NSTableView scrollRowToVisible with animation

Question

I am trying to implement an action to scroll to the top of a NSTableView, and the bottom of the NSTableView. I am using scrollRowToVisible but I'd love the action to be animated. Is there a way to do this?

Answer 1

While the NSTableView does not have a scroll property you can directly animate, you can instead, with a bit of math animate the scrolling of the NSClipView that the NSTableView lives in.

Here is how I did this (within a custom subclass of NSTableView) to smoothly animate the row at rowIndex to be scrolled to the center of the view, if possible:

        NSRect rowRect = [self rectOfRow:rowIndex];
        NSRect viewRect = [[self superview] frame];
        NSPoint scrollOrigin = rowRect.origin;
        scrollOrigin.y = scrollOrigin.y + (rowRect.size.height - viewRect.size.height) / 2;
        if (scrollOrigin.y < 0) scrollOrigin.y = 0;
        [[[self superview] animator] setBoundsOrigin:scrollOrigin];

Answer 2

If you're targeting 10.8+ and your table view is layer backed, you can do this:

[NSAnimationContext runAnimationGroup:^(NSAnimationContext *context){
    context.allowsImplicitAnimation = YES;
    [self.tableView scrollRowToVisible:someRow];
} completionHandler:NULL];

Answer 3

It does not seem to be possible. NSTableView has not supported any kind of animations up to 10.6. Starting from MasOSX10.7 some simple animations added to the class. You can animate inserting, removing and moving rows to new positions. This is it so far.

Answer 4

There's no easy way, but I would approach it by subclassing NSAnimation, and as it progresses from 0.0 to 1.0, multiply that by the total scroll distance to get your offset, and successively call scrollToPoint: to give the appearance of a smooth scrolling action. It should work in theory, though I'm not sure how well the scrollview would cooperate.