Notification of WebView's selection change

Question

I'm attempting to implement a feature where a user can select some text in a WebView and, after releasing the mouse button, a small window will pop up to allow the user to perform some operations on the selected text.

However, I'm running into some trouble with determining when the user's selection has been "confirmed", for lack of a better word, by releasing the mouse button. The WebEditingDelegate informal protocol defines a -webViewDidChangeSelection: method, but it's called every time the selection changes at all. So, for example, if the user drags across an entire line, -webViewDidChangeSelection: is called many times – once for each time the selected range changes. Obviously, this wont work, since I'd be popping up my window several times over the course of the drag.

Does anyone know of a way to accomplish what I need?

Answer 1

You could use that same method, but just test for whether the mouse is down, if so, do nothing, if the mouse is not down, assume it was just released and then show your window.

Answer 2

I think your focus on the "mouse up" as an end event might be too narrow. For instance, what happens when the user clicks and then selects text with shift-arrow keys? Shouldn't your software have the same effect in this case?

What littleknown suggested sounds reasonable for the mouse part of the equation, but I'm concerned that when the selection is changing from the mouse, you may never get a final "selection changed" when the mouse is up.

So, I would probably approach this problem with a pure NSTimer delay. every time you get a "selection changed" from the web view, reset your NSTimer. When it reaches some short elapsed time, like 0.5 seconds say, put up and/or move your window.

You could fine tune this by inspecting, at timer expiration, criteria such as whether the mouse is still down. If the mouse is down, you might just postpone the timer a little while and see if the mouse has been lifted after another half-second or so.