myActionBar.setIcon(new ColorDrawable(Color.TRANSPARENT));


private void centerActionBarTitle()
    {

        int titleId = 0;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
        {
            titleId = getResources().getIdentifier("action_bar_title", "id", "android");
        }
        else
        {
            // This is the id is from your app's generated R class when ActionBarActivity is used 
            // for SupportActionBar
            titleId = R.id.action_bar_title;
        }

        // Final check for non-zero invalid id
        if (titleId > 0)
        {
            TextView titleTextView = (TextView) findViewById(titleId);

            DisplayMetrics metrics = getResources().getDisplayMetrics();

            // Fetch layout parameters of titleTextView (LinearLayout.LayoutParams : Info from HierarchyViewer)
            LinearLayout.LayoutParams txvPars = (LayoutParams) titleTextView.getLayoutParams();
            txvPars.gravity = Gravity.CENTER_HORIZONTAL;
            txvPars.width = metrics.widthPixels;
            titleTextView.setLayoutParams(txvPars);

            titleTextView.setGravity(Gravity.CENTER);
        }
    }