Magnify UITableViewCell as it scrolls closer to center of screen

Question

I've been working at this for a good 48 hours now and can't seem to solve it on my own. What I'm trying to achieve is when a UITableViewCell is scrolled from the bottom to the top of the screen it starts small, magnifies as it reaches the center portion of the screen, and then begins to reduce in size again as it scrolls up and off of the screen (and vice versa, top to bottom). I can kind of get this to work, but it seems as though the contentView is resizing, the actual cell height (of the UITableView) is not.

What I want:

Scrolling up or down smoothly adjusts the size of all the uitableviewcells based on its y position on the screen.

What appears to be happening (though I'm having trouble confirming):

Again, it's as if the cell height is not being adjusted, but the height of the contentView is.

I can achieve this by overriding the layoutVisibleCells method of the UITableView:

func layoutVisibleCells() {

    let indexpaths = indexPathsForVisibleRows!
    let totalVisibleCells = indexpaths.count - 1
    if totalVisibleCells <= 0 { return }
    for index in 0...totalVisibleCells {
        let indexPath = indexpaths[index]
        if let cell = cellForRowAtIndexPath(indexPath) {
            var frame = cell.frame

            if let superView = superview {
                let point = convertPoint(frame.origin, toView:superView)
                let pointScale = point.y / CGFloat(superView.bounds.size.height)

                var height = frame.size.height + point.x;
                if height < 150.0 {
                    height = 150.0;
                }
                if height > 200.0 {
                    height = 200.0;
                }

                frame.size.height = height;

                NSLog("index %li: x: %f", index,frame.origin.x);

                NSLog("point at index %li: %f, %f - percentage: %f", index,point.x,point.y, pointScale);

            }

            cell.frame = frame
        }
    }
}

I took the idea for making the adjustment in this method from COBezierTableView, which is written in Swift. The rest of my project is in Obj-C, so deciphering things was a bit challenging, as I'm still learning my way there.

Any insight on my current attempt, or suggestions for how to achieve this in another, completely different way, are totally welcome. Thanks in advance.

UPDATE So I've actually found that the opposite is happening of what I suspected. The UITableViewCell frame IS being resized correctly. It's the cell's contentView that is not resizing fully. It does resize partially, but for some reason it does not resize to match the cell's frame. Not sure why ...

Magnify UITableViewCell as it scrolls closer to center of screen

0 Answers0