Unusual unwanted animation found in the iPhone application

Question

I don't like posting this, but I see unwanted animations in the iPhone app I'm working on. I have never seen this before in my applications or other applications.

This app is for iOS 4.2 and iPhone only. Strange things happen even on iPhone4.

Examples:

• When the application in question launches UIAlertView , it "flies from above or above."

• When any UITableView scrolls, the new (standard) cell data “expands to the left of the cell” when it first appears and displays in this way.

• When a UITextField has text entered into it, typing is slow and you can see that the cursor slides to the right above the new letter. If the UITextField has a clear button, it first slides on the left side to the UITextField .

• When scrolling through a UIPickerView , scrolling to the newly displayed row will “fly through” the new row data in the upper left corner.

The general behavior is similar to the old old Apple II + basic, where you can set "speed = 20" and "slow" on the computer.

What I know: This happens on several phones (4 and 3G). This does not happen in my other applications. This does not happen in other applications at all. This seems to be consistent throughout the application. This is not a small project, so I'm not sure exactly when it started, but it did not start with this behavior. There is no animation associated with the indicated items. It seems that the problem affects everything in the application.

There is even an example of free software for basic code that, when integrated into this application, prpoblem displays the same problems.

Has anyone seen this behavior before? I'm not the only developer, so is there a possible setting that someone else can set up that calls this?

Answer 1

It looks like you are leaving the UIView animation incomplete. If you start the animation, but don’t finish it, all manipulations with the UIView after this point will be animated, as you describe. Odd part - I thought UIKit would stop them for you (and register a message) if control was transferred to runloop with an open animation block. Either this is no longer happening, or you are constantly starting new blocks of animation.

You should look at your code for all instances of +[UIView beginAnimations:context:] and make sure that they are all balanced using the corresponding +[UIView commitAnimations] .