public class Main extends Activity {

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    MyWebView webview = new MyWebView(this);
    setContentView(webview);
}

class MyWebView extends WebView {
 Context context;
 GestureDetector gd;

public MyWebView(Context context) {
super(context);

this.context = context;
     gd = new GestureDetector(context, sogl);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
return gd.onTouchEvent(event);
}

 GestureDetector.SimpleOnGestureListener sogl = new GestureDetector.SimpleOnGestureListener() {
  public boolean onDown(MotionEvent event) {
   return true;
  }
  public boolean onFling(MotionEvent event1, MotionEvent event2, float velocityX, float velocityY) {
   if (event1.getRawX() > event2.getRawX()) {
    show_toast("swipe left");
   } else {
    show_toast("swipe right");
   }
return true;
  }
 };

 void show_toast(final String text) {
  Toast t = Toast.makeText(context, text, Toast.LENGTH_SHORT);
  t.show();
 }
}
}