问使用Numba @jit加速以下代码？

public class TextDrawable extends Drawable {

private final String text;
private final Paint paint;

public TextDrawable(String text) {
    this.text = text;
    this.paint = new Paint();
    paint.setColor(Color.BLACK);
    paint.setTextSize(16f);
    paint.setAntiAlias(true);
    paint.setTextAlign(Paint.Align.LEFT);
}

@Override
public void draw(Canvas canvas) {
    canvas.drawText(text, 0, 6, paint);
}

@Override
public void setAlpha(int alpha) {
    paint.setAlpha(alpha);
}

@Override
public void setColorFilter(ColorFilter cf) {
    paint.setColorFilter(cf);
}

@Override
public int getOpacity() {
    return PixelFormat.TRANSLUCENT;
}
}

EditText et = (EditText)findViewById(R.id.editText1);
String code = "+374";
et.setCompoundDrawablesWithIntrinsicBounds(new TextDrawable(code), null, null, null);
et.setCompoundDrawablePadding(code.length()*10);

<EditText
android:id="@+id/editText1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="16sp"
android:ems="10" >
  <requestFocus />
</EditText>

public class MainActivity extends Activity {

private EditText editText;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    editText = (EditText) findViewById(R.id.editText1);
    editText.setText("+374");
    Selection.setSelection(editText.getText(), editText.getText().length());
    editText.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {
            // TODO Auto-generated method stub

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub

        }

        @Override
        public void afterTextChanged(Editable s) {
            if (!s.toString().startsWith("+374")) {
                editText.setText("+374");
                Selection.setSelection(editText.getText(), editText
                        .getText().length());

            }

        }

    });
}

}