen se guardo con exito");

        //Toast.makeText(getActivity(), "image saved", 5000).show();
    } catch (Exception e) {
        e.printStackTrace();
        Log.w("LOGCAT", "No se pudo guardar la imagen...");

        //Toast.makeText(getActivity(), "error", 5000).show();
    }
    // mView.setDrawingCacheEnabled(false);
}

And then I call that method here(Frament's onCreate):

t = new Thread(){
        @Override
        public void run() {
            super.run();
            while(flag){

                Log.w("THREAD_LOG", "guardar");
                try {
                    getImagen();
                    sleep(2000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                    Log.w("THREAD_LOG", "Error: "+e.toString());
                }

            }
        }
    };

    t.start();

And I got a null pointer exception at this line mView.setDrawingCacheEnabled(true);

My code of fragment view is the next:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    v = inflater.inflate(R.layout.fragment_b, container, false);
    referencias();


    return v;
}

score 0 · Answer 1 · answered Jul 07 '14 at 15:55

0

You can get the decor view and save it instead of having to use your own view. Also drawing cache can be inconsistent at times, you should just use draw instead (since its every 2 seconds, the performance difference might be very small).

You can get the rootview using:

ViewGroup mRootView = (ViewGroup) activity.getWindow().getDecorView();

You can then getDrawingCache, and use Bitmap.Compress on it.

answered Jul 07 '14 at 15:55

Hiemanshu Sharma

7,702
1
16
13

I've got the same error but now with ViewGroup mRootView = (ViewGroup) activity.getWindow().getDecorView(); – user3773342 Jul 07 '14 at 16:15
Where is this code running? Is it running inside an activity after the setContentView? – Hiemanshu Sharma Jul 07 '14 at 16:56

How to save drawing cache every 2 seconds?

1 Answers1