Collection view cells are sometimes hidden when their frame's x-coordinate < 0

Originator:vladimir.fleurima
Number:rdar://14801742 Date Originated:08/21/2013
Status:Open Resolved:No
Product:iOS SDK Product Version:7
Classification:Serious Bug Reproducible:Always
 
Summary:
Collection view cells are sometimes hidden when applying a translation that results in their frame's x-coordinate becoming less than 0. This seems to be influenced by the zIndex set in the layout attributes applied to the particular cell.

Steps to Reproduce:
1. Run sample project provided.
2. Drag each cell to the right and to the left.

Expected Results:
The cells move laterally while remaining visible.

Actual Results:
When dragging the cell to the right, the cell remains visible.
When dragging the cell to the left, if the card isn't one of the first two cards, it becomes hidden.

Regression:

Notes:
* I noticed a similar bug in iOS 6 but never filed a radar. Sorry.
* The hidden property of the cell's layer is literally being set by the collection view. I did KVO to verify this; the code is included as part of the sample project.
* In my main project, viewing the backtrace seems to indicate that the cell is being marked for reuse for some reason.

Comments


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