title: stop a React rerender of parent component scrolling to top of page
body: <p>I have a text area which is a separate child component of an edit form, where the user can input long text.  Above it, in the parent form, I have a SAVE button that I want to disable until the user makes an actual change to the text.  I have it triggered now that when a change is made, it calls the parent component which triggers the SAVE button to enable (shows its color).  But my problem is that it also jumps to the top of the page when it does this.  The cursor stays where the user is inputting the text, but the scrollbar jumps.  I realize that the parent is rerendering because the button has changed, but I want the scroll to stay where it is, with the cursor visible.  How can I achieve this? </p>