Re: NSScroller
Re: NSScroller
- Subject: Re: NSScroller
- From: Graham Cox <email@hidden>
- Date: Fri, 8 Jan 2010 15:33:56 +1100
On 08/01/2010, at 3:21 PM, David Blanton wrote:
> I wan to send to my model code that the user scrolled the view and I want to know by how much.
>
> So, I thought I would implement trackKnob but I don't know how ....
To get the scroll position of the scrolled view is much more useful than getting the scroller's current value. [[aView scrollView] documentVisibleRect] will return a rect whose origin will be the scroll position. <aView> is any view (if it's not within a scrollview, you'll just get an empty rect).
However, I'm still wondering what business the document has knowing this. Scrolled views should work automatically and there is no reason to track scroll position. When a view is asked to draw, its dirty rects indicate what parts need drawing - by drawing only those parts you will automatically be drawing efficiently as new parts of the view are scrolled on screen. That's about the only scenario I can think of where it might matter, and it's already taken care of.
So, what are you REALLY trying to do?
--Graham
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden