Question

I’m looking to implement a pointer arrow above the currently selected toolbar icon much like the design found in Reeder and Instacast:

The pointer arrow should move across smoothly when another toolbar item is pressed. I need to be able to choose which items cause the arrow to move, as featured in Instacast and Reeder, where only certain items change the arrow position.

Can I do this without too much overhead and a lot of UIKit subclassing?

Answer 1

This shouldn’t be too bad: just take an image of the little triangle like you have in your question, and put it in a UIImageView that sits above the toolbar.

Then set it up so that when the action: for the relevant toolbar button is called, the UIImageView slides so that it’s in the right place, with animation. Something like:

[UIView beginAnimations:@"TriangleAnimation" context:NULL];
[UIView setAnimationDuration:0.25];
triangleImageView.frame = //new location here
[UIView commitAnimations];