UICollectionView reordering: when the collectionview gets scrolled while a cell is dragged for reordering, the dragged cell will not get removed from the collectionview

Originator:raise.rescue
Number:rdar://24130296 Date Originated:11-Jan-2016 05:25 PM
Status:Open Resolved:
Product:iOS SDK Product Version:iOS 9.2
Classification: Reproducible:
 
Summary:
We are using the builtin-mechanism of collectionviews to make cells reorderable by the user. While it is quite easy to use, it is also broken as soon as the collectionview gets scrolled while the user drags the cell.

Steps to Reproduce:
1. Execute the program at https://github.com/nshintio/uicollectionview-reordering on an iPhone-simulator
2. Drag a cell, move it to the bottom of the simulator so that the automatic scrolling of collectionview starts, but without triggering any reordering
3. When the original place of the dragged cell is no longer visible, drop the cell
4. The cell will stay where it is, no matter if the collectionview gets reloaded or scrolled

Please see the attached video for an example of this behaviour

Expected Results:
The position of the cell should be changed to the position where it will be moved at (even though it will be offscreen).

Actual Results:
The cell just stays where it is and will never be deleted.

Version:
iOS 9.2

Notes:


Configuration:
iPhone 4S simulator

Attachments:
'UICollectionViewReorderingBug.mov' was successfully uploaded.

Comments

The mentioned video is also attached to this issue: https://github.com/nshintio/uicollectionview-reordering/issues/9

By raise.rescue at Jan. 12, 2016, 10:33 a.m. (reply...)

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