Android Screen shots handler

Question

I have create the Handler inside the activity onCreate method. This Hanlder is responsible to take screen shots after 10 seconds. Inside the run method I have used while(flag==true) and screen the capture util flag==false, But this stuck my activity. I can not able to work. And it take the screen shot over again and again of same image because of actvity is stuck. How I can work with my screen and what I am doing handler take the screen shot after 10 seconds? The while loop stuck my app.

It Take picture but I am not able to work with my activity.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
    flag = true;


    Handler handler = new Handler();
    handler.postDelayed(new Runnable() {

        @Override
        public void run() {

            while (flag == true) {
                String SCREENSHOTS_LOCATIONS = Environment
                        .getExternalStorageDirectory().toString() + "/re/";
                // Get root view
                View view = getWindow().getDecorView().getRootView();
                // Create the bitmap to use to draw the screenshot
                final Bitmap bitmap = Bitmap.createBitmap(view.getWidth(),
                        view.getHeight(), Bitmap.Config.ARGB_8888);
                final Canvas canvas = new Canvas(bitmap);

                // Get current theme to know which background to use
                final Theme theme = getTheme();
                final TypedArray ta = theme
                        .obtainStyledAttributes(new int[] { android.R.attr.windowBackground });
                final int res = ta.getResourceId(0, 0);
                final Drawable background = getResources().getDrawable(res);

                // Draw background
                background.draw(canvas);

                // Draw views
                view.draw(canvas);
                FileOutputStream fos = null;

                try {
                    final File sddir = new File(SCREENSHOTS_LOCATIONS);
                    if (!sddir.exists()) {
                        sddir.mkdirs();
                    }

                    fos = new FileOutputStream(SCREENSHOTS_LOCATIONS + x
                            + ".jpg");
                    x++;
                    if (fos != null) {
                        if (!bitmap.compress(Bitmap.CompressFormat.JPEG,
                                90, fos)) {
                            Log.d("ScreenShot", "Compress/Write failed");
                        }
                        fos.flush();
                        fos.close();
                    }
                } catch (Exception e) {

                }
            }
        }

    }, 1000);

}

Answer 1

Maybe try using an AsyncTask or other thread. The postDelayed() function attaches to the main UI thread and locks up your app until run() is finished (which never happens because flag never equals false so the while loop becomes infinite?).

Here is an example using the ScheduledThreadPoolExecutor:

private ScheduledThreadPoolExecutor exec = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
    flag = true;

    exec = new ScheduledThreadPoolExecutor(5);
    long interval = (long) 10; // 10 seconds for you
    exec.scheduleAtFixedRate(new savePicTask(), 0, interval, TimeUnit.SECONDS);

}

class savePicTask implements Runnable {
    @Override
    public void run() {
        while (flag == true) {
            String SCREENSHOTS_LOCATIONS = Environment
                    .getExternalStorageDirectory().toString() + "/re/";
            // Get root view
            View view = getWindow().getDecorView().getRootView();
            // Create the bitmap to use to draw the screenshot
            final Bitmap bitmap = Bitmap.createBitmap(view.getWidth(),
                    view.getHeight(), Bitmap.Config.ARGB_8888);
            final Canvas canvas = new Canvas(bitmap);

            // Get current theme to know which background to use
            final Theme theme = getTheme();
            final TypedArray ta = theme
                    .obtainStyledAttributes(new int[] { android.R.attr.windowBackground });
            final int res = ta.getResourceId(0, 0);
            final Drawable background = getResources().getDrawable(res);

            // Draw background
            background.draw(canvas);

            // Draw views
            view.draw(canvas);
            FileOutputStream fos = null;

            try {
                final File sddir = new File(SCREENSHOTS_LOCATIONS);
                if (!sddir.exists()) {
                    sddir.mkdirs();
                }

                fos = new FileOutputStream(SCREENSHOTS_LOCATIONS + x
                        + ".jpg");
                x++;
                if (fos != null) {
                    if (!bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos)) {
                        Log.d("ScreenShot", "Compress/Write failed");
                    }
                    fos.flush();
                    fos.close();
                }
            } catch (Exception e) {

            }
        }
    }       
}

EDIT 1: This code works for me except I am using

numberOfSeconds = 0.5;
ScheduledThreadPoolExecutor exec = new ScheduledThreadPoolExecutor(5);
long interval = (long) (1000* numberOfSeconds); // numberOfSeconds = 10 for you
exec.scheduleAtFixedRate(new savePicTask(), 0, interval, TimeUnit.MILLISECONDS);

And instead of taking a screenshot I am taking a picture with the camera. So I'm not sure why it's not working for you.