Dear Pooja,
With Pen you intend the ink button? it's unrelated to the form editing.
For ink button:
This is the default behavior, a button click is needed to confirm the action.
If you need to confirm on the
ACTION_UP event for example, you can edit
PDFLayoutView.onTouchInk as:
case MotionEvent.ACTION_CANCEL:
m_ink.OnUp(event.getX(), event.getY());
PDFSetInk(1);
break;
Note, you will need also to enable/disable other buttons as done currently in
PDFViewController.onClick