Why is my UIView's frame changing unexpectedly after the embedded UITableView is interacted with?

Question

Consider the following UIView "MainView":

The view includes a Container View which in turn houses a UITableView controller. The container view's y coordinate starts just beneath the gradient bar. The UITableView includes the section footer at very bottom with the 'STU' label and 'chart' button.

When the UIView loads, and up-to-and-until any interaction with the tableView, MainView's dimensions are:

Frame: 0.000000x, 0.000000y, 568.000000w, 268.000000h

I have a delegate protocol set up such that tapping the chart button in the tableView will create a new view in MainView for a shadow effect via a method performing:

CGRect newFrame = self.view.frame; // self = MainView
newFrame.size.width = 100;
newFrame.size.height = 50;
UIView *backgroundShadowView = [[UIView alloc] initWithFrame:newFrame];
backgroundShadowView.backgroundColor = [UIColor blackColor];
// Do Animation

The important part above is the 'newFrame' CGRect. For some reason after interacting with the table view by tapping the chart button, or even scrolling or tapping a row, self.view.frame suddenly has the following dimensions:

Frame: 0.000000x, 52.000000y, 568.000000w, 268.000000h

And so the shadow view appears as follows, with a y origin much farther down than where it would be expected to start, just above the gradient bar.

I've adjusted the width and height of the "shadowview" for this question; normally it would be 568x268, but would extend 52 units off screen on the bottom because of this issue.

52 units is exactly the height of the statusbar (20) + navigationbar_in_landscape (32).

Of course I could manually adjust the frame dimensions, but I do not want to. I want to know why the view's frame is changing unexpectedly.

For the life of me, I cannot figure out why the view becomes suddenly offset. Any help is appreciated!!

Answer 1

Two comments.

(1)

This code was probably always wrong:

CGRect newFrame = self.view.frame; // self = MainView
newFrame.size.width = 100;
newFrame.size.height = 50;
UIView *backgroundShadowView = [[UIView alloc] initWithFrame:newFrame];

You surely want to define backgroundShadowView's frame in terms of self.view's bounds, not its frame as you are doing in the first line here.

(2)

The change in self.view.frame is probably illusory. You are probably checking this initially in viewDidLoad. But that is too soon; the view has not yet been added to the interface, and so it has not yet been resized to fit the surroundings.